Epidemiology, diagnosis, and staging of esophageal cancer

Construction of a Nine-MicroRNA-Based Signature to Predict the Overall Survival of Esophageal Cancer Patients

BACKGROUND

Esophageal cancer (EC) is a common malignant tumor. MicroRNAs (miRNAs) play a key role in the occurrence and metastasis and are closely related to the prognosis of EC. Therefore, it will provide a powerful tool to predict the overall survival (OS) of EC patients based on miRNAs expression in EC tissues and blood samples.

METHODS

Five independent databases, TCGA, GSE106817, GSE113486, GSE122497, and GSE112264, were used to construct nine-miRna signature and nomograms for prognosis. The bioinformatics analysis was used to predict the enrichment pathways of targets.

RESULTS

A total of 132 overexpressed miRNAs and 23 suppressed miRNAs showed significant differential expression in both EC serum and tissue samples compared with normal samples. We also showed that nine miRNAs were related to the prognosis of EC. Higher levels of miR-15a-5p, miR-92a-3p, miR-92a-1-5p, miR-590-5p, miR-324-5p, miR-25-3p, miR-181b-5p, miR-421, and miR-93-5p were correlated to the shorter survival time in patients with EC. In addition, we constructed a risk prediction model based on the levels of nine differentially expressed miRNAs (DEMs) and found that the OS time of EC patients with high-risk score was shorter than that of EC patients with low-risk score. Furthermore, our results showed that the risk prediction scores of EC samples were higher than those of normal samples. Finally, the area under the curve (AUC) was used to analyze the risk characteristics of EC and normal controls. By calculating the AUC and the calibration curve, the RNA signature showed a good performance. Bioinformatics analysis showed that nine DEMs were associated with several crucial signaling, including p53, FoxO, PI3K-Akt, HIF-1, and TORC1 signaling. Finally, 14 messenger RNAs (mRNAs) were identified as hub targets of nine miRNAs, including BTRC, SIAH1, RNF138, CDC27, NEDD4L, MKRN1, RLIM, FBXO11, RNF34, MYLIP, FBXW7, RNF4, UBE3C, and RNF111. TCGA dataset validation showed that these hub targets were significantly differently expressed in EC tissues compared with normal samples.

CONCLUSION

We have constructed maps and nomograms of nine-miRna risk signals associated with EC prognosis. Bioinformatics analysis revealed that nine DEMs were associated with several crucial signaling, including p53, FoxO, PI3K-Akt, HIF-1, and TORC1 signaling, in EC. We think that this study will provide clinicians with an effective decision-making tool.

Preoperative survivin mRNA detection in peripheral blood is an independent predictor of outcome in esophageal carcinoma

AIMS

Survivin (SVV) mRNA expression levels in peripheral blood of patients with gastrointestinal malignancies change significantly during the course of treatment. We wanted to scrutinize these findings in patients with esophageal carcinoma and furthermore evaluate whether the detection of mRNA and the change in detecting ability have an association with overall survival.

MATERIALS & METHODS

Whole blood was drawn 1 day pre- and 10 days post-operatively from 62 patients with esophageal carcinoma. Tumor cells were enriched from whole blood by density-gradient centrifugation prior to extraction of total cellular RNA and subsequent direct quantitative reverse transcriptase-PCR assays.

RESULTS

SVV was detectable in 48 out of 62 patients (77%). Stepwise multivariate Cox linear regression models demonstrated a significant and independent association of measured SVV with overall survival (6.6 exp[b]; 95% CI: 1.97-22.12; p = 0.002). Increased SVV levels after the operation were linked to shorter overall survival (p = 0.04).

CONCLUSION

Preoperative SVV expression levels appear to be associated with overall survival in patients with esophageal cancers. Increasing levels could potentially indicate a higher risk for shorter overall survival and therefore demand adapted treatment modalities.

Methylated DAPK and APC promoter DNA detection in peripheral blood is significantly associated with apparent residual tumor and outcome

BACKGROUND

Death-associated protein kinase (DAPK) and adenomatous polyposis coli gene (APC) have been recently shown to be associated with outcome in patients with esophageal carcinoma, especially adenocarcinoma. We wanted to validate the correlation of these two markers with outcome by detecting methylated DNA sequences in peripheral blood.

METHODS

Circulating cell-free DNA extracted from blood plasma of 59 patients with esophageal cancer was analyzed before and after surgical resection by quantitative real-time methylation-specific RT-PCR (TaqMan) assays.

RESULTS

Thirty-six of 59 patients (61.0%) with esophageal cancer had detectable levels of methylated DAPK or APC promoter DNA and preoperative detection was significantly associated with an unfavorable prognosis as revealed by multivariate Cox proportional hazards regression analysis [Exp(b) = 4.578; P = 0.01]. The combination of both markers significantly increased sensitivity and specificity for discriminating between short (<2.5 years) and long survivors (P = 0.04, ROC curve analysis). Postoperative APC detection was significantly different if residual tumor was apparent (P = 0.03).

CONCLUSIONS

Preoperative measurement of methylated DAPK and APC promoter DNA in peripheral blood may contribute to better estimate postoperative survival chances of patients with esophageal carcinoma, especially adenocarcinoma. The postoperative detection of methylated APC in peripheral blood might provide crucial information on apparent residual tumor and might be used as a "molecular" R0-Marker in addition to the pathologic examination.

Nissen fundoplication has a vagolytic effect on the lower esophageal sphincter

BACKGROUND

Laparoscopic Nissen fundoplication is an increasingly utilized option for the treatment of gastroesophageal reflux disease (GERD). However, many questions remain as to the mechanism by which this operation prevents GERD in those without hiatal hernias or incompetent lower esophageal sphincters (LES). It is known that these patients experience reflux due to excess transient lower esophageal sphincter relaxations (TLESR), inappropriate and short-lived relaxation of the LES and crural diaphragm. The purpose of this study was to determine if Nissen fundoplication affects the neural pathways involved in the TLESR reflex.

METHODS

Five dogs were anesthetized and intubated. Both vagal nerves and the right phrenic nerve were isolated. A continuous water perfusion manometric catheter was situated at the LES. The nerves were then electrically stimulated and the resultant pressure at the LES measured at baseline, and during and after an open Nissen fundoplication.

RESULTS

The mean LES pressures before dissection, after esophago-gastric mobilization, and after fundoplication were 47 +/- 13 mmHg, 21 +/- 9 mmHg, and 14 +/- 4 mmHg, respectively. All differences were significant. There was no change noted in LES pressure with stimulation of either or both of the phrenic nerves without concomitant vagal stimulation.

CONCLUSION

Nissen fundoplication may prevent GERD in those without a hiatal hernia or incompetent LES by disrupting the efferent vagal fibers to the LES. Such fibers mediate TLESR which are responsible for GERD in these patients.