The Patient's Anastrozole Compliance to Therapy (PACT) Program: a randomized, in-practice study on the impact of a standardized information program on persistence and compliance to adjuvant endocrine therapy in postmenopausal women with early breast cancer

Background: Compliance and persistence are often overlooked in adjuvant breast cancer treatment. Patients and methods: PACT was a prospective, multicenter, randomized, open, parallel-group study assessing whether educational materials (EMs) enhanced compliance with aromatase inhibitor (AI) therapy in postmenopausal women with early, hormone-receptor-positive (HR+) breast cancer. The primary end points were compliance (proportion taking >= 80% anastrozole) at 12 months and persistence (proportion reporting anastrozole intake during the study period). Results: Four thousand eight hundred and forty-four patients were randomly assigned 1:1 to receive standard therapy or standard therapy with EMs. There was no difference between arms in compliance (N = 2740; 88.5%/88.8%, respectively, P = 0.81) or persistence rates (N = 2740; 40.5%/43.0%, respectively, P = 0.18). Modified end point analyses found no differences in compliance between arms based on the classification of: (i) patients with missing documentation or follow-up visit <9 months as non-compliant (N = 4397, P = 0.15); (ii) patients with early (<= 292 days) 12-month follow-up documentation excluded (N = 4091, P = 0.19); (iii) patients reaching >= 80% compliance during individual follow-up as compliant (N = 4397, P = 0.26). Modified persistence analyses found no difference between arms (N = 4397, P = 0.37). Conclusions: Addition of EMs to standard therapy did not significantly affect compliance and persistence with adjuvant anastrozole.