Many people with obesity try to lose weight on their own. But when diet, exercise and other interventions don’t work, their doctor may recommend bariatric surgery—also known as weight-loss surgery.
Bariatric surgery typically involves a procedure to reduce the size of the stomach and, consequently, a person’s appetite. The surgery doesn’t just treat obesity, though. It also treats other conditions, like diabetes, heart disease and high blood pressure.
Recently, a growing body of research shows it also may help reduce a person’s risk of cancer—and not just the types fueled by hormones.
In this article, we’ll explore:
- What is bariatric surgery?
- Types of bariatric surgery
- Obesity and cancer risk
- Bariatric surgery and cancer risk
- Should patients at high risk of cancer consider gastric bypass?
If you’ve been diagnosed with cancer and are interested in a second opinion on your diagnosis and treatment plan, call us or chat online with a member of our team.
What is bariatric surgery?
Bariatric surgery is a procedure that helps you lose weight. It may be an option for people with severe obesity or those with a body mass index (BMI) of 40 or higher. Those with a BMI of 35 or higher and at least one associated health condition, like diabetes or high blood pressure, may also be candidates for bariatric surgery.
Weight-loss surgery is mostly performed laparoscopically, using small incisions with the aid of a camera. Small incisions may mean patients will experience fewer risks or side effects than standard surgery and potentially less pain and scarring and a faster recovery.
Types of bariatric surgery
In the United States, surgeons typically perform one of the three types of bariatric surgery listed below:
Gastric sleeve: A surgeon removes most of the stomach, leaving only a banana-shaped section that is closed with staples.
Gastric bypass, or Roux-en-Y gastric bypass: A surgeon staples the stomach, creating a small stomach pouch at the top.
Adjustable gastric band: A surgeon places a ring with an inflatable band around the top of the stomach to create a small pouch.
Less commonly, a surgeon will recommend a procedure called a duodenal switch, which is a combination of a sleeve gastrectomy and a gastric bypass.
Obesity and cancer risk
Like cancer, obesity is a complex condition, dependent on more factors than merely what you eat and how much you exercise. And it’s on the rise, jumping from a 30.5 percent prevalence rate in U.S. adults in 1999-2000 to a nearly 42 percent rate in 2017-2020.
People with obesity have an increased risk for at least 13 types of cancer, and obesity-related cancers account for 40 percent of all cancers diagnosed in the United States each year.
Bariatric surgery and cancer risk
For cancers whose growth is driven by hormones, like most breast cancer and prostate cancer, the dots between the disease and obesity are fairly easy to connect—obesity increases the production of hormones in the body that these types of cancers use as fuel to grow. It also slows down the production of other molecules that can keep hormones in check.
That’s why, in the past, scientific researchers have attempted to determine: Does bariatric surgery reduce the risk of developing hormone-driven cancers? The answer? Yes, in some cases of cancer, including postmenopausal breast cancer, endometrial cancer and ovarian cancer.
“Excess body fat produces estrogen, a hormone which cancers like uterine cancer, ovarian cancer and estrogen receptor-positive breast cancer may depend on to grow,” Joshua G. Cohen, MD, Gynecologic Oncologist and Medical Director of the Gynecologic Program at City of Hope Orange County Lennar Foundation Cancer Center, says in a recent article in MedicalNewsToday.com. “So, like links in a chain, weight loss from bariatric surgery may help reduce estrogen levels, which in turn may decrease an individual’s risk of certain gynecologic cancers,” as well as estrogen receptor-positive breast cancers and other hormone-driven cancers.
The answer is less clear about whether bariatric surgery could do the same for obesity-related cancers that aren’t usually fed by hormones, like liver and colorectal cancers. But emerging research has been promising.
A study published last year, for instance, found that bariatric surgery was associated with an almost 50 percent lower risk of developing these five non-hormonal cancers:
Gastric bypass and sleeve gastrectomy—the two types of bariatric surgery most used today—were both associated with a reduced cancer risk in the study. But gastric banding, an older procedure only rarely still used in the United States, was not. According to the latest figures from the American Society for Metabolic and Bariatric Surgery, gastric band procedures account for fewer than 1 percent of the 256,000 bariatric operations done in the United States each year, while gastric sleeves add up to nearly 60 percent. That makes sleeve surgeries the most commonly performed bariatric operation today.
Researchers believe that’s because gastric banding merely promotes weight loss, while gastric bypass and sleeve gastrectomy are thought to affect metabolism, including a reduced number of molecules that are linked to inflammation.
In August, a study published in the journal Obesity found that bariatric surgery wasn’t just linked to a lower risk of cancer, but a lower risk of dying from cancer, too. Researchers reported that people who had bariatric surgery were 25 percent less likely to develop cancer than those who didn’t and 43 percent less likely to die from the disease.
Should patients at high risk of cancer consider gastric bypass?
Healthcare providers are using the emerging findings to encourage more people with obesity to consider bariatric surgery and discuss it with their doctor—and not just adults with the condition.
The American Cancer Society published a study that found the risk of developing certain cancers, especially obesity-related cancers like colorectal and pancreatic, has been rising among young adults. That trend correlates with the rapid rise of young adults with obesity. Research published in 2021 found that more than half of U.S. adults ages 18 to 25 are overweight or obese—a major leap from the late 1970s, when the number was less than 25 percent.
Yet despite national guidelines recommending children and adults undergo screening for obesity, fewer than half of primary care doctors regularly track BMI in their patients, and only a third of patients with obesity report receiving a diagnosis of obesity or weight loss counseling.
In addition, only about 1 percent of people with obesity in the United States who are eligible for bariatric surgery actually have a weight-loss procedure. Doctors hope those numbers will grow along with bariatric surgery’s expanding list of benefits, which now includes a reduced risk of heart disease, stroke, high blood pressure, sleep apnea, diabetes and cancer.
A healthy diet and exercise remain the mainstay and most important aspects of weight loss. But if you think bariatric surgery may be an option for you, talk to your doctor to determine if you qualify for the procedure.
If you’ve been diagnosed with cancer and are interested in a second opinion on your diagnosis and treatment plan, call us or chat online with a member of our team.
