Unearthing the Roots of Chemotherapy Weight Gain
Our Researcher: Sherrie Lessans, PhD, RN
By Dan Mezibov
Nearly 90 percent of women with breast cancer will gain weight during or after chemotherapy, and those already overweight will likely add the most weight following treatment. Chemotherapy weight gain has been linked to reoccurrence of breast cancer, poorer clinical outcomes, and reduced survival odds, especially in women following menopause.
So far, studies have been unable to show that improving diet or increasing exercise can make a reliable difference in shedding excess weight in breast cancer patients who receive chemotherapy.
“We’re trying to get a handle on the underlying mechanisms and factors contributing to this weight gain,” says Sherrie Lessans, PhD, RN, UMSON assistant professor and director of the School’s Clinical Nurse Leader master’s option. She is conducting the first study in animals to explore the causes of chemotherapy-associated weight gain.
Adipose, or fat, “isn’t just a place where excess calories are stored,” Lessans explains. Adipose is a metabolically active tissue producing hormones and other critical molecules that “cross-talk” with other systems to affect biological processes — such as blood sugar levels, insulin sensitivity, and inflammation — whose role in chemotherapy weight gain remain underexplored, she points out. In post-menopausal women, fat tissue is also the major source of an enzyme that produces “bioactive” estrogens, which help promote breast tumor reoccurrence in women whose tumors are estrogen-sensitive.
Under a three-year grant from the National Institute of Nursing Research, Lessans is analyzing tissue from menopausal mice that received a combination of three drugs commonly given to women who have estrogen receptor-positive breast tumors. She is studying how the drug triplet affects muscle tissue and metabolic processes such as fat, blood sugar, and enzyme levels.
The study’s findings, Lessans explains, will help researchers better understand what’s behind chemotherapy’s effects on weight gain and design interventions to alleviate this increasingly significant problem in cancer care.