Chemotherapy for colon cancer offers no survival benefit after ten years: study

Previously, chemotherapy after surgery indicated a 5 year disease-free and overall improved survival rate than surgery alone. Since that kind of chemotherapy and immunotherapy is no longer used, Dr. Jean Grem of the University of Nebraska Medical Center in Omaha recommends testing new agents, using 3-year disease-free survival measurements instead of 5-year survival.

• In 1988, a team of researchers reported that, for patients with colon cancer, postoperative chemotherapy was associated with better 5-year disease-free and overall survival than surgery alone.
• However, this survival benefit disappeared after 10 years, according to an update of that same clinical trial that appears in the August 4 issue of the Journal of the National Cancer Institute.
• In 1977, the National Surgical Adjuvant Breast and Bowel Project (NSABP) began a randomized clinical trial, NSABP protocol C-01, to evaluate the efficacy of adjuvant chemotherapy or postoperative immunotherapy after surgery compared with surgery alone in colon cancer patients.
• This improvement was associated with fewer deaths from conditions other than colon cancer among the older patients in the trial.
• It should be noted, however, that because the chemotherapy and immunotherapy used in this trial are no longer recommended for colon cancer, it is possible that the newer chemotherapy regimens would be better than surgery alone, the authors write.
• In an editorial, Jean Grem, M.D., of the University of Nebraska Medical Center in Omaha, notes that neither of the regimens tested in this trial are currently in clinical use, so there is a need to find appropriate surrogate end points for colon cancer trials to expedite the clinical testing phase of potential new agents.
• She suggests the possibility of using 3-year disease-free survival as a surrogate end point for 5-year overall survival, noting that its advantages include "allowing more timely completion of trials, and more rapid implementation of new trials testing promising new therapies."