Overexpression of CrkL as a novel biomarker for poor prognosis in gastric cancer.

BACKGROUND: The signaling adapter protein CrkL plays vital roles in multiple cancers. However, the expression pattern of CrkL protein and its clinical significance have not been well characterized in human gastric cancer (GC) so far. OBJECTIVE: To investigate the association of tissue-based CrkL protein expression level with the clinicopathological characteristics and prognosis of GC patients. METHODS: The expression level of CrkL protein in 380 GC patients was analyzed by immunohistochemistry. The associations of CrkL protein expression level with clinicopathologicalal characteristics and clinical outcome were evaluated. RESULTS: Compared with the matched adjacent non-tumor tissues, CrkL protein expression level was significantly up-regulated in tumor tissues. In addition, there was a positive correlation between CrkL and Ki67 expression levels in GC patients. An elevated CrkL level statistically correlated with aggressive clinicopathologicalal characteristics, such as larger tumor size, deeper local invasion, more lymph node metastasis, advanced TNM stage, and poorer prognosis. Notably, multivariate analysis identified tissue-based CrkL level as an independent predictor for the unfavorable prognosis of GC. CONCLUSIONS: These results indicate that CrkL protein may serve as a novel prognostic biomarker in GC.

miR-126: An indicator of poor prognosis and recurrence in histologically lymph node-negative gastric cancer.

BACKGROUND: Few biomarkers are available for the prediction of prognosis and recurrence in lymph node (LN)-negative gastric cancer (GC) currently. miR-126 functions as a tumor suppressor in GC, however, its clinical significance in LN-negative GC remains unknown. AIM: To investigate the associations of tissue miR-126 level with the clinicopathological characteristics and clinical outcome of LN-negative GC patients. METHODS: Quantitative real-time polymerase chain reaction was performed to examine the tissue miR-126 level in 315 LN-negative GC patients who underwent curative gastrectomy with D2 lymphadenectomy. The associations of tissue miR-126 level with clinicopathological characteristics and clinical outcome were evaluated. RESULTS: Compared with matched adjacent non-tumor tissues, miR-126 expression was significantly down-regulated in tumor tissues. A reduced tissue miR-126 level statistically correlated with aggressive clinicopathological characteristics, including larger tumor size, deeper local invasion, and poorer prognosis. Notably, multivariate analysis identified advanced T stage and low miR-126 level as independent predictors of the unfavorable prognosis and recurrence of LN-negative GC. CONCLUSIONS: These results indicate for the first time that advanced T stage and low miR-126 level are predictors of unfavorable prognosis and recurrence in LN-negative GC patients. These parameters should be taken into account to stratify patients for adjuvant therapy and close follow-up.

Serum miR-126 level combined with multi- detector computed tomography in the preoperative prediction of lymph node metastasis of gastric cancer.

BACKGROUND: Predicting lymph node metastasis (LNM) accurately is vital to design optimal treatment strategies preoperatively for gastric cancer (GC) patients. However, conventional tumor biomarkers and imaging techniques are not sufficient to predict LNM before surgery. miR-126 has been reported to play important roles in tumor metastasis which may represent a novel tumor biomarker. OBJECTIVE: To assess the utility of the combination of serum miR-126 and multi-detector computed tomography (MDCT) in predicting LNM preoperatively in GC. METHODS: Quantitative real-time polymerase chain reaction was performed to examine the serum miR-126 expression levels in 338 GC patients. MDCT was also performed. The cut-off value of preoperative serum miR-126 level for LNM was determined by receiver characteristic curve (ROC) analysis. Logistic regression analysis was used to determine independent predictors for LNM. RESULTS: The serum miR-126 levels of GC patients with LNM were significantly lower compared with those without LNM (p< 0.05). In addition, the later the N stage was, the lower the serum miR-126 level was in GC patients (p< 0.05). With a cut-off value of 63.4, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of serum miR-126 for predicating LNM were 83.2%, 79.0%, 81.9%, 90.4% and 66.4%, respectively. The combination of serum miR-126 level and MDCT increased the accuracy of MDCT prediction for LNM from 69.2% to 86.7%. Serum miR-126 was an independent predictor for LNM. CONCLUSIONS: These results indicate for the first time that the combination of serum miR-126 and MDCT is useful for the prediction of LNM in GC.

Down-regulated serum miR-126 is associated with aggressive progression and poor prognosis of gastric cancer.

BACKGROUND: miR-126 functions as a tumor suppressor in gastric cancer (GC), however, the clinical significance of serum miR-126 in GC remains unclear. OBJECTIVE: To investigate the associations of serum miR-126 level with the clinicopathological characteristics and prognosis of GC patients. METHODS: Quantitative real-time polymerase chain reaction was performed to examine the expression levels of miR-126 in 338 GC patients' tissues and sera, and 50 healthy controls' sera. The associations of serum miR-126 with clinicopathological characteristics and clinical outcome were evaluated. RESULTS: Compared with the matched adjacent non-tumor tissues and normal sera, miR-126 expression was significantly down-regulated in both tumor tissues and sera of GC patients. Importantly, there was a positive correlation between tissue and serum levels of miR-126 in GC patients. A reduced serum miR-126 level statistically correlated with aggressive clinicopathological characteristics, such as larger tumor size, deeper local invasion, more lymph node metastasis, advanced TNM stage, and poorer prognosis. Notably, multivariate analysis identified reduced serum miR-126 level as an independent predictor for the unfavorable prognosis of GC. CONCLUSIONS: These results indicate for the first time that serum miR-126 may serve as a novel prognostic biomarker in GC.

Dysregulation of miR-126/Crk protein axis predicts poor prognosis in gastric cancer patients.

BACKGROUND: miR-126 functions as a tumor suppressor in gastric cancer (GC) by negatively regulating Crk protein expression post-transcriptionally. OBJECTIVE: The aim of this study was to investigate the associations of miR-126 and Crk protein expression levels, alone or in combination, with the clinicopathological characteristics and prognosis of GC patients. METHODS: The expression levels of miR-126 and Crk protein in 338 GC patients were analyzed by quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. The relationship of miR-126 and Crk protein expression with clinicopathologic characteristics and clinical outcome was evaluated. RESULTS: Compared with matched adjacent non-tumor tissues, miR-126 was significantly down-regulated while Crk protein was significantly up-regulated in tumor tissues. A reduced miR-126 expression and an elevated Crk protein expression, alone or in combination, statistically correlated with aggressive clinicopathological characteristics, such as larger tumor size, deeper local invasion, more lymph node metastasis, advanced TNM stage, and poorer prognosis. Multivariate analysis showed that combined miR-126-low/Crk protein-high expression was an independent unfavorable prognostic factor of GC. CONCLUSIONS: These results indicate for the first time that miR-126 down-regulation and Crk protein up-regulation may be synergistically associated with tumor progression in GC and may predict unfavorable prognosis of GC.

Gastric cancer surgery: Billroth I or Billroth II for distal gastrectomy?

BACKGROUND: The selection of an anastomosis method after a distal gastrectomy is a highly debatable topic; however, the available documentation lacks the necessary research based on a comparison of early postoperative complications. This study was conducted to investigate the difference of early postoperative complications between Billroth I and Billroth II types of anastomosis for distal gastrectomies. METHODS: A total of 809 patients who underwent distal gastrectomies for gastric cancer during four years were included in the study. The only study endpoint was analysis of in-patients' postoperative complications. The risk adjusted complication rate was compared by POSSUM (Physiological and operative severity score for enumeration of morbidity and mortality) and the severity of complications was compared by Rui Jin Hospital classification of complication. RESULTS: Complication rate of Billroth II type of anastomosis was almost double of that in Billroth I (P=0.000). Similarly, the risk adjusted complication rate was also higher in Billroth II group. More severe complications were observed and the postoperative duration was significantly longer in Billroth II type (P=0.000). Overall expenditure was significantly higher in Billroth II type (P=0.000). CONCLUSION: Billroth II method of anastomosis was associated with higher rate of early postoperative complications. Therefore, we conclude that the Billroth I method should be the first choice after a distal gastrectomy as long as the anatomic and oncological environment of an individual patient allows us to perform it. However more prospective studies should be designed to compare the overall surgical outcomes of both anastomosis methods.