Detection of circulating tumor cells in patients with pancreatic cancer: a preliminary result

Background/ Purpose. It has been reported that circulating tumor cells (CTCs) can be used to predict survival in metastatic breast cancer. In this preliminary study, we examined the level of CTCs in pancreatic cancer ( PC) patients to elucidate whether we could predict survival in PC. Methods. The eligible subjects, at Tokyo Medical University Hospital, were 26 patients with PC, 11 with chronic pancreatitis, and 10 healthy volunteers. Three PC patients underwent surgery, 18 patients ( who were stage IV) were treated with gemcitabine ( GEM), and 5 patients received best supportive care (BSC). Results. The CTC count was 1/7.5 ml blood or higher (defined as positive) in 11 of the 26 patients (42%; mean, 16.9/7.5 ml blood; range, 1-105/7.5 ml blood). Gemcitabine was administered to 6 of the 11 CTC-positive patients (3.8 courses on average). The treatment was continued for more than three courses in 2 patients, in both of whom the CTC count was only 1/7.5 ml blood. Operation was performed in 1 of the 11 CTC positive patients. The remaining 4 patients of the 11 CTC-positive patients received only BSC. CTC was negative in 15 patients with PC ( stage II, 1; stage III, 1; stage IVa, 7; and stage IVb, 6) and in the subjects with benign conditions. The median survival times (MSTs) of the CTC-positive and -negative patients were 110.5 and 375.8 days ( P < 0.001). When the analysis was limited to the 14 stage-IVb patients, the MSTs of the CTC-positive and -negative patients were 52.5 and 308.3 days ( P < 0.01). Conclusions. The present study demonstrated that the detection of CTCs in peripheral blood may be useful to predict prognosis in patients with PC.