Weight Gain After Breast Cancer Deadly
Study: Each 11-Pound Gain Increases Breast Cancer Death Risk 14%
Insulin-Breast Cancer Death Link
In a second study, women with invasive breast cancer and high blood levels of C-peptide, a marker of insulin secretion, were more likely to die than women with lower C-peptide levels, according to Melinda Irwin, PhD, MPH, an assistant professor at the Yale University School of Public Health in New Haven, Conn.
"Women who are heavier tend to have higher C-peptide or higher insulin levels," she tells WebMD.
Her team followed 689 women enrolled in a National Cancer Institute initiative study known as the HEAL (Health, Eating, Activity and Lifestyle) study. All had breast cancer, but not type 2 diabetes. They were all postmenopausal, either naturally or due to chemotherapy.
Irwin's team monitored health status periodically, from six months after the diagnosis until 2004 or until the patient's death, taking blood samples to measure their C-peptide levels.
The younger the women were, the more dramatic the risk of death linked with high C-peptide, she says. Women with high C-peptide levels who were ages 40 to 55 when they provided the blood samples had a nearly five times increased risk of breast cancer death compared with the same ages of women who had lower C-peptide levels.
Perspective on Weight Gain and Breast Cancer
The new findings echo previous research that has found a link not only between excess weight and death in breast cancer patients but also excess weight and breast cancer recurrence.
Excess weight can also increase risk of getting breast cancer, other research has found, at least for postmenopausal women. "In the postmenopausal period, adipose tissue is the primary source of estrogen," Nichols says. "So the greater BMI in postmenopausal women may increase exposure to circulating estrogen [thus "feeding" the cancer]."
The message is clear, Irwin says. Paying attention to diet and exercise and trying to maintain a healthy weight is crucial.