Aromatase inhibitor use, side effects and discontinuation rates in gynecologic oncology patients

Objective: Aromatase inhibitors (AI) are frequently prescribed in gynecologic oncology. We sought to define the frequency and duration of AI use, characterize AI side effects and determine the reasons for discontinuation in these patients.

Methods: Uterine and ovarian cancer patients with AI use for gynecologic cancer therapy were identified retrospectively. Data were abstracted from the electronic medical record, including cancer type, stage, prior cancer treatments, body mass index, concurrent medications, prevalence of AI side effects before and during AI therapy, length of AI treatment and reason for AI discontinuation.

Results: 146 women received AI therapy, with 68 for ovarian cancer (46.6%) and 78 for uterine cancer (53.4%). The majority (71.9%) had advanced stage disease at diagnosis. 54.1% noted AI-associated side effects within the first three visits after starting AI therapy. The most common side effects were arthralgias (29.5%), hot flashes (25.3%), new/worsening fatigue (16.4%), muscle or joint stiffness (8.2%) and myalgias (6.8%). The mean duration of therapy was 14.7 months. Gabapentin or selective serotonin reuptake inhibitor (SSRI) use was associated with decreased musculoskeletal side effects (gabapentin: p < .001, OR 0.88, 95% CI 0.83-0.94; SSRI: p < .001, OR 0.82, 95% CI 0.77-0.89). The most common reason for AI discontinuation was disease progression (87.9%), with 5.0% discontinuing due to side effects and 7.1% for other reasons.

Conclusion: AI therapy for gynecologic cancers is frequently associated with musculoskeletal side effects, but rarely leads to treatment discontinuation. Thus, AI side effects should be assessed in gynecologic cancer patients to allow potential mitigation of symptoms through adjunct therapies.