BREAST CANCER SCREENING STRATEGIES BASED ON RISK HOWARD SCHAFF, M.D. Medical director St. Alphonsus Breast Care Center
WHAT IS THE GOAL OF BREAST CANCER SCREENING? Reduce deaths due to breast cancer by detecting breast cancer EARLY when treatment is more effective. Breast cancer has to reach a certain size to be detected If a woman waits for her breast cancer to become evident as a palpable lump, it will be larger and more likely to have spread to her lymph nodes or elsewhere at the time of detection
SIZE DOES MATTER Breast cancers found with high quality two view screening mammography are relatively small, median size 1.0 1.5cm 10% of invasive cancers 1 cm or smaller have spread to lymph nodes at the time of detection 35% of invasive cancers 2 cm in size have nodal spread 60% of invasive cancers 4cm or larger have nodal spread
SIZE DOES MATTER STAGE I DISEASE = 2 cm or smaller tumor with no spread to lymph nodes = 98% 5 year disease free survival STAGE II DISEASE = 2.1 to 5 cm and/or 1 3 positive axillary nodes = 86 % 5 year disease free survival
IF BREAST CANCER IS PRESENT WILL IT BE DETECTED BY SCREENING MAMMOGRAPHY? Mammography detects most but not all cancers Depends on a variety of factors but especially how dense breast tissue is
BREAST DENSITY
DETECTION BY MAMMOGRAPHY Detects 85 90% of breast cancers in fatty or minimal scattered fibroglandular density breast Detects only 30 55% of breast cancers in heterogeneously or dense breasts.
WHAT CAN WE EXPECT FROM MODERN MAMMOGRAPHY? Risk of death from breast cancer is decreased by 30 48% by routine screening mammography compared to those not screened
IF WOMEN ARE SCREENED IS IT NECESSARY TO UNDERGO EACH YEAR? YES! In order to achieve the greatest benefit If a woman chooses to have screening mammography, it is especially important that it be performed at least every year from ages 40 49 and in the early 50 s when cancers can grow more rapidly
EXPECTED PERCENT OF WOMEN WITH BREAST CANCER WHOSE LIVES WILL BE SAVED BY SCREENING Interval 40 49 year old 50 59 year old 60 69 year old 1 year 36% 46% 44% 2 year 18% 39% 39% 3 year 4% 34% 34%
BREAST CANCER RISK STRATIFICATION Becoming increasing important as additional screening and prevention options are now available to women at different levels of risk Breast MRI Tamoxifen chemoprevention Genetic counseling and testing
RISK FACTORS FOR BREAST CANCER GENDER AGE FAMILY HISTORY Age at menarche Age at first live birth Age at menopause Previous breast biopsy Body mass index Use of hormone replacement therapy Alcohol consumption Smoking Mammographic breast density
BREAST CANCER RISK PREDICTION MODELS Most breast cancers are sporadic 15 20% are considered familial 5 10% hereditary BRCA1 and BRCA2
Gail Model Age Race Age at Menarche Age at first live birth Number of previous breast biopsies Presence of ADH First degree relative with breast cancer (mother, sisters, daughters)
Claus Model Age First degree relatives with breast cancer Maternal and paternal second degree relatives with breast cancer (aunts and grandmothers) Ages at diagnosis of breast cancer Bilateral breast cancer Ovarian cancer More than two relatives with breast cancer
Identify woman with increased risk IF increased based on either the modified Gail model or family history model, refer for risk assessment Genetic counseling Genetic testing
ULTIMATELY ASSIGNED RISK AVERAGE average lifetime risk MODERATE lifetime risk of 15 20% HIGH lifetime risk of > 25%
IMAGING STRATEGIES AND RECOMMENDATIONS
ANNUAL SCREENING MAMMOGRAPHY STARTING AT : AGE 40 for average risk AGE 25 30 for BRCA carriers and untested relatives AGE 25 30 or 10 years earlier than the age of affected relative at diagnosis with first degree relative with premenopausal breast cancer or with lifetime risk > 20% (whichever is later) 8 years after radiation therapy but not before age 25 for women who received mantle radiation between ages 10 30 Any age for women with biopsy proven lobular neoplasia, ADH, DCIS, or invasive breast cancer
MAMMOGRAPHY ALONE DOES NOT PERFORM AS WELL AS MAMMOGRAPHY PLUS SUPPLEMENTAL SCREENING IN CERTAIN SUBSETS OF WOMEN, PARTICULARLY THOSE WITH A GENETIC PREDISPOSITION AND THOSE WITH DENSE BREASTS
BREAST MRI In high risk women, MRI has been shown to have a higher sensitivity than mammography, and the combination of mammography and MRI in this population has the highest sensitivity BREAST MRI + MAMMOGRAPHY = 92.7% ULTRASOUND + MAMMOGRAPHY = 52%
SCREENING BREAST MRI RECOMMENDED FOR Women with BRCA gene mutations and their untested first degree relatives Women with a lifetime risk of 20% or greater Women who have received radiation therapy to the chest between ages 10 30 Women with other genetic syndromes such as Li Fraumeni
SCREENING BREAST MRI NOT RECOMMENDED FOR OR AGAINST Lifetime risk of 15 20% Personal history of breast cancer * History of lobular neoplasia or ADH *
SCREENING ULTRASOUND INDICATED in high risk women who cannot tolerate MRI CAN BE CONSIDERED for women with intermediate risk and dense breasts
SUMMARY HIGH RISK WOMEN Annual screening mammography and CE MRI are both indicated. US can be used in women with contraindications to MRI INTERMEDIATE RISK WOMEN Annual screening mammography. CE MRI may be indicated in some women AVERAGE RISK WOMEN Annual screening mammography