Breast Cancer Weight Gain Pinpointed
Adding pounds during chemotherapy is from inactivity, not overeating, study says
MONDAY, May 14 (HealthScout) -- As if the stress, fatigue and nausea aren't enough, many young women with breast cancer find themselves gaining weight during chemotherapy. But it may not be because they're eating too much. New research suggests that the culprit is inactivity, not diet.
The findings will draw attention to a neglected area of breast cancer research, according to a prominent spokeswoman. "We want to save lives and prevent breast cancer, but we also want to look at quality of life," says Betsy Mullen, founder and president of the Women's Information Network Against Breast Cancer.
Researchers at Duke University studied 53 pre-menopausal breast cancer patients for one year after they underwent surgery. They measured their diets, activity levels and body composition.
The results of the study appear in the May issue of the Journal of Clinical Oncology.
The women, who tended to weigh 140-150 pounds, gained an average of five pounds if they underwent chemotherapy. That may not sound like much, but the weight gain consisted mainly of fat, without the supporting muscle framework that usually comes along with it, says study co-author Wendy Demark-Wahnefried, an associate research professor at Duke University. Normally, as much as 46 percent of each pound gained is muscle, which takes up less space, she adds.
The women knew their bodies were growing more than they should, she says. "Women said they went up a dress size, which is not something you would expect with a five- to seven-pound weight gain," she says. "If all of it is fat and none of it is muscle, it's easy to believe."
In fact, the body composition of the women, whose average age was 41, shifted to that of 51-year-old women. "In effect, their bodies aged 10 years," Demark-Wahnefried says.
Chemotherapy kills cells that grow quickly, so it may be responsible for reducing muscle mass in the women, she adds.
Although it may seem surprising that chemotherapy can lead to weight gain instead of weight loss, it's not news to Mullen, who developed breast cancer at the age of 33.
"I thought at least I'll go through this and lose some weight," she recalls. "You hear so many horror stories about chemotherapy and think you'll be sick as a dog."
Mullen never actually threw up during her six months of chemotherapy, although she became tired. She did, however, gain 35 pounds.
Mullen says she has talked to hundreds of breast-cancer patients who have similar stories of weight gain.
Exercise appears to be key, Demark-Wahnefried says. But researchers aren't sure what kind is best. "The big charge for us is to nail down what those exercises might be, so we don't run women willy-nilly around the track without knowing if that will give them a payoff," she says.
She adds, however, that women should consider exercises like squats and leg presses.
"These women may not be in the mood to exercise with Lycra-clad neophytes at the gym," she says. "I don't blame them. But it's good to go out and get some aerobic activity like walking, something that gets their legs in motion. And they can do strength training in their own homes."
Mullen agrees. "You feel out of control when you get a diagnosis of cancer. Exercise, staying active, even if it's just a walk around the block, is something you have control over."
With luck, she says, weight gain will be "one less side effect you have to deal with."
What To Do
To learn more about breast-cancer survivor Betsy Mullen and her story, visit the Women's Information Network Against Breast Cancer. Visit the organization's home page here, and also check this list of links to a variety of other breast-cancer resources.
The American Cancer Society offers a fact sheet of information about risk factors for breast cancer and how to prevent it.
You also might want to read previous HealthScout articles on breast cancer.