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Radiation therapy (RT) has the potential to activate the tumor-microenvironment (TME) and promote the efficacy of immune checkpoint blockade therapy. Tumor cell-intrinsic expression of cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) plays an important role in regulations of radiation-induced activation of immune cells in the TME. However, the role of tumor cell-intrinsic cGAS-STING in radiation-mediated remodeling of the TME in esophageal squamous cell carcinoma (ESCC) is not completely understood; thus, we investigated its effect on the radiation-mediated remodeling of the TME in ESCC.We assessed the effect of tumor cell-intrinsic cGAS-STING on the expression of mediators of the immune system, including type I interferon, T-cell chemo-attractants, colony-stimulating factor-1, and interleukin 34 (IL-34), induced by radiation in ESCC cell lines. We also quantified the association between tumor cell-intrinsic expression of cGAS-STING and infiltrations of immune cells, including CD8We found that tumor cell-intrinsic expression of cGAS-STING was involved in radiation-induced infiltration of CD8The tumor cell-intrinsic expression of cGAS-STING is essential for radiation-induced activation of immune cells in the TME, but it is also involved in the recruitment of tumor-promoting M2-TAMs in ESCC. Therefore, blocking of M2-TAM infiltration by targeting IL-34 might improve the efficacy of RT and combination therapy of RT with immune checkpoint inhibitors in ESCC.

Univariate and multivariate analyses of risk factors for OS and RFS after NAC in patients with ESCC

S1. Measurement of the number of CD163+ cells and their expression intensities in ESCC specimens. S2. IHC staining of CSF-1, IL-34, E-cadherin, and vimentin in ESCC specimens. S3. Correlation between mRNA expression of CD163 and CSF-1 in patients with ESCC who underwent curative esophagectomy without any preoperative therapy. S4. The effect of CSF-1 expression of NAC responsivity and tumor progression after NAC in ESCC. S5. Involvement of higher fold-change of IL-34 expression after CDDP treatment to poorer chemo-sensitivity in ESCC cells. S6. Enhanced mRNA expression of IL-34 in CDDP-resistant human ESCC cells.

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.

Background Postoperative pneumonia is one of the major complications after esophagectomy. The aim of this study was to determine whether bacterial cultures before esophagectomy could predict occurrence of postoperative pneumonia and help treatment strategies for postoperative pneumonia. Methods Sixty-nine patients who underwent subtotal esophagectomy at Fukushima Medical University hospital between January 2017 and May 2021 were included in this study. We collected sputum, oral and/or nasopharyngeal swabs for bacterial culture preoperatively from all patients and from those who were suspected of postoperative pulmonary infections. We compared cultured pathogenic bacteria obtained preoperatively and postoperatively from patients who developed postoperative pneumonia, and investigated their association with incidence of postoperative pneumonia. Fisher’s exact test was used to compare categorical variables between groups, and Wilcoxon test was used to compare continuous variables. Risk factors for postoperative pneumonia and severe pneumonia were analyzed using multivariate logistic regression models. Results Postoperative pneumonia occurred in 22 (31%) of the 69 patients, and 13 of the 22 patients were classified as with severe pneumonia. Multivariate analysis revealed that longer operative duration (for 30 minutes increase; odds ratio 1.27, 95% confidence interval 1.01–1.51, p=0.039) and positivity for preoperative bacterial culture (odds ratio 5.03, 95% confidence interval 1.31–19.2, p=0.018) were independent risk factors for severe postoperative pneumonia, but not for all incidence of postoperative pneumonia. Of note, in only 5 out of the 22 patients with pneumonia, the same pathogen species were detected preoperatively and after the onset of pneumonia. Conclusions In conclusion, our results implied that preoperative bacterial culture may be useful to predict severe postoperative pneumonia. However, it may not be useful in determining pathogenic bacteria responsible for postoperative pneumonia.

Background: Laparoscopic and endoscopic cooperative surgery (LECS) is a well-recognized surgical procedure for gastric gastrointestinal stromal tumor (GIST). In this report, we describe the clinical outcomes of LECS procedures for gastric GIST in our institution. Methods: We performed LECS procedures, including classical LECS, inverted LECS, closed LECS, and combination of laparoscopic and endoscopic approaches to neoplasia with non-exposure technique (CLEAN-NET), in 40 gastric intraluminal and intramural type GIST patients, whose tumors were ≤ 50 mm in diameter, between September 2012 and December 2020. The patient background, surgical outcomes, postoperative morbidity and mortality, as well as the tumors' clinicopathological characteristics were analyzed retrospectively. Results: Pathological findings showed that most patients had a low or very low risk of tumor recurrence, while one patient had a high risk according to the modified-Fletcher's classification. The median length of postoperative hospital stay was 7 days. Only one patient had severe postoperative grade III complications according to the Clavien-Dindo (C-D) classification, after closed LECS, but was treated successfully with endoscopic hemostasis for postoperative hemorrhage. The remaining patients treated with LECS did not have severe complications. During the follow-up period (median, 31 months), all patients were disease-free, with no tumor recurrence or metastases. Conclusion: LECS is a safe surgical procedure for gastric intraluminal and intramural type GIST ≤ 50 mm in diameter, with good clinical outcomes.

Trastuzumab deruxtecan (T-DXd), a HER2-targeting antibody–drug conjugate with a topoisomerase I inhibitor deruxtecan (DXd), exhibits an excellent anti-tumor effect in previously treated HER2-positive tumors. A recent study demonstrated that T-DXd not only suppressed tumor growth but also enhanced anti-tumor immunity through increasing the number of tumor-infiltrating CD8+ T cells and enhancement of major-histocompatibility-complex class I expression on tumor cells in a mouse model. However, the effect of T-DXd on anti-tumor immune responses in human cancers is largely unknown. We investigated the effect of T-DXd on the expression of HLA class I and CXCL9/10/11, T-cell chemoattractants, in HER2-positive human gastric cancer (GC) cells. We found that T-DXd significantly inhibited GC cell proliferation in a HER2-dependent manner, while it slightly increased the expression of HLA class I in HER2-positive GC cells. Moreover, we revealed that T-DXd significantly induced mRNA expression of CXCL9/10/11 in HER2-positive GC cells. T-DXd-triggered up-regulation of these chemokines was mediated through the activation of DNA damage signaling pathways. These results suggest that T-DXd triggers anti-tumor immune responses at least in part through induction of the expression of HLA class I and CXCL9/10/11 on HER2-positive GC cells, resulting in the enhancement of anti-tumor immunity in human GC.

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.

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.

A 78-year-old man with a subepithelial lesion (SEL) in the gastric body and two carcinomas in the gastric antrum was referred to our hospital. Following a diagnosis of SEL, the patient was followed-up by esophagogastroduodenoscopy annually for 4 years. Although the SEL had increased in size over the years, histological evaluation of the forceps biopsies did not reveal any significant findings. We detected a hypoechoic mass in the submucosa by endoscopic ultrasonography, and suspected the lesion to be an aberrant pancreas or mesenchymal tumor. The patient first underwent endoscopic submucosal dissection for the 2 gastric cancers. Histological examination of the resected specimens revealed intramucosal well-differentiated tubular adenocarcinomas. Next, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was performed for the gastric SEL. Aspirated specimens revealed an adenocarcinoma with lymphocyte infiltration. The lesion was diagnosed as a gastric carcinoma with lymphoid stroma (GCLS). Subsequently, he underwent distal gastrectomy, and the surgical specimen was confirmed as GCLS corresponding to preoperative diagnosis. In addition, the adenocarcinoma cells were positive for Epstein-Barr (EB) virus-encoded small RNA-1 by in situ hybridization. Finally, the lesion was diagnosed as GCLS associated with EB virus. Thus, EUS-FNA is advantageous for diagnosing GCLS associated with EB virus.

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.

BackgroundSystemic 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).MethodsTotal 97 patients with pT2-4 GC who underwent curative surgery 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).ResultsThe 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.ConclusionsSIS was an independent prognostic factor for RFS and OS in pT2-4 resectable gastric cancer patients who underwent curative gastrectomy.

Highlights • A rare case of Tuberculosis Peritonitis regarding the aspect of perioperative infection control. • The importance of characteristic intraperitoneal findings, which contributes to the rapid and accurate diagnosis combined with pathological findings. • Diagnostic laparoscopy must be less invasive and more effective compared with conventional methods., 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.

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.

Background In accordance with an increase of proximal gastric cancer, proximal gastrectomy came to be widely performed. Several types of reconstructive procedures after proximal gastrectomy have been developed and it is still controversial which procedure has the advantages in preservation of postoperative gastric stump function and nutritional status after proximal gastrectomy. In this study, we retrospectively analyzed reconstructive procedures in our consecutive case series for proximal gastrectomy, with particular focus on postoperative body weight maintenance, nutritional status, and gastric remnant functional preservation. Methods We enrolled 69 patients who received proximal gastrectomy for gastric cancer in our institute from 2005 to 2020. Short-term complications, preservation of gastric remnant functions, nutritional status, and post-operative weight changes were compared. Results After proximal gastrectomy, the numbers of cases receiving Direct Esophago-Gastrostomy, Jejunal Interposition, Double Tract Reconstruction, and Double Flap Technique were 9, 10, 14, and 36, respectively. Double Flap Technique cases suffered no reflux esophagitis after surgery. Prevalence of gastric residual at 12-month after surgery of Double Flap Technique was the lowest. Double Flap Technique group has better tendency in post-operative changes of serum albumin ratios. Furthermore, post-operative body weight changes ratio of Double Flap Technique was the smallest and significantly better than Double Tract at all the time points. Conclusions Double Flap Technique after proximal gastrectomy was considered as the most effective reconstruction which can maintain body weight, cause less reflux esophagitis and gastric residual.

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 are 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.

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment play an essential role in the tumor progression of esophageal squamous cell carcinoma (ESCC). The present study aimed to investigate the expression of CAF-related molecules, versican, periostin and lumican, in cancer stroma, to provide prognostic stratification for patients with ESCC after surgery. A total of 106 patients with ESCC who underwent curative esophagectomy without preoperative chemotherapy or radiotherapy were enrolled. The expression of CAF-related stromal proteins, including versican, periostin and lumican, was examined using immunohistochemistry, and the prognostic value was assessed by Kaplan-Meier survival analysis, and univariate and multivariate Cox regression models. The expression of versican, periostin and lumican was found specifically in the stromal component of ESCC. Kaplan-Meier analysis demonstrated that, compared with a low expression level, a high expression level of versican, periostin or lumican in the cancer stroma was significantly associated with worse relapse-free survival (RFS) and overall survival times in patients with ESCC. The prognostic values of stromal versican and lumican remained significant in a stratified analysis of stage I patients. Moreover, univariate and multivariate analysis revealed that high stromal versican or lumican expression was an independent prognostic factor for RFS in the patients. The present study demonstrated that CAF-related molecules, including versican, periostin and lumican, were expressed in the stroma of ESCC, and that stromal expression of versican and lumican in particular may have clinical utility as a prognostic biomarker for poor RFS in postoperative patients with ESCC.

4027 Background: Although basic, translational and clinical research suggest a possibility of synergistic effect of radiation-induced immunogenic cell death with immune checkpoint inhibitors, the effectiveness of the combination therapy is not fully established. Therefore, we conducted a single-arm, phase 1/2 trial (ClinicalTrials.gov, NCT03453164) in gastric cancer (GC) patients treated with a combination of nivolumab and oligo-fractionated irradiation (22.5 Gy/5 fractions/5 days). Methods: Eligible patients (n = 40) had un-resectable advanced or recurrent GC which progressed after primary and secondary chemotherapy with more than one lesion assessable in diagnostic imaging (one lesion must be ≥2cm). PBMCs from enrolled patients underwent high-dimensional flow cytometry-based, multiplexed MHC multimer analysis using a total of 46 tumor-associated antigens (TAA) and 10 virus epitopes and next-generation sequencing-based repertoire analysis of TCR β-chain. Results: The disease control rate (DCR) for the non-irradiated target as abscopal effect as the primary endpoint was 22.5%, and the DCR for the irradiated lesion was 40.0%. The median survival time was 230 days (157-330 days, 95%CI) and probability of 1-year survival rate was 28.6%. Although most TAA-specific T cells could be tracked longitudinally pre- and post-treatment, some several novel TAA-specific CD8 T cells were detected de novo after irradiation, indicating that potential irradiation-driven antigen spreading. Moreover, irradiation was associated with phenotypical changes of TAA-specific CD8 T cells towards higher expressions of KLRG1, HLA-DR, TIGIT and CD160 and lower expression of CD27 and CD127. Furthermore, the T cell clonality evaluated by the inverted Pielou’s evenness indicated that longer survival patients had more diverse TCR beta repertoire during treatment in comparison to shorter survivors. Also, we confirmed several new sequence-reads after radiation and nivolumab treatment in the top 30 most frequent clonotypes. Conclusions: Taken together, our results suggest that irradiation may induce, through immunogenic cell death, an immune-modulating effect with potential antigen spreading and a more diverse TCR repertoire, ultimately resulting in better survival during combination therapy of radiation with nivolumab. Clinical trial information: NCT03453164.

Surgical resection is the most effective treatment for liposarcoma, a retroperitoneal malignant soft tissue tumor, and a reliable negative margin is required because of the high risk of local recurrence. We reported a case of pelvic liposarcoma that could be resected by laparoscopic and transsacral hybrid approach. A 60's-man had a mixed liposarcoma occupying the right rear of the pelvis in the rectum. The operation was preceded by a laparoscopic operation, and the right internal iliac artery and vein and the superior rectal artery were dissected. The tumor was separated along the right pelvic wall. The oral rectum was transected and the colon was elevated by the extraperitoneal route. After conversion to the Jackknife position, the anterior sacrum was exfoliated with the right transsacral approach, the coccyx was resected, and the rectal anus, tumor, and surrounding fatty tissue were removed as an en bloc fasion. Histopathological examination showed mixed type of liposarcoma and negative margin of the stump. The patient is alive without recurrence 8 months after the surgery.

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. 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. 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. Quantitative and qualitative analysis of CTCs may provide useful complementary predictive and prognostic information in ESCC.

INTRODUCTION: Recently in Japan, Ramucirumab (RAM) became the first anti-angiogenic agent to be approved for second-line treatment of gastric cancer. In the present study, we aimed to evaluate the efficacy and safety of RAM plus paclitaxel (PTX) in patients with unresectable and recurrent gastric cancer in our institution. PATIENTS AND METHODS: The subjects were 11 patients with unresectable and recurrent gastric cancer who received RAM plus PTX as a second- or later-line treatment at our hospital between June 2015 and September 2017, after the failure of previously-attempted treatments. We assessed the efficacy and safety of RAM plus PTX, and also compared them between patients aged

Although rectovaginal fistula is a rare complication of rectal cancer surgery, it is usually difficult to cure with conservative treatment, and patients generally need surgical intervention. A woman in her 70s underwent laparoscopic low anterior resection with right lateral lymph node dissection for rectal cancer. On postoperative day(POD)6, she had an anastomotic leakage and received conservative treatment. On POD 9, she underwent emergent laparotomy for urinary peritonitis as well as ileostomy and ureteral stenting. On POD 21, the rectovaginal fistula was confirmed with lower gastrointestinal tract fluoroscopic examination. The patient received conservative therapy for the rectovaginal fistula with estriol vaginal tablets and vaginal lavage for 2 weeks. Subsequently, the fistula was completely cured. After continuation of the estriol vaginal tablets for 4 weeks, the rectovaginal fistula has not recurred at the most recent follow-up.

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor, and it is urgently needed to develop novel therapeutic strategies including immunotherapy. In this study, we investigated the upregulation of the programmed death ligand 1 (PD‐L1) due to epithelial‐mesenchymal transition (EMT) in ESCC using an in vitro treatment system with the EMT inducer, glycogen synthase kinase (GSK)‐3 inhibitor, and we also analyzed the correlation of EMT and PD‐L1 expression in the clinical tumor samples of both tissue microarray (TMA) samples (n = 177) and whole tissue samples (n = 21). As a result, the inhibition of GSK‐3β induces EMT phenotype with upregulated vimentin and downregulated E‐cadherin as well as increased Snail and Zinc finger E box‐binding homeobox (ZEB)‐1 gene expression. Simultaneously, we showed that EMT‐converted ESCC indicated the upregulation of PD‐L1 at both protein (total and surface) and mRNA levels. Of importance, we showed that EMT‐converted tumor cells have a capability to induce T‐cell apoptosis to a greater extent in comparison to original epithelial type tumor cells. Furthermore, the immunohistochemical stains of ESCC showed that PD‐L1 expression on tumor cells was positively correlated with EMT status in TMA samples (P = .0004) and whole tissue samples (P = .0029). In conclusion, our in vitro and in vivo study clearly demonstrated that PD‐L1 expression was upregulated in mesenchymal type tumors of ESCC. These findings provide a strong rationale for the clinical use of anti‐PD‐1/anti‐PD‐L1 monoclonal antibodies for advanced ESCC patients.

Cancer vaccines and immune checkpoint inhibitors (ICI) have recently been employed as immunotherapies for esophageal squamous cell carcinoma (ESCC). Cancer vaccines for ESCC have yielded several promising results from investigator-initiated phase I and II clinical trials. Furthermore, a Randomized Controlled Trial as an adjuvant setting after curative surgery is in progress in Japan. On the other hand, ICI, anti-CTLA-4 mAb and anti-PD-1 mAb, have demonstrated tumor shrinkage and improved overall survival in patients with multiple cancer types. For ESCC, several clinical trials using anti-PD-1/anti-PD-L1 mAb are underway with several recent promising results. In this review, cancer vaccines and ICI are discussed as novel therapeutic strategies for ESCC.

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. 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. 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. 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.

Adjuvant chemotherapy is considered for patients with stage II colorectal cancer (CRC) characterized by poor prognostic clinicopathological features; however, current stratification algorithms remain inadequate for identifying high-risk patients. To develop prognostic assays, we conducted a step-wise screening and validation strategy using nine cohorts of stage II patients based on multiple platforms, including microarray, RNA-sequencing (RNA-seq) and immunohistochemistry (IHC) on formalin-fixed paraffin-embedded (FFPE) tissues. Four microarray datasets (total n = 458) were used as the discovery set to screen for single genes associated with postoperative recurrence. Prognostic values of candidate genes were evaluated in three independent microarray/RNA-seq validation cohorts (n = 89, n = 93 and n = 183, respectively), and then IHC for KRT17 was conducted in two independent FFPE series (n = 110 and n = 44, respectively). We found that high levels of KRT17 transcript expression were significantly associated with poor relapse-free survival (RFS) not only in the discovery set, but also in three validation cohorts, and its prognostic impact was independent of conventional factors by multivariate analyses. Positive staining of KRT17 protein was significantly associated with poor RFS in two independent FFPE cohorts. KRT17 protein expression had independent prognostic impact on RFS in a multivariate model adjusted for conventional variables, including high-risk clinicopathological features. In conclusion, using nine independent cohorts consisting of 997 stage II patients, we identified and validated the expression of KRT17 transcript and KRT17 protein as a robust prognostic biomarker that can discriminate postoperative stage II patients who are at high probability of disease recurrence, providing additional prognostic stratification beyond the currently available high-risk factors.

Neoadjuvant chemotherapy plus surgery is recommended for clinical StageⅡ and Ⅲ esophageal cancer treatment by the JCOG9906. In contrast, definitive chemoradiotherapy(dCRT)is also a curative treatment. We encountered a case of recurrence in the cervical lymph nodes that was confirmed 6 years later, although thoracic esophageal cancer had completely disappeared following dCRT. Since there was no recurrence or metastasis in the primary lesion or other organs, we performed bilateral cervical lymph node dissection. There were 3 lymph node metastases among the dissected cervical lymph nodes pathologically. After the surgery, no relapses have occurred without the adjuvant chemotherapy.

We report 2 cases of superficial non-ampullary duodenal tumor resected using laparoscopic endoscopic cooperative surgery( LECS). A man in his5 0's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the anal side of the papilla of Vater that measured 5 mm. We performed LECS, and pathologic examination revealed tubular adenoma with no tumor cellsat the edge of the specimen. A man in his 80's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the posterior wall above the papilla of Vater that measured 10 mm. The biopsy showed a well-differentiated adenocarcinoma. We performed LECS, and the pathological examination revealed a tubular adenocarcinoma in the mucosal layer with no carcinoma cells at the edge of the specimen. As the treatment strategy for superficial duodenal tumors has not established yet, further accumulation of cases and investigation are necessary.

A case complicated with colorectal and prostate cancers in paraneoplastic(subacute)cerebellar degeneration(PCD)is extremely rare. We report a retrospective case of rectal carcinoma with paraneoplastic cerebellar degeneration. A 79-year-old man with Parkinson's disease was unable to walk because of paralysis. Brain MRI showed cerebellar atrophy. He was admitted to our hospital for anal bleeding and was diagnosed with colon cancer. An associated diagnosis of PCD was made. After resection, his paralysis and dysarthria were resolved to the extent of beingable to walk and speak fluently. Brain MP-RAGE showed no findings suggestive of metastasis or atrophy. He was treated surgically, which resulted in a transient improvement in PCD symptoms. Per blood testing, cytokines IL-6 and IL-10 were lower postoperatively. Immunosuppressive levels of myeloid- derived suppressor cells(MDSCs)were lower compared with the preoperative values. Thus, innate immunocompetence and resolution of paralysis followed the surgical intervention.

Immunotherapy has become a promising treatment strategy for cancer. Immune checkpoint blockade with anti-CTLA4 mAb and anti-PD-1 mAb has demonstrated clear evidence of objective responses including improved overall survival and tumor shrinkage, driving renewed enthusiasm for cancer immunotherapy in multiple cancer types including esophageal squamous cell carcinoma (ESCC). There are several clinical trials using anti-PD1 mAb for ESCC in early phases and the results are currently promising. In this review, recent advances in cancer immunotherapy for ESCC are discussed with particular focus on immune checkpoint inhibitors and cancer vaccine.

Background Recently, endoscopic submucosal dissection (ESD) has been used as a less invasive treatment for superficial esophageal cancer. Additional treatment is often required after non-curative resection to prevent local recurrence and lymph node metastasis. Here, we present the outcomes of various additional treatments for patients with superficial esophageal cancer who underwent ESD. Methods Between 2006 and 2017, we performed ESD in 179 patients (210 lesions) with superficial esophageal cancer and 44 cases resulted in the non-curative resection diagnosed by the pathological examination. Among them, 29 patients received additional treatment, whereas 15 patients with no additional treatment were followed up. Additional treatment included esophagectomy (8 patients), chemoradiotherapy (15 patients), ablation using argon plasma coagulation (4 patients), and chemotherapy alone (2 patients). We examined the clinicopathological characteristics and prognosis of patients in the additional esophagectomy group (S group) and chemoradiotherapy group (CRT group). Results Twenty-three patients with pT1a-MM, pT1b, lymphatic invasion, venous invasion, and positive resection margins (both horizontal and vertical) were divided into two treatment groups. Clinicopathological characteristics of patients in the S and CRT groups were not significantly different. Pathological findings after additional esophagectomy showed one residual tumor and one lymph node metastasis. There were no recurrences in the two groups. There was no statistically significant difference in the 5-year overall survival rate between the S group (87.5%) and the CRT group (93.3%). One patient from the S group died due to respiratory pneumonia, and one patient died due to radiation pneumonia. However, five out of the 15 (33.3%) patients who were followed up with no additional treatment developed recurrence. The 5-year overall survival rate was 40.4%, which was not significantly different from that in the additional treatment group. However, the 5-year relapse-free survival rate (30%) was significantly different from that in the additional treatment group (P > 0.05). Conclusion Additional treatment is essential after non-curative endoscopic submucosal resection for esophageal cancer. Additional esophagectomy and chemoradiotherapy were both safe and effective in this cohort. Disclosure All authors have declared no conflicts of interest.

A 55-year old man underwent distal gastrectomy with lymphadenectomy for gastric cancer(T1N0M0, Stage I A). Six months after the radical operation, he presented with multiple liver metastases. Based on immunohistochemical examination, he was diagnosed with AFP-producing gastric cancer and metachronous liver metastases. He underwent a surgery to remove the liver metastases. Two months after the surgery, recurrent tumors were found in the lung and remnant liver. He received chemotherapy(S-1/CDDP and CPT-11/CDDP)for the recurrent tumor and lived for 15 months after the surgical intervention.

Background Circulating tumor cells (CTCs) in patients with malignant tumors can be used as a prognostic marker. Recently the existence of mesenchymal CTCs have been detected by new methods. However, it has been not yet clarified how CTCs are associated with the treatment effects in esophageal cancer patients. We assessed CTCs in esophageal cancer patients and investigated the relationship between CTCs and treatment effect. Methods Seven patients who had potential of curative resection have been enrolled and peripheral blood samples (10ml) were collected before and after treatment. All patients received chemotherapy (5-FU and cisplatin) and four patients of them received as neoadjuvant therapy. Other patients received only chemotherapy and radiation therapy without operation. CTCs were analyzed using a Microfluidic Chip devise provide with the Nihon Gene Research Laboratories. This system can isolates CTCs from blood samples, based on their size and deformability differences from blood cells. Phenotypes of CTCs are determined by staining and scanning systems. A previous report revealed that this method had higher sensitivity for CTCs than conventional methods (the Cell Search system) in 61 metastatic breast cancer. Results Treatments effects were stable disease or better in all cases. Multiple CTCs were detected in all cases before treatment. Five patients had epithelial CTCs and others had only mesenchymal CTCs. Total number of CTCs after treatment whose data can be available decreased except for two cases. One patient had no CTC after treatment. Two cases have been currently analyzing. Conclusion CTCs may exist almost all patients of Stage II or more esophageal cancer. Decreasing the number of CTCs after treatment suggests some relationship between CTCs and treatment effect, and the accumulation of more cases is necessary. Disclosure All authors have declared no conflicts of interest.