Abstract Breast cancer diagnosis and death has risen in low to middle income countries (LMIC) in the past 20 years. Early detection, diagnosis and treatment in the LMIC setting are thought to impact morbidity and survivorship. The population of South Florida is composed of a significant portion of Afro-Caribbean immigrants from LMICs. We compared a cohort of recent Haitian immigrants with residents in Haiti who had a diagnosis of breast cancer to evaluate the effects of geographical location on presentation, treatment and outcomes. Methods: Retrospective cohort study. Participants were Haitian females with breast cancer that were living in Miami and presented to the University of Miami/Jackson Memorial Hospital (UM/JMH) between 2008 and 2014 and patients living in Haiti and presented to the Breast Cancer Treatment program at the Hospital Bernard Mevs Project Medishare (HBMPM) from 2013 to 2015 with a new diagnosis or who had been diagnosed as far back as 2008 and were presenting for continuation of care. The main outcome was the relationship between cohort location and breast cancer characteristics and cancer–specific survival by log-rank. Cox proportional hazards regression was used to compare breast cancer–specific survival overall and analyzed by stage and other significant explanatory factors. Results: 102 patients from UM/JMH and 94 patients from HBMPM were included in the analysis. The cohort in Haiti presented after longer median duration of symptoms (20 vs 3 months, p<0.001) and more advanced stage (31% Vs 20% with locally advance and 27% vs 19% with metastatic disease). The median age of diagnosis was 55 years in Miami compared to 50 years in Haiti (p=0.03). In Miami all patients had estrogen receptor (ER) and her-2 status ascertained at diagnosis, whereas only 52% and 27% of the Haitian cohort had them. Tumor characteristics in Miami vs Haiti in patients with reported status: ER + 74% (n=102) vs 55% (n=49), p=0.02, her-2+ 20% (n=102) vs 28% (n=25), p=0.36, triple negative 27% (n=102) vs 28% (n=25),p=0.49. Treatment modalities and censoring was available for all the patients in Miami and 72 patients in Haiti. In Haiti, radiation therapy was not widely available compared to Miami. Once patients had known ER and her-2 status, there was no difference in treatment with hormonal therapy (p=0.97) but none of the patients in Haiti received her-2 directed therapy (p<0.001). 50% of the patients with unknown ER status in Haiti received Tamoxifen. Twice as many Haitian women died after a median follow-up of 23 months (12% vs 24%), with median survival of 53 months for Haitians in Haiti (not reached for Miami cohort). Breast cancer specific survival was significantly different in the two cohorts (p<0.000). After exploratory analysis, the risk of death was higher for Haitians in Haiti than Haitians in Miami [HR 3.13 (CI 1.50-6.51)] and was higher for more advanced disease [HR 2.58 (CI 1.67-3.99)]. No other variable or interaction reached statistical significance in our model. Conclusion: Haitian women diagnosed with breast cancer in Haiti experience a significantly worse outcome than Haitians living in Miami that appears to be related to a more advanced stage, younger age, more ER negative tumors and lack of timely effective treatments including restricted access to trastuzumab and radiation. In addition there is a difference in the age of breast cancer onset (Caucasian 62, African American 58, Haitian American 55, Haitian 50) and ER positivity (Caucasian 70%, African American 48%, Haitian American 74%, Haitian 55%) depending on race and ethnic group that raises the question of whether there are disparities within subgroups of women of African origin who have breast cancer. Confounding epigenetic-related variables may impact survival and they need further exploration in these populations. Citation Format: Alexandra Gomez, Vincent DeGennaro, Jr., Sophia George, Estefania Santamaria, Gustavo Westin, Gabriel Dieudina, Judith Hurley. Presentation, treatment, and outcomes of Haitian women with breast cancer in Miami and Haiti: Disparities in breast cancer. A retrospective cohort study. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C55.