ROCHESTER, Minn., May 16 This release is being sent in a social media format, by Mayo Clinic in conjunction with the National Cancer Institute, part of the NIH.
* A new study being presented at the American Society of Clinical Oncology meeting in Chicago (Abstract #4020), may change treatment practice in about 25 percent of patients with colon cancer and is the basis for proposed changes to the way colorectal cancers will be staged.
* This new study, using National Cancer Institute (NCI) SEER population-based statistic registries from 1992 to 2004, and phase III clinical trial data, shows that outcomes of patients with positive nodes (Stage III) in colorectal cancer interact, to a greater extent than previously thought, with how deeply the cancer penetrates the bowel wall.
* Survival outcomes depend on the thickness of the primary cancer within or beyond the bowel wall in addition to whether nodes are positive or negative. A patient with a node positive 'thin' lesion (i.e., confined to the bowel wall) has a stage III cancer with better survival outcomes than a patient with a Stage II node negative 'thick' cancer that penetrates beyond the bowel wall. The current standard of practice for colon cancer patients is that all or most Stage III patients receive chemotherapy after surgical removal of their cancer, but Stage II patients do not routinely receive chemotherapy. In a separate National Cancer Data Base (NCDB) analysis, patients with Stage III colon cancers confined to the bowel wall who did not receive chemotherapy still had better survival than Stage II patients.
* Guidelines for adjuvant therapy may need re-examination in future clinical trials as well as more research into the molecular basis for the interplay between a primary cancer's ability to penetrate the bowel wall and to spread to regional nodes.
* Also, the survival of patients whose cancers invade beyond the bowel wall to involve adjacent structures or organs is worse than that of patients whose cancers merely penetrate to the surface of the bowel wall (the reverse had been thought to be true).
* This abstract/poster will be presented by Dr. Leonard L. Gunderson, M.D., a radiation oncologist from Mayo Clinic, Scottsdale, Ariz., and Vice Chair of the Hindgut Task Force of the American Joint Commission on Cancer (AJCC) that proposes changes to current guidelines. J. Milburn Jessup, M.D., NCI, part of the National Institutes of Health, is the chair of the Task Force.
* J. Milburn Jessup, M.D.: "These proposed changes could lead to real clinical benefit for many colorectal cancer patients and also lessen the amount of treatment that patients with thin lesions may need."
* John E. Niederhuber, M.D., Director, NCI: "Simple advances in treatment that are derived by comparing national statistics to clinical data are greatly welcomed and are an excellent example of moving the field forward by some basic, low-cost methods."
* Leonard L. Gunderson, M.D.: "The current SEER analysis confirms that patients with node positive colon or rectal cancers that do not extend beyond the bowel wall have better survival than previously thought."
* For still images related to colorectal cancer, go to: http://visualsonline.cancer.gov/details.cfm?imageid=1768; http://visualsonline.cancer.gov/details.cfm?imageid=2345
* For video of chemotherapy and other treatments, go to: http://www.cancer.gov/newscenter/pressreleases/b-roll-treatment.
SOURCE Mayo Clinic Public Affairs; National Cancer Institute