Abstract

INTRODUCTION. The progressive incorporation of high-cost oral antineoplastic drugs (DACO) has improved oncology treatment regimens but introduced challenges such as regimen complexity, drug interactions, and toxicity. In Chile, the Oncology Agreement (CO) of the Arturo López Pérez Foundation (FALP) co-finances high-cost therapies; however, adherence to these drugs and their relationship with progression-free survival (PFS) have not been previously evaluated. OBJECTIVE. To measure adherence to DACO among CO beneficiaries and assess its impact on PFS. A prospective 12-month follow-up study was conducted, including CO-affiliated patients who received DACO in 2020–2021 and provided informed consent. Adherence was assessed monthly using the SMAQ questionnaire, and demographic, clinical, and treatment-related variables were collected. PFS was estimated using the Kaplan–Meier method, and comparisons were performed using the log-rank test. RESULTS. Of 92 eligible beneficiaries, 49 (53.3%) agreed to participate. According to SMAQ, adherence was 100% throughout the follow-up period. A total of 36.7% experienced disease progression, with age emerging as a significant factor (p=0.0377). The 12-month PFS probability was 0.5, showing a notable increase in progression risk after month 7 (p< 0.001). Although most participants were insured under the private system (Isapre, 67.3%), a higher proportion of public insurance beneficiaries (FONASA, 43.3%) was observed among those who progressed, although this difference was not statistically significant. CONCLUSION. Systematic follow-up and the removal of financial barriers may explain the high adherence observed. Nevertheless, the occurrence of progression in over one-third of participants indicates that adherence alone does not ensure tumor control. These findings highlight the need for comprehensive monitoring strategies and person-centered communication to optimize outcomes in patients receiving oral oncology therapies. © 2025, Escuela de Enfermeria Pontificia Universidad Catolica de Chile. All rights reserved.