Systemic inflammation score as a preoperative prognostic factor for patients with pT2-T4 resectable gastric cancer: a retrospective study.

BACKGROUND: Systemic inflammation has been reported to be associated with cancer progression and metastasis. Systemic inflammation score (SIS), calculated from preoperative serum albumin level and lymphocyte-to-monocyte ratio, has been shown to be a novel prognostic factor for several types of tumors. This study aimed to evaluate the prognostic value of the SIS in patients with pT2-4 resectable gastric cancer (GC). METHODS: Total 97 patients with pT2-4 GC who underwent curative surgery from 322 cases between 2009 and 2015 in Fukushima Medical University Hospital were included. We performed univariate and multivariate analyses to evaluate the usefulness of preoperative SIS and other prognostic factors for relapse-free survival (RFS) and overall survival (OS). RESULTS: The higher SIS score was associated with undifferentiated cancer and recurrence. Univariate analysis of RFS identified deeper tumor invasion and higher SIS were significant risk factors and multivariate analysis revealed that both of them were independent prognostic factors for RFS. As for OS, age, tumor invasion, SIS and LNR were significantly correlated with RFS. In multivariate analysis, tumor invasion, SIS and LNR were independent prognostic factors for OS. CONCLUSIONS: SIS was an independent prognostic factor for RFS and OS in pT2-4 resectable gastric cancer patients who underwent curative gastrectomy.

Laparoscopic total gastrectomy performed for juvenile polyposis of the stomach: A case report.

INTRODUCTION AND IMPORTANCE: Juvenile polyposis of the stomach (JPST) is a very rare disease and has been reported to have malignant potential. Total gastrectomy has been recommended as a standard treatment. Recently, the usefulness of laparoscopic surgery for this disease has been reported; however, in laparoscopic surgery, maintaining the surgical space is difficult because of the distended and thickened stomach wall that polyposis causes. CASE PRESENTATION: A 64-year-old woman was admitted to our hospital because she became malnourished due to loss of appetite. She had no family history of gastrointestinal polyposis and was diagnosed with gastric polyposis and polyp-related anemia eight years previously. She received endoscopic submucosal dissection of early gastric cancer twice in another hospital. Thereafter, the patient received an annual upper gastrointestinal endoscopy and took iron supplements for anemia due to occasional bleeding from polyps. However, the number of polyps increased over time. Enhanced computed tomography showed gastric wall thickening and multiple gastric polyps. She was diagnosed as having JPST and underwent laparoscopic total gastrectomy. She was discharged on postoperative Day 10. CLINICAL DISCUSSION: In the present case, similar to previous cases, standard laparoscopic surgery could be performed although the patient had excessive distention and congestion of the stomach. This report suggests that laparoscopic surgery is a safe and feasible option for patients with JPST and is preferable because of better cosmetic effects, especially for young female patients. CONCLUSION: We successfully performed laparoscopic surgery to treat a rare case of JPST.

Role of the cGAS-STING pathway in regulating the tumor-immune microenvironment in dMMR/MSI colorectal cancer.

Deficient mismatch repair (dMMR)/microsatellite instability (MSI) colorectal cancer (CRC) has high immunogenicity and better prognosis compared with proficient MMR (pMMR)/microsatellite stable (MSS) CRC. Although the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been considered to contribute to the high number of CD8+ TILs, its role in dMMR/MSI CRC is largely unknown. In this study, to examine the role of the cGAS-STING pathway on the recruitment of CD8+ TILs in dMMR/MSI CRC, we used public datasets and clinical tissue samples in our cohorts to evaluate the expression of cGAS, STING, and CD8+ TILs in pMMR/MSS and dMMR/MSI CRCs. According to the analysis of public datasets, the expression of cGAS-STING, CD8 effector gene signature, and CXCL10-CCL5, chemoattractants for CD8+ TILs which regulated by the cGAS-STING pathway, was significantly upregulated in dMMR/MSI CRC, and the expression of cGAS-STING was significantly associated with the expression of CD8 effector gene signature. Immunohistochemistry staining of the clinical tissue samples (n = 283) revealed that cGAS-STING was highly expressed in tumor cells of dMMR CRC, and higher expression of cGAS-STING in tumor cells was significantly associated with the increased number of CD8+ TILs. Moreover, we demonstrated that the downregulation of MMR gene in human CRC cell lines enhanced the activation of the cGAS-STING pathway. Taken together, for the first time, we found that dMMR/MSI CRC has maintained a high level of cGAS-STING expression in tumor cells, which might contribute to abundant CD8+ TILs and immune-active TME.

Incidence of upper extremity deep vein thrombosis in the retrosternal reconstruction after esophagectomy.

BACKGROUND: Upper extremity deep vein thrombosis (UEDVT) is relatively rare but cannot be negligible because it can cause fatal complications. Although it is reported that the occurrence rate of UEDVT has increased due to central venous catheter (CVC), cancer, and surgical invasion, there is still limited information for esophagectomy. The aim of this study was to evaluate the clinical factors, including CVC placement and thromboprophylaxis approach, as well as retrosternal space's width as a predictive factor for UEDVT in patients receiving esophagectomy. METHODS: This study included 66 patients who underwent esophagectomy with retrosternal reconstruction using a gastric tube. All patients routinely underwent contrast-enhanced computed tomography (CT) on the 4th postoperative day. Low-molecular-weight-heparin (LMWH) was routinely administered by the 2nd postoperative day. To evaluate retrosternal space's width, (a) The distance from sternum to brachiocephalic artery and (b) the distance from sternum to vertebra were measured by preoperative CT, and the ratio of (a) to (b) was defined as the width of retrosternal space. RESULTS: Among all patients, 11 (16.7%) suffered from UEDVT, and none was preoperatively received CVC placement, while 7 were inserted in non-UEDVT cases. Retrosternal space's width in patients with UEDVT was significantly smaller than that in patients without UEDVT (0.17 vs. 0.26; P < 0.0001). A cutoff value of the width was 0.21, which has high sensitivity (87%) and specificity (82%) for UEDVT prediction, respectively. CONCLUSION: The existence of CVC may not affect the development of UEDVT, but preoperative evaluation of retrosternal ratio may predict the occurrence of UEDVT.

Validation of Gene Expression-Based Predictive Biomarkers for Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is widely used for patients with locally advanced rectal cancer. However, response to nCRT varies substantially among patients, highlighting the need for predictive biomarkers that can distinguish non-responsive from responsive patients before nCRT. This study aimed to build novel multi-gene assays for predicting nCRT response, and to validate our signature and previously-reported signatures in multiple independent cohorts. METHODS: Three microarray datasets of pre-therapeutic biopsies containing a total of 61 non-responders and 53 responders were used as the discovery cohorts to screen for genes that were consistently associated with nCRT response. The predictive values of signatures were tested in a meta-analysis using six independent datasets as the validation cohorts, consisted of a total of 176 non-responders and 99 responders. RESULTS: We identified four genes, including BRCA1, GPR110, TNIK, and WDR4 in the discovery cohorts. Although our 4-gene signature and nine published signatures were evaluated, they were unable to predict nCRT response in the validation cohorts. CONCLUSIONS: Although this is one of the largest studies addressing the validity of gene expression-based classifiers using pre-treatment biopsies from patients with rectal cancer, our findings do not support their clinically meaningful values to be predictive of nCRT response.

[A Case of Laparoscopic Surgery for Preoperatively Diagnosed Gastric Metastasis of Lung Cancer].

The patient was a 66-year-old male who had undergone an operation for lung cancer and solitary brain metastases. Follow- up PET-CT after 1 year detected FDG accumulation in the stomach. We performed esophagogastroscopy and found an approximately 20 mm-sized Type 2 tumor on the greater curvature of the upper stomach. A pathological diagnosis of lung adenocarcinoma metastasis in the stomach was made. Laparoscopic surgery was performed on the metastatic lesion to prevent bleeding and perforation, and resection was achieved with minimal invasion. The current development of chemotherapy, including immunotherapy, has contributed to the improved prognosis of cancer patients, including those with lung metastasis in the stomach. Considering these backgrounds, preventive surgical resection under laparoscopy may be an effective approach for improving prognosis and preventing acute life-threatening adverse events. We report this case along with a literature review.

Long-term Outcomes of Lower Rectal Cancer Patients Treated with Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection after Preoperative Radiotherapy or Chemoradiotherapy.

OBJECTIVES: The standard strategy for advanced rectal cancer (RC) is preoperative short-course radiotherapy (SCRT)/chemoradiotherapy (CRT) plus total mesorectal excision (TME) in Western countries; however, the survival benefit of adding chemotherapy to radiotherapy remains unclear. There is accumulating evidence that either SCRT/CRT or lateral pelvic lymph node dissection (LPND) alone may not be sufficient for local control of advanced RC. We herein retrospectively evaluated the clinical outcomes of patients who were treated by SCRT/CRT+TME+LPND, particularly focusing on the prognostic impact of lateral pelvic lymph node metastasis (LPNM). METHODS: Patients diagnosed as having clinical Stage II and III lower RC who received SCRT/CRT+TME+LPND between 1999 and 2012 at our hospital were enrolled. Adverse events (AEs), surgery-related complications (SRC), and therapeutic effects were retrospectively analyzed. RESULTS: Fifty cases (SCRT:25, CRT:25) were analyzed. No significant differences were observed in overall survival (OS), relapse-free survival (RFS), local recurrence (LR), AE, and SRC between the SCRT and CRT groups, although the pathological therapeutic effect was higher in the CRT group. The patients with LPNM showed significantly inferior 5-year OS and 5-year RFS than those without LPNM. CONCLUSIONS: There were no significant differences in OS, RFS, or LR between SCRT and CRT, although CRT had a significantly greater histological therapeutic effect. The prognosis of the pathological LPNM-positive cases was significantly poorer than that of pathological LPNM-negative cases.

Circulating tumor cells after neoadjuvant chemotherapy are related with recurrence in esophageal squamous cell carcinoma.

BACKGROUND: Circulating tumor cells (CTCs) are known to be a systemic process of malignant progression of cancer cells and there is a possibility that analysis for CTCs as a liquid biopsy become predictive or prognostic tools for cancer patients. METHODS: In the present study with the novel CTCs detection system (Celsee system®), we performed quantitative and qualitative analysis of CTCs in patients with esophageal squamous cell carcinoma (ESCC) receiving neoadjuvant chemotherapy (NAC) with 5FU + CDDP regimen. CTCs are defined as having both DAPI positive and CD45 negative. Vimentin-positive CTCs were defined as mesenchymal-type CTCs (M-CTCs), while epithelial-type CTCs (E-CTCs) were only positive for pan-cytokeratin. RESULTS: At the baseline, there are detectable amounts of CTCs in all patients (n = 30) at all stages, and there were no significant differences of total CTCs, E-CTCs, or M-CTCs numbers between stages. Of importance, among total CTCs, M-CTCs are more dominant than E-CTCs in number. Also, there was no significant change of detectable amounts and phenotype of CTCs before and after NAC (n = 24). Of note, early recurrent group indicated that there was an elevated total CTCs number before NAC and an increased M-CTCs after NAC in comparison to those in non-recurrent group. CONCLUSIONS: Quantitative and qualitative analysis of CTCs may provide useful complementary predictive and prognostic information in ESCC.

Neoadjuvant Chemotherapy Induces IL34 Signaling and Promotes Chemoresistance via Tumor-Associated Macrophage Polarization in Esophageal Squamous Cell Carcinoma.

The tumor microenvironment (TME) plays a key role in the efficacy of neoadjuvant chemotherapy (NAC) in solid tumors including esophageal squamous cell carcinoma (ESCC). However, the TME profile of ESCC treated with NAC is not fully understood. In this study, we investigated the effect of NAC on the TME especially tumor-associated macrophages (TAM), the important immunosuppressive components of the TME, in ESCC. We quantified the expression of CD163, a crucial marker of TAM, in pretherapeutic biopsy and surgically resected ESCC specimens from patients who received NAC (n = 33) or did not receive NAC (n = 12). We found that NAC dramatically increased the expression of CD163 on TAMs in ESCC. Colony-stimulating factor 1 (CSF-1) and IL34 are crucial cytokines that recruit monocytes into tumor sites and differentiate them into TAMs. Interestingly, NAC significantly upregulated the expression of IL34 but not CSF-1 on tumor cells, and the frequencies of CD163+ TAMs were significantly correlated with IL34 expression in ESCC after NAC. The expression of IL34 in NAC-nonresponsive patients was significantly higher than that in NAC-responsive patients, and patients with IL34-high ESCC exhibited worse prognosis as compared with patients with IL34-low ESCC. We also demonstrated that 5-fluorouracil (5-FU)/cisplatin preferentially increased mRNA expression of IL34 on human ESCC cell lines. Human peripheral blood monocytes co-cultured with ESCC cells treated with 5-FU/cisplatin increased the expression of CD163, which was attenuated by the treatment with CSF-1R inhibitors. These data suggest that IL34 expression by NAC shifts the TME toward CD163+ TAM-rich immunosuppressive and chemo-insensitive microenvironment in ESCC. IMPLICATIONS: The blockade of IL34 signaling may offer a novel therapeutic strategy against chemoresistance in ESCC by inhibiting M2-TAM polarization.

PD-L1 overexpression in EBV-positive gastric cancer is caused by unique genomic or epigenomic mechanisms.

Epstein-Barr virus-positive gastric cancer [EBV (+) GC] is a distinct GC subtype with unique genetic and epigenetic aberrations. Here, we examined resected GC samples and publicly available microarray data and The Cancer Genome Atlas (TCGA) database to identify the mechanism underlying overexpression of PD-L1 in EBV (+) GC. We found that high levels of PD-L1 overexpression in EBV (+) GC were caused by focal amplification of CD274. By contrast, relatively high expression of PD-L1 in tumor tissue and infiltrating immune cells correlated with CD8 lymphocyte infiltration and IFN-γ expression via IRF3 activation. Since we reported previously that PD-L1 expression is associated both with the presence of CD8 T cells in the tumor microenvironment and with IFN-γ expression in GC, we examined a database to see whether IFN-γ-associated overexpression of PD-L1 plays a significant role in EBV (+) GC. Immunohistochemical staining showed that expression of the IRF3 signature in clinical GC samples was higher in EBV (+) than in EBV (-) cases. The data presented herein reveal a unique dual mechanism underlying PD-L1 overexpression in EBV (+) GC: high focal amplification of CD274 or IFN-γ-mediated signaling via activation of IRF3.

[Significance and Treatment Strategy of Glasgow Prognostic Score in High Risk Stage â ¡ Colorectal Cancer].

In this study, we investigated the usefulness of Glasgow prognostic score(GPS)as a prognostic factor for Stage Ⅱ colorectal cancer, and the treatment strategy by individualizing adjuvant chemotherapy. We enrolled 86 patients with Stage Ⅱ primary colorectal cancer who underwent curative resection. This study examines the prognostic significance of clinicopathological factors and GPS, NLR, LMR, PLR. Multivariate analyses was performed to evaluate the factors affecting recurrence free survival. The 5-year OS was 92.5%, and the RFS was 86% in Stage Ⅱ colorectal cancer. The recurrence rate was 12.8%. In multivariate analysis, GPS(HR: 13.66, p=0.005)was extracted as an independent poor prognosis factor. In comparison of survival rates, RFS of GPS 0, 1 was 95.2% and that of GPS 2 43.8%, and GPS 2 had a significantly poor prognosis(p< 0.01). GPS 2 is an independent high risk factor for recurrence of Stage Ⅱ colorectal cancer. In order to improve the prognosis of Stage Ⅱ colorectal cancer, individualized adjuvant chemotherapy is important.

Therapeutic potential of anti-VEGF receptor 2 therapy targeting for M2-tumor-associated macrophages in colorectal cancer.

BACKGROUND: Although immunotherapy with immune checkpoint inhibitors (ICIs) has become a standard therapeutic strategy in colorectal cancer (CRC) exhibiting microsatellite instability-high, limited patients benefit from this new approach. To increase the efficacy of ICIs in CRC patients, it is crucial to control the function of immunosuppressive cells in the tumor microenvironment. M2-tumor-associated macrophages (TAMs) are key immunosuppressive cells and promote tumor growth, angiogenesis, and epithelial-mesenchymal transition. In the present study, we focused on the VEGF signaling pathway in M2-TAMs to control their inhibitory function. METHODS: We evaluated the population of M2-TAMs, the VEGF receptor 2 (VEGFR2) expression on M2-TAMs, and the correlation between HIF-1α-positive cells and VEGFR2 expression levels on M2-TAMs in CRC using the analysis of The Cancer Genome Atlas colorectal adenocarcinoma dataset (n = 592), the flow cytometry of freshly resected surgical specimens of CRC (n = 20), and the immunofluorescence staining of formalin-fixed paraffin-embedded whole tissue samples of CRC (n = 20). Furthermore, we performed a functional assay of M2 macrophages through the VEGF/VEGFR2 signaling pathway in vitro. RESULTS: The population of M2-TAMs and their VEGFR2 expression significantly increased in the tumor compared to the normal mucosa in the CRC patients. HIF1-α-positive cells significantly correlated with the VEGFR2 expression level of M2-TAMs. M2 macrophages induced by cytokines in vitro produced TGF-ß1 through the VEGF/VEGFR2 signaling pathway. CONCLUSIONS: Our results suggest that anti-VEGFR2 therapy may have therapeutic potential to control the immune inhibitory functions of M2-TAMs in CRC, resulting in enhanced efficacy of immunotherapy with ICIs.

Selective sensitivity of EZH2 inhibitors based on synthetic lethality in ARID1A-deficient gastric cancer.

BACKGROUND: AT-rich interactive domain 1A (ARID1A) is a tumor suppressor gene that is frequently mutated in gastric cancer (GC). Although ARID1A mutations are not a druggable target for conventional treatments, novel therapeutic strategies based on a synthetic lethal approach are effective for ARID1A-deficient cancers. The histone methyltransferase EZH2 acts in a synthetic lethal manner in ARID1A-mutated ovarian cancer, although its role in GC remains unknown. METHODS: The selective sensitivity of the EZH2 inhibitors for ARID1A-deficient GC cells was evaluated using cell viability and colony formation assays. The expression of PI3K/AKT signaling genes were investigated using TCGA's cBioPortal database to determine whether the homeostasis between ARID1A and EZH2 is related to cell proliferation and survival via the PI3K/AKT signaling pathway. We also evaluated the phosphorylation of PI3K/AKT signaling proteins in ARID1A knock downed ARID1A-WT GC cells. RESULTS: EZH2 inhibitors decreased the viability of ARID1A-deficient cells in a dose-dependent manner and demonstrated the selective sensitivity to ARID1A-deficient cells in vitro experiment system. Bioinformatics approach revealed that the PI3K/AKT signaling was tended to be activated in ARID1A-deficient GC enhancing cell viability and, furthermore, down-regulation of EZH2 in ARID1A-deficient GC was related to normalization of PI3K/AKT signaling pathway. The cell experiment revealed that phosphorylated AKT was upregulated in ARID1A-deficent GC cells. CONCLUSIONS: The present findings provide a rationale for the selective sensitivity of EZH2 inhibitors against ARID1A-deficient GC and suggest the potential efficacy of targeted therapy using EZH2 inhibitors in this patient population.

ARID1A deficiency in EBV-positive gastric cancer is partially regulated by EBV-encoded miRNAs, but not by DNA promotor hypermethylation.

AT-rich interactive domain 1A (ARID1A), which is a tumor suppressor gene, is frequently mutated in Epstein-Barr virus-positive gastric cancer [EBV (+) GC]. While most ARID1A mutations in GC are truncating mutations, leading to loss of ARID1A protein expression, epigenetic modifications appear to contribute to ARID1A deficiency in EBV (+) GC harboring wild-type ARID1A. Based on the significant role of epigenetic modifications in EBV (+) GC that contributes to ARID1A deficiency, the methylation status of ARID1A was evaluated in EBV-infected cells and GC patients using a publicly available microarray and the Cancer Genome Atlas (TCGA) database. EBV-encoded miRNAs that potentially target ARID1A were identified as an additional epigenetic modulator by computational prediction. In vitro experiments were conducted to evaluate how EBV-encoded miRNAs affected ARID1A mRNA and protein levels. In clinical GC samples, the expression of predicted miRNAs and ARID1A and the mutation status of ARID1A was evaluated. As results, ARID1A was not hypermethylated in EBV (+) GC samples or EBV-infected GC cells. EBV infection did not alter ARID1A mRNA levels, suggesting that ARID1A protein deficiency was caused by post-transcriptional gene silencing in ARID1A-WT EBV (+) GC. Overexpression of miR-BART11-3p and miR-BART12, which were identified as miRNAs that potentially bind ARID1A, suppressed ARID1A protein expression in MKN7 and NCI-N87 cells. Highly expressed miR-BART11-3p and miR-BART12 were correlated with decreased ARID1A levels in GC tumors which did not harbor ARID1A mutations. The present findings revealed that ARID1A expression was epigenetically regulated by miR-BART11-3p and miR-BART12 in EBV (+) GC.

Diagnosis and treatment of gastric hamartomatous inverted polyp (GHIP) using a modified combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (modified CLEAN-NET): a case report.

BACKGROUND: Gastric hamartomatous inverted polyp (GHIP) is a pathological condition where enlarged gastric glands with cystic dilatation grow in the submucosa. It is difficult to excise the tissue due to its location. In addition, even if the tissue is taken correctly, making an accurate diagnosis is difficult due to foveolar epithelium in the tissue, which can be misdiagnosed as gastric mucosal epithelium. Thus, an accurate diagnosis of GHIP is rarely established from a biopsy alone preoperatively. We here report a case of GHIP with a central dimple, which was diagnosed and treated using a modified combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (modified CLEAN-NET). CASE PRESENTATION: A 60-year-old man with a submucosal tumor (SMT) in the stomach was referred to our hospital by a primary care doctor. On examination, a gastrointestinal stromal tumor was suspected. Modified CLEAN-NET was performed for diagnostic and therapeutic purposes. The histopathological examination of the resected specimen showed an enlarged gland duct in the submucosal layer. This finding, along with immunostaining results, led to the diagnosis of GHIP. The postoperative course was uneventful without any symptoms. CONCLUSIONS: GHIP should be considered among the differential diagnoses of SMT of the stomach. Modified CLEAN-NET may be beneficial in the removal of SMTs such as GHIP with a central dimple because it can avoid stomach deformation of the stomach and tumor dissemination.

Tuberculous peritonitis; The effectiveness of diagnostic laparoscopy and the perioperative infectious prevention: A case report.

BACKGROUND: Tuberculous peritonitis (TBP) is uncommon in Japan, and its diagnosis with conventional methods is time taking and requires a high clinical index of suspicion. Laparoscopy with peritoneal biopsy is a tool for rapid and accurate diagnosis of TBP. However, few cases have mentioned the infectious control and prevention during the perioperative period. This case is written following the SCARE scale for case report writing. CASE PRESENTATION: A 30-year-old man from Southeast Asia with a past medical history of pulmonary tuberculosis at 3-year-old admitted to our institution with abdominal pain and slight fever lasting for a week. With the elevation of inflammatory response and CA125, we conducted CT (Computed tomography). Not only ascites, panniculitis with peritoneal nodules, and the thickening of the omentum were found. Considering the possibility of malignancy and TBP, we performed a diagnostic laparoscopy. Slightly cloudy ascites, peritoneal and thickening omentum with white nodules were seen, and pathological diagnosis from the omentum during the operation raised the possibility of TBP due to its caseating granuloma and these findings allowed us to start the rapid treatment. CONCLUSION: We reported the effectiveness of diagnostic laparoscopy along with the aspect of perioperative prevention for TBP.

A TGFß-Dependent Stromal Subset Underlies Immune Checkpoint Inhibitor Efficacy in DNA Mismatch Repair-Deficient/Microsatellite Instability-High Colorectal Cancer.

Patients with DNA mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal cancer represent a biomarker-defined population with distinct clinicopathologic features who are susceptible to immune checkpoint inhibitors (ICI). However, their survival outcomes vary considerably and nearly half of them exhibit primary resistance to current ICIs, suggesting substantial molecular heterogeneity even among tumors with dMMR/MSI-H. We conducted an extensive analysis of the tumor microenvironment (TME) using multiple transcriptomic, proteomic, and IHC cohorts of colorectal cancer, comprising 222 dMMR/MSI-H and 1440 MMR-proficient/microsatellite stable tumors. We developed a TGFß-responsive stromal gene signature and then identified a unique poor prognostic subgroup of patients with dMMR/MSI-H colorectal cancers, characterized by the upregulation of transcriptional programs, including the TGFß-rich active TME, angiogenesis, M2 macrophage polarization, and the extracellular matrix signature predictive of ICI resistance. The TGFß-dependent stromal subset within dMMR/MSI-H tumors exhibiting poor survival outcomes was further recapitulated by proteomic datasets and IHC for VCAN protein expressed by cancer-associated fibroblasts. Meanwhile, this dMMR/MSI-H stromal subgroup was enriched neither with CD8+ T-cell infiltration nor common genomic alterations, such as mutation density and BRAF mutations, compared with dMMR/MSI-H tumors without TGFß-dependent stromal activation. In conclusion, this study revealed a novel stromal subgroup of patients with dMMR/MSI-H colorectal cancer, demonstrating a TGFß-rich tumor-promoting TME and unfavorable survival outcomes. IMPLICATIONS: Dual inhibition of immune checkpoints and TGFß signaling may offer a promising strategy for these patients.

Immune suppression caused by PD-L2 expression on tumor cells in gastric cancer.

BACKGROUND: Gastric cancer (GC) patients with PD-L1-negative tumor occasionally have a favorable response to anti-PD-1 mAb. The aim of the present study was to investigate the regulatory mechanism and immunosuppressive role of PD-L2 in GC. METHODS: We used immunohistochemistry to evaluate the expression of PD-L2 in primary tumors from 194 patients with GC. The mechanism of PD-L2 expression was assessed in TCGA stomach adenocarcinoma tissue dataset and in vitro assay using GC cell lines. The immunosuppressive role of PD-L2 was evaluated by cytotoxicity of CTL clone against PD-L2 expressing GC cells. RESULTS: PD-L2 was expressed on tumor cells (TCs) of 28.4% patients and PD-L2 expression on TCs was significantly associated with tumor progression. TCGA dataset revealed that IFN-γ and, to a lesser extent, IL-4 signature significantly correlated with PD-L2 expression. In vitro assay showed that IFN-γ and, also to a lesser extent, IL-4 can upregulate PD-L2 expression on GC cells. Anti-PD-L2 mAb significantly enhanced the cytotoxicity of CTL clone against GC cell lines expressing PD-L2. CONCLUSIONS: PD-L2 is expressed on GC cells and PD-1/PD-L2 interaction are functionally involved in anti-tumor CTL activities. PD-L2 expression should be considered when determining the optimal immunotherapy for GC.

Higher modified Glasgow Prognostic Score and multiple stapler firings for rectal transection are risk factors for anastomotic leakage after low anterior resection in rectal cancer.

OBJECTIVE: Anastomotic leakage (AL) is one of the most devastating complications of rectal cancer surgery. Not only does AL result in reduced quality of life, extended hospitalization and impaired defecatory function, it also has a high local recurrence rate. In this study, we investigated risk factors for AL as it may help to decrease its occurrence and improve patient outcomes. METHODS: This study was a retrospective, single-institution study of rectal cancer patients who underwent elective low anterior resection between April 2002 and February 2018 at Fukushima Medical University Hospital. Patients were divided into two groups according to the presence of AL. Patient-, tumor-, and surgery-related variables were examined using univariate and multivariate analyses. RESULTS: One hundred sixty-one patients, average age 63.5±11.5 years, were enrolled in the study. The overall AL rate was 6.8% (11/161). In the univariate analysis, modified Glasgow Prognostic Score (mGPS)=2 (p=0.003), use of multiple staplers (≥3 firings) for rectal transection (p=0.001) and intraoperative bleeding (≥250 g) were significantly associated with AL incidence. Multivariate analysis identified that mGPS = 2 (odds ratio [OR]: 19.6, 95% confidence interval [CI]: 2.96-125.00, p=0.002) and multiple firings (OR: 18.19, CI: 2.31-111.11, p=0.002) were independent risk factors for AL. CONCLUSION: Higher mGPS score and multiple firings were independent risk factors for AL.

Characterization of tumor-infiltrating immune cells in relation to microbiota in colorectal cancers.

BACKGROUND: Several articles have recently reported that certain colon microbiota can improve the efficacy of cancer immunotherapy. To develop new treatment strategies, including immunotherapy for colorectal cancer (CRC), we evaluated the correlations between subpopulations of tumor-infiltrating immune cells (TIICs) and intestinal microbiota in CRC. METHODS: Fresh surgically resected specimens, formalin-fixed paraffin-embedded whole tissue samples, and stool samples were collected. TIICs including Tregs, Th17 cells and tumor-associated macrophages (TAMs) in the surgically resected specimens were analyzed using flow cytometry. FOXp3, CD8, CD163, and phosphorylated-STAT1-positive TIICs in the whole tissue samples were analyzed using IHC, and intestinal microbiota in the stool samples was analyzed using 16S metagenome sequencing. TIICs subpopulations in the normal mucosa and tumor samples were evaluated, and the correlations between the TIIC subpopulations and intestinal microbiota were analyzed. RESULTS: FOXp3lowCD45RA+ Tregs were significantly reduced (p = 0.02), FOXp3lowCD45RA- Tregs were significantly increased (p = 0.006), and M1 TAMs were significantly reduced in the tumor samples (p = 0.03). Bacteroides (phylum Bacteroidetes) and Faecalibacterium (phylum Firmicutes) were increased in the patients with high numbers of Tregs and clearly high distribution of FOXp3highCD45RA- Tregs, which are the effector Tregs. Faecalibacterium, Ruminococcaceae, Eubacterium (phylum Firmicutes), and Bacteroides were increased in patients with a high distribution of M1 TAMs. CONCLUSIONS: The findings of the present study indicate that immune responses to tumors are suppressed in the tumor microenvironment of CRC depending on the increment of Tregs and the reduction of M1 TAMs and that intestinal microbiota might be involved in immunosuppression.