Study: Obese Women With Colon Cancer at Higher Risk of Death

Obesity increases the risk of death from colon cancer in women, but not men, according to researchers at the Dana-Farber Cancer Institute in Boston.

The researchers, based on a study involving more than 3,000 patients with stage II and III colon cancer, reported in the journal Cancer that women with a body mass index (BMI) of at least 30 had about a one-third greater overall mortality than women of normal weight.

Obese women also appeared to be somewhat more likely to suffer relapses of their colon cancer, the researchers said.

But no similar link between obesity and a higher risk of death or cancer recurrence was found in men with colon cancer -- an outcome that came as something of a surprise since previous studies have found obese men more likely to develop colon cancer than obese women.

The researchers speculated that the reason why obese women, and not obese men, have a worse overall survival rate may be linked to higher levels in women of the obesity-associated protein leptin, higher insulin resistance, and more adult-onset diabetes.

The women also have higher C-reactive protein levels, and more circulating estrogen, the researchers said. All of these factors may have a tumor promoting effect.

For both obese men and women, being overweight did have one benefit. The researchers found they were less likely than their thinner counterparts to suffer serious side effects from their chemotherapy.

Other sources: Dana-Farber Cancer Institute