Does Fasting and Exercise Help Side Effects in Advanced Breast Cancer?

Sylvester researchers co-lead an NCI-funded grant to study how these lifestyle changes might improve treatment-related side effects in advanced HR+ breast cancer.

Studies show that it’s not only what one eats but also when one eats that could help to relieve cancer treatment-related side effects.

Sylvester Comprehensive Cancer Center researchers are investigating the impact overnight fasting and exercise for patients with advanced breast cancer.

Prolonged overnight fasting, which aligns daily food intake with one’s circadian rhythm by halting food intake in the evening and fasting for the next 12 to 18 hours, can help some cancer patients through side effects experienced during treatment, such as fatigue, depression, sleep disturbance and anxiety.

Supervised exercise programs have been shown to have similar benefits for some with cancer.

To study the quality-of-life-enhancing potential of prolonged overnight fasting and exercise specifically in women being treated for advanced breast cancer, the National Cancer Institute (NCI) has funded the five-year, $4 million Prolonged Overnight Fasting and/or Exercise on Fatigue and Other Patient Reported Outcomes in Women with Hormone Receptor Positive Advanced Breast Cancer (FastER) trial—a collaboration between Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine and Dana-Farber Cancer Institute.

New Breast Cancer Treatments and Side Effects

More than 40,000 women in the U.S. die each year of metastatic breast cancer, or cancer that has spread from the breast to other areas of the body. The vast majority of these women have hormone receptor-positive (HR+) tumors, according FastER multiple principal investigator Tracy E. Crane, Ph.D., RDN, co-lead of the Cancer Control research program and director of lifestyle medicine, prevention and digital health at Sylvester.

A photo of Tracy Crane, Ph.D., RDN.
Tracy Crane, Ph.D., RDN, is the FastER principal investigator.

Standard first-line treatment for patients with advanced HR+ breast cancer includes an inhibitor of cyclin-dependent kinase 4/6 (CDK4/6) in combination with hormone therapy, which helps advanced breast cancer patients live longer than ever before, according to Dr. Crane.

“But there is a price, as even the newer, more targeted therapies have significant toxicity,” she said.

These therapies can cause fatigue, low levels of white blood cells and gastrointestinal symptoms. The addition of hormonal therapies can result in menopausal symptoms, mood disorders and impaired sleep.

For some patients, the side effects can become debilitating, resulting in them discontinuing treatment.

“As treatments improve, more research is needed to understand and help manage these symptoms, so women can complete their treatment and have longer and better lives,” Dr. Crane said.

While there are studies that show lifestyle strategies can significantly improve quality of life and physical function in early-stage breast cancer, less information exists about lifestyle strategies in advanced cancer. FastER aims to fill the gap by looking at how exercise and fasting might restore alignment of circadian activity rhythms and improve treatment tolerability in advanced cancer survivors.

FastER Facts

Researchers at Sylvester and Dana-Farber are studying a diverse group of 260 women with advanced, hormone receptor-positive (HR+) breast cancer who are starting on a CDK4/6 inhibitor and hormonal therapy.

The women in the study will be randomly assigned to a 12-week program in one of four groups:

  • Supportive care
  • Prolonged overnight fasting only
  • Supervised exercise only
  • Prolonged overnight fasting and supervised exercise

All participants will work with a health coach on the goals specific to their group. In particular, participants in the exercise groups will receive in-person and remote instruction on resistance and cardio exercises with a certified exercise trainer.

At 12 weeks, six months and 12 months, the study’s investigators will compare levels of;

  • Patient-reported fatigue, depression, anxiety and quality of life
  • Physical function and activity, as well as sleep quality, blood levels of inflammation and body composition
Sylvester Comprehensive Cancer Center medical oncologist Carmen Calfa
Carmen Calfa, M.D., is co-director of Sylvester’s Cancer Survivorship Clinical Programs.

Their goals are to better understand the impacts of supervised exercise and prolonged overnight fasting, alone or in combination, on women undergoing treatment for advanced HR+ breast cancer

The study’s co-investigator, Carmen Calfa, M.D., breast medical oncologist medical and co-director of Cancer Survivorship Clinical Programs at Sylvester, cares for women going through treatment for advanced breast cancer.

“We owe it to our patients to continue the search for new effective and non-toxic strategies, not only to prolong life but to improve quality of life,” Dr. Calfa said. “This opportunity to study the effectiveness of lifestyle interventional strategies  in women with advanced breast cancer gives me hope that, in the most holistic way, we can contribute to improving outcomes.”  

Enrollment in the study is anticipated to open in early 2024. For more information, check the Crane Lab website.

Tags: breast cancer, Dr. Carmen Calfa, Dr. Tracy Crane