Chemo for Colon Cancer Has Risen, Upping Survival

NEW YORK (Reuters Health) - From 1990 to 2002, the use of chemotherapy in addition to surgery for advanced colon cancer has risen from 39 to 64 percent with a corresponding 16 percent increase in the proportion of patients surviving for five years, new research shows.

In the case of advanced "stage III" colon cancer, the main treatment is surgical removal of the cancer. In 1990, a National Institutes of Health Consensus Conference recommended add-on, or adjuvant, chemotherapy for patients with stage III colon cancer, according to the report in 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 this recommendation 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," Jessup told Reuters Health.

In 1991, surgery alone and surgery plus chemotherapy were associated with 5-year survival rates of 54 and 62 percent, respectively. By 1997, the most recent year with analyzable survival data, the corresponding rates were 50 and 66 percent.

Masked by the overall increase in chemotherapy use are differences in its usage by gender, age and ethnicity.

"Women with stage III disease do not seem to receive adjuvant chemotherapy as frequently as men," 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."

Also, compared with the patterns seen in younger patients, the "use of chemotherapy by elderly patients increased only slightly during the study period," 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," Jessup pointed out. Nonetheless, "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 (variants) that have been linked to race."

While the findings indicate that survival has increased for patients with stage III disease, present-day rates may be even better, Jessup said. "Our data predate the use of some newer (chemotherapy drugs) that may further improve outcome." SOURCE: Journal of the American Medical Association, December 7, 2005.