More than a decade after new treatment guidelines for the disease were issued, many patients with advanced colon cancer are not getting chemotherapy after surgery, despite clear-cut evidence it boosts survival, a study found.
Blacks, women and elderly patients were found to be less likely to get chemo, even though such treatment was shown to improve survival in all groups.
About two-thirds of the patients who received chemotherapy in addition to surgery were alive after five years, compared with about half of those who had surgery alone, according to the study in Wednesday’s Journal of the American Medical Association. On average, chemotherapy improved the five-year survival rate by about 16 percent.
“It gives you quite a lot of edge,” said study co-author Dr. J. Milburn Jessup of the National Cancer Institute and Georgetown University Medical Center.
The National Institutes of Health published guidelines in 1990 recommending chemotherapy after surgery for stage III colon cancer, in which the cancer has spread to the lymph nodes of the abdomen. Colon cancer is the second deadliest cancer for Americans after lung cancer.
The researchers analyzed data from nearly 86,000 patients at 560 U.S. hospitals who were entered into a national cancer database, and found that the share of those who received surgery plus chemo went from 39 percent in 1991 to 64 percent in 2002.
Similarly, studies presented at an American Society of Clinical Oncology meeting in May showed significant variation in the treatment given to patients with cancer of the breast or stomach.
The disparity found in the JAMA study narrowed for blacks over the decade, until it was no longer significant in 2002. But the gap remained wide for women and even wider for elderly patients. Jessup would not speculate about the reason for the disparities.
“A lot of patients still don’t get treated despite very promising data,” said Dr. Wells Messersmith at the Johns Hopkins Kimmel Cancer Center, who was not involved in the research. He said nearly all his stage III patients receive chemotherapy after surgery.
Some patients fear chemotherapy and do not realize new medications can lessen its side effects, he said. And some doctors do not have the means to provide the best treatment or do not keep up with the research, Messersmith said.
Dr. Mark Zalupski of the University of Michigan, who was not involved in the research, said colon cancer patients in their 80s are more likely to have other health problems that might make chemotherapy after surgery less practical.
Elderly patients also sometimes refuse chemotherapy, he said.
“In my own practice, I’ve seen older patients who don’t want to be bothered with the burdens of therapy. They’ve lived their lives and will sort of take their chances,” Zalupski said.
