Obesity affects more than 35 percent of women in the United States. A University of Colorado Cancer Center study shows that women with obesity are also more likely to experience a recurrence of breast cancer once their treatment is complete, and they may respond differently to treatment.

Elizabeth Wellberg, PhD

Elizabeth Wellberg, PhD

Elizabeth Wellberg, PhD, a CU Cancer Center member, has shown for the first time that an otherwise normal process that allows the body to store excess energy can produce an unwanted result when it occurs in fat cells near breast tumors.

“Our study investigated how obesity, metabolic disease, and weight gain influence the tumor’s response to therapy,” says Elizabeth Wellberg, an assistant professor in the University of Colorado School of Medicine’s Department of Pathology. “We found that in the obese, weight gain caused the production of growth factors in the fat tissue. This process is necessary for energy storage; however, the growth factors produced by the fat can stimulate tumors.”

Wellberg says the growth factors that stimulate tumor growth also can be predictive of whether certain types of breast cancer may be resistant to hormone therapies that can be curative in other types of breast cancer.

 “Years ago, scientists discovered that there are different kinds of breast cancer that need to be treated as different diseases,” says Wellberg. “Now we know obesity is a relevant and critical biological variable that influences the way breast cancer responds to treatment.”

Wellberg believes the association between obesity and other cancer types in humans means it is critical to include obesity in preclinical cancer studies.

“We are among the first to study estrogen-dependent human breast tumors in a preclinical model of obesity, metabolic disease, and weight gain,” says Wellberg. “We hope that our publication helps other investigators incorporate obesity into their preclinical cancer studies to expand on our findings.”

The study, FGFR1 underlies obesity-associated progression of estrogen receptor–positive breast cancer after estrogen deprivation, was published online by JCI Insight, a peer-reviewed journal by the American Society for Clinical Investigation.

This research was supported by Susan G. Komen, National Institutes of Health  (National Cancer Institute, National Institute of Child Health and Development, National Institute of Diabetes and Digestive Kidney Diseases), Nutrition and Obesity Research Center, Breast Cancer Research Foundation, Botwinick-Wolfensohn Foundation (in memory of Mr. and Mrs. Benjamin Botwinick), Cancer League of Colorado, and University of Colorado Department of Medicine Team Science Award.