Background: The rheumatic adverse effects accompanying treatment with aromatase inhibitors (AIs) in hormone-dependent breast cancer represent an area of clinical relevance and emerging concern. This report describes these rheumatic complaints detailing their clinical pattern.
Methods: During 1-year period, 18 consecutive postmenopausal women (mean age, 58.33 years; range, 52-66 years) in treatment with AIs for hormone-dependent breast cancer (mean duration of therapy, 12.0 months; range, 9.1-17.7 months) were referred for evaluation in the outpatient clinic of the rheumatology unit in relation to rheumatic complaints. According to a routine protocol planned with oncologists, patient evaluations consisted of a complete clinical examination with careful assessment of rheumatic complaints and related physical symptoms, followed by laboratory testing and a bone scintiscan. In no cases were rheumatic complaints present before AI therapy.
Results: On the basis of clinical data and investigations and by applying accepted diagnostic criteria, a diagnosis of an undifferentiated spondyloarthropathy was reached in 10 (55.5%) of the 18 patients studied, and an oligoarthritis was shown in 2 more patients (11.1%), whereas a simple arthralgia was found in the remaining 6 patients (33.3%). In the patients meeting criteria as belonging to a spondyloarthritic subset, a family history positive for psoriasis and celiac disease was shown in 2 and 1 instance, respectively, whereas HLA-CW6 and HLA-B27 were detected in 3 and 1 case. A high serum level of anti-cyclic citrullinated peptide antibodies was shown in 1 patient with oligoarthritis. Most of the patients (16/18) were treated with nonsteroidal anti-inflammatory drugs or with corticosteroids. Methotrexate (10 mg weekly) was added in 3 of these patients, nonresponders. Aromatase inhibitor discontinuation was needed in the remaining 2 cases with spontaneous resolution of symptoms over time.
Conclusions: Data from the present study emphasize a previously unsuspected high prevalence of defined arthritides underlying these rheumatic complaints. Therefore, investigative efforts should be addressed to better clarify the clinical and pathogenetic significance of these important consequences of AI therapy. An accurate monitoring of rheumatic complaints has to be suggested to patients taking AI therapy, with a rapid referral to a rheumatologist in the case of consistent suspicion of an inflammatory arthritis.