Abstract P5-12-02: Can a supervised exercise program compared to usual care prevent aromatase inhibitor-induced musculoskeletal pain in women with breast cancer?
Authors: Sanmugarajah J , Allan S , Bagchi R , Laakso E-L 
Published: March 2017

Background: Aromatase Inhibitors (AIs) are commonly prescribed as hormone therapy for post-menopausal women with estrogen receptor-positive breast cancer. A number of authors have reported AI side effects that include increased risk for developing osteoporosis, joint pain, weight gain and depression. For example, 30-40% of post-menopausal women treated with AIs experience mild to severe joint pain. Although the exact causes of AI-induced joint pain are unknown, the side-effects are most likely due to low estrogen levels in the body. . Denysschen et al. (2014) reported a significantly lower number of painful joints, reduced depressive symptoms, increased muscle strength, and improvement in quality of life in patients with AI-induced joint pain after an 8 week upper and lower body resistance exercise program. Objective: To investigate whether a supervised exercise program could reduce or prevent musculoskeletal pain in patients with breast cancer undergoing AI therapy. Methods: Twenty participants with breast cancer have thus far been randomised to either: (a) usual care and advice regarding benefits of regular exercise; or (b) usual care + 12 week supervised and home-based exercise program consisting of upper and lower body resistance exercises with self-selected aerobic exercises. Participants accrued 150 mins / week of moderate intensity aerobic exercise at 60-70% HRmax on 5 or more days of each week including 2 supervised sessions / week. Initial exercise intensity is individualized and generally begins at 55% to 60% of HRmax (15 to 30 minutes per session) and progresses to 60% - 70% of HRmax by week 6. Strength training consisted of 2 supervised sessions per week, of two sets of 10 to 12 repetitions of eight different strength exercises at 60% to 75% of estimated one repetition maximum. On at least 3 other days, using the same dosing principles participants executed 4 lower and 4 upper body resistance exercises at home using resistance bands. The primary outcome measures were pain (brief pain inventory; BPI) scores and grip strength (JAMAR dynamometer (kg)) measured at baseline, 3, 6 and 12 months. Two-way repeated ANOVAs were undertaken to evaluate differences between groups and factors. Results: Mean pain scores across 12 months were largely maintained (p&gt;0.05) for participants undertaking the exercise program compared to control participants whose mean BPI scores progressively increased from baseline through to 12 month follow-up. In the exercise group, mean pain scores increased by one BPI unit between baseline and 12 month follow-up. In the control group, mean pain scores increased by five BPI units between baseline and 12 month follow-up. A clinically significant difference in BPI scores is a change of two or more BPI units (Mease et al, 2011). Grip strength measures were significantly different (P&lt;0.001) between groups at each time point with a trend towards improved grip strength between baseline and 6 months in the exercise group. Grip strength decreased in both groups between 6 and 12 months. Conclusion: By managing physical performance and pain as side effects of AIs, a 12 week supervised exercise program may contribute to preventing non-adherence with or withdrawal from AI therapy.

Citation Format: Sanmugarajah J, Allan S, Bagchi R, Laakso E-L. Can a supervised exercise program compared to usual care prevent aromatase inhibitor-induced musculoskeletal pain in women with breast cancer? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-12-02.