BMI and weight gain unrelated to colon cancer recurrence risk

NEW YORK (Reuters Health) - There is no apparent relationship between body mass index (BMI) or weight gain after treatment for colon cancer and recurrence or survival, US and Canadian researchers report in the September 1st issue of the Journal of Clinical Oncology. However, there is an indication of an increased risk of colon cancer recurrence in extremely overweight patients, the researchers add.

The results suggest that patients with stage III colon cancer -- lymph node positive without spread to distant organs - who are moderately to severely obese "may have an increased risk of cancer recurrence," lead investigator Dr. Jeffrey A. Meyerhardt told Reuters Health.

Although obesity is known to be a risk factor for the development of colon cancer, the influence of BMI on the outcome of patients with established cancer is uncertain.

To investigate further, Dr. Meyerhardt of the Dana-Farber Cancer Institute, Boston, and colleagues conducted a prospective observational study of 1,053 patients taking part in a trial of adjuvant chemotherapy. In all, 35% of patients were overweight (BMI, 25 to 29.9 kg/m2) and 34% were obese (BMI of 30 kg/m2 or higher).

After a median follow-up of more than 5 years, 369 of the patients had cancer recurrence and 261 died.

There were no overall differences in survival in patients with high BMI compared to normal-weight patients, but those with a BMI of 34 or more were at increased risk of cancer recurrence or death (odds ratio, 1.24).

The researchers achieved similar results when only baseline BMI was considered, indicating that in general, weight change was not a significant factor.

In conclusion, Dr. Meyerhardt added, "it is clear that such patients with stage III colon cancer should receive chemotherapy and chemotherapy should be based on actual body weight."

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