Published on October 24, 2016

Put down the fork and lower your cancer riskPut down the fork and lower your cancer risk

Did you know that being overweight increases your risk of cancer? If not, you’re not alone. A recent survey by Cancer Research UK [pdf] revealed that three out of four people living in the United Kingdom were unaware of a link between obesity and cancer. People aren’t much more educated in the U.S.

“Many, many patients seem surprised by that news. I think we’ve done a much better job at publicizing it as a risk for heart disease than we have for cancer,” said medical oncologist Jennifer Crook, MD, who practices at the Davenport-Mugar Cancer Center at Cape Cod Hospital.

Women, especially, are at risk because two of the most common cancers linked to obesity are breast cancer and endometrial cancer. Dr. Crook pointed to the Women’s Health Initiative Study of 73,913 women who were followed for 12 years. The study found that being overweight (defined as having a BMI of 30 or higher) increased the incidence of all obesity-related cancers by seven percent for every 10-year increment that an adult is overweight.

It increased the risk of post-menopausal breast cancer by five percent for each 10-year increment of being overweight, and the risk of endometrial cancer by 17 percent every 10 years. Those with the highest BMI of over 35 fared even worse. In that population, the risk of postmenopausal breast cancer rose eight percent every 10 years and the endometrial cancer risk rose 37 percent.

“It’s pretty significant if you think about the fact that most women gain weight in the peri-menopausal period,” said Dr. Crook. “Assuming they live to the average age of mid 80’s, that’s cumulatively a lot of years. When you do the math it adds up to a big risk.”

Survival Rates Are Up, But So Is Obesity

Fortunately, endometrial/uterine cancer is usually caught early, she added. The main symptom is post-menopausal vaginal bleeding and most women take this unusual symptom seriously and seek medical care. A hysterectomy is performed and the cure rate is high when diagnosed early enough.

“Our cure rates for breast cancer are better than they’ve ever been,” Dr. Crook said. “If you compare our survival and longevity data now with the numbers from the 1980’s or 1990’s, it’s gone up consistently. But now, unfortunately, the obesity rate has gone up too.”

In fact, she pointed out that for the first time ever, in 2014, the United States became the country with the highest rates of obesity in the world. The Centers for Disease Control and Prevention estimates that 36.5 percent of adult Americans are obese.

“That’s more than a third of our population and that’s a frightening place to be,” Dr. Crook said. “In Massachusetts, 24 percent of the population is obese. In fact, we’re pretty low in the state ranking so we are doing a little better here than most places.”

Even though breast and endometrial cancers carried some of the highest risks, a new report published in the New England Journal of Medicine on August 25, 2016 indicated that obesity also increases the risk for ovarian cancer for women.