Diagnosis of ovarian adenocarcinomas is based on histopathologic analysis of tumor tissue obtained by invasive biopsies. However, invasive biopsies are associated with procedural expenses, sequelae, and risk of complications. Though immunocytochemistry (ICC) profiling of circulating tumor cells (CTCs, defined as EpCAM+, panCK+, CD45-) has been previously considered for diagnosis in some cancers, the attempts have been unsuccessful. We used a novel approach for enrichment of sufficient viable CTCs that permit meaningful ICC profiling for diagnosis of ovarian cancers in suspected cases. We obtained 15 mL of venous blood draw from 248 patients with confirmed diagnosis of ovarian cancer. PMBCs were isolated by centrifugation. CTCs were enriched from PBMC using an epigenetically acting enrichment process that is lethal towards normal (nonmalignant) cells but confers survival privilege on apoptosis-resistant CTCs. Harvested CTCs were confirmed by immunostaining for EpCAM and pan-CK. Deep ICC profiling of these CTCs was performed with organ-specific markers CA125 and WT1 as well as P63 as a nonspecific marker. Viable CTCs could be obtained from 225 samples (90.7%) out of 248. Among the 100 samples characterized by deep ICC profiling, 70 samples (70%) were positive for CA125 and WT1. None of the samples was positive for P63. Our results show that ICC-based characterization of CTCs can provide necessary diagnostic information noninvasively to substitute conventional procedures dependent on tissue extraction.

Citation Format: Dadasaheb B. Akolkar, Darshana Patil, Revati Patil, Pradip Devhare, Pradip Fulmali, Pooja Fulmali, Shoeb Patel, Navin Srivastava, Vineet Datta, Cynthe Sime, Ajay Srinivasan, Rajan Datar. Noninvasive liquid biopsies for guideline-compliant diagnostic assessment in ovarian cancers [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B16.