Comparative analysis of capture methods for genomic profiling of circulating tumor cells in colorectal cancer.

The genomic profiling of circulating tumor cells (CTCs) in the bloodstream should provide clinically relevant information on therapeutic efficacy and help predict cancer survival. Here, we contrasted the genomic profiles of CTC pools recovered from metastatic colorectal cancer (mCRC) patients using different enrichment strategies (CellSearch, Parsortix, and FACS). Mutations inferred in the CTC pools differed depending on the enrichment strategy and, in all cases, represented a subset of the mutations detected in the matched primary tumor samples. However, the CTC pools from Parsortix, and in part, CellSearch, showed diversity estimates, mutational signatures, and drug-suitability scores remarkably close to those found in matching primary tumor samples. In addition, FACS CTC pools were enriched in apparent sequencing artifacts, leading to much higher genomic diversity estimates. Our results highlight the utility of CTCs to assess the genomic heterogeneity of individual tumors and help clinicians prioritize drugs in mCRC.

CA19-9 capability as predictor of pancreatic cancer resectability in a Spanish cohort.

CA19-9 serum has been suggested as a marker of unresectability but different cut-off levels have been published. A cut-off of 500 U/ml is currently considered in an international consensus as biological criteria of borderline resectable pancreatic adenocarcinoma. To evaluate whether serum CA19-9 threshold of 500 U/ml could be adequate predictor of resectability in pancreatic adenocarcinoma. Multicenter, observational, prospective study performed in Spain including 203 patients diagnosed with pancreatic adenocarcinoma. 43 (21.2%) cases were resectable and 160 (78.8%) unresectable. Among the 176 preoperative CA19-9 available values, 98 (58.3%) were ≤ 500 U/ml and 73 (42.7%) > 500 U/ml. Resectability rate in those patients with CA19-9 ≤ 500 U/ml was 60% while it was found to be 18% when CA19-9 > 500 U/ml. Statistical model to predict resectability based on CA19-9 provide an AUC of 0.6618 (95% CI 0.53-0.83) when only CA19-9 values > 500 U/ml are studied. Serum levels of CA19-9 higher than 500 U/ml are indicative of unresectable disease, however reduced sensitivity and specificity lead to a limited clinical applicability for resectability.