Weight-loss surgery may do more than help morbidly obese people shed extra pounds; it may also lower their chances of a cancer diagnosis, according to a recent study HealthDay News reported.

Researchers from the Universidade Federal do Rio Grande do Sul in Brazil found that bariatric surgery reduces the risk of cancer to rates almost similar to those of people of normal weight.

"Bariatric surgery is associated with reduced cancer risk in morbidly obese people [to that of normal-weight people]," the researchers wrote in their study.

A morbidly obese person is roughly 100 pounds overweight, with a body-mass index of 40 or higher. Cancer rates in obese people are as high as 2.12 cases per 1,000 person-years.

For the study, researchers examined results from 13 relevant studies that focus on the incidence of cancer in patients following bariatric surgery. These include both controlled and uncontrolled studies, and the relevant information of more than 54,000 participants.

Researchers found that cancer only occurred in 1.06 cases per 1,000 person-years, up to 23 years after the surgery was performed. This is markedly better than the rate for the global population of obese people.

It is still unknown whether the lower cancer rates following bariatric surgery are related to the metabolic changes associated with weight loss, or if lower body mass indexes following surgery result in earlier diagnosis and improved cancer treatment outcomes among patients.

Dr. Cy Stein, chair of medical oncology and experimental therapeutics at the City of Hope Medical Center in Duarte, Calif., told Healthday News that the results are probable.

"[Since] the evidence that obesity is related to an increased risk of cancer is significant, even in the modestly obese. There is an association [between obesity and cancer]," Stein, who was not involved in the study, said. "It is a risk factor for cancer development."

The findings were recently published in Springer's journal Obesity Surgery.