Comparable Access, Different Outcomes: Breast Cancer Survival Among Syrian Refugees and Turkish Patients in Türkiye

Background: Breast cancer outcomes are influenced by tumor biology, stage at diagnosis, and access to timely care. Refugee populations may experience disparities in cancer outcomes despite formal access to healthcare services. Türkiye hosts the largest population of Syrian refugees globally and provides universal access to oncology care, offering a unique context to examine equity in breast cancer outcomes. Methods: We performed a retrospective cohort study of female patients diagnosed with invasive breast cancer between 2013 and 2022 at two tertiary oncology centers in Gaziantep, Türkiye. Patients were grouped as Syrian refugees or Turkish citizens based on recorded nationality. Baseline clinicopathologic features and stage at diagnosis were compared between groups. Overall survival (OS) was estimated by the Kaplan-Meier method and compared using log-rank tests. Survival analyses were performed overall and stratified by stage category (I-III vs. IV). Cox proportional hazards regression was used to evaluate the association between ethnicity and OS with adjustment for stage and molecular subtype (and other prespecified covariates as appropriate). Treatment delivery patterns (systemic therapy and radiotherapy) were descriptively compared to evaluate access after entry into care. Results: Among 499 patients (150 Syrian refugees; 349 Turkish citizens), Syrian patients were younger at diagnosis and more frequently presented with de novo metastatic disease. In the overall cohort with survival data (n = 430), unadjusted OS differed by ethnicity; however, survival differences were attenuated after stratification by stage. In stage I-III disease, OS did not significantly differ between groups, and in stage IV disease, median OS was comparable between ethnicities. In multivariable analysis adjusting for stage and molecular subtype, ethnicity was not independently associated with OS, whereas stage and molecular subtype remained prognostic. Treatment delivery patterns in both the non-metastatic and metastatic settings were broadly similar between groups. Conclusions: Within a universal healthcare system, the dominant disparity between Syrian refugees and Turkish citizens was more advanced stage at presentation. After accounting for stage and tumor biology, ethnicity itself was not independently associated with overall survival, suggesting that efforts to reduce outcome gaps should prioritize earlier diagnosis and linkage to care.