Treatment outcomes and the associated factors among breast cancer patients in Tanzania: a retrospective cohort study.

Background: Breast cancer (BC) is the second most prevalent cancer among women in sub-Saharan Africa. Despite dedicated efforts to enhance BC care in the region through improving diagnostic and treatment services, little is known about the treatment outcomes of BC patients and the predictors of outcomes in our local settings have not been enumerated. This study aimed to investigate the treatment outcomes and the associated factors among BC patients in Tanzania. Materials and methods: This was a retrospective cohort study at Muhimbili National Hospital and Ocean Road Cancer Institute in 2022. It involved female patients 18 years and above who were confirmed to have BC by histology. A sample size of 240 was determined to be adequate to detect a survival difference between the stages. Using Research Electronic Data Capture, clinical characteristics were collected from patients' treatment records and survival status was ascertained both by case notes or phone calls to patients or next of kin. Data were transferred into Statistical Package for the Social Sciences version 27 for subsequent analysis where continuous variables were summarised as proportions. We used chi-square and Fisher's exact tests to determine the association between various patients' characteristics and treatment outcomes. Kaplan-Meyer analysis was used to determine survival and a p-value less than 0.05 is considered statistically significant. Results: In total, 298 BC patients were studied with a mean age of 53.2 ± 13.6 (27-89). Invasive ductal carcinoma, parity and late stage at presentation were predominant features in these patients. A triple negative subtype was identified in 35.2% of the women. Only 27.9% and 33.6% of the patients received neoadjuvant and adjuvant chemotherapy respectively, while 8.1% of the patients were palliated. The overall 5 years survival was 29.7%, while being significantly poor in patients with advanced stages of the disease. Luminal subtypes, parity, menopausal status and age had some influence on BC survival among our patients but not in a significant manner. Conclusion: Mastectomy is predominantly offered to BC patients in Tanzania with no standardisation of use of chemo/radiation both in neo/adjuvant settings. Some important prognostic factors were missing including a lack of standardised work up of patients. With the predominance of advanced stage at presentation, BC carries unacceptable high mortality in Tanzania. Efforts to detect BC early, understand patients' perception of their disease and standardisation of care are needed to successfully implement treatment guidelines.