Major Staging Systems
Staging of cancer has evolved over many years. Many groups have developed different staging systems. Some cover all cancer sites. Others are limited to particular ages, histologies, sites, study groups, or medical specialties. The major staging systems in use in cancer registries include: Summary Staging and American Joint Committee on Cancer (AJCC) TNM Staging System. Since Summary Staging is the topic of this training module, it will be covered in detail in the following sections. However, a brief description of the AJCC/UICC TNM Staging System is presented here for your information.
American Joint Committee on Cancer (AJCC/UICC TNM) Staging System
The concept of a classification scheme that would encompass all aspects of cancer in terms of primary tumor (T), regional lymph nodes(N), and distant metastasis (M) was first introduced by the International Union Against Cancer (UICC), in 1958 for worldwide use. Staging schemes were developed by AJCC (the American contingency of the UICC) to be consistent with the practice of medicine in the United Stages and used the basic premise of the TNM system: cancer of similar histology or site of origin share similar patterns of growth and extension. It is identical to the classification of the International Union Against Cancer (UICC).
The AJCC staging scheme is based on the evaluation of the T, N, and M components and the assignment of a stage grouping. The T element designates the size and/or invasiveness of the primary tumor. The N component designates the presence or absence of tumor in the regional lymph nodes. The M component identifies the presence or absence of distant metastases, including the spread to (or involvement of) lymph nodes that are beyond regional lymph node drainage.
The general rules for the AJCC staging system are defined in the AJCC Manual for Staging of Cancer.
Site Specific Staging Systems
Unlike staging systems that encompass all tumor types, the following staging systems are site specific.
The Dukes staging system is a classic albeit dated method for describing extent of disease for colorectal cancer. It was created by Sir C.E. Dukes, a British pathologist, in 1929. Simpson and Mayo modified Dukes' scheme for colon cancer in 1939. Further modifications were made by Astler, Coller, and others. The Dukes staging system and its modifications are still in use by many clinicians today. In 1998, the TNM system was modified to correspond with the Dukes system.
The Whitmore-Jewett Staging system, sometimes called the Jewett Staging System is a popular staging classification system prostate cancer. The system was created in 1975 and it classifies all prostatic cancers into one of four stages. These may be numbered 1-4 or distinguished by the letters A-D. Later, it was modified by the AJCC and UICC to include subcategories. It was created by The American Urological Association (AUA). However, urologists are abandoning both the Whitmore-Jewett and the AUA staging schemes and adopting the AJCC staging schemes.
Some other existing staging schemes include: Jewett and Strong for bladder (later modified by Marshall and was referred to as Jewett-Marshall Staging); FIGO staging system describing for female reproductive organ tumors; the Ann Arbor classification, a staging scheme commonly used for the staging of lymphomas; Breslow's microstaging and Clark's level of invasion, two classification schemes for melanoma, and many others.
A note about Collaborative Stage
You may be wondering why Collaborative Stage is not mention here. Collaborative stage is not a staging system. Rather, it is a unified data collection system. Collaborative Stage is designed to provide a common data set to meet the needs of all three staging systems, TNM, SEER EOD, SEER SS, and provide a comprehensive system to improve data quality by standardizing rules for timing, clinical and pathologic assessments, and compatibility across all of these systems for all cancer sites. For more information, see the Introduction to Collaborative Staging module.