(Ivanhoe Newswire) -- Obese patients with colon cancer may have a greater chance of dying from the disease compared to those at a normal weight.

Every year in the United States, roughly 150,000 people are diagnosed with colon cancer. A new study involved 4,381 patients with stage II or II colon cancer who were treated with chemotherapy, 20 percent of whom were obese.

"Obesity has long been established as a risk factor for cancer, but our study in colon cancer patients shows that obesity predicts a poorer prognosis after the cancer is surgically removed," Frank A. Sinicrope, M.D., a professor of medicine and oncology at the Mayo Clinic in Rochester, N.Y., was quoted as saying.

Researchers found obesity's impact on prognosis was more prominent for men than women. Men in the highest body mass index had a 35 percent higher risk of death compared to normal weight men.

"We do not know if this is due to biology or the way we measure obesity," Dr. Sinicrope said. "Body mass index is a limited measure and there is evidence that abdominal fat may be a better predictor of colon cancer risk and perhaps prognosis in men than in women. There is also the potential influence of menopausal status and hormone replacement therapy in women."

Experts say more studies are revealing obesity's role in patient prognosis, unrelated to stroke or heart disease, yet many patients are still unaware of their risk.

Source: Clinical Cancer Research, March 2010