EPV178/#166 Identification of biomarkers and targets for the immunotherapy of patients with clear cell ovarian cancer: a systematic literature review

Objectives Clear cell ovarian cancer (OC) is a rare type of epithelial cancer commonly associated with endometriosis. Biomarkers for the early detection of clear cell OC and targets for immunotherapy both have the potential to improve outcomes for patients. Our review aims to evaluate the existing literature to determine whether any antigens could fulfil this remit. Methods A literature search was carried out to identify biomarkers using the following free text and MeSH terms: (‘clear cell’ OR ‘clear-cell’) AND (ovar*) AND (cancer* OR malignan* OR tumour* OR tumor* OR neoplasm* OR carcinoma*) AND (biomarker* OR protein* OR antigen* OR target*) AND (immuno* OR treat* OR diagnosis OR detect*). Inclusion criteria was primary research articles on human adult females including at least 10 clear cell carcinoma patients. Exclusion criteria included reviews; case series and reports paediatrics; animal; cell line; clear cell recurrence; metastasis from another primary cancer and prognostic biomarker studies. Results 6,750 articles were identified from searching multiple databases from 1904–2021. Duplicates were removed (n=2076) and all texts were screened against the inclusion and exclusion criteria which identified 24 gene transcripts/proteins and 2 antibodies within 32 articles identifying single or multiple targets. Conclusions Current findings suggest there are possible candidates to act as biomarkers and targets for immunotherapy. The biomarkers show a sensitivity and specificity up to 100% in single and multiple targets when differentiating clear cell from other subtypes of epithelial OC. With further analysis this will show the potential of these biomarkers to act as targets for immunotherapy.