Abstract LB-148: CTCs positively correlate clinical manifestations in Indian oral cancer patients
Authors: Khandare Jayant , Qayyumi Burhanuddin Nuruddin , Bharde Atul , Aland Gourishankar , Jayant Sreeja , Tripathi Swati , Singh Nitin , Badwe Reecha , D'Souza Alain , Singh Balram , Arora Smriti , Kale Narendra , Vasudevan Aravindan , Prabhash Kumar , Chaturvedi Pankaj 
Published: September 2020

Abstract
Head and neck squamous cell carcinoma is leading cancer in the Indian subcontinent with Oral squamous cell carcinoma (OSCC) as the most frequent subtype. Conventionally OSCC is classified as a locoregional disease and its increased frequency is attributed to lack of good biomarkers compared to other epithelial cancers. At the time of diagnosis, above 50% of cases present the manifestation of advanced-stage disease, and are predisposed to disease failure in spite of appropriate treatment. Thus, early diagnosis of OSCC can significantly reduce the disease burden. Here we describe a novel, regulatory approved method to establish Circulating tumor cells (CTCs) presence in peripheral blood of OSCC Indian patients and its positive correlation with various clinicopathological parameters, suggesting the potential use of CTCs as a significant parameter to stratify oral cancer with respect to the disease advancement. Methods: In a cross-sectional observational study, 230 OSCC patients at the different pathological stage of the disease and treatment mode were enrolled. CTCs were isolated using approved OncoDiscover liquid biopsy technology (Drug controller general of India approved)', platform technology based on immunomagnetic CTC enumeration. CTCs were detected for cytokeratin 18 (CK18 marker) presence and well-defined, DAPI-stained nuclei. Enumerated CTC subsequently analyzed for various clinic-pathological parameters such as pstage, extra-capsular spread (ECS), lymphovascular emboli (LVE), perineural invasion (PNI) and depth of invasion (DOI). CTC cut off values were obtained to differentiate early vs advanced stages with respect to different clinical stages and parameters.Results: CTCs obtained from peripheral blood of OSCC patients correlated positively with the cancer stages (clinical as well as pathological) as well as aggressive pathological features such as presence or absence of ECS, LVE, PNI and DOI. Interestingly, with the presence of aggressive pathological features that often suggest the poor outcome of the disease, we observed a 25-50 % increase in CTC number. On the other hand early stage, treatment naïve patients had a lower number of CTCs. Mean CTC number in advanced-stage patients was 50 % higher than early-stage OSCC patients. Conclusions: Efficient and rapid isolation of CTCs from peripheral blood of OSCC patients using proprietary technology suggested a positive correlation between CTC number and pathological stages of the disease. Considering a positive correlation of CTC number with various pathophysiological features, CTC can be contemplated as a reliable parameter to predict the disease outcome in oral cancer. The consistent presence of CTC across all disease stages also suggests a probable nature of OSCC as a biological systematic disease.
Citation Format: Jayant Khandare, Burhanuddin Nuruddin Qayyumi, Atul Bharde, Gourishankar Aland, Sreeja Jayant, Swati Tripathi, Nitin Singh, Reecha Badwe, Alain D'Souza, Balram Singh, Smriti Arora, Narendra Kale, Aravindan Vasudevan, Kumar Prabhash, Pankaj Chaturvedi. CTCs positively correlate clinical manifestations in Indian oral cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-148.