Jennifer A. Ligibel, MD

Exercise Studies in Patients With Breast Cancer

Our research concentrates on the relationship between exercise and weight and breast cancer outcomes. Many studies over the past 20 years have demonstrated that women who are overweight at the time of their breast cancer diagnosis have a higher risk of recurrence and breast cancer-related death than do leaner women. A recent report from the Nurses' Health Study group has demonstrated that weight gain after diagnosis is also a poor prognostic marker in both pre- and postmenopausal women; another report from the same group demonstrated that women who exercised after breast cancer diagnosis had a lower risk of cancer recurrence than did sedentary women, even if they did not lose weight as a result of their increased physical activity.The mechanism linking exercise and weight with breast cancer outcome is not well understood. It is known that obese women have higher levels of insulin and other hormones related to energy balance. Preclinical studies have implicated insulin and a number of adipocytokines (hormones derived from adipose tissue) in the malignant transformation of breast cells in vitro. A recent clinical study has also demonstrated that breast cancer patients with higher fasting insulin levels at the time of diagnosis are at increased risk of developing a breast cancer recurrence or dying than are patients with lower insulin levels.We are conducting a series of pilot trials of exercise interventions in breast cancer patients to evaluate both the feasibility of exercise in different breast cancer populations and the impact of exercise on insulin and other hormones related to energy balance. We hope to use the knowledge gained from these pilot trials to help design a larger randomized trial of exercise in breast cancer patients to better study the impact of physical activity on breast cancer outcomes.