Obesity is associated with an increased risk of developing many different cancers. In United States, obesity is related to fourteen percent of all cancer deaths in men and twenty per cent of such deaths in women, according to background information in the study.
Data from the study of Swedish obese subjects (SOS, for its acronym in English) had previously shown that bariatric surgery has favorable effects on weight, diabetes, other cardiovascular risk factors, structure and cardiac function and quality of life related to health. For the study, Sjöström and colleagues collected data from more than 2.010 obese patients who underwent surgery to lose weight and compared with 2.037 for obese patients that were not surgery. People who underwent the surgery lost about 44 pounds (twenty pounds), while those who did not have increased three pounds (just over a kilo).
For nearly eleven years of monitoring, researchers found that women who had undergone surgery to lose weight reduced their risk of cancer by 42 percent, compared with women who did not have surgery. There was no reduction in the risk of cancer among obese men who received surgery, the study authors noted.
Andrew G. Renehan, Department of Surgery, School of Oncology and imaging at the University of Manchester in United Kingdom, and author of an accompanying editorial in the same publication, points out that this study, together with data from other research shows that reducing weight through bariatric surgery is associated with cancer prevention.
“This study strengthens the hypothesis that the relationship between obesity and cancer is causal,” said Renehan. “Although the beneficial effects of weight reduction appear to favor women, it is necessary to further investigate the mechanisms underlying the relationship between body fat and cancer development.”
Renehan said: “Obesity causes cancer, but the obesity epidemic is waning and we now have proof that we can reverse its effect on cancer risk.”
Dr. Len Lichtenfeld, deputy medical officer of the American Cancer Society, said that preventing obesity in the first place is the best way to reduce cancer risk.
“The American Cancer Society believes that maintaining a healthy body weight, follow a healthy diet and exercise are important in our effort to reduce the risk of cancer,” Lichtenfeld stressed. “The question is how to create a culture where children and adults focus on healthier lifestyles and better alternatives, so we do not have to confront this growing epidemic of obesity.”
