Posted by December 8th, 2005
Although adjuvant chemotherapy after surgery has been recommended as standard treatment for stage III colon cancer since 1990, about 1/3 of stage III patients in the United States don’t receive it. In addition, women and the elderly are less likely to be treated according to a study published in the December 7, 2005 issue of the *Journal of the American Medical Association.*
After two randomized clinical trials showed that stage III colon cancer patients had better survival when they were treated with 5FU (fluorouracil) and levamisole after surgery, a National Institutes of Health Consensus Conference in 1990 recommended chemotherapy for all stage III colon cancer patients who were not enrolled in a clinical trial. Further clinical trials during the 1990′s found that leucovorin was as effective as levamisole and not as toxic, so six months of 5FU modified by leucovorin became standard treatment. Recent studies have shown that oxaliplatin added to a 5FU leucovorin regimen improves survival even more, and the combination of 5FU, leucovorin, and oxaliplatin is now the common adjuvant chemotherapy for stage III patients who have had surgery to remove cancer from their colons.
For the JAMA study, researchers analyzed records of nearly 86,000 patients with stage III colon cancer reported by 560 health care facilities from 1990 through 2002. In stage III colon cancer, cancer has spread from the colon to nearby lymph nodes. In the mid-eighties before the Consensus Conference, only 10% of stage III patients had adjuvant chemo. In 1990, after the Consensus recommendation, 39% of patients were receiving chemotherapy, but the percentage increased to 64% by 2002.
Overall, chemotherapy improved survival by about 16%. The greatest improvement was for those whose cancers were well or moderately differentiated (low or moderate grade) while chemotherapy gave patients with poorly differentiated tumors little survival advantage over surgery alone.
In 1990 blacks were less likely to receive adjuvant chemotherapy, but that difference had disappeared by 2002. However, blacks tended to have poorer survival in every time period examined.
Women and people over 80 benefited equally well from chemotherapy, but were less likely to have it prescribed for them.
The research team, led by J. Milburn Jessup, MD summarized their findings:
In summary, 15 years after the NIH Consensus Conference, adjuvant chemotherapy use has increased to include nearly two thirds of patients with stage III colon cancer patients. Patients receiving adjuvant therapy for stage III colon cancer, especially low-grade cancer, have an increased survival benefit of 16%.
The benefit of adjuvant chemotherapy seems to be lower in blacks and patients with high-grade cancers. Women have the same benefit but are less often treated. Elderly patients have the same benefit as younger patients but are also less frequently treated.
They also pointed out that more study is needed to see what impact the newer treatments with oxaliplatin and iriotecan will have.
Future studies are needed to identify whether newer agents such as irinotecan and oxaliplatin may be more effective in patients with high-grade cancers or in blacks than the 5-fluorouracil and leucovorin regimens that were dominant during the time that the cohorts reported herein were followed up for survival.
Find more discussion about the study on [MedPage Today](http://www.medpagetoday.com/Gastroenterology/ColonCancer/tb/2274) and from [USA Today](http://www.usatoday.com/news/health/2005-12-07-colon-cancer_x.htm)