Obesity increases risk of thyroid cancer for men and women alike, metastudy finds

A comprehensive survey of five previous research initiatives found that obesity increases the risk of thyroid cancer for both men and women.

Published in the journal Cancer Epidemiology, Biomarkers and Prevention, the meta-study determined that the risk of thyroid cancer increases for obese men at roughly the same rate as it does for women. Previous studies had only established a strong connection between the two for women.

Dozens of studies have already established that obesity increases the overall risk of cancer. A survey of hundreds of research papers, published in the journal The Lancet, said that a high body mass index (BMI) can predispose men and women to breast, bowel, skin and kidney cancers.

Thyroid cancer may now be added to that list.

Researchers associated with the National Cancer Institute (NCI) analyzed the data collected in medical studies of nearly 850,000 participants.

Over a 10-year period, more than 1,100 individuals - or approximately 1 percent - had been diagnosed with thyroid cancer. This rate approximates the lifetime risk of thyroid cancer in the U.S., which the NCI places at just under 1 percent.

The team found that higher BMIs increased the risk of thyroid carcinomas. This effect was the same for men and women alike. Among people of either sex, having a BMI in the overweight range increased the likelihood of thyroid cancer by 20 percent.

Those who were classified as obese had an even higher risk. Compared to people of normal weight, obese men and women had a 53 percent higher rate of thyroid cancer.

The team concluded that when it comes to this disease, obesity is a risk factor for both men and women. They added that the increase in thyroid cancer diagnoses over the previous three decades may be due in part to the spread of obesity in the U.S.

Two-thirds of American adults are either overweight or obese, according to the Centers for Disease Control and Prevention.