Abstract INTRODUCTION: The protracted Syrian conflict has forcibly displaced more than half the pre-conflict population of 22 million people with 6.7 million IDPs (internally displaced people.) 80% of IDPs are women and children. Given a lack of humanitarian funding for oncology services, NGOs like the Syrian-American Medical Society (SAMS), have used private funding to establish oncology services. We sought to explore differences in breast cancer diagnosis and treatment among IDPs and host populations in SAMS oncology centre in Idlib governorate. METHODS: Charts of women seen diagnosed with breast cancer at the SAMS Oncology Centre in Idlib governorate between March 2018 and February 2021 were reviewed. Clinicopathologic data was extracted, and non-parametric statistical analyses were performed to compare citizens vs. those who were displaced. RESULTS: Data for 188 patients were available; for 108/188 (57%) details of IDP versus host status was available. 61/108 (56%) were IDPs, 47 (44%) were host. The median age at diagnosis was similar between citizens and those who were displaced. Further, the clinicopathologic features and treatment between these two groups were similar. The time between onset of symptoms and diagnosis was imilar between the host population and IDPs (median 125.5 days vs. 77 days, respectfully, p=0.255), although there was a trend towards a shorter time from diagnosis to initiation of treatment for IDPs (median 19 days vs. 14 days, p=0.051). CONCLUSION: From this cohort study, it is notable that there were no significant differences in the tumor size, node positivity or grade at diagnosis. Further, although IDPs are usually considered to have more challenging access to healthcare services compared to host populations, it was notable that there was no significant difference between the time of onset of symptoms to diagnosis between the two groups, and a trend towards a shorter time to treatment. Although this may be related to the relatively small sample size, it may also reflect other commitments of host populations (e.g., employment) that may delay care, or the work of humanitarian organizations in reaching displaced populations. Further, given that in northwest Syria, more than 65% of the 4-4.6 million people in the area are IDPs, access to care between the two groups may be similar. Further work is required to explore this. Table. Citation Format: Anees Chagpar, Aula Abbara, Alaa Alshemali, Fares Alahdab, Moahmed Hamze, Bassel Attassi, Jude Alawa, Sydney Cech, Lawrence Tang, Kaveh Khoshnood. BREAST CANCER DIAGNOSIS AND TREATMENT AMONG DISPLACED AND HOST POPULATIONS IN NORTH-WEST SYRIA [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-10-11.