IHS Area Cancer Mortality Rate

Transcription

1 CANCER MORTALITY Among Native Americans in the United States + Regional Differences in Indian Health, & Trends Over Time, Department of Health and Human Services Public Health Service Indian Health Service Office of Health Programs Division of Clinical and Preventive Services Cancer Prevention and Control ProgTam

2 Cancer Mortality Among Native Americans in the United States: Regional Differences in Indian Health, & Trends Over Time, Sarah Valway, D.M.D., M.P.H. Editor and Principal Investigator Indian Health Service Cancer Prevention and Control Program Martin Kileen, M.D., Director, Sarah Valway, D.M.D., M.P.H., Epidemiologist Roberta Paisano, M.H.S.A., Public Health Advisor Ellen Ortiz u.s. Department of Health and Human Services Public Health Service Indian Health Service Indian Health Service Everett R. Rhoades, M.D., Director Michael Lincoln, Deputy Director Robert Marsland, Director of Headquarters Operations W. Craig Vanderwagen, M.D. Associate Director, Office of Health Programs

3 Contents Page Background Information Purpose and Description of Cancer Mortality Among Native Americans in the United States Overview of the Indian Health Service Program Indian Health Service Structure Service Population Statistics Sources and Limitations of Data Population Statistics Mortality Statistics Cancer Mortality Among Native Americans in the United States Regional Differences in Indian Health, & Trends Over Time, Tables and Charts Part Regional Differences in Indian Health, Cancer Site Groupings for ICD9 Coded Mortality Data Table 2 Indian Health Sepvice Area Offices Chan 4 Service Population by Area, Table 2 4 Estimated Native American Populations in Selected States, Table 3 5 AgeAdjusted Cancer Mortality Rates All Sites, Both Sexes Chan Total Number of Deaths and AgeAdjusted Rates Table 4 8 Males Chan 3 9 Females Chan 4 9 AgeAdjusted Cancer Mortality Rates Oral Cavity and Pharynx, Both Sexes Chan 5 20 Total Number of Deaths and AgeAdjusted Rates Table 5 20

4 Contents (cont) Page AgeAdjusted Cancer Mortality Rates Esophagus, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 6 2 AgeAdjusted Cancer Mortality Rates Stomach, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 7 22 Males Chart 8 23 Females Chart 9 23 AgeAdjusted Cancer Mortality Rates Colon, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 8 24 Males Chart 25 Females Chart 2 25 AgeAdjusted Cancer Mortality Rates ColonlRectum, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 9 26 Males Chart 4 27 Females Chart 5 27 AgeAdjusted Cancer Mortality Rates Liver, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 0 28 Males Chart 7 29 Females Chart 8 29 AgeAdjusted Cancer Mortality Rates Gallbladder, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 30 Males Chart 20 3 Females Chart 2 3 AgeAdjusted Cancer Mortality Rates Pancreas, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 2 32 Males Chart Females Chart AgeAdjusted Cancer Mortality Rates Lung, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 3 34 Males Chart 26 Females Chart AgeAdjusted Cancer Mortality Rates Kidney, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 4 36 Males Chart Females Chart AgeAdjusted Cancer Mortality Rates Breast, Females Chart Total Number of Deaths and AgeAdjusted Rates Table 5 38 II

5 Contents (cont) Page AgeAdjusted Cancer Mortality Rates Cervix, Females Chart Total Number of Deaths and AgeAdjusted Rates Table 6 39 AgeAdjusted Cancer Mortality Rates Corpus Uterus, Females Chart Total Number of Deaths and AgeAdjusted Rates Table 7 40 AgeAdjusted Cancer Mortality Rates Ovary, Females Chart Total Number of Deaths and AgeAdjusted Rates Table 8 4 AgeAdjusted Cancer Mortality Rates Prostate, Males Chart Total Number of Deaths and AgeAdjusted Rates Table 9 42 AgeAdjusted Cancer Mortality Rates Hodgkin's Lymphoma, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table AgeAdjusted Cancer Mortality Rates NonHodgkin's Lymphoma, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table 2 44 Males Chart Females Chart AgeAdjusted Cancer Mortality Rates Multiple Myeloma, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table Males Chart 4 47 Females Chart AgeAdjusted Cancer Mortality Rates All Leukemias, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table Males Chart 44 Females Chart AgeAdjusted Cancer Mortality Rates IIIDefioed/Uokoown Sites, Both Sexes Chart Total Number of Deaths and AgeAdjusted Rates Table Males Chart 4 5 Females Chart 48 5 Leading Causes of Cancer Mortality, , by IDS Area and Sex by Number of Cancer Deaths Table by Average Annual AgeAdjusted Rates Table 26 54

6 Contents (cont) Page Cancer Mortality, Tables by Area Aberdeen Area Table 27 Total Number of Deaths and Average Annual AgeAdjusted Rates, Alaska Area Table 28 Total Number of Deaths and Average Annual AgeAdjusted Rates, Albuquerque Area Table 29 Total Number of Deaths and Average Annual AgeAdjusted Rates, Bemidji Table 30 Total Number of Deaths and Average Annual AgeAdjusted Rates, Billings Table 3 Total Number of Deaths and Average Annual AgeAdjusted Rates, California Table 32 Total Number of Deaths and Average Annual AgeAdjusted Rates, NasbviUe Table 33 Total Number of Deaths and Average Annual AgeAdjusted Rates, Navajo Table 34 Total Number of Deaths and Average Annual AgeAdjusted Rates, Oklaboma Table 35 Total Number of Deaths and Average Annual AgeAdjusted Rates, Pboenix Table 36 Total Number of Deaths and Average Annual AgeAdjusted Rates, Portland Table 37 Total Number of Deaths and Average Annual AgeAdjusted Rates, Tucson Table 38 Total Number of Deaths and Average Annual AgeAdjusted Rates, All 2 IHS Areas Table 39 Total Number of Deaths and Average Annual AgeAdjusted Rates, IHS Areas (California, Oklaboma, and Portland excluded) Table 40 Total Number of Deaths and Average Annual AgeAdjusted Rates, Part 2 Trends in Cancer Mortality, 968 to 987: Native Americans in Selected States Compared to U.S. All Races All Cancers Both Sexes Chart Males Chart 50 0 Females Chart 5 _ 02 IV

7 Contents (com) Page Colorectal Cancer Both Sexes Chart Males Chart Females Chart Lung Cancer Both Sexes Chart Males Chart Females Chart Breast Cancer (Females) Chart Cervical Cancer Chart 59 0 References v

8 Purpose and Description of Cancer Mortality:Regional Differences in Indian Health & Trends Over Time, The Indian Health Service (IHS) Regional Differences in Cancer Mortality attempts to provide basic statistical information to parties interested in cancer in the IRS. The tables and charts contained herein describe the administrative, or area, divisions of the IHS, the estimated service population for each area, and mortality from 984 to 988 for malignant neoplasms. Regional differences are depicted and comparisons made to the general U.S. population where appropriate. Historical trend data for malignant neoplasm mortality is not yet available for each IHS area. However, historical trend information for the entire IHS for all malignant neoplasms can be found in the IHS companion publication called Trends in Indian Health. In addition, this publication also includes some cancer mortality trends from 968 to 987 for Native Americans in selected states. It is the intention of this publication to provide more detailed information about the impact of cancer on Native American people than is currently available in other IHS publications. Specifically this publication provides cancer mortality data for each cancer site and for each IRS Area, examined in the same manner and the same time frame, making Area comparisons easy and reliable. Hopefully, this publication will be used to help determine Regional, Area, or Tribal priorities in cancer prevention programs. For example, while strategies to prevent lung cancer, primarily tobacco cessation programs, should be part of all IRS health programs throughout the country, there may need to be differing degrees and levels of intervention in different areas of the country. This is due to the fact that lung cancer mortality rates differ dramatically throughout the IRS. Lung cancer mortality rates for the Southwest, i.e. Albuquerque, Navajo, Phoenix, and Tucson Areas, are well below the U.S. rates for both males and females, while rates in the Northern part of the country, i.e., Aberdeen, Alaska, and Billings, are much higher than rates in the Southwest IHS Areas and are equal to or greater than U.S. rates. In the general U.S. population, femal~ have a lung cancer mortality rate approximately /3 that of males. The IHS data do not show the same pattern. In the Alaska Area, females have a lung cancer mortality rate 2.6 times the U.S. rate for females and a rate that is almost as high as that for Alaska Area males. In the Billings Area, females have a lung cancer mortality rate 2.5 times the U.S. rate for females and a rate equal to that for Billings Area males. (See Charts 25, 26, 27 and Table 3) For cervical cancer, where there is an easy and inexpensive preventive intervention, Le., PAP smear screening, the data presented in this publication indicate that all IRS Areas had cervical cancer mortality rates higher than the U.S. rate. Extra efforts may be needed in the Billings Area, where the cervical cancer mortality rate was the highest, over 5 times the U.S. rate. Close examination of the data by Area and Tribal leaders, as well as other interested parties may also point to other differences among IRS Areas that would necessitate different approaches to prevention efforts. (See Chart 32 and Table 6) Throughout this publication, the tables provide detailed data, while the charts graphically show the regional differences. Statistically significant differences in mortality rates, as compared to the U.S. rates, are noted on the tables. A table and its corresponding chart(s) appear next to each other. However, a chart that is selfexplanatory may not have a corresponding table.

9 Overview of the Indian Health Service Program The Department of Health and Human Services (DHHS), primarily through the Indian Health Service (IHS) of the Public Health Service (PHS), is responsible for providing Federal health services to American Indians and Alaska Natives. Federal Indian health services are based on the laws which the Congress has passed pursuant to its authority to regulate commerce with the Indian Nations as explicitly specified in the Constitution and in other pertinent authorities. The Indian Health program became a primary responsibility of the PHS under P.L , the Transfer Act, on August 5, 954. This Act provides "that all functions, responsibilities, authorities, and duties... relating to the maintenance and operation of hospital and health facilities for Indians, and the conservation of Indian health... shall be administered by the Surgeon General of the United States Public Health Service." The IHS goal is to elevate the health status of American Indians and Alaska Natives to the highest possible level. The mission is to ensure equity, availability, and accessibility of a comprehensive high quality health care delivery system providing maximum involvement of American Indians and Alaska Natives in defining their health needs, setting priorities for their local areas, and managing and controlling their health program. The IHS also acts as the principal Federal health advocate for Indian people by assuring they have knowledge of and access to all Federal, State, and local health programs to which they are entitled as American Indians and Alaska Natives. It is the responsibility of the IHS to work with these programs so they will be cognizant of entitlements of Indian people. The IHS has carried out its responsibilities through developing and operating a health service delivery system designed to provide a broadspectrum program of preventive, curative, rehabilitative, and environmental services. This system integrates health services delivered directly through IHS facilities and staff with those purchased by IHS through contractual arrangements, taking into account other health resources to which American Indians and Alaska Natives have access. Tribes are also actively involved in program implementation. The 975 Indian SelfDetermination Act, P.L as amended, builds upon IHS policy by giving Tribes the option of staffmg and managing IHS programs in their communities, and provides for funding for improvement of Tribal capability to contract under the Act. The 976 Indian Health Care Improvement Act, P.L as amended, was intended to elevate the health status of American Indians and Alaska Natives to a level equal to that of the general population through a program of authorized higher resource levels in the IHS budget. Appropriated resources were used to expand health services, build and renovate medical facilities, and step up the construction of safe drinking water and sanitary disposal facilities. It also established programs designed to increase the number of Native American health professionals for Native American health needs and to improve health care access for Native American people living in urban areas. The operation of the IHS health services delivery system is managed through local administrative units called service units. A service unit is the basic health organization for a geographic area served by the IHS program, just as a county or city health department is the basic health organization in a State health department. These are defmed areas, usually centered around a single federal reservation in the continental United States, or a population concentration in Alaska. A few service units cover a number of small reservations; some large reservations are divided into a number of service units. The service units are grouped into larger culturaldemographic management jurisdictions which are administered by IHS Area Offices. 2

10 Indian Health Service Structure The IHS is composed of regional administrative units called Area Offices. There is also an IHS Headquarters Office in Tucson, Arizona, the Office of Health Program Research and Development, which is responsible for administering health services delivery. For the present statistical purposes, the Tucson Office is also considered an Area Office, thereby making 2 IHS Areas in total (Chart I). These 2 Areas are: Aberdeen Bemidji Nashville Phoenix Alaska Billings Navajo Portland Albuquerque California Oklahoma Tucson As of October, 988, the Area Offices consisted of 27 basic administrative units called service units. Of the 27 service units, 52 were operated by Tribes. The number of service units within an IHS Area ranged from 2 in Tucson to 2 in California. The IHS operated 43 hospitals, 66 health centers, 5 school health centers, and 60 health stations. Tribes operated 7 hospitals, 73 health centers, 2 school health centers, 65 health stations, and 73 Alaska village clinics. Both the California and Portland Areas had no hospitals, while Phoenix and Aberdeen had 8 and 9 hospitals respectively. Tucson had the fewest health centers with 3, and Oklahoma the most, with 27. IHS Service Population Statistics The IHS service population counts are based on official U.S. Census county data. The Census Bureau enumerates those individuals who identified themselves as American Indian or Alaska Native, however, the Census Bureau does not publish data on a Tribal basis. The IHS service population (eligible population) is estimated by counting those American Indians and Alaska Natives who reside within the geographic areas in which the IHS has responsibilities ("on or near" reservations). These people mayor may not use IHS services. Based on the 980 U.S. census, approximately 50% of people who identified themselves as American Indian or Alaska Native were considered eligible for IHS services, by the residence criteria cited above. Native American population estimates beyond the Census year are projected by the IHS through linear regression techniques, using 0 years of Native American birth and death data provided by the National Center for Health Statistics (NCHS). From 984 to 988, the average annual IHS service population for the entire country was 988,244. The Tucson Area had the smallest average service population (8,704) and the Oklahoma Area had the largest average'annual population (98,67). The IHS service population is increasing at a rate of approximately 2.7% per year. Based upon 980 Census data, the IHS service population is younger, less educated, and poorer than the U.S. all races population. For the entire IHS service population, 3.6% were less than 6 years of age, compared to 8.6% for the U.S. all races population. However, there was considerable variation by area with California at 0.8% and Aberdeen Area at 6.6% of the population being less than 6 years of age. Only 5% of the entire IHS service population was greater than 64 years of age compared to % in the general U.S. all races population. Again, there was variation by area with Albuquerque Area at 4.3% and Oklahoma Area at 7.6% of the population greater than 64 years of age. The median years of school completed was greater than 2 for half of the IHS Areas, compared to an IHSwide figure of 2. and a U.S. all races figure of 2.5. However, in the Alaska and Navajo Areas 3

11 the median number of years of school completed was 9.3. The median household income for the entire IHS service population was $,47, while for the U.S. all races it was $6,84. The Navajo Area had the lowest median household income at $8,42, and the Alaska Area the highest at $5,750. Sources and Limitations of Data Population Statistics IHS service population estimates are made based upon data from the U.S. census Bureau. The 980 service'population was approximately 3% higher than that estimated in 979. The 980 Census was probably more reliable with respect to Indian data than the 970 Census. This was because the Census Bureau made a concerted effort to increase participation of American Indians and Alaska Natives through publicity campaigns, direct involvement with tribal groups, and increased concentration on Indian geographic areas. The IHS smoothed the population estimated for in order to show a more gradual transition to the population enumerated during the 980 Census. The degree to which this may be a problem in the future, when final counts are available from the 990 Census is unknown. Mortality Statistics American Indian and Alaska Native vital event statistics are derived from data furnished annually to the IHS by the National Center for Health Statistics (NCHS). NCHS obtains birth and death records for all U.S. residents from the State departments of health, based upon information reported on official State birth and death certificates. Those records identified as pertaining to the American Indians and Alaska Natives are provided to the IHS. The IHS records contain the same basic demographic items as the vital events records maintained by NCHS for all U.S. residents, but with names, addresses, and record identification numbers deleted. It should be noted that Tribal identity is not recorded on these records. TI\e data are subject to the degree of accuracy in the reporting by the States to NCHS. NCHS does perform numerous edit checks, and imputes values for nonresponses. The accuracy of the reporting of race, age at death, and place of residence on State death certificates is being evaluated based on linked birthdeath infant mortality data and from the 986 National Mortality Followback Survey conducted by NCHS. The IHS funded an oversampling of American Indian and Alaska Natives in this survey, to evaluate the accuracy of reporting of various demographic items in Indian death certificates. The IHS also plans to use the National Death Index (NDI) maintained by NCHS to determine the extent of the underreporting of Indian race in death certificates. The project involves submitting an extract of the IHS patient registration file to NCHS to be used in the match with the NDI. IHS will then target the "problem" states for special efforts aimed at improving the reporting of race. It is already known that there is an underreporting of Indian race on State death certificates in California. It also appears that this problem exists in the Oklahoma and Portland Areas. Therefore, throughout this publication, the mortality rates that are shown for these 3 Areas are suspect and should be interpreted with caution. As a result, this publication shows IHSwide mortality rates with and without the data for these 3 Areas. 4

12 With the exception of cancer mortality trends from 968 to 987, the Native American vital events data in this publication pertain only to those American Indians and Alaska Natives residing at the time of their death in the counties that make up the IRS service areas. This contrasts with the Trends in Indian Health publication which shows vital event statistics for all American Indians and Alaska Natives residing in the Reservation States, whether or not they are considered eligible for IRS services. Calculation done on a Reservation State basis include all counties in the state, even those outside the IHS Service area. Reservation State vital event rates tend to be lower than the IHS service rates. The Native American population is considerably younger than the U.S. all races population. Therefore the mortality rates presented in this publication have been ageadjusted, so that appropriate comparisons can be made between population groups. The ageadjusted mortality rates were computed by the direct method, that is, by applying the agespecific rates for a given cause of death to a standard population age distribution. In this publication, cancer mortality rates were adjusted to the 970 U.S. standard population, based on toyear age groups, so as to be able to compare IHS data with published data from the National Cancer Institute. An adjusted rate that was computed based on a small number of deaths should be interpreted with caution since the observed rate may be very different from the true underlying rate. The yearly IRS publication, Trends in Indian Health, as well as the Regional Differences in Indian Health, adjust rates to the 940 census. Therefore, rates in this publication cannot be directly compared to rates in the other IRS publications. However, ratios between U.S. and IRS Areas can be compared between t)e publications. 5

13 Cancer Mortality Among Native Americans in the United States: Regional Differences in Indian Health, & Trends Over Time, Introduction Over the past 35 years, extensive efforts by the Indian Health Service to improve the health of Native Americans in the United States (US) have resulted in marked decreases in infectious disease and infant and maternal mortality,2. Additionally, life expectancy at birth for Native Americans throughout the US has risen dramatically, from 5 years in 940 to 7 years in 980,2. With these improvements in health and this increased life span, chronic diseases have begun to impact heavily on the Native American community. Malignant neoplasms are now the third leading cause of death for Native Americans throughout the country,2. In spite of this, cancer mortality among Native Americans has not been well described. While there are isolated reports from North Carolina 3 and for a single Tribe in New York 4,5, most published studies on cancer mortality among Native Americans have been done in the southwestern part of the US and in Alaska 67. These studies have shown that, while total cancer mortality for all Native Americans appears to be lower than the cancer mortality for the US White population 68, there are regional differences and differences in mortality from specific types of cancer that are striking 37. Overall cancer mortality rates for Native Americans in different parts of the country, except for Alaska, have been shown to be significantly lower than the US rates 38,2. However, in Alaska, overall cancer mortality rates have not differed significantly from the US rates 37. Excess mortality was seen among Native Americans in Alaska for, nasopharyngeal, kidney, salivary gland, and esophageal cancers 3,5, as well as for multiple myeloma 6. For Alaska and the southwest US excess mortality was seen for gallbladder cancer, especially among females 6,7,3,7. In the southwest US, excess mortality was seen for stomach cancer 7,0. Varying degrees of excess cervical cancer mortality was seen in all regions studied 38,3. Deficits in cancer mortality were seen in Alaska for lymphomas and leukemias 6, in Alaska and North Carolina for prostate cancer 3,6,3,5, and for pancreatic cancer in New Mexico 6,7. In all regions studied, varying degrees of deficits in cancer mortality were seen for breast cancer 3 8,3,5. Lung cancer mortality among Native Americans in New Mexico was significantly lower than US rates 6,7,. However, lung cancer mortality in Alaska has been increasing rapidly from rates significantly lower than US rates in the mid960's to rates as high as the US rates by ,7. These studies document that there are marked regional differences in cancer mortality among Native Americans in the US and that results apply only to the region under study. They clearly demonstrate that combined data for the entire US do not adequately describe cancer mortality for specific Native American groups. Additionally, these studies were done using different methodologies and during different time periods, further complicating pooling of data and making comparisons difficult. The purpose of this publication is to provide information that is currently not available about cancer mortality among Native Americans in the US. Part describes cancer mortality overall and by cancer site from 984 to 988 for both sexes combined and for each sex by each of the 2 6

14 Indian Health Service (IHS) Areas shown in Chart. Part 2 describes trends in cancer mortality for a 20 year period (968 to 987) for Native Americans from 0 states. Methods Mortality data from 984 through 988 (part ) and from 968 to 987 (part 2) for persons identified as Native American were obtained from the National Center for Health Statistics (NCHS). These data include a single underlying cause of death and a maximum of 20 contributing causes of death. (Prior to 979, a maximum of 4 contributing causes of death were coded.) The underlying cause of death is determined according to standard criteria from data listed on the death certificate. Only those Native American deaths in which the underlying cause of death was cancer were included. Part : Part Regional Differences in Cancer Mortality, The IHS obtains the NCHS mortality data tapes for persons listed as Native American. Based upon information available about the deceased person's residence at the time of death, the IHS assigned each person to the appropriate IHS Area (Chart I). As is evident from Chart, not all parts of the US are included in the IRS Areas. Based upon data from the 980 census, approximately 50% of all Native Americans in the US reside within the geographic boundaries of the IHS Areas. Only those deaths that occurred among Native Americans residing within the boundaries of IRS Areas were included in this part of the investigation. To help control for fluctuations in rates that occur when there is a relatively small population and a small number of deaths, five years of data were examined, 984 to 988. Data were examined for all cancer deaths combined as well as for specific types of cancer (Table ). Average annual ageadjusted mortality rates were calculated using the cumulative 984 to 988 estimated population for each IHS Area (Table 2: data from the Indian Health Program Statistics Branch). The IHS projected these population estimates with linear regression from the 980 census, based upon 0 years (978 to 987) of birth and death data for Native Americans in the US. All rates were adjusted by the direct method to the 970 US standard population. US all races cancer mortality rates from 984 to 988, adjusted to the 970 US standard population, were used for comparison 8. Part 2: Cancer Mortality, Trends Over Time, The NCHS mortality data for 20 years, 968 to 987, for persons identified as Native American were examined. Dap were grouped into regional areas based upon the state of residence at the time of death. Because there is evidence (primarily for infant mortality from linked birth and death certificates) to suggest that accurate coding of Native American race on death certificates may be a problem in some areas of the country,925, only 0 states that did not appear to have major problems with racial misclassification at death and that had large Native American populations were included. These 0 states were grouped into five regions that approximate IHS Areas. These five regions were: ) Alaska; 2) Arizona and New Mexico; 3) Michigan, Minnesota, and Wisconsin; 4) North Dakota, South Dakota, and Montana; and 5) Oklahoma. Data were examined for all cancers combined and for four specific types of cancer; colorectal, lung, breast, and cervical cancer. These four were chosen because there are known treatment interventions that could greatly decrease mortality or because they are preventible cancers. To help control for fluctuations in rates that occur when there is a relatively small population and a small number of deaths, data were examined by 5year time intervals and in 5year moving 7

15 averages; i.e., 968 to 972, 969 to 973, 970 to 974, etc. Average annual ageadjusted monality rates were calculated using the midpoint population estimate for each 5year time period; e.g., for the 968 to 972 time interval, the 970 estimated population was used (Table 3: data from the Indian Health Program Statistics Branch». Population estimates from 970 through 985 for the total Native American population in the 0 states included in this study were obtained from the IHS. The IHS projected these population estimates from the 980 census with linear regression, based upon 0 years (978 to 987) of birth and death data for Native Americans in the US. All rates were adjusted by the direct method to the 970 US standard population. US all races cancer mortality rates, adjusted to the 970 US standard population, for the midpoint of each 5year time period for which Native American rates were examined were used for comparison 8. For example, for the 969 to 973 time period or Native Americans, the US 97 rates were used for comparison. Results Part : Part Regional Differences in Cancer Mortality, From 984 through 988, the average annual ageadjusted cancer monality rate for all cancers for both sexes combined was 3.9/00,000 for all IHS Areas.* This rate was significantly lower than the 984 through 988 US all races rate of 7.3/00,000. When the three IHS Areas where there appear to be some problems with accurate reporting of Native American race on death certificates (California, Oklahoma, and Portland Chart ) are excluded, the IHS rate was 48.5/00,000. While this rate was still lower than the US rate, it was not significantly lower. There was wide variation among the IHS Areas; California had the lowest overall cancer mortality rate (8.9/00,000) and Alaska had the highest (2.3/00,000). Four IHS Areas, Alaska, Aberdeen, Bemidji, and Billings Areas, had rates for both sexes combined that were higher than the US rate. For the Alaska and Billings Areas, these rates were significantly higher that the US rate. When cancer mortality rates were examined by specific cancer site and by sex, wide variation among the IHS Areas as well as varying rankings by Area were seen. Lung cancer was the leading cause of cancer mortality for the US as well as for all IHS Areas combined and for nine of the 2 IHS Areas. However, for three IHS Areas, Albuquerque, Navajo, and Phoenix, illdefined/unspecified cancer was the leading cause of cancer mortality for both sexes. Detailed results for individual cancer sites are shown in Charts 2 through 48 and Tables 4 through 24. For each IHS Area, the five leading causes of cancer mortality are shown by number of deaths and percentage of all cancer deaths (Table 25) and by ageadjusted mortality rates (Table 26). Detailed data by cancer site (number of deaths and ageadjusted average annual rates) for each IHS Area are shown in Tables 27 through 40. Part 2: Cancer Mortality, Trends Over Time, Cancer mortality rates for Native Americans in the 0 states examined showed marked differences (Charts 49 to 59). For all cancers, Native Americans from Alaska and North Dakota/South Dakota/Montana had rates for both sexes combined that were consistently at or greater than the US all races rales, while the other regions had rates lower than the US rates (Chart 49). For males, all regions, except ArizofUl/New Mexico, had rates over time that slowly increased but * Numbers of deaths and agespecific rates are not included in this publication but may be obtained by contacting the IHS Cancer Prevention and Control Program, 240 2th St NW, Albuquerque NM, 8702 FrS , commercial (505) In addition, slides of all the charts in this publication are available on loan from the above office. 8

16 that still remained lower than the US rates. In Arizona/New Mexico, where cancer mortality rates for males were the lowest of the regions studied, there was no evident increase over the 20 years examined. Cancer mortality rates for males showed wide variation among the regions, with the rate in Alaska being the highest and consistently being at least.5 to 2 times the rate for Arizona/New Mexico (Chart 50). For females, Alaska and North Dakota/South Dakota/Montana consistently had rates significantly higher than the US rates for females. The other three regions had rates for females that were lower than the US rates and also at least 50% lower than the rates for Alaska or North Dakota/South Dakota/Montana (Chart 5). For colorectal cancer (Chart 52), the mortality rates for Alaska were consistently higher than the US rate, primarily due to the extremely high rate of colorectal cancer mortality among females (Chart 54). Arizona/New Mexico had the lowest rates of the regions examined, rates that were consistently about onefourth the US rates. Lung cancer mortality in the US has been slowly and steadily rising since 970, for both males and females. For Native Americans, lung cancer mortality rates for Arizona/New Mexico have consistently remained less than onefourth the US rates (Charts 55 to 57). However, in the northern part of the US; Alaska, North Dakota/South Dakota/Montana, and Michigan/Minnesota/Wisconsin, lung cancer mortality rates have been rising dramatically. In Alaska and Michigan/Minnesota/Wisconsin, lung cancer mortality rates now exceed the US rates for both sexes combined and the rate for North Dakota/South Dakota/Montana is now not signific~tly different from the US rate (Chart 55). While lung cancer mortality rates for males have increased markedly in all regions, except ArizonalNew Mexico where there has been very little increase, (Chart 56) all regions still had rates lower than the US. However, for Alaska, the rate is now not significantly different from the US rate. The more dramatic increase in lung cancer mortality occurred among females (Chart 57). In Alaska, North Dakota/South Dakota/Montana, and Michigan/Minnesota/Wisconsin the lung cancer mortality rates for females have risen from rates lower than the US rates to rates 2.5,.5, and.5 times the US rates, respectively. Rates for Arizona/New Mexico, however, have remained relatively flat at less than onethird the US rate. Breast cancer mortality rates for Native American females have consistently remained much lower than the US rates (Chart 58). However, the data also show that in recent years, breast cancer mortality appears to be increasing in some regions. When these data are compared to IRS Areaspecific data (Chart 3, Table 5), breast cancer mortality rates from 984 through 988 for two IHS Areas (Aberdeen and Nashville) approach US rates and are not significantly different from US rates. In contrast to breast cancer mortality, cervical cancer mortality rates, except for the Michigan/Minnesota/Wisconsin region, have consistently been significantly higher than the US rates (Chart 59). In the North Dakota/South Dakota/Montana region, cervical cancer mortality has decreased significantly by more than 50%. However, the rate is still more than 3 times the US rate. For the Michigan/Minnesota/Wisconsin region, cervical cancer mortality also decreased significantly and is now not significantly different from the US rate. Discussion The data presented here demonstrate that Native Americans throughout the US carry very different cancer mortality burdens. In general, Native Americans in the southwestern part of the country had lower cancer mortality rates than those in the northern part of the country. However, within any IHS Area or geographic region, mortality rates for specific cancers were not all lower or her than the US rates. For each specific type of cancer and for each sex, varying rankings by IRS areas or regions were found. 9

17 Reasons for the variability in cancer mortality seen among Native Americans from different parts of the country are not entirely known. Access to care or later stage diagnosis in different areas could cause different mortality patterns. The degree to which this may be the case is unknown, since there are not tumor registries throughout the country that adequately represent Native Americans. However, some of the variability in rates would be expected. It is known that the prevalence rates for alcoholism,2,2,26,27 and obesity 2830, as well as dietary patterns 2830, vary considerably throughout the country. Additionally, smoking prevalence among Native American adults is relatively low in Arizona and New Mexico 9,3, but over 50% in the northern part of the country 3,32, increasing rapidly in Alaska to rates now over 60% 7,3,33, and over 60%70% in a study of Chippewa Tribes in Wisconsin (personal communication Dr. Dan Peterson, Centers for Disease Control). These differences in risk factors could easily explain some of the variation seen in cancer mortality in different parts of the country. There are several well recognized and documented limitations with death certificate data for examining causespecific mortality These include racial misclassification, errors in residence at time of death, and errors in reporting the precise cause of death. There is evidence to suggest that, at least in the recent past, racial misclassification of Native Americans on death certificates may be a problem in some regions of the country 925. Additionally, data show that Native Americans die more often than Whites of "signs, symptoms, and illdefined conditions" 37. These two latter problems would lead to underestimations of the true overall cancer mortality rates as well as underestimations of mortality for specific types of cancer. Another contributor to underestimating mortality from specific cancers would be deaths coded to illdefined/unspecified cancers. While many deaths coded thus would indeed be unknown types of cancer, many would also be incorrectly coded due to incomplete data on the death certificate. IHS Area mortality data support this last hypothesis since illdefmed cancers were the leading cause of cancer mortality for the Albuquerque, Navajo, and Phoenix Areas, and in the Aberdeen, Alaska, Albuquerque, and Billings IHS Areas, the illdefined cancer mortality rates were significantly higher than the US rates. All rates in this publication were derived using projections from the 980 census. The degree to which there may be errors in the accurate counting of Native Americans is not precisely known. However, evidence would suggest that any errors that may have occurred would be in undercounting. Provisional data from the 990 census show that the 990 estimated total Native American population in the US exceeds estimates based on the 980 census, but not in all parts of the country 38,IHS data. Errors in using population figures that may be lower than the true numbers would lead to overestimations of the true cancer mortality rates for regions of the country where this was a problem. Despite these limitations, the findings shown here clearly demonstrate that Native Americans throughout the US have very different cancer mortality patterns. Unfortunately there are not sufficient data on cancer incidence among Native Americans to examine whether the same holds true for cancer incidence or survival. Presently, the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) populationbased tumor registry infonnation about cancer incidence among Native Americans includes only limited Native American populations. Seventyfive percent of their data on Native Americans comes from the New Mexico Tumor Registry which includes Native Americans in Arizona and New Mexico. The results of this study examining cancer mortality clearly showed that Native Americans in Arizona and New Mexico have markedly different cancer mortality patterns from other Native Americans in the US. This finding, along with differences in risk factors, would lead one to presume that cancer incidence patterns would also differ. In order to better understand the extent of cancer among Native Americans in the US, collaborative efforts between the IHS, SEER, and statebased tumor registries need to be 0

18 undertaken to be able to adequately describe incidence of cancer among Native Americans. This would help in developing preventive programs and intervention strategies that need to be targeted appropriately for the population being treated. Until such data are available, cancer mortality data can give some indication as to the extent of the problem and can help provide direction when deciding y.'here limited resources would have the most beneficial impact.

19 Table Cancer Site Groupings for ICD9 Coded Mortality Data Underlying Cause of Death Oral Cavity and Pharynx Lip Tongue Salivary Gland Floor of the Mouth Gingiva and other mouth Tonsil Oropharynx Nasopharynx Hypopharynx Other mouth/pharynx Digestive System Esophagus Stomach Small intestine Colon exc. rectum Rectum and rectosigmoid Anus, anal canal, & anorectum Liver & Intrahepatic duct Liver Intrahepatic bile duct Gallbladder Other biliary Pancreas Other digestive system Respiratory System Nose, nasal cavity, middle ear Larynx Lung & bronchus Other respiratory Bone and joints Soft tissue (including heart) Malignant melanoma Other skin Breast Female genital system Cervix Corpus uterus Uterus, NOS Ovary Vagina Vulva Other female genital system ICD9 Code , , , , , , , ,75._ , _ _, , 84.8,

20 Table (continued) Cancer Site Groupings for ICD9 Coded Mortality Data Underlying Cause of Death Male genital system Prostate Testis Penis Other male genital system Urinary system Urinary bladder Kidney & renal pelvis Ureter Other urinary system Eye & orbit Brain and other nervous system Endocrine system Thyroid Other endocrine (including thymus) Lymphomas Hodgkin's disease NonHodgkin's lymphomas Multiple myeloma Leukemias Lymphocytic Acute lymphocytic Chronic lymphocytic Other lymphocytic Myeloid Acute myeloid Chronic myeloid Other myeloid Monocytic Acute monocytic Chronic monocytic Other monocytic Other leukemias Illdefined and unspecified sites ICD9 Code 85._ , _ 64.0, , , , ~.O ~. ~.2~ ,203., , , , ,202.3,

21 Indian Health Service Areas rf%..... </.. 7' D Chart Estimated Indian and Alaska Native Service Population by Indian Health Service Area, Area Aberdeen 70,623 73,469 75,45 77,46 79,52 Alaska 7,528 73,6 75,784 78,037 80,382 Albuquerque 5,20 52,423 53,66 54,926 56,26 Bemidji 46,89 48,53 49,624 5,90 53,443 Billings 4,684 42,847 44,037 45,257 46,505 California 7,806 73,686 75,74 77,895 80,26 Nashville 35,478 36,028 36,59 37,66 37,756 Navajo 62,048 66,567 7,200 U5,969 80,852 Oklahoma 89,874 94,82 98,547 m, ,496 Phoenix 82,486 84,767 87,62 89,68 92,30 Portland 96,34 98,774 00,93 03,49 05,42 Tucson 7,826 8,252 8,693 9,44 9,606 Table 2 * These population figures differ slightly from those published in the 99 Trends in Indian Health. The figures listed here reflect adjustments made in May 99, subsequent to the publication of the 99 Trends in Indian Health 4

22 Table 3 Estimated Native American Populations for Selected States, 970 to 985 Michigan, N. Dakota, Arizona & Minnesota, & S.Dakota.& Year Alaska New Mexico Wisconsin Montana Oklahoma ,654 68,600 58,906 73,864 98, ,96 77,507 63,47 76,73 05, ,79 86,407 68,038 79,597 2, ,440 95,33 72,6CYl 82,463 9, , ,24 77,68 85,329 26, ,98 23,24 8,733 88,96 33, , ,020 86,299 9,063 4, ,70 230,926 90,865 93,929 48, , ,867 95,429 96,795 55, , ,732 99,996 99,66 65, , ,634 04,56 02,528 69, , ,322 06,604 05,082 73, ,586 27,273 08,834 08,425 76, , ,500,49,865 80, , ,988 3,577 5,397 85, , ,744 6,92 9,437 89,427 * Populations estimates are for Pan 2 Cancer Mortality: Trends over Time,

23 Part Charts & Tables for I!tANCER II MORTALITY I I I I Among I I J I Native Americans I... I in the I I IUnited States I I i ~ ' I Regional Differences in Indian Health

24 AgeAdjusted Cancer Mortality Rates, All Sites, By IHS Area, Both Sexes, IHS Total 9* Areas=48.5 I 250 Chart 2 From 984 to 988, the ageadjusted cancer mortality rate for both sexes, for all cancers, was 3.9/00,000 for the entire IHS service population. When the 3 IHS Areas with apparent problems in underreporting of Indian race on death certificates are excluded, the rate was 48.5/00,000. Of the IHS Areas, Alaska and Billings Areas had rates significantly higher than the US rate. The rates for Aberdeen and Bemidji Areas, while higher than the US rate, were not significantly higher. All other IHS Areas had rates significantly lower than the US rate. 8 Total Number of Deaths and AgeAdjusted Cancer Mortality Rates, All Cancer Sites, by IHS Area, U.S.AII Races AIIIHS Areas 9* IHS Areas 2 Aberdeen* Alaska* Albuquerque* Bemidji* Billings* California Nashville* Navajo* Oklahoma Phoenix* Portland Tucson* Both Sexes N Rate ** ** ** ** ** ** ** ** ** ** Males N Rate ** ** ** ** ** 95.3 ** ** ** Females N Rate ** ** ** ** ** **... Rate per 00,000 per year adjusted to the 970 U.S. population. Rates based on small numbers of deaths should be interpreted with caution. 2 The 3 IHS Areas without an asterisk (California, Oklahoma, Portland) appear to have a problem with underreporting Indian race on death certificates. Therefore a separate IHS total (9 IHS Areas) is presented excluding these 3 Areas. ** Denotes a rate si nificantl different from the U.S. rate. Table 4 Table 4 lists the total number of deaths due to all cancers from 984 to 988, and the ageadjusted rate per 00,000 population per year by IHS Area, for both sexes combined, males, and females.

25 AgeAdjusted Cancer Mortality Rates. All Sites By IHS Area, Males, IHS Total 9* Areas=42.6 o Rate per 00,000 per year Adjusted to the 970 U.S. population Excluding California, Oklahoma, and Portland Areas Chart 3 For males, from 984 to 988, the ageadjusted cancer mortality rate for all cancers was 33.9/00,000 for the entire IRS service population. When the 3 IHS Areas with apparent problems in underreporting of Indian race on death certificates are excluded, the rate was 42.6/00,000. Both of these rates are significantly lower than the US rate for males. All IRS Areas had cancer mortality rates for males that were lower than the US rate. For 9 IHS Areas, the rates were significantly lower than the US rate. AgeAdjusted Cancer Mortality Rates. All Sites. By IHS Area, Females, r U.S.=39.5 _ IHS Total 9* Areas= Chart 4 For females, from 984 to 988, the ageadjusted cancer mortality rate for all cancers was 3/00,000 for the entire IRS service population. When the 3 IRS Areas with apparent problems in underreporting of Indian race on death certificates are excluded, the rate was 54.00,000. In contrast to males, where all IHS Area rates were lower that the US rate, for females, IHS Areas had rates ranging from less than /2 to.6 times higher than the US rate. Of the IHS Areas, Alaska and Billings, Aberdeen, and Bemidji Areas had cancer mortality rates for females that were significantly higher than the US rate for females. Five other IRS Areas had rates for females that were significantly lower than the US rate. 9