Patients with stage III colon cancer treated with 5-FU-based chemotherapy after complete surgical removal of their tumor after 1995 had improved overall survival with no change in time to recurrence compared to patients treated before 1995. In contrast, patients with stage II colon cancer treated after 1995 had longer time to recurrence and time from recurrence to death compared to those patients treated prior to 1995, according to Mayo Clinic and Gr Hospitalier Pitie-Salpetriere, Paris, researchers. They will present the study's findings on June 4-8, 2010, at the American Society of Clinical Oncology (www.asco.org/) annual meeting in Chicago.
"By combining information from 21 cancer treatment trials for patients with stage II and stage III colon cancer, our analysis determined that those patients treated after 1995 had improved overall survival," says Dan Sargent, Ph.D., Mayo Clinic biostatistician, North Central Cancer Treatment Group (NCCTG) statistician and senior author on the study.
The analysis compared patient data from more than 18,000 patients with stage II and stage III colon cancer treated with 5-FU-based chemotherapy after their primary tumor had been surgically removed for the time period 1978-1995 versus 1996-2007.
"Patients with stage II colon cancer treated after 1995 had had longer time to recurrence, possibly due to improvements in surgery and pathology" says Dr. Sargent. "In addition, after 1995, both stage II and stage III colon cancer patients treated after surgery with the same 5-FU-based chemotherapy after surgery had improved overall survival. This finding provides evidence to support previous findings that access to new medical therapies introduced in the mid-1990s as well as the expanded use of surgery for patients recurrent disease have meaningfully improving overall survival for patients treated in this setting."
The findings arise from analysis of combined data collected within an expanded database by the Adjuvant Colon Cancer End Points (ACCENT) Group, a consortium of scientists. The ACCENT database includes data from more than 33,500 patients from the United States, Canada, Australia and Europe. ACCENT, chaired by Dr. Sargent, is supported by the NCCTG.