Anna E. Prizment, a postdoctoral fellow at the University of Minnesota, Masonic Cancer Center, and colleagues used data from the Iowa Women's Health Study, which included 1,096 women diagnosed with colon cancer who were observed during a maximum 20-year period, during which 493 died -- 289 died from colon cancer.
Women classified as obese, with a body mass index of at least 30 kg/m2, had a 45 percent increased overall mortality rate, while women with a BMI less than 18.5 kg/m2, (underweight) had an 89 percent increased mortality rate compared to those with normal BMI.
"Maintaining a healthy body weight is beneficial for post-menopausal women. This may also be beneficial for those diagnosed with colon cancer later in life. It looks like abdominal obesity may be a useful indicator of higher colon cancer mortality," Prizment says in a statement. "It is too early to say whether a decrease in weight characteristics after diagnosis will also decrease mortality risk; at that point it may be too late. Therefore, it's best to maintain a normal, healthy body weight throughout life."
The findings are published in the Cancer Epidemiology, Biomarkers & Prevention.