Factors associated with adherence and persistence to hormonal therapy in women with breast cancer

ABSTRACT: Introduction: Hormonal therapy in breast cancer is essential to the transition from active treatment to care survival, because it improves long-term survival and provides a better quality of life. reducing hospital costs as well. However, adherence and persistence in the recommended treatment are important to achieve the desirable results. Methodology: This is a cohort retrospective study of 182 women on hormonal treatment identified at a high complexity oncology unit, in the southeastern region of Brazil, and followed-up until 2014. We performed a bivariate analysis to analyze the factors associated with adherence and we conducted the multivariate Cox regression to identify variables associated with discontinuity of treatment over time. Results: Overall adherence was 85.2% and persistence was 45.4% at the end of 5 years. No association was found between the studied independent variables and adherence. Women with advanced stage (HR = 2.24; 95% confidence interval 1.45 - 3.45), who did not undergo surgery (HR = 3.46; 95%CI 2.00 - 5.97), and with three or more hospitalizations (HR = 6.06; 95%CI 2.53 - 14.54) exhibited increased risk of discontinuity. Discussion: The variables associated with persistence reflect the relation between the highest disease severity and the discontinuity of adjuvant hormonal treatment. Conclusion: Despite the high adherence level, there is a progressive increase in non-persistence among women on hormonal therapy, influenced by characteristics related to disease severity, which contributes to an inadequate therapeutic response.

摘要：
引言：乳腺癌内分泌治疗是从积极治疗过渡至生存关怀的核心环节，其不仅可提升患者长期生存率、优化生活质量，同时还能降低住院成本。然而，严格遵循并持续接受推荐治疗方案，是达成预期治疗效果的关键前提。

研究方法：本研究为回顾性队列研究（retrospective cohort study），纳入巴西东南部地区某高复杂度肿瘤诊疗科室的182名接受内分泌治疗的女性患者，随访至2014年。本研究采用双变量分析探究与治疗依从性相关的影响因素，并通过多变量Cox回归（multivariate Cox regression）分析识别随时间推移与治疗中断相关的变量。

研究结果：随访至5年末，受试者总体治疗依从率为85.2%，持续治疗率为45.4%。本研究未发现所纳入的自变量与治疗依从性存在显著关联。其中，疾病晚期患者（风险比（hazard ratio, HR）=2.24；95%置信区间（confidence interval, CI）1.45~3.45）、未接受手术治疗者（HR=3.46；95%CI：2.00~5.97）以及住院次数≥3次者（HR=6.06；95%CI：2.53~14.54），其治疗中断风险显著升高。

讨论：与治疗持续性相关的变量反映出疾病严重程度越高，辅助内分泌治疗（adjuvant hormonal therapy）中断的相关性越强。

结论：尽管本次研究中患者的治疗依从率较高，但接受内分泌治疗的女性患者的治疗中断率呈进行性升高，且受疾病严重程度相关特征的影响，这将导致患者无法获得充分的治疗应答。