Gastroenterology Update, September 15, 2011

Plasma MicroRNAs for Early Detection of Pancreatic Cancer

Plasma microRNAs (miRNAs) were effective for distinguishing pancreatic cancer (PCa) from non-PCa (normal + chronic pancreatitis or CP), according to a study published recently in the International Journal of Cancer.

The researchers from the department of gastroenterology at the Changhai Hospital in Shanghai, China, found that the combination of several miRNAs (miR-16, miR-196a, and CA19-9) was more effective for PCa diagnosis. This was especially true in early tumor screening.

For the study, plasma RNAs were extracted from 140 PCa patients, 111 CP patients, and 68 normal controls. In addition, the relative abundances (RAs) of seven miRNAs (miR-16, 21, 155, 181a, 181b, 196a, 210) were measured using real-time polymerase chain reaction and the diagnostic ability of the miRNAs for PCa and correlation with clinical characteristics were analyzed.

“All seven miRNAs were significantly aberrantly up-regulated in the PCa group compared with both the CP and normal groups, between which only four miRNAs (miR-155, 181a, 181b, 196a) were significantly different. Logistic modeling proved that only miR-16 and miR-196a possessed an independent role in discriminating PCa from normal and CP,” the researchers wrote in the study abstract.

“Furthermore, after including serum CA19-9 in the logistic model, the combination of miR-16, miR-196a and CA19-9 was more effective for discriminating PCa from non-PCa (normal + CP) (AUC-ROC, 0.979; sensitivity, 92.0%; specificity, 95.6%), and for discriminating PCa from CP (AUC-ROC, 0.956; sensitivity, 88.4%; specificity, 96.3%) compared with the miRNA panel (miR-16 + miR-196a) or CA19-9 alone. Most significantly, the combination was effective at identification of tumors in stage 1 (85.2%).”

Expression of Certain Protein in Pancreatic Adenocarcinoma Found to be Unfavorable Prognostic Marker

S100A11, a member of S100 protein family, has been shown to be one of the up-regulated proteins that have not been associated with pancreatic carcinoma, according to previously published research from the department of gastroenterology at the Affiliated Hospital of Nantong University in China.

In a newly published study, the research team has found that S100A11 might be a significant tumor marker for pancreatic adenocarcinoma. It might also be an unfavorable predictor for prognosis of patients who have undergone surgical resection, according to the study, which was published in Medical Oncology.

For the newer study, the researchers considered the relation between S100A11 expression and the clinicopathological variables and outcome in patients with pancreatic adenocarcinoma.

The researchers took 78 pairs of specimens of human pancreatic adenocarcinoma tissues and adjacent nontumorous tissues and performed immunohistochemistry analysis for S100A11.

“S100A11 expression in pancreatic adenocarcinoma (62/78) was significantly higher than that in the adjacent nontumorous tissues (19/78) (P=0.000). High expression of S100A11 was associated with the lymph node metastasis and histological differentiation (P=0.003 and 0.004, respectively). Univariate analysis showed that S100A11 expression was associated with poor prognosis (P=0.0000),” the researchers wrote in the study abstract.

“Multivariate analysis using the Cox regression model indicated that age ≥65 years, CA19-9 ≥1,000 U/ml and positive S100A11 were independent prognostic indicators of pancreatic adenocarcinoma (P = 0.002, 0.004 and 0.001, respectively).”

SourcesCombination of Pasma MicroRNAs with Serum CA19-9 for Early Detection of Pancreatic Cancer [International Journal of Cancer]High Expression of S100A11 in Pancreatic Adenocarcinoma is an Unfavorable Prognostic Marker [Medical Oncology]