Rise in chemotherapy for colon cancer coincides with improved survival

From 1990 to 2002, the use of adjuvant chemotherapy for stage III colon cancer rose from 39% to 64% with a corresponding increase in 5-year survival of 16%, new research shows.

Based on trial results showing improved survival with a 5-fluorouracil-based regimen, the 1990 National Institutes of Health Consensus Conference recommended adjuvant chemotherapy for patients with stage III colon cancer, according to the report in the December 7th issue of the Journal of the American Medical Association.Dr. J. Milburn Jessup, from the National Cancer Institute in Rockville, Maryland, and colleagues looked at the implementation of adjuvant chemotherapy and the impact, if any, on survival. Data from 85,934 patients in 560 hospital cancer registries were included in the analysis.During the study period, “the difference in survival between surgery alone and surgery plus chemotherapy increased,” Dr. Jessup told Reuters Health.In 1991, surgery alone and surgery plus chemotherapy were associated with 5-year survival rates of 54% and 62%, respectively. By 1997, the most recent year with analysable survival data, the corresponding rates were 50% and 66%.Masked by the overall increase in chemotherapy use are differences in uptake of this modality by gender, age and ethnicity.”Women with stage III disease do not seem to receive adjuvant chemotherapy as frequently as men,” Dr. Jessup said. “We think this finding is real, but we don’t know why it’s happening. The results indicate that when chemotherapy is given, women get just as much benefit as men.” Compared with the patterns seen in younger patients, the “use of chemotherapy by elderly patients increased only slightly during the study period,” Dr. Jessup said. As with the gender findings, the survival benefit seen in elderly patients was similar to that seen in younger patients, he added.”In the early and middle parts of the study, chemotherapy use by African Americans lagged behind that of other ethnic groups, but by the end, they had caught up,” Dr. Jessup pointed out. “Interestingly, the survival of blacks who received chemotherapy was lower than that of their white counterparts. The reasons for this are unclear, but may relate to genetic polymorphisms that have been linked to race.” While the findings indicate that chemotherapy use and survival has increased for patients with stage III disease, the rates listed may underestimate present day survival, Dr. Jessup said. “Our data predate the use of some newer chemotherapeutic agents, such as irinotecan and oxaliplatin, that may further improve outcome.”(Source: JAMA 2005;294:2703-2711: Reuters Health: Anthony J. Brown, MD: Oncolink: December 2005.)