Survival and predictors of breast cancer mortality in South Ethiopia: A retrospective cohort study

Abstract

Background Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death in over 100 countries. In March 2021, the World Health Organization called on the global community to decrease mortality by 2.5% per year. Despite the high burden of the disease, the survival status and the predictors for mortality are not yet fully determined in many countries in Sub-Saharan Africa, including Ethiopia. Here, we report the survival status and predictors of mortality among breast cancer patients in South Ethiopia as crucial baseline data to be used for the design and monitoring of interventions to improve early detection, diagnosis, and treatment capacity. Methods A hospital-based retrospective cohort study was conducted among 302 female breast cancer patients diagnosed from 2013 to 2018 by reviewing their medical records and telephone interviews. The median survival time was estimated using the Kaplan-Meier survival analysis method. A log-rank test was used to compare the observed differences in survival time among different groups. The Cox proportional hazards regression model was used to identify predictors of mortality. Results are presented using the crude and adjusted as hazard ratios along with their corresponding 95% confidence intervals. Sensitivity analysis was performed with the assumption that loss to follow-up patients might die 3 months after the last hospital visit. Results The study participants were followed for a total of 4,685.62 person-months. The median survival time was 50.81 months, which declined to 30.57 months in the worst-case analysis. About 83.4% of patients had advanced-stage disease at presentation. The overall survival probability of patients at two and three years was 73.2% and 63.0% respectively. Independent predictors of mortality were: patients residing in rural areas (adjusted hazard ratio = 2.71, 95% CI: 1.44, 5.09), travel time to a health facility ≥7 hours (adjusted hazard ratio = 3.42, 95% CI: 1.05, 11.10), those who presented within 7–23 months after the onset of symptoms (adjusted hazard ratio = 2.63, 95% CI: 1.22, 5.64), those who presented more than 23 months after the onset of symptoms (adjusted hazard ratio = 2.37, 95% CI: 1.00, 5.59), advanced stage at presentation (adjusted hazard ratio = 3.01, 95% CI: 1.05, 8.59), and patients who never received chemotherapy (adjusted hazard ratio = 6.69, 95% CI: 2.20, 20.30). Conclusion Beyond three years after diagnosis, patients from southern Ethiopia had a survival rate of less than 60% despite treatment at a tertiary health facility. It is imperative to improve the early detection, diagnosis, and treatment capacities for breast cancer patients to prevent premature death in these women.

Geospatial disparities in survival of patients with breast cancer in sub-Saharan Africa from the African Breast Cancer-Disparities in Outcomes cohort (ABC-DO): a prospective cohort study

“…In a retrospective cohort of 302 patients with breast cancer from two major cancer referral centres for southern Ethiopia, rural residence (HR 2·71, 95% CI 1·44–5·09) and travel time exceeding 7 h (3·42, 1·05–11·10) were associated with mortality. 9 The methods for determining rural or urban residence and travel time were not specified, and 19% of the cohort was lost to follow-up, with substantial uncertainty in the date of censoring or death. 9 In a cohort of 609 patients with breast cancer constructed, at least in part, retrospectively at a tertiary referral centre for Osun state in Nigeria, GIS-based travel time exceeding 30 min was associated with an HR of 1·65 (1·17–1·33), adjusting for age, education, and socioeconomic position.…”

“… 9 The methods for determining rural or urban residence and travel time were not specified, and 19% of the cohort was lost to follow-up, with substantial uncertainty in the date of censoring or death. 9 In a cohort of 609 patients with breast cancer constructed, at least in part, retrospectively at a tertiary referral centre for Osun state in Nigeria, GIS-based travel time exceeding 30 min was associated with an HR of 1·65 (1·17–1·33), adjusting for age, education, and socioeconomic position. 8 This association is stronger than our data suggest, which could be explained by shorter median follow-up time (1 year vs 3·7 years in ABC-DO) that started at hospital presentation ( vs diagnosis in ABC-DO), as well as biases related to loss to follow-up and misclassification in the date of censoring.…”

“… 5 , 6 , 7 , 8 However, to our knowledge, only two studies have examined geospatial characteristics in relation to breast cancer survival in sub-Saharan Africa, finding a higher rate of death associated with rural residence and travel time among patients with breast cancer in Nigeria (n=609) and Ethiopia (n=302). 8 , 9 Both constructed their patient cohorts retrospectively, with potentially differential misclassification in the date of censoring or death expected.…”

Building Pathology Capacity in Sub-Saharan Africa to Improve Breast Cancer Diagnosis and Treatment: Training Laboratory Technicians in High-quality Manual Immunohistochemistry

“…The 1-year webinar covered the practical aspects of preparing samples from FNA for manual IHC in resource limited settings. The interactive webinar was attended by 98 participants from eight SSA countries, many of whom remarked on the high importance and relevance of the topic [17][18][19][20][21][22].…”