A University of Cincinnati professor has won a $2 million federal grant to study the impact of bariatric or weight-loss surgery on cancer rates in severely obese adults.
He hopes to find out if the effects of the surgery differ based on patient characteristics including gender, race or ethnicity.
Lead investigator Dr. Daniel Schauer, an assistant professor in the UC College of Medicine, will oversee a team of researchers at UC and five other sites tasked with reviewing the health outcomes of more than half a million patients.
Obesity is believed to be responsible for approximately 85,000 new cases of cancer in men and women each year.
About 15 million adults in the United States suffer from severe obesity, defined as having a body mass index (BMI) of 30. The body mass index compares weight to height.
For example, a person who is 6 feet tall and weighs 225 pounds has a BMI of 30.5. You can find a calculator at www.cdc.gov/healthyweight/assessing/bmi.
“Obesity is a growing problem in the United States, and research has established that obesity is strongly associated with cancer,” Schauer said in a release. “What we would like to look at is, ‘Does intentional weight loss reduce your risk of cancer in severely obese patients?’ In this study, the method of intentional weight loss is bariatric surgery.”
Bariatric surgery reduces stomach size and limits caloric intake in patients; gastric bypass surgery is the most common form of this surgery.
During the procedure the stomach is made smaller by creating a pouch at the top of the organ by using surgical staples. The smaller stomach is connected directly to the middle portion of the small intestine, bypassing the rest of the stomach and the upper portion of the small intestine.
Schauer and his team will examine the rate of cancer for 35,000 patients who had weight-loss surgery from 2005 to 2012 and compare it with a comparable group of 500,000 patients who did not have the weight-loss surgery, says Schauer, also a physician with UC Health and a member of both the UC Cancer Institute and the Center for Clinical Effectiveness.
The data will be provided by the HMO Research Network. The researchers hope to have initial results next year.
While obesity is a well-established risk factor for several types of cancer, “clinical trials to specifically examine whether intentional weight loss reduces cancer risk have not been done and data from observational studies is sparse,” he said. The study will look at all types of cancer initially, “and then we will break it down by the obesity associated cancers with the most common being post-menopausal breast cancer in women,” Schauer said.
Schauer says the study will also determine whether weight-loss surgery alone can reduce the risk of cancer or whether that risk is primarily affected by the amount of weight lost.
Money for the study comes from the National Cancer Institute.