The CIRAS study: a case control study to define the clinical, immunologic, and radiographic features of aromatase inhibitor-induced musculoskeletal symptoms

Aromatase inhibitors (AIs) are widely prescribed for post-menopausal hormone receptor-positive breast cancer; however, musculoskeletal symptoms limit their tolerability. The purpose of this study was to determine whether joint pain in women receiving AIs is associated with inflammatory arthritis as measured by the disease activity score-28 (DAS-28), and to evaluate association with tenosynovitis on ultrasound. A total of 48 postmenopausal women with stage I-III breast cancer and hand pain were recruited from the Lombardi Comprehensive Cancer Center. Those receiving AIs were cases (n = 25), and those not receiving AIs were controls (n = 23). During a single study visit, subjects underwent blinded rheumatologic evaluation, DAS-28, health assessment questionnaires, autoantibodies, inflammatory markers, hand X-ray, and hand Duplex ultrasound. There were no significant differences between cases and controls in DAS-28, or inflammatory markers. A positive ANA (titer > 1:160) was found in ten patients, four of whom met criteria for autoimmune disease (two with rheumatoid arthritis and two with Sjogren's syndrome, equally distributed among cases and controls). This highlights the importance of considering underlying autoimmune disease in subjects with musculoskeletal complaints. Morning stiffness was more prolonged in women receiving AIs, but this did not reach statistical significance (P = 0.07). Ultrasound evidence of flexor tenosynovitis was common in both groups. Although tenosynovitis was not correlated with AI use (P = 0.26), there was a trend toward an association between tenosynovitis and morning stiffness (P = 0.089). While aromatase inhibitor-induced musculoskeletal symptoms (AIMSS) were more common in subjects receiving AIs, they were not unique to AI users. There was no association between presence of AIMSS features and other chemotherapy or medication exposures. Although the majority of subjects had been using AIs for more than 6 months, this study did not find evidence for inflammatory arthritis in women with hand pain receiving AIs. Further studies are needed to develop a case definition of AIMSS, and to confirm whether these symptoms are attributable to AI use.