To improve the identification for CTCs with weak or negative CK and diploid CTCs in pancreatic cancer, we combined immune-staining of CK, CD45, DAPI and fluorescence in situ hybridization with the centromere of chromosome 8 (CEP8) probe method. CTCs in 3.75 mL of blood were depleted for CD45 positive cells with anti-CD45 antibodies and identified by combining CK, CD45, DAPI and CEP8 in 61 cases including 22 pancreatic cancers, 3 borderline pancreatic solid pseudopapillary tumors, 6 pancreatic benign tumors, and 30 healthy individuals. We found that enriched cells could be classified into 5 patterns: CK+CD45-DAPI+CEP8=2 (2 hybridization signals), CK+CD45-DAPI+CEP8>2 (>2 hybridization signals), CK-CD45-DAPI+CEP8>2, CK-CD45-DAPI+CEP8=2, and CK+/-CD45+DAPI+CEP8=2 or >2. Among 22 pancreatic cancers, CK+CD45-DAPI+CEP8=2 and CK+CD45-DAPI+CEP8>2 patterns were identified in two cases, and CK-CD45- DAPI+CEP8>2 pattern was identified in 16 cases. CK-CD45-DAPI+CEP8=2 and CK+/-CD45+DAPI+CEP8=2 or >2 patterns were detected in pancreatic cancers, other pancreatic diseases and healthy individuals. Among the five patterns, CK+CD45-DAPI+CEP8=2, CK+CD45-DAPI+CEP8>2 and CK-CD45-DAPI+CEP8>2 were considered as CTCs, while CK-CD45-DAPI+CEP8=2 and CK+/-CD45+DAPI+CEP8=2 or >2 were considered as indeterminate cells. When the cutoff value was set as 2 cells/3.75 mL based on ROC curve, the sensitivity and specificity in the diagnosis of pancreatic cancer was 68.18 and 94.87%, respectively. Dynamically monitoring CTCs changes prior to and after surgery in pancreatic patients revealed that CTCs count decreased in 3 days after surgery, but increased in 10 days after surgery in most patients. During our one and a half year follow-up, CTCs positive patients showed metastasis and worse survival rate.
Keywords: CK; FISH; circulating tumor cells; pancreatic cancer; pattern.
© 2014 UICC.