Clinical outcomes disparities in prostate cancer in the Caribbean: Results from 504 patients from the Martinique cohort.

314 Background: Ethnic and geographic disparities in cancer care access is an issue. French West Indies has one of the world highest incidence of prostate cancer (PC) related to African ancestry in indigenous population and specific environmental carcinogens. The HOXB13 X285K germline mutation is linked to strong family risk and poor prognosis in men with PC. The HOXB13 study enrolled prospectively patients diagnosed with PC in order to determine the prevalence of HOXB13 X285K germline mutation in Martinique. We reported here clinical data from all the cohort. Methods: Patients with a history of PC were proposed to participate to this single center study. Germline HOXB13 X285K mutation screening was performed by sequencing germline DNA according to the Sanger method. We reported clinical-pathological features and outcomes from medical reports from patients enrolled. Progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Results: We reported a cohort from 504 patients diagnosed with PC between 1999 and 2024 in the unique institution of cancer care in Martinique. The prevalence of HOXB13 X285K germline mutation was 0.99% (5/504) in our cohort, higher than the rate of 0.01% in all comers previously reported. Median age was 63.5 years (36-91). A PC family history of 1st or 2nd degree was found in 33% (166/504). Median BMI was 25 kg/m² and was ≥30 kg/m² in 7.5 %. Risk assessment according to D’Amico was low, intermediate, and high in 11.7%, 35.3%, and 52% respectively. Out of 504 patients, 61 had d e novo metastatic PC (12.1%). The Gleason score was 6, 7, 8-10 in respectively 25%, 49.2%, and 24.2%. Concerning treatment of localized cancer, 44.2% received surgery (R1 in 34%), 47% radiotherapy, 39% hormonotherapy, 8.8% active surveillance, 5.2% brachytherapy and 0.2% HIFU. After local treatment, 34.5% relapsed with median PFS of 3.5 years. Median time between pathology results and therapy initiation was about 5 months (0-4030 days).With median follow up of 5.3 years (2 months-26 years), 42 patients were dead at the time of analyses, median OS was not reached. Conclusions: We reported data from a large homogenous cohort of PC from diversity. Indigenous population from Caribbean Island is underrepresented in clinical trials. However, this population seems to be diagnosed at a younger age, have a longer time from diagnosis to initiation of treatment, a lower access to clinical trials, and an adverse outcome than those diagnosed in the rest of mainland France addressing the disparities in cancer care access. The higher incidence of HOXB13 X285K germline mutations in this population may explain the aggressive profile. To note, this germline mutation was found 100 times higher in local population with PC than in general population (around 0.01%).