Abstract: PNFLBA-17
Sources of Funding: None

Introduction

Circulating tumor cell (CTC) is reported in several studies as a promising predictor of survival or treatment response. However, CTC detection by using immunohistochemical techniques some limitations, such as dead cancer cells could be detected, insufficient sensitivity, or inability to detect epithelial-mesenchymal transformation (EMT). OBP-1101 is a novel adenovirus-derived detection marker for cancer cells. Green Fluorescent Protein (GFP) protein gene expression is controlled by telomerase promoter in OBP-1101 and might be resolve above-mentioned problems.

Methods

After IRB approval, 15 ml blood samples were collected from 49 patients with prostate cancer at Kobe University Hospital. Detection of CTC using OBP-1011 was performed and these results were compared with patient demographics. Clinical stage, Gleason score, PSA, NCCN risk classification were analyzed whether they correlate with GFP positivities. In addition, results of immunohistochemical staining using EpCAM antibody and PSMA antibody were compared with GFP positivities.

Results

GFP positive CTC was detected in 26 cases (53.1%). EpCAM positive CTC was detected in 28 cases (57.1%). Among 28 EpCAM positive cases, PSMA positive CTCs were detected in 25 cases (89.3%). On the other hand, PSMA positive CTCs were detected only in 4 cases (8.2%). None of the Clinical stage, Gleason score, PSA, risk classification correlated with GFP positivity or EpCAM positivity.

Conclusions

The CTCs detected by using OBP-1101 could have different characteristics from those detected by using epithelial markers. These characteristics to detect EMT might be markers of worse clinical outcomes and change clinical decision making.

Funding

None