Excess Pounds Raise Women's Cancer Risk

By Steven Reinberg
HealthDay Reporter
Thursday, November 8, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, Nov. 7 (HealthDay News) -- A study of more than 1 million British women finds that overweight or obesity is to blame for about 5 percent of all cancer cases.

That's about 6,000 out of the 120,000 cancers affecting British women each year.

The study, by researchers from the University of Oxford, found that overweight and obese women are at higher risk of developing and dying from cancer, including breast cancer in postmenopausal women, colon cancer in premenopausal women, and pancreatic and kidney cancer generally.

"Among middle-aged and older women in the U.K., around 5 percent of all new cancers each year are actually due to overweight or obesity," estimates lead researcher Gillian Reeves, a statistical epidemiologist at Oxford's Cancer Research UK Epidemiology Unit.

"It is important that women be aware that being overweight carries some excess risk of certain types of cancers," Reeves said. "This is something they need to take into consideration alongside what we know are very strong adverse effects of being overweight on diseases like diabetes and heart disease."

In the study, Reeves and colleagues looked at the relationship between body-mass index (BMI), and cancer in 1.2 million British women aged 50 to 64, who took part in the Million Women Study. In the U.K., about 23 percent of all women are obese and 34 percent are overweight, according to national statistics.

During 5.4 years of follow-up, the researchers found more than 45,000 new cancers and more than 17,200 deaths from cancer. Being overweight or obese was linked to an increased incidence for all cancers combined, according to the report in the Nov. 7 online edition of the British Medical Journal.

Being overweight or obese can significantly increase the risk of some cancers in women, Reeves' group found.

Specifically, obese and overweight women were twice as likely to develop endometrial cancer and cancer of the esophagus compared with normal weight women. In addition, overweight and obese women had a 53 percent greater risk of kidney cancer, a 50 percent greater risk of multiple myeloma and a 24 percent greater risk of pancreatic cancer compared with their normal weight counterparts.