Article Text
Abstract
Introduction Circulating tumour cells (CTC) disseminate from a tumour into the blood circulation with the potential to form distant metastases, thus making them promising prognostic biomarkers. There is a lack of data exploring the relationship between CTC status and primary tumour size (PTS) of the pelvic mass in epithelial ovarian carcinomas (EOC). This study aimed to examine this relationship in high-grade serous carcinomas (HGSC) and non-HGSC EOC.
Methods Peripheral blood samples were collected from 52 treatment-naive patients (46 HGSC, 6 non-HGSC). A subset underwent ovarian vein sampling during primary cytoreductive surgery (11 HGSC, 6 non-HGSC). Whole blood was enriched using the Parsortix®PR1 system. CTCs were enumerated by immunophenotyping: EpCAMpos/panCytokeratinpos,Hoechstpos,CD45neg. PTS (maximum dimension) was recorded from baseline CT scans. The cut-off for CTC status (positive/negative) was set at 1.
Results In advanced HGSC (III, IV), there was no statistical difference in peripheral CTC count per 7.5mL blood or PTS, although a trend towards higher peripheral CTC count and smaller PTS was observed in stage III versus stage IV. CTCpos HGSC ovarian vein samples had significantly smaller PTS than HGSC ovarian vein CTCnegpatients (p=0.0121). HGSC ovarian vein CTC count also inversely correlated with PTS (r=-0.7356, p=0.0128). Conversely, in non-HGSC, there was a trend towards larger PTS in CTCpos ovarian vein samples compared to CTCneg ovarian vein samples.
Conclusion/Implications To our knowledge, this is the first study exploring the relationship between CTCs and PTS in EOC. The inverse correlation between CTCs and PTS in HGSC likely stems from the extensive peritoneal seeding characteristic of its biology.