Adherence to endocrine therapy and sexual dysfunction in patients older than sixty-five years with early estrogen receptor-positive breast cancer

Abstract

Introduction: Studies of adjuvant endocrine therapy (ET) for early-stage estrogen receptor-positive breast cancer have
a suboptimal number of patients older than 65 years included. Objective: This study aimed to evaluate adherence to
adjuvant ET, quality of life and sexual dysfunction in women >65 years with early breast cancer. Methods: Women with
early-stage estrogen receptor-positive breast cancer on adjuvant ET for at least six months were invited to participate of
this study. Patients were stratified according to age ≤65 and >65 years. Adherence was assessed with Morisky Medication
Adherence Scale (MMAS-8). Quality of life was assessed using EORTC QLQ C30 and BR-23 forms. Sexuality was assessed
with the Female Sex Function Index Questionnaire. Results: From June 2021 to March 2024, 774 women from 14 Brazilian
institutions were recruited. Mean age was 62 years, mean tumor size was 2.24 cm, and mean duration of ET was 3.2 years.
About 191 patients (24.7%) were >65 years, 69.6% of them were highly adherent to ET, and 70.7% had sexual dysfunction.
In comparison with women ≤65 years, older women were associated with private healthcare insurance (p=0.003), lived
with no partner (p<0.0001), had lower level of education (p=0.0009), had prior lumpectomy (p=0.0017), prior sentinel node
biopsy (p=0.03), had no prior chemotherapy (p<0.0001), used aromatase inhibitors (p<0.0001), and were also more associated
with higher adherence (p=0.0009). There was no difference in sexual dysfunction between the groups. Patients >65 years
had higher quality of life scores for emotional, cognitive, and social functioning, body image, and future perspective.
Conclusion: Patients older than 65 years had less aggressive treatments, better domains in quality of life, and higher
adherence to ET than patients aged up to 65 years. In this context, sexual dysfunction affects women of both age groups.