Background: Population-based cancer survival is a core indicator of health system performance and equity yet remains poorly characterised in many low- and middle income countries and Small Island Developing States (SIDS). In Seychelles, breast cancer is the most common cancer among women and a leading cause of cancer-related mortality. Civil registry and national cancer registry data over a period of a decade (2014 – 2024) indicate a high and fluctuating incidence, persistently high mortality, and a substantial burden of late-stage diagnosis.
However, survival outcomes have not previously been quantified limiting the ability to evaluate the effectiveness of breast cancer diagnosis and early detection, assess performance of treatment services, identify inequities in cancer care by age, stage and geographical location, and benchmark national performance against international standards.
Objectives: This study aims to estimate population-based breast cancer incidence, mortality and survival rates among Seychellois women and to identify disparities in outcomes by key demographic and clinical characteristics.
Methods: This is a retrospective, population-based cohort study including all
Seychellois women diagnosed with breast cancer between 2014 and 2019 and followed up to 31 December 2024. Data were derived from multiple sources, comprising the Civil Registration and Vital Statistics (CRVS), Seychelles National Cancer Registry (SNCR) and patient hospital-based medical records. We calculated age-standardised values for incidence and mortality rates for breast cancer using the WHO 2000-2024 standard population. We define survival time from date of diagnosis to death or last follow-up. We will use Kaplan–Meier methods to estimate 2- and 5-year survival probabilities, with log-rank tests comparing survival across age groups, stage at diagnosis, and geographical residence. Multivariable Cox proportional hazards regression will assess the independent association of age, stage, and geography with mortality risk.
Results: Final survival estimates will be available by the time of the conference.
Age-standardised incidence rates varied over the study period, initially declining from 75/100,000 in 2014 to 38/100,000 in 2017 and the rising and plateauing to an average of 63/100,000 between 2018 and 2024. Age-standardised mortality rates fluctuated considerably, with the lowest rates of 10/100,000 in 2020 to the highest of 30/100,000 in 2016, 2018 and 2021. Over most of the study period more than half (52-64%) of women were diagnosed at stages III and IV, except between 2017 and 2020  when  only about a third (36%) were diagnosed in these stages. Incidence and mortality rates varied by age and geographic location, although no specific pattern was noted. These patterns suggest potential inequities in breast cancer survival outcomes that will be further elucidated by the forthcoming survival analyses.
Conclusions / Implications: This study will deliver the first population-based breast cancer survival estimates for Seychelles, with a focus on age-, stage-, and geography-related disparities. By integrating survival outcomes with established national trends in incidence, mortality, and stage at diagnosis, the findings will provide critical evidence to inform cancer control planning, resource allocation, and early detection strategies. The results will be directly relevant to policymakers in Seychelles and other SIDS facing similar constraints in cancer surveillance and service delivery.