COMPliance and Arthralgia in Clinical Therapy: the COMPACT trial, assessing the incidence of arthralgia, and compliance within the first year of adjuvant anastrozole therapy

Abstract

Background: This prospective study evaluated the relationship between arthralgia and compliance during the first year of adjuvant anastrozole therapy in postmenopausal women with hormone receptor-positive early breast cancer.

Patients and methods: COMPliance and Arthralgia in Clinical Therapy (COMPACT) was an open-label, multicenter, noninterventional study conducted in Germany. Patients had started adjuvant anastrozole 3-6 months before the study start. The primary end points were arthralgia, compliance, and the relationship between compliance and arthralgia, assessed at specific time points.

Results: Overall, 1916 patients received upfront anastrozole. Mean arthralgia scores were increased from baseline at each visit up to 9 months. Compliance with anastrozole therapy gradually decreased over time from baseline to 9 months (P<0.001). At 9 months, investigators estimated that >95% of patients were compliant versus patient reports of <70%. There was a significant association between arthralgia mean scores and noncompliance at 6 months (P<0.0001), 9 months (P<0.0001), and overall (P<0.0001). Over time, new events or impairment of existing arthralgias were reported in 14% (3 months), 11% (6 months), and 9% (9 months) of patients.

Conclusion: Arthralgia is important in the clinical management of women with early breast cancer and may contribute to noncompliance and clinical outcomes.

Clinicaltrialsgov identifier: NCT00857012.

Keywords: anastrozole; aromatase inhibitors; arthralgia; breast neoplasms; patient compliance.