Description: FRIDAY, Dec. 7 (HealthDay News) -- Obesity and diabetes -- risk factors so often linked to heart disease -- can also affect the incidence and severity of cancer, a collection of four new studies suggests.

The findings, presented Friday at the American Association for Cancer Research's Sixth Annual International Conference on the Frontiers of Cancer Prevention Research in Philadelphia, link weight gain and diabetes to a number of malignancies, including breast, prostate and colorectal cancer.

"All of these are consistent with what we would expect with the occurrence of each of these cancers or cancer survival," said Elizabeth Platz, associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health. "Metabolic perturbations enhance certain cancers. Insulin and other hormonal factors influence cell growth and make cells multiply."

Women with diabetes have a 50 percent increased risk of developing colorectal cancer, according to the first study, by researc