WASHINGTON -- Women with breast cancer have more aggressive disease and lower survival rates if they are overweight or obese, according to findings published in the March 15 issue of Clinical Cancer Research.
"The more obese a patient is, the more aggressive the disease," said Massimo Cristofanilli, associate professor of medicine at The University of Texas Anderson Cancer Center. "We are learning that the fat tissue may increase inflammation that leads to more aggressive disease."
Cristofanilli and colleagues observed 606 women with locally advanced breast cancer. These women were classified by body mass index into three groups: normal or underweight, overweight and obese.
At five years, overall survival was 56.8 percent among obese women, 56.3 percent among overweight women and 67.4 percent among normal weight women. The 10-year survival rate was 42.7 percent among obese women, 41.8 percent among overweight women and 56.5 percent among normal weight women.
The rate of inflammatory breast cancer, previously shown to have worse outcomes than non-inflammatory breast cancer, among obese women was 45 percent compared with 30 percent in overweight women and only 15 percent in women considered normal weight, researchers found.
Risk of breast cancer recurrence was also higher in obese or overweight women. "Obesity goes far beyond just how a person looks or any physical strain from carrying around extra weight. Particular attention should be paid to our overweight patients," Cristofanilli said.
Cristofanilli said physicians need to pay close attention to breast cancer patients because commonly used drugs, such as tamoxifen, tend to increase weight gain during treatment.
