Adherence to endocrine therapy and its relation to disease-free survival among breast cancer patients visiting an out-patient clinic at Khartoum Oncology Hospital, Sudan.

Rationale: Adherence to endocrine therapy provides substantial reduction in breast cancer (BC) relapses and improve survival. Hence, non-adherence remains an under reported issue mainly in developing countries.

Aims And Objectives: The aim of this study is to evaluate the adherence to endocrine therapy (tamoxifen [TAM] and aromatase inhibitors [AIs]) among BC patients visiting an out-patient clinic (2015-2016) in Khartoum Oncology Hospital, Sudan.

Methods: Adherence was assessed using pills count and self-reporting methods. A total of 172 patients were interviewed. Also, records were reviewed for demographic and other cancer characteristics.

Results: The patients' mean age at diagnosis was 53 years, with the highest frequency at (41-60) years. Invasive ductal carcinoma 69.2% formed the main pathological diagnosis. T2 tumour size (51.2%) and lymph node involvement (N1) (31.4%) were most evident. Also, the majority of patients were stage III (45.9%) and grade II (48%). The studied women were postmenopausal (49.4%) and premenopausal (47.7%). Regarding hormonal receptors, about 68% were oestrogen (ER)+/progesterone (PR)+ and 23.3% were ER+/PR-. Studying adherence, almost (93%) of the studied group were ≥80% adherent to TAM and AIs. The hormonal therapy persistence mean was 27.2 ± 22.5 months (40-96). While adherence percentage mean was 93.7 ± 13.6% (0%-100%). Also disease-free survival (DFS) mean was 36.3 ± 32.7 months (4-312). Adherence to hormonal therapy and persistence were significantly correlated (P < .000). Also, statistically significant association was found between hormonal therapy adherence (≥80%) and patient poor to average economic status (P = .006), and the marital status "married" (P = .008).

Conclusions: A high rate of adherence (93%) to endocrine therapy was estimated in the present study. Also, a positive association was found between the hormonal therapy persistence, and the DFS year's groups (P = .000), and the hormonal therapy types (P = .000). Adherence to hormonal therapy and persistence were significantly correlated (P < .000).