According to a new study about obesity and cancer carried out by a team of researchers in the University of Cincinnati’s College of Medicine between 2005 and 2012 (with patients being followed up till 2014), morbidly obese patients who had undergone bariatric surgery significantly reduced their cancer risk by up to 30%. Dr. Daniel Schauer who led the study said that findings in the study proved that bariatric surgery was especially effective in lowering the risk of the patients involved developing obesity-associated cancers.
Obesity and Cancer: What is the Link?
Overall, obesity has been linked to 13 or more different types of cancers which also account for up to 40% of all diagnosed cancer cases in the United States alone. All patients who develop post-menopausal breast cancer and endometrial cancers are women. These cancer types are linked to obesity and also highly linked to estrogen levels.
These include; pancreatic cancer, colon cancer, endometrial cancer (cancer affecting the lining of the uterus) and post-menopausal breast cancer.
These findings were based on reviews of medical records from 22,198 patients who had undergone bariatric surgery procedures and another 66,427 patients who had no surgery performed between the years 2005 to 2012. Of these morbidly obese patients who were included in the study, more than 80% were female.
The research team led by Dr. Schauer also found that bariatric surgery greatly reduced the risk of developing pancreatic cancer at 54% and endometrial cancer at 50% in morbidly obese patients who had had the procedure done. Post-menopausal cancer and colon cancer risk was also highly reduced by up to 42% and 41 % reduction rates respectively.
The team was surprised by the significant rate of impact of bariatric surgery in reducing the cancer risk. “What’s surprising is how great the risk of cancer was reduced”, States Dr. Schauer.
The findings which have also been published online in the Annals of Surgery concluded that patients who had had bariatric surgery performed lowered their risk of developing any type of cancer during the follow-up period by up to 33% as compared to those who had not undergone the weight-loss procedure.
This shows that while bariatric surgery not only reduced the risk of severely obese patients developing obesity-linked cancers, it was also beneficial in the reduction of the risk of obese patients developing any other type of cancer.
Obesity and cancer: is it hormonal?
Dr. Schauer attributes the reduction of cancer risk of the patients developing post-menopausal breast cancer and endometrial cancer after a bariatric surgery to the reduction of estrogen levels after the weight-loss procedure. He also explained that the rate of pancreatic cancer risk for morbidly obese patients that was observed was due to the reduction of insulin and diabetes risk.
Dr. Schauer says that Bariatric surgery helps lower the levels of insulin in the body which in turn lowers the risk of patients developing diabetes which is also believed to be a risk factor for pancreatic cancer.
He however said that risk factors and mechanisms for colon cancer are far more complex.
According to the study, no significant link was found between bariatric surgery and cancer cases in men. Dr. Schauer attributes this to the fact that over 80% of all the patients who were included in the study were women.
The study targeted women mostly because bariatric surgery greatly impacts the two major cancer types (endometrial and post-menopausal breast cancers) that specifically affects women.
Dr. Schauer further says that the procedure is very beneficial for severely obese patients (even without considering cancer risk) and that the findings that prove bariatric surgery also significantly reduces cancer risk simply provides another reason to consider the procedure as a treatment option.
“I think considering cancer risk is one small piece of the puzzle when considering bariatric surgery, but there are many factors to consider. Reductions in diabetes, hypertension, and improvements in survival and quality of life are reason enough,” says Schauer. “The study provides an additional reason to consider bariatric surgery.”