An observational study in High Grade Serous Ovarian Cancer and Folate Receptor Alpha Positive, sponsored by Hellenic Cooperative Oncology Group. Recruiting at 1 site in Greece. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by Hellenic Cooperative Oncology Group · Observational
This is a single-country, retrospective, observational biomarker study conducted in Greece to evaluate Folate Receptor Alpha (FRα) expression in patients with high-grade serous ovarian, fallopian tube, and primary peritoneal cancer at the time of diagnosis. Approximately 200 eligible female patients (≥18 years) diagnosed between 1 January 2001 and 30 July 2025 will be included from around 15 clinical sites affiliated with the Hellenic Cooperative Oncology Group.
Historically collected Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples stored in the Hellenic Cooperative Oncology Group biobank will be analyzed centrally using the Ventana FOLR1 RxDx assay to determine FRα expression. Only samples collected at initial diagnosis will be included; relapse samples will be excluded.
The primary objective is to assess the prevalence of FRα-positive status, defined as ≥75% viable tumor cells with moderate (2+) and/or strong (3+) membrane staining. Secondary objectives include evaluation of intra-tumoral heterogeneity, concordance between primary and metastatic lesions, prevalence of lower FRα expression levels, and associations between FRα expression and clinical characteristics, BRCA/HRD status, progression-free survival (PFS), and overall survival (OS).
All analyses will be descriptive, with additional exploratory statistical methods including chi-square tests, Cohen's kappa, correlation analyses, ANOVA, Kaplan-Meier survival analysis, and Cox proportional hazards models. Data will be retrospectively collected from the Hellenic Cooperative Oncology Group registry and medical records and entered into a secure REDCap eCRF system.
2,757 studies on the registry are indexed under Ovarian Neoplasms; 735 are open to participants now.
This study's planned enrollment of 200 is close to the median of 200 across 537 observational studies indexed under Ovarian Neoplasms.
Browse Ovarian Neoplasms studies →Hellenic Cooperative Oncology Group is the lead sponsor of 60 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population will consist of approximately 200 female patients aged ≥18 years with histologically confirmed high-grade serous epithelial ovarian, fallopian tube, or primary peritoneal cancer. Tumor tissue samples will be retrospectively collected from the HeCOG biobank and affiliated clinical sites between January 1, 2001 and July 30, 2025. Only samples with adequate tissue quality for immunohistochemical analysis will be included. Cases with non-epithelial ovarian tumors or non-high-grade serous histologies (e.g., endometrioid, mucinous, or clear cell carcinoma) will be excluded.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
This cohort includes approximately 200 eligible female patients aged 18 years or older diagnosed with high-grade serous ovarian, fallopian tube, or primary peritoneal cancer between 1 January 2001 and 30 July 2025. Patients are identified retrospectively from approximately 15 clinical sites in Greece affiliated with the Hellenic Cooperative Oncology Group. Historically collected Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples obtained at the time of initial diagnosis and stored in the Hellenic Cooperative Oncology Group biobank will be analyzed centrally using the Ventana FOLR1 RxDx assay to determine Folate Receptor Alpha (FRα) expression.
FRα-Positive Status
Assessment of FRα-positive status at diagnosis, defined as ≥75% of viable tumor cells demonstrating moderate (2+) and/or strong (3+) membrane staining by immunohistochemistry.
Time frame: Baseline
FRα expression
Qualitative assessment of FRα expression in tumor samples at diagnosis based on immunohistochemical staining intensity (2+ and 3+) and distribution across viable tumor cells.
Time frame: Baseline
FRα expression levels
Assessment of FRα expression levels categorized according to the percentage of viable tumor cells showing moderate (2+) and/or strong (3+) membrane staining, grouped into predefined categories (0-24%, 25-49%, 50-74%, and ≥75%).
Time frame: Baseline
FRα expression levels and PFS/OS
Evaluation of the association between FRα expression levels (0-24%, 25-49%, 50-74%, ≥75%) and clinical outcomes, including progression-free survival (PFS) and overall survival (OS).
Time frame: From initiation of first-line treatment until disease progression, death, or last follow-up, whichever occurs first (for PFS); and until death from any cause or last follow-up (for OS), assessed up to 120 months
FRα expression score
Quantitative assessment of FRα expression as a continuous variable, defined as the percentage of viable tumor cells demonstrating moderate (2+) and/or strong (3+) membrane staining.
Time frame: Baseline
FRα expression score and BRCA/HRD status
Assessment of the association between FRα expression score and tumor molecular status, including BRCA mutation status and homologous recombination deficiency (HRD), in samples obtained at diagnosis.
Time frame: Baseline
Plan to share: No
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Hellenic Cooperative Oncology Group