ADHERENCE TO ADJUVANT ENDOCRINE THERAPY AND ITS DETERMINING FACTORS IN PATIENTS WITH BREAST CANCER

Abstract

Objective: This study aims to investigate the adherence rates to adjuvant hormone therapy in patients with early-stage
breast cancer. Methods: Breast cancer patients with early invasive disease who are being treated with adjuvant hormone
therapy for at least 6 months in a private oncology service were evaluated for adherence rates. Data collection was done
using the RedCap software. The MMAS-8 scale was used to assess adherence to treatment, dividing patients into three
groups as follows: low (<6 points), medium (6–8 points), or high adherence (8 points). Demographic and clinical characteristics were assessed for the three adherence groups. Results: From June to December 2021, a total of 60 patients were
recruited. The median age was 60.3 years, and 23.3% were premenopause. About demographic statistics, 80% have a college degree, 35% live alone, and 30% have comorbidities. About breast cancer, 50% were in stage I, 50% received chemotherapy, 10% received HER2 blockade, and 26 patients (43.3%) used letrozole. Analyzing adherence, 45% had low/medium
adhesion and 55% had high adhesion. There was no association between adherence rates and demographics, clinical and
pathological characteristics, except for ECOG Performance Status (PS). All patients with PS ECOG 1 had low/medium
adherence (p=0.036). More patients who live alone had low or medium adherence, whereas more patients who live together
had high adherence. There was no difference in the type of hormonal treatment and adherence. Conclusion: Preliminary
results show high adherence in only 55% of patients, lower than reported in previous studies. This result draws attention
because it can compromise survival. We will continue the recruitment of patients in the private service and start in the
public service to assess the rate of adherence in a larger population and the relationship with demographic characteristics.