Introduction: Major pathologic response after neoadjuvant chemotherapy (NAC) for NSCLC has been defined as 10% or less residual viable tumor without distinguishing between histologic types. We sought to investigate whether the optimal cutoff percentage of residual viable tumor for predicting survival differs between lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC). Methods: Tumor slides from 272 patients treated with NAC and surgery for clinical stage II-III NSCLC (ADC, n ¼ 192; SCC, n ¼ 80) were reviewed. The optimal cutoff percentage of viable tumor for predicting lung cancer-specific cumulative incidence of death (LC-CID) was determined using maximally selected rank statistics. LC-CID was analyzed using a competing-risks approach. Overall survival was evaluated using Kaplan-Meier methods and Cox proportional hazard analysis. Results: Patients with SCC had a better response to NAC (median percentage of viable tumor: SCC versus ADC, 40% versus 60%; p ¼ 0.027). Major pathologic response (10% viable tumor) was observed in 26% of SCC cases versus 12% of ADC cases (p ¼ 0.004). The optimal cutoff percentage of viable tumor for LC-CID was 10% for SCC and 65% for ADC. On multivariable analysis, viable tumor 10% or less was an independent factor for better LC-CID (p ¼ 0.035) in patients with SCC; in patients with ADC, viable tumor 65% or less was a factor for better LC-CID (p ¼ 0.033) and overall survival (p ¼ 0.050). Conclusions: In response to NAC, the optimal cutoff percentage of viable tumor for predicting survival differs between ADC and SCC. Our findings have implications for

Neoplastic cancer cells and cancer stroma (including infiltrating immune cells) determine the biology and prognosis of cancer. Various types of adaptive and innate immune cells are known to infiltrate the cancer stroma. However, the patterns and spatial distribution of immune cell infiltration as well as its association with tumor histology remain poorly understood. To address these issues, we comprehensively analyzed the infiltrating immune cells present in lung adenocarcinoma. The principal types of both adaptive and innate infiltrating immune cells were immunohistochemically evaluated in the predominant histologic components of 111 lung adenocarcinomas. The same analysis was also carried out on 143 samples of histologic subtypes making up more than 20% of tumors. As a result, plasma cells and B cells with interfollicular distribution were almost exclusively observed in invasive histologic subtypes, while an increased number of mast cells were observed in noninvasive histologic subtypes. Cluster analysis revealed four distinct immunosubtypes (CD8, mast cell, macrophage/dendritic cell, and plasma cell subtypes) based on the infiltrating immune cell profiles. These immunosubtypes correlated with histologic subtypes, and univariate and multivariate analyses identified the plasma cell subtype as an independent negative prognostic factor. These plasma cells may be one of the major producers of the immunosuppressive cytokine IL35 in cancer stroma.

Pancreatic ductal adenocarcinoma (PDA) is a highly aggressive and often lethal malignant tumor. Several studies have shown that epithelial-mesenchymal transition (EMT) is frequently observed in clinical samples of PDA and is related to high metastatic rates and poor outcomes. To identify candidate molecules regulating EMT in PDA, we previously used cDNA microarray analysis and identified integrin b4 (ITGB4) as one of the genes upregulated in high-EMT xenografts derived from PDA patients. The aim of the current study was to clarify the clinicopathological and functional significance of ITGB4 overexpression in PDA. ITGB4 upregulation in high-EMT xenografts was confirmed by immunohistochemistry. Immunohistochemical analyses of 134 surgically resected PDA cases revealed intratumoral heterogeneity with respect to ITGB4 expression and showed that cancer cells undergoing EMT often display strong diffuse ITGB4 expression. High levels of ITGB4 expression were significantly correlated with the hallmarks of EMT (solitary cell infiltration, reduced E-cadherin expression, and increased vimentin expression), with high tumor grade, and with the presence of lymph node metastasis, and showed an independent prognostic effect. Immunocytochemical analyses of PDA cell lines revealed that localization of ITGB4 changed from regions of cell-cell contact to diffuse cytoplasm and cell edges with occasional localization in filopodia during EMT. Knockdown of ITGB4 reduced the migratory and invasive ability of PDA cells. Overexpression of ITGB4 promoted cell scattering and cell motility in combination with downregulation of E-cadherin and upregulation of vimentin expression. In conclusion, we elucidated the prognostic and clinicopathological significance of ITGB4 overexpression in PDA and also the potential role for ITGB4 in the regulation of cancer invasion and EMT. Pancreatic cancer is the fourth most common cause of cancer death in men and women in the United States. 1 Despite medical improvements, pancreatic cancer remains one of the most lethal malignancies: the 5-year survival rate for patients with pancreatic cancer is only about 6%. 1 Pancreatic ductal adenocarcinoma (PDA), characterized by the formation of ducts resembling pancreatic ducts, is the most common histologic type of pancreatic cancer. Resectability is considered to be the most significant prognostic factor; however, at the time of diagnosis, only about 20% of patients with PDA are surgically resectable because of distant metastases or major vessel involvement. 2 Even after curative surgery, the 5-year survival rate is 10%-25%, mainly due to the highly aggressive biological behavior of this tumor, such as the high rate of local recurrence, peritoneal dissemination, liver metastases, and lymph node recurrence. 3 The epithelial-mesenchymal transition (EMT) is a series of cellular and molecular processes during which polarized epithelial cells lose cell-cell and cell-basement membrane interactions at the same time as acquiring mesenchymal and migratory properties. EMT is no...