Study: Diet, exercise improve outcomes of chemotherapy for women with breast cancer

A new Yale Cancer Center study finds a targeted diet and exercise intervention could improve outcomes for women undergoing chemotherapy for breast cancer.

Finishing chemotherapy is crucial for improving breast cancer treatment odds, but many patients with breast cancer do not follow their full treatment plan because of the side effects that come along with chemotherapy drugs.

"We hear from women all the time that they wish they had better tools to help them ward off side effects like fatigue and weight gain," says Tara Sanft, MD, lead author and associate professor of medicine (medical oncology), who is also medical director of the Smilow Cancer Hospital Survivorship Clinic.

"We wanted to see whether a healthy diet and exercise intervention for early-stage breast cancer could help with side effects and allow women to have an easier time completing more of their chemotherapy."

In the study, published September 1st in the Journal of Clinical Oncology, Sanft and colleagues, including senior author Melinda Irwin, Ph.D., member of Yale Cancer Center, offered women recently diagnosed with breast cancer targeted interventions aimed at adopting dietary and physical activity guidelines with the goal of fighting chemotoxicity and improving therapy adherence.

The researchers say women who received the intervention, which included regular counseling sessions, reported increases in exercise and fruit and vegetable intake. Relative dose intensity (RDI), a measure of chemotherapy completion, was not significantly higher for the intervention group, but researchers were surprised to find 53% of women who received the intervention experienced a pathologic complete response (PCR or disappearance of all invasive cancer cells in the breast), compared to just 28% of women in the control group.

"Further explanation is needed since it wasn't the primary outcome of our study," says Irwin, also associate dean of research at Yale School of Public Health, "but there's an exciting possibility that diet and exercise can influence chemotherapy outcomes through factors other than just how much of chemotherapy was completed."

She says the results prove that people can develop healthier habits during treatment for cancer, even if they didn't have them before. "Even at diagnosis," Sanft says, "it is not 'too late' for oncologists to recommend these healthy behaviors to patients."