ROCHESTER, MINN. -- Older patients diagnosed with mid-stage colon cancer benefit as much from chemotherapy after surgery as younger patients with the disease, according to a study led by the North Central Cancer Treatment Group, a clinical trials cooperative group based at Mayo Clinic in Rochester, Minn.
The study results, published in the Oct. 11 issue of New England Journal of Medicine, conclude that age alone should not determine whether an older patient is offered chemotherapy after surgery for treatment of stage II and III colon cancer.
Daniel J. Sargent, Ph.D., a Mayo Clinic statistician and lead researcher on the study, analyzed the medical records of 3,351 patients diagnosed with colon cancer. These patients had previously participated in seven different randomized clinical trials conducted around the world to test the effectiveness of 5-FU based surgical adjuvant chemotherapy for colon cancer.
"We found that patients age 70 and older, who were judged by their physicians to be fit enough to undergo chemotherapy, had the resiliency to successfully withstand the side effects," says Dr. Sargent. "Most importantly, the older patients benefited as much from the chemotherapy as younger patients."
The study showed that chemotherapy reduced the risk of death after surgery for colon cancer by 24 percent. The overall five-year survival rate for patients who had chemotherapy after surgery was 71 percent, compared with 64 percent for patients who did not receive chemotherapy.
Annually in this country about 96,000 people are diagnosed with colon cancer, and 46,000 people die of the disease. Colon cancer ranks second to lung cancer in the number of deaths it causes each year.
People age 70 years and older comprise more than 50 percent of patients with colon cancer. As people age, the risk of colon cancer increases.
According to Richard Goldberg, M.D., a Mayo Clinic oncologist and co-researcher on the study, chemotherapy treatment after surgery is known to significantly improve the survival rate of patients with stage III colon cancer and may benefit some patients with stage II colon cancer. These cancers are considered mid-stage and potentially curable.
However, he says, questions often arise whether elderly patients can physically withstand chemotherapy treatments. New or existing medical problems are more common in older patients and may interfere with the ability of elderly patients to tolerate the side effects of chemotherapy.
This study dispels some of those concerns.
"The results of our study should reduce concerns about excess toxicity and reassure physicians and patients that selected patients over the age of 70 can tolerate and benefit from chemotherapy as much as younger patients," says Dr. Goldberg.
Journal
New England Journal of Medicine