Influence of Aromatase Inhibitors on Pain and Pain Sensitivity in Women with Breast Cancer

Aromatase Inhibitor-associated MusculoSkeletal Syndrome (AIMSS), reported by 36-87% of women with breast cancer undergoing AI therapy, may reduce quality of life and medication adherence. The objective of this analysis was to compare clinical pain and generalized pain sensitivity between breast cancer patients who did or did not receive AI therapy. Breast cancer patients were prospectively enrolled and assessed for clinical pain and pain sensitivity preoperatively and 12 months postsurgically using the Brief Pain Inventory and the Breast Cancer Pain Questionnaire (BCPQ). Quantitative sensory testing (QST) included measurement of pressure pain threshold and tolerance, temporal summation of pain, and painful after-sensations after mechanical pinprick at non-surgical body sites. Outcomes were compared between participants with and without AI therapy by Mann-Whitney U test and Chi-square test at pre- and post-surgical timepoints. Patients (n=155) with a mean age of 57 underwent breast conserving surgery (54%), with 56% receiving radiation therapy, and 30% chemotherapy. Aproximately 1/3 (32%) received AI therapy. No statistically significant differences in clinical pain or pain sensitivity were observed between groups before AI therapy (preoperatively). However, those who received AI therapy reported a greater number of nonsurgical body sites with pain (p=0.014) with a trend towards higher overall pain severity (p=0.084). Most frequently reported pain locations in patients receiving AI were knee (28.3%), lower back (26.1%), neck/shoulders (19.6%), hip (17.4%), and ankle/foot (17.4%), and these patients reported greater knee (p=0.042), ankle/foot (p=0.023), and lower back (p=0.056, trend) pain than patients without AI therapy. On QST, the AI group reported greater painful after-sensations (p=0.012) and a trend of lower pressure pain tolerance (p=0.086). These findings suggest that AI therapy increases diffuse clinical joint-related pain and may result in greater generalized pain sensitivity, suggesting a need for further investigation of the role of central sensitization in AIMSS. NIH K23 GM110540. PI: Kristin Schreiber.