Loss of Grip Strength, BMI, and Adjuvant Endocrine Therapy Breast Cancer

Early stage hormone receptor positive breast cancer is typically treated with adjuvant
endocrine therapy in order to decrease risk of breast cancer recurrence and to improve
overall survival from the disease. Typical agents used for treatment include tamoxifen and
the aromatase inhibitors. In postmenopausal women, aromatase inhibitor therapy is
increasingly common because it is associated with fewer long-term serious toxicities
compared to tamoxifen. However, aromatase inhibitors cause arthralgias in 40-50% of
patients, which can influence adherence to therapy and can lead to treatment discontinuation
in a minority of cases. The mechanism underlying development of this toxicity remains
unclear, and predictors of who will develop these symptoms remain undefined. Initial reports
suggest that grip strength decreases during aromatase inhibitor therapy, and that body-mass
index may influence development of this symptom. Therefore, this longitudinal study has been
developed to determine change in grip strength over time in women treated with aromatase
inhibitors and tamoxifen, as well as to identify potential associations between change in
grip strength and BMI. Patient self-reported symptoms will also be collected. A total of 115
women with early stage breast cancer who are initiating therapy with either an aromatase
inhibitor or tamoxifen will be enrolled.