Obesity can increase the risk of colon cancer recurrence, according to a new patient study.

Colon cancer may recur after treatment. Researchers at the University of Pittsburgh now reveal that obesity is a factor which may increase the risk of colon cancer recurrence. They followed a group of 4,288 patients with colon cancer who had enrolled in clinical trials. More than half of the patients were overweight and 5.5 per cent had a body mass index of 35 or more which is classified as severe obesity.

Those falling into the severe obesity category were one third more likely to experience a recurrence of colon cancer than those of normal weight and to die prematurely for this reason. The doctors say this is comparable to the difference in survival between those treated with surgery alone and those treated with surgery or chemotherapy.

Those who were underweight, with a body mass index of 18.5 or less had twice the risk of death compared to those of normal weight. But this increased death risk related to non-cancer causes. The mechanism connecting obesity and cancer recurrence is not understood. It may relate to the existence of other, obesity-related, health problems which interfere with cancer treatment. Or there may be a role for insulin or related factors, levels of which may be abnormal in obesity, in promoting cancer growth.

Source
Journal of the National Cancer Institute 15th November 2006