Time course of arthralgia among women initiating aromatase inhibitor therapy and a postmenopausal comparison group in a prospective cohort
We gratefully acknowledge the BCAT Study Team: Tonya Brown, Jessica Islam, Danielle LaMorte, Ashley Pasquariello, Angel Sherrill, Bradley Shields, and Angela Zito. We gratefully acknowledge programming support from Joseph Burden, Gregory Todd Salter, Mikhail Zemmel, and Scott Sobecki, contributions to screening provided by the Vanderbilt Cancer Trials Information Program, and statistical expertise provided by Chiu-Lan (Heidi) Chen and Jonathan Schildcrout. This study was conducted in collaboration with the Vanderbilt Ingram Cancer Center, Vanderbilt Internal Medicine, Vanderbilt Institute for Medicine and Public Health, Vanderbilt Division of Rheumatology and Immunology, Vanderbilt Epidemiology Center, Vanderbilt Bioinformatics, Vanderbilt Biostatistics, Vanderbilt REACH for Survivorship, Meharry Medical College/Nashville General Hospital, and Northwestern University.
More than 80,000 postmenopausal breast cancer patients in the United States each year are estimated to begin a 5-year course of aromatase inhibitors (AIs) to prevent recurrence. AI-related arthralgia (joint pain and/or stiffness) may contribute to nonadherence, but longitudinal data are needed on arthralgia risk factors, trajectories, and background in postmenopause. This study sought to describe 1-year arthralgia trajectories and baseline covariates among patients with AI and a postmenopausal comparison group.
Patients initiating AIs (n = 91) were surveyed at the time of AI initiation and at 6 repeated assessments over 1 year. A comparison group of postmenopausal women without breast cancer (n = 177) completed concomitantly timed surveys. Numeric rating scales (0–10) were used to measure pain in 8 joint pair groups (bilateral fingers, wrists, elbows, shoulders, hips, knees, ankles, and toes). Poisson regression models were used to analyze arthralgia trajectories and risk factors.
By week 6, the AI-initiating group had more severe arthralgia than did the comparison group (ratio of means = 1.8, 95% confidence interval = 1.24-2.7, P = .002), adjusting for baseline characteristics. Arthralgia then worsened further over 1 year in the AI group. Menopausal symptom severity and existing joint-related comorbidity at baseline among women initiating AI were associated with more severe arthralgia over time.
Patients initiating AI should be told about the timing of arthralgia over the first year of therapy, and advised that it does not appear to resolve over the course of a year. Menopausal symptoms and joint-related comorbidity at AI initiation can help identify patients at risk for developing AI-related arthralgia. Cancer 2013;119:2375–2382. © 2013 American Cancer Society.