biostudies-literatureLeung YYJanet D. Cottrelle FoundationAlberta Precision LaboratoriesCancer Research SocietyVGH and UBC Hospital FoundationGynecologic Cancer Initiative at the University of British ColumbiaCure our Ovarian CancerBC Cancer FoundationNCI NIH HHSManagement Office at APL NASAOvarian Cancer Canadae74https://www.ebi.ac.uk/biostudies/studies/S-EPMC12426737biostudies-literatureUnknown36(5)<h4>Objective</h4>With the development of novel antibody-drug conjugates (ADCs), folate receptor alpha (FOLR1) is a promising therapeutic target for the treatment of platinum-resistant tubo-ovarian carcinomas. The main aims of this study were to assess FOLR1 protein expression in a large cohort of ovarian carcinoma histotypes. To inform future clinical trial design we identified molecular correlates of FOLR1 expression in low-grade serous carcinoma (LGSC).<h4>Methods</h4>One thousand five hundred forty-seven ovarian carcinoma samples from 5 different Canadian cohorts were successfully evaluated by immunohistochemistry for FOLR1 expression using the PS2+ system. Statistical analyses with clinicopathological parameters, LGSC molecular subtypes, and overall survival (OS) were performed.<h4>ReJournal of gynecologic oncologyFOLR1 as a therapeutic target in platinum-resistant ovarian carcinoma: unique expression patterns across ovarian carcinoma histotypes and molecular subtypes of low-grade serous carcinoma.PMC12426737RS21-609P30 CA118100RS21-608Hoenisch JTinker AVBittner MKobel MCarey MSLlaurado-Fernandez MKim HWong NKYSchmid JCameron ADa-Anoy AGhesquiere CCook LCGaillard SLeung YYDhillion GDawson AfalseFOLR1 as a therapeutic target in platinum-resistant ovarian carcinoma: unique expression patterns across ovarian carcinoma histotypes and molecular subtypes of low-grade serous carcinoma.<h4>Objective</h4>With the development of novel antibody-drug conjugates (ADCs), folate receptor alpha (FOLR1) is a promising therapeutic target for the treatment of platinum-resistant tubo-ovarian carcinomas. The main aims of this study were to assess FOLR1 protein expression in a large cohort of ovarian carcinoma histotypes. To inform future clinical trial design we identified molecular correlates of FOLR1 expression in low-grade serous carcinoma (LGSC).<h4>Methods</h4>One thousand five hundred forty-seven ovarian carcinoma samples from 5 different Canadian cohorts were successfully evaluated by immunohistochemistry for FOLR1 expression using the PS2+ system. Statistical analyses with clinicopathological parameters, LGSC molecular subtypes, and overall survival (OS) were performed.<h4>Re2025-01-01T00:00:00Z2025 Sep2026-04-08T18:37:06.949Z2026-04-08T10:01:49.784ZS-EPMC124267374015091010.3802/jgo.2025.36.e74