Lymph node micrometastasis and its correlation with MMP-2 expression in gastric carcinoma

AIM： To examine matrix metalloproteinase-2 （MMP-2） expression in gastric cancer tissues and to evaluate its relationship with lymph node micrometastasis. MATERIALS： The authors studied 850 lymph nodes resected from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenetomy using reverse transcription polymerase chain reaction （RT-PCR） assay in addition to H-E staining. MMP-2 expression of the tumor tissues was detected by immunohistochemical technique （EliVision^TM plus）. RESULTS： MMP-2 expression was positive in 21 （70%） cases and negative in g （30%） cases. No significant correlations were found between MMP-2 expression and other variables such as age, gender, tumor location, tumor diameter, Lauren classification and lymphatic invasion. In contrast, MMP-2 expression correlated significantly with depth of tumor infiltration （P = 0.022）, lymph node metastasis （P = 0.030） and tumor differentiation （P = 0.043）. Lymph node micrometastases were detected in 77 （12.5%） lymph nodes of 14 （46.7%） gastric carcinoma patients. MMP-2 expression was positive in 12 （85.7%） of the 14 patients with lymph node micrometastasis, and in g （56.3%） of the 16 patients without lymph node micrometastasis （P = 0.118）. CONCLUSIONS： Our results demonstrate that MMP-2 expression has significant correlation with tumor invasion, tumor differentiation and lymph node metastases. MMP-2 expression may be an important biological characteristics and significant prognostic parameter of gastric carcinoma. We also conclude that MMP-2 may participate in the development of lymph node micrometastasis of gastric carcinoma. Further investigations are needed to draw a conclusion.

Expression of E-cadherin in gastric carcinoma and its correlation with lymph node micrometastasis

AIM: To examine the expression of E-cadherin in the primary tumor and to evaluate its relationship with lymph node micrometastasis (LNM).METHODS: The authors studied 850 lymph nodes resected from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenectomy using reverse transcription polymerase chain reaction (RT-PCR) assay in addition to H&E staining. Cytokeratin-20 (CK-20)gene marker was used in this assay. The level of E-cadherin expression in the primary tumor was examined by immunochemical technique (EliVisionTM plus).RESULTS: LNM was detected in 77 (12.5%) lymph nodes of 14 patients (46.7%) with gastric carcinoma. The incidence of LNM was significantly higher in the diffuse type (12 of 19 cases, 63.2%) than in the intestinal type of gastric carcinoma (2 of 11 cases, 18.2%, P = 0.026). The incidence of LNM also increased in accordance with the depth of tumor invasion. The loss of expression of E cadherin in primary tumors was found in 14 (46.7) of 30 tumors. The absence of E-cadherin expression was significantly associated with the Lauren classification (P = 0.026), lymph node metastasis (P = 0.011), the grade of differentiation (P = 0.004) and the lymphatic invasion (P = 0.001). Expression of E-cadherin was negative in 10 (71.4%) of the 14 patients with LNM, and in 4 (25%) of the 16 patients without LNM (P = 0.026). CONCLUSION: The current results indicate that the RT PCR assay is useful for the detection of LNM and can significantly increase the detection rate of lymph node metastasis in patients with gastric carcinoma. The Laurenclassification and depth of tumor invasion are significantlyassociated with lymph node micrometastases. Our findings also indicate that E-cadherin may play an important role in determining the growth type and differentiation of gastric carcinoma. The loss of E-cadherin expression may contribute to LNM.

Clinical significance of molecular diagnosis for gastric cancer lymph node micrometastasis

Advances in molecular diagnostic tools have allowed the identification of lymph node micrometastasis(LNM),including isolated tumor cells,in cancer patients. While immunohistochemistry and reverse transcription-polymerase chain reaction have been used to identify LNM in patients with gastric cancer,the clinical significance of this finding remains unclear. Recently,minimally invasive treatments,such as endoscopic submucosal dissection and laparoscopic surgery,are widely performed to help improve postsurgical quality of life(QOL). However,it is important to maintain the balance between QOL and curability when making treatments decision for patients with gastric cancer. If minimally invasive surgery based on accurate intraoperative LNM diagnosis was established,it could be performed safely. Therefore,we reviewed the clinical significance of LNM detected by molecular techniques as an important target for treatment decision making with gastric cancer patients.

Influence of lymph node micrometastasis on the staging system for gastric cancer

Objective The aim of this study was to investigate the effect of lymph node micrometastasis on the prognosis of patients with gastric cancer and the necessity of integrating it into the gastric cancer staging system.Methods In total,241 patients with gastric cancer were included.Hematoxylin and eosin staining of lymph nodes was performed,and negative lymph nodes were evaluated by immunohistochemistry to detect micrometastases.Differences in survival rates between stages were evaluated.Results(1)A total of 78 patients(32.4%)had lymph node micrometastases.Compared with the group without micrometastases,the overall recurrence rate,lymph infiltration,vascular invasion,and nerve invasion rate in the micrometastasis group were significantly higher(P<0.05).(2)According to the standard N staging system,the rates of disease-free survival(DFS)for the N0,N1,N2,N3a,and N3b groups were 96.0%,84.0%,67.6%,59.0%,and 21.7%,respectively.There was no significant difference in survival between N2 and N3a.The cumulative survival curves for N2 and N3a intersected.(3)The N stage of 38 patients(15.8%)differed between the traditional system and the new N staging system reflecting micrometastasis.The DFS for N0,N1,N2,N3a,and N3b were 97.0%,86.3%,74.2%,65.4%,and 29.2%,respectively.There was no significant difference in survival between N2 and N3a,but the cumulative survival curves for N2 and N3a did not intersect.(4)Based on a Cox multivariate analysis,various independent risk factors for recurrence were identified(P<0.05).Conclusion Lymph node micrometastasis is an important risk factor for gastric cancer recurrence.Lymph node micrometastasis should be considered in TNM staging to determine prognosis and optimal treatment strategies.