New AJCC Cancer Staging Manual reflects changes in cancer knowledge

Abstract

The seventh edition of the AJCC Cancer Staging Manual and Handbook, prepared by the American Joint Committee on Cancer (AJCC) and published this past fall, goes into effect for all newly diagnosed cancer patients this month. The manual is the “gold standard to help the cancer patient-management team determine the correct stage for patients and allow the most appropriate cancer plan,” according to the AJCC. Proper staging also enables patient participation in clinical trials and reporting on cancer incidence and outcomes. The latest update of the manual, previously updated in 2002, includes major revisions to many chapters, including breast, colon, prostate, and kidney. New primary site chapters have been added for a variety of cancers, including those for bile ducts, distal bile ducts, cutaneous squamous-cell carcinoma, Merkel-cell carcinoma, and cancer of the adrenal gland. Each new edition of the manual involves the collaboration of hundreds of people worldwide, including specific multidisciplinary task forces who are assigned to each featured disease site. “It has been 7 years since our last publication, and we think that's a reasonable amount of time to look at outcome studies that are using current staging strategies and see if anything new needs to be added,” notes Frederick Greene, MD, chairman of surgery at Carolinas Medical Center in Charlotte, North Carolina, and editor of the manual's sixth edition. In melanoma, for example, scientists have recognized that factors such as the Breslow thickness of a lesion as well as whether or not it is ulcerated or has become mitotic need to be incorporated into the staging strategy, he says. One of the most important changes in the manual is the recognition that anatomically based staging alone is insufficient to guide the clinical treatment of many types of cancers, according to Stephen Edge, MD, senior editor of the manual's seventh edition and chair of breast surgery at Roswell Park Cancer Institute in Buffalo, New York. The AJCC uses the TNM staging system-which is based on the extent of the tumor (T), the extent of spread to the lymph nodes (N), and the presence of metastasis (M). “We've specifically charged the task forces with identifying nonanatomic prognostic factors that are critical to defining the cancer stage,” Dr. Edge says, adding that the AJCC recognizes that many diseases will not have nonanatomic factors. One key example of a disease that cannot be staged using TNM anatomical staging alone is prostate cancer. Physicians must have information on a patient's Gleason's score and prostate-specific antigen score to develop an appropriate treatment plan. These details are included in the chapter on prostate cancer. Testicular and esophageal cancers are other examples of diseases in which specific biomarkers are incorporated into staging, Dr. Edge notes. In breast cancer, information on a tumor's estrogen receptor status and HER2 protein status are also crucial. Although it is impossible to formulate a treatment plan without them, these factors are not spelled out in the manual as part of the staging process. However, the AJCC does recommend that tumor registries collect this information for all patients. Similarly, the task forces are now being asked to include staged groupings of relevant nonanatomic prognostic factors. “This is in preparation for the next generation of clinical tools that will incorporate these prognostic factors into models that will predict risk of recurrence, response to treatment, and survival for individual patients,” Dr. Edge says, adding that AJCC expects to be a clearinghouse to validate and develop such models. Also, the AJCC manual editors are working with software manufacturers to develop some electronic formats that can interact with staging forms and be incorporated into electronic medical records. Another major advance reflected in new elements of staging is the ability of pathologists to see increasingly smaller cancer sites, Dr. Greene notes. “I give a lot of kudos to the pathology community for pushing the envelope on what we can see,” he says. “Sentinel node biopsy in breast cancer, melanoma, and other diseases was made possible by pathologists' ability to examine nodes in a very important way.” Dr. Edge praises the high level of international collaboration on the manual, which included large-scale international efforts among physicians and scientists to produce chapters for various disease sites. The worldwide TNM staging systemis coordinated with the International Union Against Cancer (UICC), headquartered in Geneva, Switzerland. The staging manual is one of the most widely distributed medical publications. Some 60,000 to 80,000 copies are expected to be sold.