Study found it might cut chances to levels of normal-weight people, but experts view finding with caution
By Kathleen Doheny
FRIDAY, June 13, 2014 (HealthDay News) -- Weight-loss surgery may do more than lower the risk of heart problems and improve type 2 diabetes in obese patients: A new review suggests it may also lower their chances of a cancer diagnosis.
"Bariatric surgery is associated with reduced cancer risk in morbidly obese people [to that of normal-weight people]," the team of Brazilian researchers wrote. Their report was published recently in the journal Obesity Surgery. A morbidly obese person is roughly 100 pounds overweight, with a body-mass index (BMI) of 40 or higher.
Cancer experts in the United States who reviewed the findings were not completely convinced that surgery can reduce cancer risk to that of normal-weight people. But they agreed that obesity raises the risk of certain cancers.
The Brazilian researchers, from the Hospital Sao Lucas in Porto Alegre and other institutions, pooled the results of 13 studies including more than 54,000 people. Each study looked at cancer rates after weight-loss surgery.
Cancer rates in obese people are as high as two per 1,000 person-years (the number of years times the number of people in a population affected by a certain illness).
However, in those who had the surgery, the researchers found the rate was about one per 1,000 person-years, or nearly that of normal-weight people. The follow-up ranged from two to 23 years after the surgery.
The risk reduction with weight loss surgery is "probably true," said Dr. Cy Stein, chair of medical oncology and experimental therapeutics at the City of Hope Medical Center in Duarte, Calif.
It would make sense, he said, 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]. It is a risk factor for cancer development."
According to the American Cancer Society, an estimated one of three cancer deaths in the United States is linked to excess weight, poor diet and/or inactivity. The link between weight and cancer is strongest, the society says, for breast cancer in women past menopause, colon and rectal cancers, and cancers of the esophagus, kidney, pancreas and uterine lining (endometrium).