Trends in female breast cancer incidence and mortality in adolescents and young adults in Sub-Saharan Africa from 1990 to 2023.

Abstract

e22585 Background: Breast cancer (BC) among adolescent and young adults (AYA), defined as individuals aged 15 to 39 years, is a growing public health concern globally. Sub-Saharan Africa (SSA) has a predominantly young population, yet temporal and regional trends in BC incidence and mortality among AYA women remain poorly characterized. This study analyzes trends in AYA BC incidence and mortality rates in SSA from 1990 to 2023 to guide strategic cancer control planning efforts. Methods: Data on BC incidence and mortality among AYA women in 46 SSA countries were extracted from the 2023 Global Burden of Disease database, representing the most recent available country-level estimates. Age-standardized rates are reported per 100,000 population. Temporal trends in incidence and mortality rates by country and region (Eastern, Western, Central, and Southern) were assessed by calculating estimated annual percentage change (EAPC) with 95% uncertainty intervals (UI). Results: There were an estimated 59,462 new cases of BC among AYA women in SSA in 2023, with an age-standardized incidence rate (ASIR) of 24 (95% UI: 16–32). The incidence of AYA BC increased significantly from 1990 to 2023, with an EAPC of 2.3% (95% UI: 1.8–2.7). All four regions had statistically significant increases in incidence, with the highest in Southern SSA (EAPC: 4.0%, 95% UI: 3.8–4.3) and the lowest in Eastern SSA (EAPC: 1.5%, 95% UI: 1.0–2.1). Thirty-eight of 46 countries had statistically significant increases in AYA BC. São Tomé and Príncipe, Zimbabwe, Cape Verde, and South Africa had the largest increases in incidence, while Central African Republic had the lowest. Four countries (Mozambique, Rwanda, Madagascar, and Tanzania) experienced decreasing incidence between 1990 and 2023. In 2023, there were 24,252 deaths from AYA BC in SSA, with an age-standardized mortality rate (ASMR) of 9.7 (95% UI: 6.7–13). Côte d'Ivoire had the highest ASMR (18, 95% UI: 11–26). Central SSA had the highest ASMR (15, 95% UI: 9.2–21), while Southern SSA had the lowest (5.1, 95% UI: 3.5–6.9) in 2023. The overall ASMR increased by 1.6% (95% UI: 1.2–2.1) from 1990 to 2023. Thirty-five of 46 countries had increased ASMR, 5 countries had decreased ASMR, and 6 countries had no statistically significant change in ASMR. Conclusions: The rising burden of AYA BC in SSA is particularly concerning given the region’s high BC mortality rates. Regional variations in the incidence and mortality of AYA BC were also observed, underscoring the need for further cancer epidemiology research dedicated to SSA. These findings may inform cancer policy, public health interventions, and resource allocation, highlighting the needs of the AYA population. Future studies should explore modifiable risk factors contributing to the rising incidence of AYA BC in SSA and health systems efforts to improve access to care for patients in the region.