Obesity Surgery May Cut Cancer Risk

June 18, 2008— -- Last week, Caelie Haines took her 14-year-old daughter to Six Flags Theme Park near Washington, D.C. The roller coasters made the teen ecstatic, but it wasn't just the thrill of the speed. It was the fact that her mother could finally ride with her.

"The last time we were there, I couldn't fit on the rides," Haines says. Their previous trip took place before her August 2006 weight-loss surgery, when she weighed 316 pounds.

Since the procedure, the 38-year-old has shed nearly 150 pounds. As she had hoped, her high blood pressure, sleep apnea and borderline diabetes went away. But she had never imagined that the surgery might protect her from the disease that has affected her mother -- cancer.

Bariatric surgery for weight loss may reduce a person's risk of developing cancer by about 80 percent, according to a study presented today at the annual meeting of the American Society for Metabolic and Bariatric Surgery. Severely obese people who underwent surgery had an 85 percent drop in breast cancer and a 70 percent decrease in colon cancer compared with people who didn't have surgery.

Researchers at McGill University in Montreal looked at nearly 6,800 severely obese people -- some who elected to undergo surgery and others who didn't. Their body mass index (BMI), an indicator of body fat based on height and weight, fell into one of two categories: above 40, or above 35 if they had another weight-related condition, including high blood pressure, type-2 diabetes or sleep apnea. A BMI between 18.5 and 24.9 is considered normal.

During the past few years, published studies from the United States and Sweden have also shown that bariatric surgery may lower cancer risks. The current research extends this by looking at individual cancers.

These findings add to the list of ways that bariatric surgery may improve overall health. It also helps lessen diabetes, high blood pressure, sleep apnea, arthritis and infertility.

"No other operation has ever done so much to help so many," says Dr. Daniel Jones, chief of the section of minimally invasive surgery at Beth Israel Deaconess Medical Center in Boston.

Today, 64 million Americans are considered obese, and the American Cancer Society lists obesity among the major risk factors for cancer.

Though the decision to have major surgery should not be taken lightly, the benefits may outweigh the risks for many.

"People need to know that in addition to the other known benefits of weight loss surgery... they may protect themselves from cancer," says lead study author Dr. Nicolas Christou, director of bariatric surgery at McGill University.

Haines' 61-year-old mother has battled both bladder and cervical cancer, so Haines says she's thankful that the surgery may lower her chance of suffering from the same disease.

"To know that it's helped even in ways I wasn't aware of, it's wonderful," she says.

Not an Easy Way Out

Weight-loss surgery began in the 1960s, but it was considered a "taboo" among doctors even into the 1990s, Jones says.

This attitude was shaped by the high rates of complications and death from the surgery. In addition, many members of the medical community and the general public believed, as some still do, that obesity is related to a person's lack of willpower and can be fixed simply by diet and exercise.

"People think it's an easy way out," Haines says about the choice to have surgery. "It's not."

Both of Haines's sisters were overweight, and she had tried dozens of diets since she was 10 years old. The only one that worked was NutriSystem, plus two hours of exercise daily -- a task that became impossible after she became pregnant with her daughter.

"I knew there was no way that I could ever lose that weight other than surgery," she says.

Haines' choice has become more popular in recent years. The number of bariatric surgeries rose from 13,386 in 1998 to 121,055 in 2004, according to the Agency for Healthcare Research and Quality.

At the same time, bariatric surgery became safer, with the death rate declining to 19 out of every 10,000 patients. This is in part due to advances in surgical techniques.

Haines opted for the most common procedure, the Roux-en-Y, in which the stomach is stapled to become the size of a walnut. This tiny pouch is then connected to the middle of the small intestine, bypassing much of the stomach and part of the small intestine. The surgery can be performed laparoscopically, through tiny incisions in the abdomen.

Other types of weight-loss surgery leave the intestinal route intact. These include stomach stapling, which makes the stomach smaller, and adjustable gastric banding, in which a band around the stomach creates a pouch to limit the amount of food that a person can eat.

"Bariatric surgery is not rocket science," says Dr. Walter Pories, director of the Metabolic Institute at East Carolina University in Greenville, N.C. "All it does is change the plumbing of the gut."

The Cancer and Obesity Connection

Scientists don't yet know why weight-loss surgery may lower cancer risk, so Pories says it's too early to recommend bariatric surgery for obese people who are at risk for cancer.

What's more, bariatric surgery patients are a unique population.

"In addition to the fact that these folks lose weight, surgery changes their anatomy and may change the way nutrients are processed," says Eugenia Calle, managing director of analytic epidemiology for the American Cancer Society.

Therefore, the decreased cancer risk may not translate to people who lose weight without surgery.

Still, doctors are hopeful that this evidence may jump-start even more people to lose weight.

"In a country with one in five Americans obese, this holds a carrot for getting the weight off either by diet, exercise and, when need be, surgery to promote health," Jones says.

Though Haines didn't know about the possible cancer benefit when she had the surgery, she now sees it as another incentive to maintain her 169-pound figure.

"I've seen my mom go through cancer treatment, and I know how hard it is on the family," Haines says. "I want to be here a really long time for my daughter."