Immunophenotypic features of metastatic lymph node tumors to predict recurrence in N2 lung squamous cell carcinoma.

Patients with mediastinal lymph node metastasis (N2) in squamous cell carcinoma (SqCC) of the lung have poor prognosis after surgical resection of the primary tumor. The aim of this study was to clarify predictive factors of the recurrence of pathological lung SqCC with N2 focusing on the biological characteristics of both cancer cells and cancer-associated fibroblasts (CAFs) in primary and metastatic lymph node tumors. We selected 64 patients with pathological primary lung N2 SqCC who underwent surgical complete resection and investigated the expressions of four epithelial-mesenchymal transition-related markers (caveolin, clusterin, E-cadherin, ZEB2), three cancer stem cell-related markers (ALDH-1, CD44 variant6, podoplanin) of cancer cells, and four markers of CAFs (caveolin, CD90, clusterin, podoplanin) in both primary and matched metastatic lymph node tumors in the N2 area. In the primary tumors, the expressions of all the examined molecules were not related to recurrence. However, in the metastatic lymph node tumors, high clusterin and ZEB2 expressions in the cancer cells and high podoplanin expression in the CAFs were significantly correlated with recurrence (P = 0.03, 0.04, and 0.007, respectively). In a multivariate analysis, only podoplanin expression in the CAFs in metastatic lymph node tumors was identified as a significantly independent predictive factor of recurrence (P = 0.03). Our study indicated that the immunophenotypes of both cancer cells and CAFs in metastatic lymph node tumors, but not primary tumors, provide useful information for predicting the recurrence of pathological N2 lung SqCC.

Thoracoscopic modified pleural tent for spontaneous pneumothorax.

OBJECTIVES: We developed a modified pleural tent (m-tent) procedure and used it in our hospital in almost 30 consecutive patients with spontaneous pneumothorax. The objective of this study was to clarify the feasibility and effectiveness of a thoracoscopic m-tent for the treatment of spontaneous pneumothorax. METHODS: From July 2013 to November 2014, 107 patients with spontaneous pneumothorax were treated in our institution. Eighty-nine of these patients were analysed retrospectively. The inclusion criteria for thoracoscopic m-tent for spontaneous pneumothorax were multiple and widespread bullae, postoperative relapse and secondary spontaneous pneumothorax. The surgical procedures were usually performed through three ports. After bullectomy, an m-tent is made to strip the parietal pleura off the chest wall from about the level of the fourth or fifth rib to the apex, and two or three ligations are then applied to fix the pleural tent and lung parenchyma. Patients in whom an m-tent was not indicated underwent bullectomy plus coverage using absorbable materials. RESULTS: Twenty-seven patients underwent bullectomy plus m-tent (m-tent group) and 62 underwent bullectomy plus coverage over a staple line using an absorbable material such as a polyglycolic acid sheet or nitrocellulose sheet (coverage group). No severe postoperative complications were observed in either group. The m-tent and coverage groups showed significant differences in operation time (129 vs 86 min, mean), haemorrhage (12.8 vs 7.2 ml), postoperative hospital stay (3.7 vs 2.9 days) and postoperative painkiller intake (8.6 vs 6.8 days). Recurrence was observed in 1 (3.7%) and 2 patients (3.2%), respectively. CONCLUSIONS: The thoracoscopic m-tent procedure requires a longer operation, a longer hospital stay and greater painkiller intake. However, these differences are acceptable, and an m-tent should be considered as an option for pleural reinforcement in spontaneous pneumothorax, especially in patients who are complicated with severe pulmonary emphysema, widespread bullae or recurrent pneumothorax.

Ezrin-expressing lung adenocarcinoma cells and podoplanin-positive fibroblasts form a malignant microenvironment.

PURPOSE: Cancer cells and cancer-associated fibroblasts (CAFs) together create the tumor microenvironment, which affects malignant behavior. Lung adenocarcinomas with CAFs expressing podoplanin (PDPN) are clinically aggressive, but the molecular mechanism underlying this phenomenon has not been established. So we identified the characteristic immunophenotype of lung adenocarcinoma cells coexisting with PDPN-expressing CAFs (PDPN-CAFs) and examined how it relates to an aggressive clinicopathological outcome. METHODS: We analyzed the clinicopathological characteristics of 119 adenocarcinomas with a uniform size (2-3 cm). The expression levels of ten invasiveness-related proteins which related to cell adhesion and invasiveness, such as Ezrin, were examined in cancer cells from PDPN-CAFs (+) cases and from PDPN-CAFs (-) cases (n = 20 each). To examine the functional importance of the identified protein on the invasion phenotype, we performed wound healing and a Matrigel invasion assay using shRNA-knockdown lung adenocarcinoma cells (PC-9). RESULTS: The PDPN-CAFs (+) cases had significantly higher rates of node metastasis (p < 0.01) and vascular invasion (p < 0.01). The cancer cells from the PDPN-CAFs (+) cases also had a significantly higher staining score for Ezrin (p < 0.01) than those from the PDPN-CAFs (-) cases. The migration and invasion activities of the shEzrin-induced PC-9 cells were significantly lower than those of the control cells. CONCLUSIONS: Our results indicated that within a tumor microenvironment composed of PDPN-CAFs, increased Ezrin expression in cancer cells might play a key role in the invasiveness of lung adenocarcinoma.

Identification of biological properties of intralymphatic tumor related to the development of lymph node metastasis in lung adenocarcinoma.

BACKGROUND: Intralymphatic tumors in the extratumoral area are considered to represent the preceding phase of lymph node metastasis. The aim of this study was to clarify the biological properties of intralymphatic tumors susceptible to the development of lymph node metastasis, with special reference to the expression of cancer initiating/stem cell (CIC/CSC) related markers in cancer cells and the number of infiltrating stromal cells. MATERIAL AND METHODS: Primary lung adenocarcinomas with lymphatic permeation in the extratumoral area were retrospectively examined (n = 107). We examined the expression levels of CIC/CSC related markers including ALDH1, OCT4, NANOG, SOX2 and Caveolin-1 in the intralymphatic cancer cells to evaluate their relationship to lymph node metastasis. Moreover, the number of infiltrating stromal cells expressing CD34, α-smooth muscle actin, and CD204 were also evaluated. RESULTS: Among the intralymphatic tissues, low ALDH1 expression in cancer cells, high SOX2 expression in cancer cells, and a high number of CD204(+) macrophages were independent predictive factors for lymph node metastasis (P = 0.004, P = 0.008, and P = 0.028, respectively). Among these factors, only low ALDH1 expression in cancer cells was significantly correlated with the farther spreading of lymph node metastasis (mediastinal lymph node, pathological N2) (P = 0.046) and the metastatic lymph node ratio (metastatic/resected) (P = 0.028). On the other hand, in the primary tumors, ALDH1 expression in the cancer cells was not associated with lymph node metastasis. Intralymphatic cancer cells expressing low ALDH1 levels exhibited lower E-cadherin expression levels than cancer cells with high levels of ALDH1 expression (P = 0.015). CONCLUSIONS: Intralymphatic cancer cells expressing low levels of ALDH1 and infiltrating macrophages expressing CD204 have a critical impact on lymph node metastasis. Our study also highlighted the significance of evaluating the biological properties of intralymphatic tumors for tumor metastasis.