Cancer Staging. Introduction. Overview

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1 Many Hearts Many Minds One Goal Volume 2 Number 3 May 2005 Cancer Staging bt Maureen MacIntyre, Director, Surveillance and Epidemiology Unit, Cancer Care Nova Scotia and Dr. Eva Grunfeld, Clinician Scientist and Director, Health Services and Outcomes Research, Cancer Care Nova Scotia Introduction Understanding the extent of a cancer at the time of diagnosis is perhaps the single most important determinant of the future care plan and ultimately the patient s outcome. Commonly referred to as staging the cancer, this concept of determining disease extent incorporates various clinical parameters and applies a standardized approach to assign a stage value. Clinicians use this knowledge to select the most appropriate treatment plan for the patient. It is important for all health professionals involved in the care of the cancer patient to understand stage information, the important role it plays in organizing patient care, assessing treatment outcomes and supporting cancer surveillance and research. Survival of Female Breast Cancer Patients by stage of disease at diagnosis followed to end of 2003 % Survival Years Since Diagnosis Local (early stage) Regional (lymph node involvement) Distant (metastatic spread) This issue of In Practice is devoted to cancer staging; the concept, its application and a detailed outline of the TNM stage system, which is widely used across North America. TNM examples are provided for the most common cancers: breast, lung, prostate and colorectal cancer. These account for approximately 60% of all new cancer diagnoses each year in Nova Scotia (Saint Jacques et al, 2002). This information complements an article in the February 2005 issue of the Cancer Care Nova Scotia (CCNS) newsletter that provided an introduction to staging intended to educate the general public. Overview Staging describes the extent of a cancer at diagnosis based on: the tumour size (T); the degree to which it has spread to the regional lymph nodes (N); or metastasized to other parts of the body (M). In addition to this anatomic approach, staging systems may also take into account other prognostic factors such as histology, grade or serum tumour markers. Staging systems must also have flexibility to adapt over time as new knowledge on prognostic factors is ascertained (Hutchinson et al, 1997). Stage systems provide a common language that physicians and other health professionals can use to communicate prognosis and decide on treatment options for a specific case. Long-term use and collection of stage data is valuable for epidemiological and research purposes as similar types of cancer can be grouped for analysis or selected for special studies. Recent breast cancer survival for Nova Scotia is shown in the graph above where analysis has included stage information to group cases.

2 Staging Systems A variety of staging systems have been developed since the early 1920 s, with many focused on a specific type of cancer. The Dukes system for colorectal disease and Ann Arbor classification for lymphomas may be familiar to many cancer care providers. Perhaps the most widely used stage system in the world is the TNM (i.e. Tumour, Node, Metastases). The TNM system is now in its 6 th edition and applies to the majority of solid tumours. TNM originated in France in the 1940 s and has been supported and published since that time by the International Union Against Cancer (UICC). The United States based American Joint Committee on Cancer (AJCC) has published TNM-based staging material for 45 years (see AJCC Cancer Staging Manual 6 th ed. 2002). Both the UICC and AJCC TNM versions are now synchronized for both release date and content. Features of TNM Anatomically based, the TNM system utilizes three main elements when considering stage assessment. The use of numerical subsets for each component indicates the progressive extent of the cancer (AJCC Cancer Staging Manual 6 th ed. 2002). The following table outlines the overall framework by element. Tumour (T) extent of the primary tumour TX Primary tumour cannot be evaluated T0 No evidence of primary tumour Tis Carcinoma in situ (early cancer that has not spread to neighbouring tissue) T1, T2, T3, T4 Size and/or extent of the primary tumour NX N0 Regional Lymph Nodes (N) Absence or presence and extent of regional lymph node involvement Regional lymph nodes cannot be evaluated No regional lymph node involvement (no cancer found in the lymph nodes) N1, N2, N3 Involvement of regional lymph nodes (number and/or extent of spread) MX M0 M1 Distant Metastasis (M) Absence or presence of distant metastasis Distant metastasis cannot be evaluated No distant metastasis (cancer has not spread to other parts of the body) Distant metastasis (cancer has spread to distant parts of the body) cancers that may have a different prognosis, an additional letter may be used with the number to subgroup (e.g. T2a versus T2b). Letter assignment is also used in a progressive fashion. A final overall rule related to use of TNM is that for it to be properly applied, cases should be histologically confirmed. Timing of TNM Assignment TNM further allows the case to be staged at different points in time relative to diagnosis. A clinical or ctnm is based on evidence before primary treatment which may be gleaned from physical examination, imaging, and in some cases, even surgical exploration. A pathological or ptnm is again based on evidence before treatment but including details gathered from the surgery and subsequent pathological examination. It is also possible to stage a case at recurrence after a disease-free interval at which time an r precedes the TNM designation. This may not be seen on a frequent basis. Should the tumour only be found after death, the TNM assignment would be preceded by an a, signifying autopsy. Stage Grouping Considering the various numerical assignments that are possible within the TNM framework, multiple combinations of T, N and M are possible for any specific disease. To simplify use of the TNM system and increase its value as a communication tool, these combinations have been arranged into a smaller number of stage groupings, usually zero through four (i.e. 0, I, II, III, IV). If justified, TNM may divide a group using a letter (e.g. a or b ). In many situations stage group may be the piece of information that is most easily communicated to and retained by the patient. Family physicians and other health care professionals may see the full TNM stage or just the stage group in documentation that is received from the cancer specialist. In cases where the numerical progression or assignment is not sufficient to adequately differentiate a subset of

3 TNM Examples for Major Cancer Types The following tables are specific to each of the major cancer sites and provide the overall stage groupings along with the applicable T, N and M combinations possible within the disease. All tables are reproduced from the AJCC Cancer Staging Manual, Sixth Edition, Breast Stage Group T Value N Value M Value Stage 0 Tis N0 M0 Stage I T1 or T1mic N0 M0 Stage II A T0 N1 M0 T1 or T1mic N1 M0 T2 N0 M0 Stage II B T2 N1 M0 T3 N0 M0 Stage III A T0 N2 M0 T1 or T1mic N2 M0 T2 N2 M0 T3 N1 M0 T3 N2 M0 Stage III B T4 N0 M0 T4 N1 M0 T4 N2 M0 Stage III C Any T N3 M0 Stage IV Any T Any N M1 Colorectal Note The comparable match between TNM, Dukes and the Modified Astler Coller colorectal classification has been added since these systems are still in use by some practitioners. Stage T Value N Value M Value Dukes Modified Group Astler- Coller 0 Tis N0 M0 - - I T1 N0 M0 A A T2 N0 M0 A B1 IIA T3 N0 M0 B B2 IIB T4 N0 M0 B B3 IIIA T1-T2 N1 M0 C C1 IIIB T3-T4 N1 M0 C C2/C3 IIIC Any T N2 M0 C C1/C2/C3 IV Any T Any N M1 - D Prostate TNM groupings for prostate also include Gleason score (assigned by the pathologist) directly in the grouping assignment. The AJCC uses this table for adenocarcinomas and squamous carcinomas. Sarcomas and transitional cell tumours are classified using other genito-urinary tables. Stage Group T Value N Value M Value Gleason Score Stage I T1a N0 M0 G1 Stage II T1a N0 M0 G2, 3-4 T1b N0 M0 Any G T1c N0 M0 Any G T1 N0 M0 Any G T2 N0 M0 Any G Stage III T3 N0 M0 Any G Stage IV T4 N0 M0 Any G Any T N1 M0 Any G Any T Any N M1 Any G

4 Lung Stage Group T Value N Value M Value Occult TX N0 MO Carcinoma Stage 0 Tis N0 MO Stage IA T1 N0 MO Stage IB T2 N0 MO Stage IIA T1 N1 MO Stage IIB T2 N1 MO T3 N0 MO Stage IIIA T1 N2 MO T2 N2 MO T3 N1 MO T3 N2 MO Stage IIIB Any T N3 MO T4 NX, N0, N1, N2 MO Stage IV Any T Any N M1

5 What Lies Ahead Staging is critical to understanding an individual patient s cancer. It provides important insight into prognosis and guides treatment decisions. In addition, it offers tools for studying the disease on a population level which, in turn, assists with enhancing and improving treatment and understanding of the disease. As we learn more about cancer and the prognosis of the disease, staging systems are becoming more refined and, by necessity, more complex. The AJCC has already started preparations for the 7 th Edition of TNM with an expected release date of To improve how health professionals in Nova Scotia can benefit from the use of stage information, the Nova Scotia Cancer Registry has begun work to capture stage information on all newly diagnosed cancers. More information The following websites may be helpful in providing you with more information about cancer staging or they may be useful for patients and families who have questions. American Joint Committee on Cancer Canadian Cancer Society National Cancer Institute Surveillance Epidemiology End Results Program In addition, Cancer Care Nova Scotia has introduced the Oncology Interactive Education Series (OIES), which is available at various health facilities across the province. The computer-based program includes information for patients, families and health professionals. It is available in CD format, is disease-specific and includes explanations using TNM staging. For more information about OIES, contact Sandra Cook, project manager, by at sandra.cook@ccns.nshealth.ca. or by phone at CCNS also has a limited supply of an AJCC five-card, quick reference pocket set of TNM staging information for Breast, Lung, Prostate, Colorectal and Cervix diagnoses. If you would like a copy, please contact us by at info@ccns.nshealth.ca or by phone at

6 Cancer Care Nova Scotia is a program of the Department of Health. Its mandate is to evaluate, coordinate and strengthen the cancer system in Nova Scotia. Cancer Care Nova Scotia works with and supports professionals and stakeholders in the health care system to bring about patient-centred change. Its ultimate goal is to reduce the burden of cancer on individuals, families, communities and the health care system. In Practice is a supplement to Cancer Care Nova Scotia s newsletter. It is written specifically for primary care practitioners with information that we hope will make a difference in your cancer practice. Please contact Christine Smith, Communications Coordinator, Cancer Care Nova Scotia, by phone at or by at christine.smith@ccns.nshealth.ca with comments or suggestions for future topics. References 1. Saint-Jacques N, MacIntyre M, Dewar R, Johnston G, Cancer Statistics in Nova Scotia: A Focus on Surveillance and Epidemiology Unit, Cancer Care Nova Scotia; Hutchinson C, Roffers S, Fritz A, Cancer Registry Management Principles & Practice. National Cancer Registrars Association, Iowa, Kendall/Hunt Publishing Co.; Greene F, Page D, Fleming I, Fritz A, Balch C, Haller D, Morrow M, AJCC Cancer Staging Manual Sixth Edition. New York, Springer-Verlag; Tower Road 5th Floor Bethune Building Halifax, NS B3H 2Y9 Department of Health