Aromatase Inhibitor-Induced Arthralgia Among Patients With Early Breast Cancer: Prevalence, Treatment Nonadherence,...

Aromatase inhibitor (AI)-induced arthralgia (AIA) can lead to treatment discontinuation and worse disease outcomes. This study assessed the prevalence of AIA, nonadherence to AI therapy, and supportive care strategies (SCS) among patients with early-stage breast cancer.

Patients with early-stage breast cancer treated with adjuvant AI therapy were included from the CANTO cohort. AIA was defined as any-grade articular or muscular pain (CTCAE version 4.0) at years 1, 2, 4, and 6 after diagnosis (corresponding to 3-6 months, 1, 3, and 5 years of AI exposure, respectively). We assessed nonadherence to AI therapy, defined as any interruption and/or discontinuation of AI. We evaluated the use of nonpharmacologic SCS, including meeting physical activity recommendations (≥10 metabolic equivalent task hours per week [MET-h/week]) and consultations with physical therapists, manual osteopaths, or acupuncturists, as well as pharmacologic SCS, including duloxetine use and AI switching. Multivariable logistic regression models were used to test associations among reported AIA, self-reported nonadherence to AI therapy, and SCS use.

Among 4,854 postmenopausal patients, 85.9% reported AIA at least once, including 68.5% at year 2 and 65.4% at year 4. Nonadherence to AI therapy was reported by 18.4% of patients with AIA compared with 6.8% of those without AIA (adjusted odds ratio [aOR], 2.35; 95% CI, 1.51-3.64), whereas permanent discontinuation was reported by 14.1% versus 3.4%, respectively. Subsequent physical therapy was consistently more frequent in patients reporting AIA (42.2% vs 31.2% at year 4; 37.8% vs 29.2% at year 6). The aOR for consulting physical therapists among patients reporting AIA at year 2 was 1.40 (95% CI,1.13-1.74). In contrast, other nonpharmacologic SCS use was not associated with reporting AIA. Switching AIs (19.7% vs 8.7%) was also associated with reporting AIA (aOR, 2.47; 95% CI, 1.59-3.83). Only 1.4% patients with AIA reported duloxetine use (vs 0.5%).

Although AIA was highly prevalent and associated with nonadherence to AI therapy among patients with early-stage breast cancer, uptake of recommended SCS was suboptimal and inconsistent. This study highlights gaps in guideline-concordant SCS implementation and underscores the need for efforts to maximize treatment retention during AI therapy.