Breast cancer mortality increases with body mass index

NEW YORK (Reuters Health) - A higher body mass index (BMI) is associated with lower survival rates in women with breast cancer, according to a report in the July 10th issue of the Journal of Clinical Oncology.

"We have found strong evidence that high BMI and a recent pregnancy are associated with a poorer prognosis after a diagnosis of breast cancer," Dr. Gillian C. Barnett told Reuters Health. "Our study suggests that advice on weight loss should be given to all obese patients with breast cancer."

Dr. Barnett from Addenbrooke's Hospital, Cambridge, UK and colleagues investigated the impact of established risk factors for incident breast cancer on overall survival after a diagnosis of breast cancer, using data from the Studies of Epidemiology and Risk Factors in Cancer Heredity.

Women with the highest BMIs were 52 percent more likely to die than women with the lowest BMIs, the investigators report. BMI is the ratio of weight to height, which is often used to see if a patient's weight is outside normal parameters.

"The Women's Interventional Nutritional Study reported improved event-free survival in women randomly assigned to a reduced fat diet (associated with weight loss)," Barnett pointed out. "Further definitive clinical weight loss intervention trials in breast cancer populations are required to further clarify the relationship between breast cancer mortality and BMI."

Survival was also significantly worse in women who had four or more full-term pregnancies and in women whose last pregnancy was more recent, the report indicates.

In contrast, the team found that prognosis improved with recent alcohol consumption, with light to moderate drinking reducing the risk of dying by 22 percent.

"The association between alcohol consumption and improved survival is surprising," Barnett commented. "The results of several other studies have not shown such an association."

SOURCE: Journal of Clinical Oncology, July 10, 2008.