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

Completed

Brief Summary: 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.

Recruitment & Eligibility

Inclusion Criteria

Stage 0-III breast cancer who are scheduled to receive endocrine therapy with tamoxifen or an aromatase inhibitor
All prior surgery and chemotherapy should be complete
Age 18 and above and postmenopausal

Exclusion Criteria

Major rheumatologic disorders
Concomitant sex hormone containing drugs or Leutinizing Hormone Releasing Hormone agonist therapy
For those subjects initiating treatment with an aromatase inhibitor, prior tamoxifen within 4 weeks of enrollment
For those subjects initiating treatment with tamoxifen, prior aromatase inhibitor within 4 weeks of enrollment

Arm && Interventions

Group	Intervention	Description
AI therapy	anastrozole, letrozole, exemestane	Subjects who started treatment with any of the three aromatase inhibitor (AI) medications
Tamoxifen	Tamoxifen	Subjects who started treatment with tamoxifen

Primary Outcome Measures

Name	Time	Method
Effect of Change in Body Mass Index on Change in Grip Strength With Aromatase Inhibitor Therapy	baseline and 12 months	Change in BMI between baseline and 12 months of endocrine therapy

Secondary Outcome Measures

Name	Time	Method
Effect of Medication on Change in Grip Strength	baseline and 12 months	Effect of either aromatase inhibitor or tamoxifen therapy on change in grip strength between baseline and 12 months
Association Between Baseline Body Mass Index and Discontinuation of Aromatase Inhibitor Therapy Within the First 12 Months	baseline and 12 months	Associations between baseline BMI and whether or not aromatase inhibitor-treated patients discontinued treatment by 12 months. In the original statistical analysis plan, it was only intended to examine the association with aromatase inhibitor-treated patients, and not tamoxifen-treated patients. The numbers below reflect the number of patients in each group who discontinued initial endocrine therapy within the first 12 months of treatment