BackgroundThe immune contexture predicts prognosis in human colorectal cancer (CRC). Whereas tumour-infiltrating CD8+ T cells and myeloid CD16+ myeloperoxidase (MPO)+ cells are associated with favourable clinical outcome, interleukin (IL)-17-producing cells have been reported to correlate with severe prognosis. However, their phenotypes and functions continue to be debated.ObjectiveTo investigate clinical relevance, phenotypes and functional features of CRC-infiltrating, IL-17-producing cells.MethodsIL-17 staining was performed by immunohistochemistry on a tissue microarray including 1148 CRCs. Phenotypes of IL-17-producing cells were evaluated by flow cytometry on cell suspensions obtained by enzymatic digestion of clinical specimens. Functions of CRC-isolated, IL-17-producing cells were assessed by in vitro and in vivo experiments.ResultsIL-17+ infiltrates were not themselves predictive of an unfavourable clinical outcome, but correlated with infiltration by CD8+ T cells and CD16+ MPO+ neutrophils. Ex vivo analysis showed that tumour-infiltrating IL-17+ cells mostly consist of CD4+ T helper 17 (Th17) cells with multifaceted properties. Indeed, owing to IL-17 secretion, CRC-derived Th17 triggered the release of protumorigenic factors by tumour and tumour-associated stroma. However, on the other hand, they favoured recruitment of beneficial neutrophils through IL-8 secretion and, most importantly, they drove highly cytotoxic CCR5+CCR6+CD8+ T cells into tumour tissue, through CCL5 and CCL20 release. Consistent with these findings, the presence of intraepithelial, but not of stromal Th17 cells, positively correlated with improved survival.ConclusionsOur study shows the dual role played by tumour-infiltrating Th17 in CRC, thus advising caution when developing new IL-17/Th17 targeted treatments.

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The goal of this study was to determine the frequency of HLA class II antigen expression in colorectal carcinoma (CRC) tumors, its association with the clinical course of the disease, and the underlying mechanism(s). Two tissue microarrays constructed with 220 and 778 CRC tumors were stained with HLA-DR, DQ, and DP antigen-specific monoclonal antibody LGII-612.14, using the immunoperoxidase staining technique. The immunohistochemical staining results were correlated with the clinical course of the disease. The functional role of HLA class II antigens expressed on CRC cells was analyzed by investigating their in vitro interactions with immune cells. HLA class II antigens were expressed in about 25% of the 220 and 21% of the 778 tumors analyzed with an overall frequency of 23%. HLA class II antigens were detected in 19% of colorectal adenomas. Importantly, the percentage of stained cells and the staining intensity were significantly lower than those detected in CRC tumors. However, HLA class II antigen staining was weakly detected only in 5.4% of 37 normal mucosa tissues. HLA class II antigen expression was associated with a favorable clinical course of the disease. In vitro stimulation with interferon gamma (IFNγ) induced HLA class II antigen expression on two of the four CRC cell lines tested. HLA class II antigen expression on CRC cells triggered interleukin-1β (IL-1β) production by resting monocytes. HLA class II antigen expression in CRC tumors is a favorable prognostic marker. This association may reflect stimulation of IL-1β production by monocytes.

Background: VATS is currently the most popular form of access for lung cancer resection in the UK. However, there is limited comparative information from high quality randomised controlled trials and no information on early oncologic outcomes for quality assurance for a minimal access approach. VIOLET is the largest randomised trial conducted to date to compare clinical efficacy, safety and oncologic outcomes of VATS versus open surgery for lung cancer. Method: VIOLET is a parallel group randomised trial conducted across 9 UK thoracic surgery centres. Participants with known or suspected primary lung cancer were randomised in a 1:1 ratio to VATS (one to four ports) or open lobectomy. Randomisation was stratified by surgeon. Patients within clinical stage cT1-3, N0-1 and M0 using TNM 8 with disease suitable for VATS or open surgery were eligible to join the trial. We report on early outcomes in the period from randomisation to hospital discharge after surgery. Result: From Jul 2015 to Feb 2019, 2,109 patients were screened to randomise 503 participants to VATS (n¼247) or open (n¼256) lobectomy. The mean age (SD) was 69 (8.8) years and 249 (49.5%) were male. Baseline clinical T category was cT1 333 (67.3%), cT2 125 (25.2%), cT3 37 (7.5%) with cN0 466 (94%) and cN1 30 (6%). Lobectomy was undertaken in 221 (89.5%) patients randomised to VATS and 232 (90.6%) patients randomised to open surgery. The in-hospital mortality rate was 1.4% (7/502) and the conversion rate from VATS to open was 5.7% (14/246) with the main reasons listed as pleural adhesions (n¼4) and bleeding (n¼4). There were no differences in R0 resection; which was 98.8% ( 218/223) in the VATS group and 97.4% (228/234) in the open group; P¼0.839 or in nodal upstaging from cN0/1 to pN2 disease which was observed in 6.2% (15/244) of the VATS group and 4.8% (12/252) of the open group; P¼0.503. The median (visual analogue) pain score was 4 (interquartile range, IQR 2 to 5) in both groups on day one with 3 (1 to 5) in the VATS group and 4 (2 to 5) in the open group on day two. A significant reduction of overall in-hospital complications was observed in patients receiving VATS at 32.8% (81/247) compared to open 44.3% (113/255) surgery; P¼0.008 without any difference in serious adverse events between the two groups, which was 8.1% (20/247) for VATS and 7.8% (20/255) for open surgery; P¼0.897. Patients randomised to VATS had a shorter median (IQR) length of stay of 4 (3 to 7) versus 5 (3 to 8) days compared to patients randomised to open surgery, P¼0.008. Conclusion:In early stage lung cancer, VATS lobectomy is associated with significantly lower in-hospital complications and shorter length of stay compared to open lobectomy. This was achieved without any compromise to early oncologic outcomes (pathologic complete resection and upstaging of mediastinal lymph nodes) nor any difference in serious adverse events in the early post-operative period.