Evaluation of Aromatase Inhibitor-Related Arthralgia in Early Breast Cancer Patients

ABSTRACT Introduction Aromatase inhibitors (AI) have demonstrated a disease-free survival benefit compared with tamoxifen as adjuvant therapy in the treatment of hormone-dependent early breast cancer in postmenopausal women. Although the AI are associated with fewer thromboembolic events and endometrial abnormalities than tamoxifen, an increase in arthralgia, skeletal, and muscle pain has been reported and cited as the primary reason for discontinuation of AI therapy. The aim of our study was to evaluate the incidence and the impact of the arthralgia syndrome in our population. Methods Postmenopausal patients with the diagnosis of early-stage hormone-sensitive breast cancer receiving AI therapy at our institution were included prospectively between 2010-2012. We performed a specific survey to evaluate articular toxicity collecting presence of arthralgias, EVA scale, use of analgesic, start time and localization of the pain. Clinical data was collected from our department database. Univariate analysis was used to compare those with AI-related arthralgia and different demographic and clinical features. Results A total of 83 women were included, with a mean age 63.2, BMI 28.4, menopause mean age 48.2. Regarding to the features of the primary tumor, 81.9% had ductal carcinoma histology, 28.9% stage I, 54.2% stage II, 16.8% stage III. At the moment of the evaluation, 68.7% (57/83) were receiving treatment with anastrozole, 15.7% (13/83) letrozole, 15.7% (13/83) exemestane. 86.7% (72/83) had joint pain, of them 68.1% (49/72) related their pain to the hormone therapy, 31.9% (23/72) to previous diseases or another treatments. The articulations more frequently affected were located in the back, knees and hands. Regarding to the pain intensity, mean maximum EVA was 6.03, minimum 1.06. Only 2 of the patients affected stopped therapy, and it was changed for another aromatase inhibitor. No differences were seen between the different aromatase inhibitors. Conclusions The incidence of arthralgia associated with aromatase inhibitors was superior in our series compared with results previously published in clinical trials. Further research in this field should be developed to clarify the prevalence and severity of joint symptoms related to AI and to define factors that may be associated with an increased risk of this treatment-related adverse effect. Disclosure All authors have declared no conflicts of interest.