The clinical importance of micrometastases within the lymphatic system in patients after total gastrectomy

HMMR promotes peritoneal implantation of gastric cancer by increasing cell-cell interactions

BACKGROUND

Distant metastasis is the prominent factor for cancer-induced death of gastric cancer in which peritoneum is one of the dominating targets of gastric cancer metastasis. However, there is still a lack of effective predictive indicators and treatment methods for gastric cancer patients with peritoneal metastasis.

METHODS

A clustering assay was used to investigate the cell aggregates formation ability. While the soft agar assay and anoikis assay were performed to detect the anchorage-independent growth and anoikis-resistant ability respectively. Luciferase activity assay, western blotting and immunofluorescence were used to explore the effect of HMMR on AKT signaling activity. The peritoneal implantation model was examined to explore the role of HMMR in vivo.

RESULTS

Silencing of HMMR expression markedly reduced the peritoneal metastasis of gastric cancer cells through reducing cell-cell interactions. Mechanistically, HA-HMMR could activate Akt signaling, thus succeeding in distant colonization and metastatic outgrowth. Importantly, inducible depletion of HMMR significantly abrogates peritoneal implantation of gastric cancer in vitro and in vivo.

CONCLUSION

Our study highlights that HMMR promotes peritoneal implantation of gastric cancer. A better understanding of HMMR's functions and mechanism might provide a novel therapeutic target and prognostic marker for metastatic gastric cancer.

Clinical significance of lymph node micrometastasis in T1N0 early gastric cancer

To investigate the significance of lymph node micrometastasis in T1N0 early gastric cancer. Lymph node micrometastasis may be a key mechanism in the recurrent T1N0 EGC patients after surgical treatment. It's unknow whether it is safe to leave the lymph nodes with micrometastasis untreated after ESD. A total of 106 T1N0 EGC patients were enrolled in this study. Immunohistochemical technique with CAM5.2 was employed to detect lymph node micrometastasis, and Immunohistochemical with D2-40 was used to detect the lymphatic vessels. Prognostic significance of lymph node micrometastasis and the relationship of lymph nodes micrometastasis with Clinicopathological features were analyzed. Twenty-two of the 106 T1N0 EGC cases were detected with lymph nodes micrometastasis, with the detection rate of 20.8%. The median survival time of the group with positive lymph nodes micrometastasis was lower than that of the group with negative micrometastasis, 48 vs 60 months. The incidence of lymph nodes micrometastasis in submucosal T1N0 EGC was 23.9%, while no micrometastasis was found in the mucosal T1N0 EGC. Of all the 30 cases according with the expanded ESD indications, six patients were found with lymph nodes micrometastasis. The occurrence of lymph node micrometastasis was common in T1N0 EGC. The cases with positive lymph nodes micrometastasis showed a lower median survival time than those with negative micrometastasis. lymph nodes micrometastasis incidence was higher in the submucosal ECG than in the mucosal ECG. lymph nodes micrometastasis was also found in the cases according to the expanded ESD indications.

Prognostic significance of VEGF-C in predicting micrometastasis and isolated tumour cells in N0 oral squamous cell carcinoma

BACKGROUND

Lymph node metastasis in oral squamous cell carcinoma (OSCC) is a well-known independent prognostic factor. However, the identification of occult tumour cells within the lymph nodes has remained a challenge for the pathologist as well as the clinician.

OBJECTIVE

The aim of this study was to determine the prevalence of micrometastasis and isolated tumour cells (ITCs) in pathologically staged N0 OSCC of the tongue and buccal mucosa and to assess its correlation with vascular endothelial growth factor C, (VEGF-C) expression in the primary tumour.

METHODS

Thirty-four cases of N0 OSCC comprising of 17 cases each from the tongue and buccal mucosa were evaluated by immunohistochemistry for VEGF-C expression. The corresponding lymph nodes from levels I and II were pathologically examined and cross-detected for micrometastasis and ITCs with desmoglein 3 (DSG3).

RESULTS

The prevalence of micrometastasis and ITCs in OSCC of the tongue and buccal mucosa was 23.5% and 17.6%, respectively. A total of 12 out of 151 lymph nodes contained micrometastatic tumour foci and ITCs. A higher expression of VEGF-C in the primary tumour was associated with a greater probability for the occurrence of micrometastasis and ITCs in the lymph nodes.

CONCLUSION

High expression of VEGF-C in the primary tumour may be a good determinant for detection of occult tumour cells in the lymph nodes of OSCC cases.