Objective: to describe the rheumatic aspects of arthralgia associated with aromatase inhibitor therapy in a clinical case series.Material and methods. The article presents a series of clinical cases – 16 patients (mean age 61±14 years) with histologically verified breast cancer (BC) and the onset of musculoskeletal pathology during hormone therapy with aromatase inhibitors (letrozole, anastrozole, exemestane). The laboratory and instrumental examination data, including ultrasound, joint X-rays, general and immunological blood tests with the determination of rheumatoid factor (RF), antibodies to cyclic citrullinated peptide (ACCP), CRP and antinuclear factor (ANF) are presented. The detected musculoskeletal pathology was compared with valid classification and/or diagnostic criteria for rheumatic diseases.Results and discussion. In 10 (63%) cases, musculoskeletal pathology debuted in the first 3 months of therapy with aromatase inhibitors and in all patients it was represented by inflammatory manifestations, including clinically significant synovitis (n=13), tenosynovitis (n=12), enthesitis (n=5), morning stiffness in the joints >30 min (n=6) and inflammatory rhythm lower back pain (n=1). In 15 (94%) patients, ultrasound showed signs of synovitis (with increased vascularization in 5 cases), tenosynovitis in 15 (94%), and erosions in 1 (6%). X-rays showed osteoarthritis in 12 patients, and chronic erosive arthritis in 2. Increased ESR >30 mm/h and CRP level >5 mg/l were present in 6 (38%) and 7 (44%) patients, respectively; ANF (Hеp2) titer 1/160 was found in 8 (53%) out 15 examined patients. RF and ACCP were not detected in any case. During rheumatological examination, the following were diagnosed: polymyalgia rheumatica (n=1), undifferentiated arthritis (n=6), psoriatic arthritis (n=1), rheumatoid arthritis (n=1), recurrent proliferative synovitis of the knee joints with a pronounced exudative component (n=3), inflammatory lesions of periarticular tissues (n=4).Conclusion. Based on the obtained data, it can be assumed that arthralgias induced by breast cancer hormone therapy may be a manifestation of inflammatory diseases of the musculoskeletal system. Given the heterogeneity of manifestations of musculoskeletal pathology in such patients, a complete rheumatological examination is necessary to establish the diagnosis and conduct adequate therapy.
