By Margarita Nahapetyan
According to a new evidence from Sweden, overweight women could lower their risk of developing cancer by up to 40 per cent by undergoing weight-loss surgery. However, the benefit is not applicable to men.
Weight loss (bariatric) surgery usually involves reducing the size of the stomach. This means that after the operation individuals are able to consume just small amounts of food at a time, and less food is absorbed into the body. Weight loss surgery works quite well for many people who are extremely overweight or obese. People tend to lose a lot of weight in a short period of time after surgery, and are more likely to maintain the lost weight, when compared to people who lose weight by diet and exercise alone.
However, weight loss surgery involves some big risks. So when people make their choice it is important they understand that the risks of surgery in their case will be outweighed by the benefits.
In the new study, the investigators set to find out what happens to people who had bariatric surgery in the long term, and to see whether their health was better than it would have been if they had not had the procedure performed. More than 2,000 obese patients - 1420 female and 590 male - were tracked for the period of 10.9 years after they had their stomachs stapled. The decision to undergo the procedure was based on patient choice. Researchers also followed roughly equal number of matched controls - 2,037 people - who were obese but did not undergo the surgery.
The results revealed that:
Overall, 5.8 per cent of people who had underwent bariatric surgery, developed cancer in the following 10 years, when compared to 8.2 per cent of individuals who had not had surgery. That means the risk of the disease was nearly 30 per cent less for people who had had surgery.
When analyzing the results of male and female participants separately, surgery seemed to have no effect on men's risk of getting cancer, with 38 cases observed in the surgery group, and 39 in the non-surgery group.
People with stomach surgery lost on average 20 kilograms (44 pounds), whereas people without surgery gained on average one kilogram (2 pounds).
In their previous studies, the scientists were not able to figure out whether or not weight-loss surgery would be beneficial when it comes to cancer prevention. It has been known that obesity is associated with a higher rates of cancer incidence because fat cells produce the hormones that can lead to the development of the deadly disease. And now, it seems likely for women, the reduction in risk of developing cancer after weight loss surgery is quite reliable. Researchers say that the reduction is significant and that other investigators have come up with similar results.
They added that for now they are not sure whether or not the same benefit ca be applied to men as the majority of the people in the study - 71 per cent - were women. There may have been too few male participants to participate in the study to have a reliable picture of what happens to their risk. On the other hand, the experts concluded, it may have been that the types of cancers that are mostly triggered by obesity, are more prevalent in women than men.
The study was carried out by the experts from a number of Swedish universities and from the Swedish Institutes of Medicine. It was published in a medical journal called The Lancet Oncology. The funding came from a combination of government grants and money from pharmaceutical companies and a surgical instrument manufacturer.