Age likely a factor in colon cancer chemotherapy

Older patients with colon cancer are less likely to receive chemotherapy after surgery than younger people but have fewer serious side-effects when they do get the treatment, U.S. researchers said on Tuesday.

When older patients do receive the treatment, it tends to be at a less toxic dose and over a shorter period than younger patients receive, according to a study in the Journal of the American Medical Association.

Clinical trials have shown that surgery with chemotherapy helps patients live longer than surgery alone but it is not an option always open to the elderly, said Dr. Robert Fletcher of Harvard Medical School.

Researchers analyzed data on 675 stage III colon cancer patients in five regions across the United States who had surgery.

"One of the main reasons people shy away from giving these drugs to older patients is that they might have more adverse events and we saw no evidence ... that there was an increase in those adverse events," Fletcher said at a briefing.

The researchers said the older patients who did get chemo got lower doses and tended to be healthier than the average elderly cancer patients.

Fletcher said they looked at potentially serious complications, not adverse reactions from the drugs themselves, such hair loss or fatigue.

"We were looking at clinical events that patients might experience that would change their care, prolong their stay in the hospital, perhaps lead to their death," Fletcher said.

"As others have shown, we also saw that the older patients in the community were less likely to get chemotherapy," Fletcher said.

A perception that older people have "fewer years to live" is also a factor in why they may not receive chemotherapy, Fletcher said.

Doctors also cite lack of clinical trials showing effectiveness in elderly patients, multiple illnesses and drug toxicity as the most common reasons for not treating older patients with chemotherapy after surgery, the study said.

Dr. Katherine Kahn of RAND Corporation and colleagues analyzed the use of chemotherapy and side effects by age in a study of 675 patients, tracking them for up to 15 months after their diagnosis.

The study found that 75 percent of the patients received chemotherapy after surgery. Of the 202 patients 75 years and older, half received chemotherapy compared with 87 percent of younger patients.

Among patients receiving chemotherapy, adverse events were lower for patients 75 years and older compared with younger patients, the researchers said.

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By JoAnne Allen

WASHINGTON (Reuters)