
- Researchers investigated the effects of bariatric surgery for weight loss on cancer risk and mortality.
- They found that bariatric surgery reduced cancer risk by 25% and mortality by 43%, especially in women.
- However, further studies are needed to understand underlying mechanisms.
Around 21% of deaths in the United States in 2019 were linked to cancer. Thirteen types of cancer are linked to obesity, including
Currently,
While studies show that higher body mass index (BMI) is linked to increased cancer risk, it is less clear whether ways to reduce BMI reduce cancer risk.
Studies
Understanding more about the effects of bariatric surgery on cancer rates and outcomes could inform preventive strategies for cancer.
Recently, researchers analyzed long-term healthcare data from patients who had bariatric surgery. They found that the surgery was linked to lower cancer incidence and cancer mortality.
The study was published in the journal
- Gastric bypass: reducing the size of the stomach and directing food to the middle part of the small intestine
- Gastric banding: when a silicon band is placed around the stomach to reduce stomach capacity
- Sleeve gastrectomy: when part of the stomach is separated and removed from the body
- Duodenal switch: a combination of a sleeve gastrectomy and a gastric bypass
Ultimately, the researchers found that patients who had bariatric surgery were 25% less likely to develop any cancer compared to the nonsurgical comparison group. They were also 43% less likely to die from cancer than those who did not undergo surgery.
Men vs. women
Women who underwent surgery were 41% less likely to develop obesity-related cancers, such as breast, ovarian, uterine, and colon cancer. Additionally, they had a 47% reduced mortality for any kind of cancer compared to women who did not undergo surgery. This included a 55% reduced mortality for obesity-related cancers and a 38% reduced mortality for non-obesity-related cancers.
Meanwhile, bariatric surgery was not linked to reduced overall cancer mortality or obesity-related cancer mortality in male patients. It was, however, linked to 51% lower cancer mortality with non-obesity-related cancers.
The researchers wrote that the sex-specific findings are consistent with
The researchers also noted that cancer mortality was significantly lower after gastric bypass surgery than after gastric banding or sleeve gastrectomy. They noted that the sample size for a duodenal switch was small and that it was thus not possible to compare it to gastric bypass surgery.
Dr. David Voellinger, a bariatric surgeon at Novant Health in Charlotte, North Carolina, who was not involved in the study, told MNT that the study highlighted the effects of weight loss in treating cancer.
“Bariatric surgery can be used to not only decrease the incidence of certain cancers but also decrease the mortality associated with them. Also, primary care physicians and oncologists should look more closely at weight loss and bariatric surgery as tools for treating cancer,” he said.
“This study adds to the large body of literature that there are major benefits to bariatric surgery in [people with obesity] provided stringent selection criteria are used. Future studies are needed to see if similar long-term benefits occur in patients who undergo medical treatment with some of the newer drugs such as Ozempic and Mounjaro.”
— Dr. Anton Bilchik, Ph.D., surgical oncologist, chief of medicine, and director of the Gastrointestinal and Hepatobiliary Program at Saint John’s Cancer Institute at Providence Saint John’s Health Center in Santa Monica, California, who was not involved in the study, speaking to MNT.
“The study’s implications are that there are many long-term benefits of weight loss surgery; when people think of obesity, increased cancer risk is not the first thing that usually comes to mind,” Dr. Mir Ali, bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA, who was not involved in the study, told MNT.
“This study may help people who meet the criteria for surgery but are still hesitant to take that step see the additional scope of benefits,” he added.
Things to consider before surgery
Dr. Cohen suggested, however, that women considering treatments that affect hormone production, such as birth control pills or bariatric surgery, should first speak with a healthcare professional about potential health risks.
“While bariatric surgery may be an effective treatment for severe obesity, it is also an intermediate– to high-risk surgery,” he said.
He added that the best way to ‘stop cancer’ is to prevent it in the first place—by adopting a healthy diet and an exercise routine.
“Working with your medical provider and a nutrition counselor is very important to help you meet your goals and incorporate positive changes that fit your lifestyle to help reduce your risk of developing cancer,” he concluded.