Tumor-infiltrating monocytic myeloid-derived suppressor cells contribute to the development of an immunosuppressive tumor microenvironment in gastric cancer.

BACKGROUND: Gastric cancer (GC) is characterized by an immunosuppressive and treatment-resistant tumor immune microenvironment (TIME). Here, we investigated the roles of different immunosuppressive cell types in the development of the GC TIME. METHODS: Single-cell RNA sequencing (scRNA-seq) and multiplex immunostaining of samples from untreated or immune checkpoint inhibitor (ICI)-resistant GC patients were used to examine the correlation between certain immunosuppressive cells and the prognosis of GC patients. RESULTS: The results of the scRNA-seq analysis revealed that tumor-infiltrating monocytic myeloid-derived suppressor cells (TI-M-MDSCs) expressed higher levels of genes with immunosuppressive functions than other immunosuppressive cell types. Additionally, M-MDSCs in GC tissues expressed significantly higher levels of these markers than adjacent normal tissues. The M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues. Among the immunosuppressive cell types assessed, the M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues; moreover, their presence was most strongly associated with a poor prognosis. Immediate early response 3 (IER3), which we identified as a differentially expressed gene between M-MDSCs of GC and adjacent normal tissues, was an independent poor prognostic factor in GC patients (P = 0.0003). IER3+ M-MDSCs expressed higher levels of genes with immunosuppressive functions than IER3- M-MDSCs and were abundant in treatment-resistant GC patients. CONCLUSIONS: The present study suggests that TI-M-MDSCs, especially IER3+ ones, may play a predominant role in the development of the immunosuppressive and ICI-resistant GC TIME.

The degree of satisfaction and level of learning in male and female surgical residents: a nationwide questionnaire survey of graduating residents in Japan.

PURPOSE: Since 2002, the Japan Surgical Society has established a board certification system for surgeons to be certified for a specialty. Surgery remains a male-dominated field in Japan. This study aimed to clarify if the Japanese surgical residency training system is equally suitable for female and male residents. METHODS: The Japan Surgical Society conducted the first questionnaire survey regarding the system of surgical training for the residents in 2016. The questionnaire included the degree of satisfaction with 7 aspects of the training system, including the number and variety of cases experienced and duration and quality of instruction, and the learning level for 31 procedures. The degree of satisfaction and level of learning were compared between female and male residents. RESULTS: The degree of satisfaction was similar for all items between female and male residents. Female residents chose breast surgery as their subspecialty more frequently than male residents and were more confident in breast surgery procedures than male residents. Conversely, fewer female residents chose gastrointestinal surgery and were less confident in gastrointestinal surgery procedures than male residents. CONCLUSION: Female residents were as satisfied with the current surgical training system as male residents. However, there may be room for improvement in the surgical system, considering that fewer applications for gastrointestinal surgery come from female residents than from males.

Validation study of a skill assessment tool for education and outcome prediction of laparoscopic distal gastrectomy.

BACKGROUND: The Japanese operative-rating scale for laparoscopic distal gastrectomy (JORS-LDG) was developed through cognitive task analysis together with the Delphi method to measure intraoperative performance during laparoscopic distal gastrectomy. This study aimed to investigate the value of this rating scale as an educational tool and a surgical outcome predictor in laparoscopic distal gastrectomy. METHODS: The surgical performance of laparoscopic distal gastrectomy was assessed by the first assistant, through self-evaluation in the operating room and by video raters blind to the case. We evaluated inter-rater reliability, internal consistency, and correlations between the JORS-LDG scores and the evaluation methods, patient characteristics, and surgical outcomes. RESULTS: Fifty-four laparoscopic distal gastrectomy procedures performed by 40 surgeons at 16 institutions were evaluated in the operating room and with video recordings using the proposed rating scale. The video inter-rater reliability was > 0.8. Participating surgeons were divided into the low, intermediate, and high groups based on their total scores. The number of laparoscopic surgeries and laparoscopic gastrectomy procedures performed differed significantly among the groups according to laparoscopic distal gastrectomy skill levels. The low, intermediate, and high groups also differed in terms of median operating times (311, 266, and 229 min, respectively, P < 0.001), intraoperative complication rates (27.8, 11.8, and 0%, respectively, P = 0.01), and postoperative complication rates (22.2, 0, and 0%, respectively, P = 0.002). CONCLUSIONS: The JORS-LDG is a reliable and valid measure for laparoscopic distal gastrectomy training and could be useful in predicting surgical outcomes.

Influence of endoscopic resection on additional laparoscopic distal gastrectomy: a propensity score-matching analysis.

PURPOSE: There is no definite evidence of the feasibility and safety of laparoscopic distal gastrectomy (LDG) for patients who have undergone incomplete endoscopic resection (ER). We investigated the influence of ER prior to LDG by a propensity score matching analysis. METHODS: We retrospectively analyzed the outcomes of gastric cancer patients who underwent LDG with or without prior ER from 2000 to 2014. Propensity score matching was performed to compare the two groups of patients. RESULTS: After matching, 47 patients in the ER group and 94 patients in the non-ER group were selected from a total of 365 patients. A residual tumor was observed in 10 of 47 patients (21.3%). The mean number of dissected lymph nodes in the non-ER group (39.4 ± 14.5) was higher than that in the ER group (31.7 ± 13.5) (P = 0.003). However, other perioperative data, such as the operation time and blood loss volume were similar. The complication rate of the ER group (17.0%) and the non-ER group (9.6%) did not differ to a statistically significant extent (P = 0.2). Among these patients, 6 died during the 5-year follow-up period, but no patients showed signs of recurrence. CONCLUSION: ER prior to surgical resection showed no significant influence on postoperative complications or mortality. LDG can be safely performed to achieve radical resection after incomplete ER.

Are graduating residents sufficiently competent? Results of a national gap analysis survey of program directors and graduating residents in Japan.

PURPOSE: To evaluate the self-assessed competency of graduating residents (GRs) in Japan upon completion of their residency and to identify the gap between their competency and the competency expected by their program directors (PDs). METHOD: A list of 31 essential surgical procedures was compiled according to the consensus of surgical educators from around the country. A survey with this list was sent to all 909 GRs and their 611 PDs in 2016. The GRs rated their competency to perform these procedures and the PDs were asked to evaluate the expected competency of their GRs using the Zwisch Scale. RESULT: The response rate was 56.3% for the GRs and 76.8% for the PDs. Fewer than half of the GRs who responded felt confident performing ten (32%) of the surgical procedures evaluated. For most procedures, the GRs' self-reported competency was lower than the expectation reported by their PDs. This gap was more than 10% for 13 of the procedures. CONCLUSION: More than half of the GRs in Japan lacked the confidence in their skill to perform one-third of the surgical procedures selected for evaluation in this study. These findings should be used to update the surgical education curriculum in Japan.

Is there disparity between regions and facilities in surgical resident training in Japan? Insights from a national survey.

PURPOSE: This study sought to assess the disparity between regions and facilities in surgical resident training in Japan via a national level needs-assessment. METHODS: A survey was sent to all 909 graduating residents of 2016. Residents trained in the six prefectures with a population of 7 million or more were included in the large prefecture (LP) group. Residents trained in the other 41 prefectures were included in the small prefecture (SP) group. Each group was further divided into a university hospital (UH) group and a non-university hospital (NUH) group. RESULTS: The response rate was 56.3% (n = 512). Excluding nine residents who did not report their prefectures and facilities, surveys from 503 residents were analyzed. The UH group received significantly more years of training. In the SP and UH groups, there were significantly fewer residents who had performed 150 procedures or more under general anesthesia in comparison to the LP and NUH groups, respectively. Self-assessed competencies for several procedures were significantly lower in the SP and UH groups. CONCLUSION: Disparity in surgical resident training was found between regions and facilities in Japan. The surgical residency curriculum in Japan could be improved to address this problem.

Long-term Outcomes of Laparoscopic Versus Open Surgery for Clinical Stage II/III Gastric Cancer: A Multicenter Cohort Study in Japan (LOC-A Study).

OBJECTIVE: A large-scale multicenter historical cohort study was conducted to investigate the efficacy of laparoscopic gastrectomy (LG) in comparison to open gastrectomy (OG) for locally advanced gastric cancer. BACKGROUND: LG is now practiced widely, but its applicability for advanced gastric cancer is still controversial. As oncologic outcomes of randomized trials are still pending, there is an urgent need for information that would be relevant to current practice. METHODS: Through a consensus meeting involving surgeons and biostatisticians, 30 preoperative variables possibly influencing the choice of surgical approach and associated with outcome were identified to enable rigorous estimation of propensity scores. A total of 1948 consecutive patients who underwent gastrectomy for clinical stage II/III gastric adenocarcinoma between 2008 and 2014 were identified, and their clinical data were collected from 8 participating hospitals. After propensity score matching, 610 cases (OG = 305, LG = 305) were finally selected for comparison of long-term outcomes. RESULTS: In the propensity-matched OG and LG populations, the mean observation period was 3.5 and 3.4 years, and the 5-year overall survival was 53.0% and 54.2%, respectively. The hazard ratio (LG/OG) for overall survival was 1.01 (95% confidence interval, 0.80-1.29), and noninferiority of LG was demonstrated statistically as the upper 95% confidence limit was less than the prespecified margin (1.33). The recurrence rate was 30.8% and 29.8% for OG and LG, respectively, and the hazard ratio for recurrence was 0.98 (95% confidence interval, 0.74-1.31). The patterns of recurrence in the 2 groups were similar. CONCLUSIONS: This observational study strictly adjusted for confounding factors has provided evidence to suggest that LG is oncologically comparable to OG for locally advanced gastric cancer. The validity of this result will be examined in ongoing randomized trials.

A snapshot of surgical resident training in Japan: results of a national-level needs assessment survey.

PURPOSE: To evaluate the status of surgical training in Japan through a national-level needs assessment. METHODS: A survey was sent to all 909 graduating residents (GRs) and their 611 program directors (PDs) for the year 2016. A working group of surgical educators from around the country was formed under the education committee of the Japan Surgical Society. The survey items were developed by consensus of this working group. The survey investigated the knowledge and problems of the current curriculum, and the status of the current residency training. RESULTS: The response rates were 56.3% of the GRs and 76.8% of the PDs. Among the participants, 47.6% of the GRs and 29.4% of the PDs believed that the residency curriculum did not match the clinical experience. Over 80% of the GRs and PDs agreed on the importance of training outside of the OR, whereas only 13% of the GRs had received such training regularly. Trainees also reported a lower satisfaction rate about the opportunity to train outside of the OR. CONCLUSION: This national-level needs assessment of surgical training in Japan identified several gaps in the curriculum. These results provide valuable data to assist the ongoing efforts for surgical residency curriculum improvement.

Molecular Characteristics of Pancreatic Ductal Adenocarcinomas with High-Grade Pancreatic Intraepithelial Neoplasia (PanIN) Are Different from Those without High-Grade PanIN.

AIMS: We reported that pancreatic ductal adenocarcinomas (PDACs) without high-grade pancreatic intraepithelial neoplasia (PanIN) in the vicinity had worse prognoses than PDACs with high-grade PanIN. However, the molecular characteristics of PDACs with and without high-grade PanIN have not been compared. The aim of this study is to clarify the molecular characteristics of PDACs with and without high-grade PanIN. METHOD AND RESULTS: We reviewed all of a consecutive series of 100 patients with PDACs and divided them into 2 groups: the PDACs with PanIN-2 or PanIN-3 in the background (the PanIN-high group, n = 60) and the PDACs without PanIN-2 or PanIN-3 in the background (the PanIN-low group, n = 40). We evaluated the p53, p16, and SMAD4 expressions in the invasive ductal carcinoma (IDC) components by immunohistochemical staining. KRAS mutation was also analyzed in 80 tumors. The PanIN-low group showed significantly more frequent "high p53 expression" and "loss of SMAD4 expression" than the PanIN-high group (p = 0.048 and p = 0.019, respectively). Loss of p16 expression was not significantly different between the groups. The rate of KRAS wild type was significantly higher in the PanIN-low group than the PanIN-high group (p = 0.024). CONCLUSIONS: Our results demonstrated that the molecular characteristics in the PDACs with high-grade PanIN were different from those in the PDACs without high-grade PanIN. PDACs without high-grade PanIN may develop via a pathway other than the PanIN-carcinoma sequence.

Remote transmission of live endoscopy over the Internet: Report from the 87th Congress of the Japan Gastroenterological Endoscopy Society.

Live demonstration of endoscopy is one of the most attractive and useful methods for education and is often organized locally in hospitals. However, problems have been apparent in terms of cost, preparation, and potential risks to patients. Our aim was to evaluate a new approach to live endoscopy whereby remote hospitals are connected by the Internet for live endoscopic demonstrations. Live endoscopy was transmitted to the Congress of the Japan Gastroenterological Endoscopic Society by 13 domestic and international hospitals. Patients with upper and lower gastrointestinal diseases and with pancreatobiliary disorders were the subjects of a live demonstration. Questionnaires were distributed to the audience and were sent to the demonstrators. Questions concerned the quality of transmitted images and sound, cost, preparations, programs, preference of style, and adverse events. Of the audience, 91.2% (249/273) answered favorably regarding the transmitted image quality and 93.8% (259/276) regarding the sound quality. All demonstrators answered favorably regarding image quality and 93% (13/14) regarding sound quality. Preparations were completed without any outsourcing at 11 sites (79%) and were evaluated as 'very easy' or 'easy' at all but one site (92.3%). Preparation cost was judged as 'very cheap' or 'cheap' at 12 sites (86%). Live endoscopy connecting multiple international centers was satisfactory in image and sound quality for both audience and demonstrators, with easy and inexpensive preparation. The remote transmission of live endoscopy from demonstrators' own hospitals was preferred to the conventional style of locally organized live endoscopy.

Technical feasibility of laparoscopic total gastrectomy with splenectomy for gastric cancer: clinical short-term and long-term outcomes.

BACKGROUND: Since its widespread acceptance for the treatment of early gastric cancer, laparoscopic gastrectomy has been gaining popularity as a treatment option for advanced gastric cancer. However, laparoscopic total gastrectomy (LTG) with splenectomy is seldom performed, because of its difficulty of removal of station 10 lymph nodes; splenectomy is technically essential for complete removal of these lymph nodes. The purpose of this study was to describe the details of the LTG procedure and to evaluate the short- and long-term outcomes of LTG with splenectomy. METHODS: Of 725 consecutive patients with gastric cancer who underwent laparoscopic gastrectomy with lymph node dissection in our institution from January 1996 to December 2012, 18 consecutive patients who underwent LTG with splenectomy were enrolled in this study. RESULTS: No operative mortality occurred, and the pathological margins were free from cancer cells in all patients. The mean operation time was 388 min (range 324-566 min). The mean volume of blood loss was 45 ml (range 5-347 ml), and the mean number of dissected lymph nodes was 51 (range 40-105). Postoperative morbidity occurred in six patients (33.3%) (each with grade B postoperative pancreatic fistula, postoperative bleeding, chylous ascites, atelectasis, ileus, and intra-abdominal infection). Five patients (27.8%) developed recurrence (four in the peritoneum and one in the liver), and the overall 3- and 5-year survival rates were 83.0 and 72.6%, respectively. CONCLUSIONS: Considering the 0% mortality rate and low rates of postoperative morbidity and locoregional recurrence, LTG with splenectomy is technically and oncologically acceptable. This procedure can be expanded to include advanced gastric cancer, which generally requires splenectomy for lymph node dissection.

Outcomes of cervical end-to-side triangulating esophagogastric anastomosis with minimally invasive esophagectomy.

BACKGROUND: Esophagogastric anastomosis after esophagectomy has been performed with a variety of techniques during the past decade. However, anastomotic leakage and stricture are still important clinical problems after esophagogastric anastomosis, causing burdensome symptoms and poor quality of life. Herein, we describe a novel cervical end-to-side triangulating esophagogastric anastomoasis using linear stapler. METHODS: A total of 90 patients (85 % male; mean age 63 years) with thoracic esophageal cancer who underwent cervical end-to-side esophagogastric triangular anastomosis using a linear stapler after minimally invasive esophagectomy between November 2006 and April 2013 were retrospectively reviewed. RESULTS: The median operation time was 602 min (range 424-936 min). The volume of blood loss during the entire operative procedure was 127 ml (range 0-700 ml). There were no cases of anastomotic leakage in this study, although four patients (4.4 %) developed dysphagia associated with benign anastomotic stricture formation. All patients with a benign anastomotic stricture underwent balloon dilation, which resulted in improvement in their symptoms. CONCLUSIONS: Considering the absence of anastomotic leakage and low rate of anastomotic stricture formation in this study, our modified triangular esophagogastric anastomosis technique appears promising and may contribute to reduced morbidity and mortality rates following esophagectomy.

Surgery of upper GI gastrointestinal stromal tumors: our experience, prognostic analysis.

BACKGROUND/AIMS: To review our treatment experience of gastrointestinal stromal tumors (GISTs) of the upper gastrointestinal tract and identify the prognostic factors that influence tumor recurrence. METHODOLOGY: Data of 46 consecutive patients with upper GI GISTs who underwent surgery from 1988 to 2011 were reviewed. The overall and disease-free survival rates and influence of clinicopathologic variables on disease-free survival rate were evaluated. RESULTS: The median age was 64 years (range, 20-86 years). R0 resections were performed in 43 (93.5%) patients. With a median follow-up time of 33 months (1-275 months), there were 5 (10.9%) recurrences and 2 mortalities in the high-risk group. The overall survival and recurrence-free survival rates at 5 years were 92.1% and 84.6%, respectively. Male gender, tumor size of >10 cm, high numbers of mitotic figures, R1 resection, high risk according to the Joensuu criteria, and a Ki-67 index of >10% were associated with a poor prognosis. CONCLUSIONS: Surgical resection of low- and intermediate-risk GISTs has excellent results. High counts of mitotic figures, male gender, incomplete resection, large tumor size, and a high Ki-67 index are associated with a poor prognosis.

Micro RNA-373 is down-regulated in pancreatic cancer and inhibits cancer cell invasion.

BACKGROUND: Micro RNAs (miRNAs) are small noncoding RNAs that have gained attention as key molecules in the malignant characteristics of cancers, and several recent investigations also have identified some miRNAs as potential key regulators to inhibit the malignant characteristics of tumors. MiRNA-373 (miR-373) has recently been reported to induce E-cadherin, which is a key regulator of epithelial-mesenchymal transition (EMT). However, the role of miR-373 in the characteristics of cancer cells is not still well known. METHODS: We investigated the expression levels of miR-373 in pancreatic cancer cell lines and its effect on the invasiveness of pancreatic cancer by using in vitro and in vivo models. We also analyzed the expression of miR-373 using formalin-fixed paraffin-embedded (n = 152) and microdissected frozen (n = 57) samples from pancreatic tissues. RESULTS: The levels of miR-373 expression were low in pancreatic cancer cell lines. In formalin-fixed paraffin-embedded and microdissected frozen samples, miR-373 expression was significantly down-regulated in pancreatic cancer compared with that in healthy pancreas (P < 0.001 and P = 0.005, respectively). We also found that reexpression of miR-373 repressed transforming growth factor-ß-induced EMT, leading to inhibition of invasiveness of cancer cells. Furthermore, reexpression of miR-373 significantly inhibited peritoneal dissemination in vivo (P < 0.001). CONCLUSIONS: MiR-373 is down-regulated in pancreatic cancer, and its reexpression represses the invasiveness of pancreatic cancer cells.

Laparoscopic total gastrectomy for remnant gastric cancer: feasibility study.

BACKGROUND: The benefits and feasibility of laparoscopic surgery for remnant gastric cancer are still unclear. The purpose of this study was to describe the detailed procedure and to evaluate the clinical short-term outcomes of laparoscopic total gastrectomy (LTG) compared with open total gastrectomy (OTG) for remnant gastric cancer (RGC). METHODS: Of 1,247 consecutive patients who underwent gastrectomy for gastric cancer in our department at Kyushu University Hospital from January 1996 to May 2012, 22 patients who underwent successful curative resection of RGC with precise nodal dissection were enrolled in this study. Twelve patients underwent LTG and the remaining ten patients underwent OTG. We analyzed the clinical short-term outcomes of LTG and compared the results between LTG and OTG groups to evaluate the safety and feasibility of LTG. RESULTS: Twelve patients with RGC successfully underwent LTG without open conversion and morbidity. The mean operation time of LTG, 362.3 ± 68.4 min, was significantly longer than that of OTG (p = 0.0176), but the mean blood loss of LTG, 65.8 ± 62 g, was smaller than that of OTG (p < 0.01). The mean postoperative times to resumption of water and food intake were significantly shorter in the LTG group than in the OTG group (p < 0.01). The overall 3-year survival rate was comparable between the LTG and OTG groups (77.8 vs. 100 %; p = 0.9406). CONCLUSIONS: This study shows that LTG is a feasible and reliable procedure for the treatment of RGC in terms of short-term outcomes.

Renal Failure Without Hemodialysis Is a Risk Factor for Postoperative Complications in Colorectal Cancer Surgery.

Background/Aim: Surgical outcomes of colorectal cancer (CRC) in patients with renal failure (RF) remain to be clarified. The objective of this research was to investigate how RF impacts the surgical outcomes in patients with CRC. Patients and Methods: A retrospective analysis was performed on clinical data from 633 patients who underwent colorectal resection for CRC between January 2017 and December 2021. Outcomes of the patients with and without RF were compared. RF was defined as estimated Glomerular Filtration Rate less than 30. Results: Forty-five (7%) patients with RF were identified. RF was a significant risk factor for postoperative complications after colorectal cancer surgery (odds ratio=2.19, 95% confidence interval=1.08-4.42, p=0.0284). The patients with RF had significantly more comorbidity (p=0.016), and higher American Society of Anesthesiologists physical status (p<0.01). Hemoglobin level (p<0.01) and PNI (p<0.01) were significantly lower in those with RF. Postoperative complications were significantly higher (p=0.016), and the postoperative hospital stay was significantly longer (p<0.01) among patients with RF compared to those without RF. Patients with RF, excluding those undergoing hemodialysis, had significantly more complications compared to those without RF (p=0.004). Conclusion: Careful attention should be paid to perioperative management in RF colorectal cancer patients.

Feasibility of laparoscopic gastrectomy for advanced gastric cancer with positive peritoneal cytology.

PURPOSE: The role of gastrectomy for patients with positive peritoneal cytology, but a negative macroscopic peritoneal implant (P-/cy+), remains unclear. The aim of this study was to evaluate laparoscopic gastrectomy for P-/cy+ patients. METHODS: This study reviewed a prospectively maintained gastric cancer database of gastric-cancer patients those underwent surgical resection. P-/cy+ gastric cancer that had invaded the subserosa, or deeper layers, of the stomach wall without distant organ metastases was considered operable in this institution. P-/cy+ patients underwent either open or laparoscopic gastrectomy with D2 lymphadenectomy. The short-term results were examined to assess differences in outcome between the two groups. RESULTS: Eighteen P-/cy+ patients without distant organ metastases underwent surgery between 2000 and 2010. Laparoscopic gastrectomy was performed in nine patients and open gastrectomy in nine patients. The estimated blood loss was significantly smaller, the resumption of food intake earlier, and the length of postoperative hospital stay shorter in the patients that underwent laparoscopic gastrectomy than in the patients that underwent open gastrectomy. There were no significant differences in the 2-year survival rates between the groups. CONCLUSION: Laparoscopic gastrectomy for P-/cy+ patients is a minimally invasive and safe oncologic procedure with good short-term results.

[Surgical treatment of gastroentero-pancreatic neuroendocrine tumor].

The treatment of choice for gastroentero-pancreatic neuroendocrine tumor(NET)is resection. Because it is difficult to determine the histological grade of NET before operation, the treatment strategy is usually made based on an imaging study including the tumor's size. Some selected gastrointestinal NETs are indicated for endoscopic resection, while others are resected surgically with lymph node dissection. The types of resections for pancreatic NETs vary from enucleation to pancreatectomy with or without regional lymph node dissection, based on the type of excessive hormone, tumor size, distance from the main pancreatic duct, and the presence of type 1 multiple endocrine neoplasia. Hepatic metastases are also resected, if indicated, and even in patients having unresectable metastatic lesions, multidisciplinary therapy including reduction surgery of over 90% of tumor volume might lead to a favorable prognosis. Postoperative adjuvant therapy is recommended for neuroendocrine carcinoma, while there is no evidence to support adjuvant therapy for curatively resected well-differentiated NET.

Single-cell transcriptome analysis reveals functional changes in tumour-infiltrating B lymphocytes after chemotherapy in oesophageal squamous cell carcinoma.

BACKGROUND: Tumour immune microenvironment is related with carcinogenesis and efficacy of immunotherapy. B cells play major roles in humoral immunity, but detailed functions of tumour-infiltrating B lymphocytes (TIL-Bs) are unknown. Therefore, our aim was to investigate the functional heterogeneity of TIL-Bs in oesophageal squamous cell carcinoma (ESCC) and lymph nodes (LNs) during chemotherapy. METHODS: Single-cell transcriptome analysis was performed on 23 specimens. We also performed immunohistochemical analysis of immunoglobulin κ C (IGKC), an antibody-secreting cell (ASC) marker, in 166 ESCC samples and evaluated the implication of IGKC in 2-year recurrence free survival (RFS) and 3-year overall survival (OS). RESULTS: A total of 81,246 cells were grouped into 24 clusters. We extracted B cell clusters based on canonical markers and identified 12 TIL-B subtypes in ESCC. We found that several functions, such as co-stimulation and CD40 signalling, were enhanced in TIL-Bs after chemotherapy. The proportion of naive B cells (NBCs) decreased and B cell activation genes were up-regulated in NBCs after chemotherapy. The proportion of ASCs in tumours increased with the loss of migratory abilities and antibody production in ASCs was promoted after chemotherapy. Differentially expressed genes up-regulated with chemotherapy in ASCs correlated with prolonged survival with oesophageal cancer (p = .028). In a metastatic LN, the ASC proportion increased and B cell differentiation was enhanced. In immunohistochemical analysis, RFS and OS of high IGKC expression cases were significantly better than those of low IGKC expression cases (RFS: p < .0001, OS: p < .0001). And in multivariable analysis, the expression of IGKC was an independent favourable prognostic factor for RFS (hazard ratio (HR): 0.23, 95% confidence interval (CI): 0.12-0.45, p < .0001) and OS (HR: 0.20, 95% CI: 0.086-0.47, p = .0002) in ESCC. CONCLUSIONS: Our findings provide novel insights for the heterogeneity of TIL-Bs during chemotherapy and will be useful to understand the clinical importance of TIL-Bs.

MicroRNA-10a is overexpressed in human pancreatic cancer and involved in its invasiveness partially via suppression of the HOXA1 gene.

BACKGROUND: There is increasing evidence that microRNAs are differentially expressed in many types of cancers. Despite progress in analyses of microRNAs in several types of cancers, the functional contributions of microRNAs to pancreatic cancer remain unclear. METHODS: In the present study, the expression levels of specific microRNAs identified by microarray analyses were examined in a panel of 15 pancreatic cancer cell lines. We then investigated the functional roles of these microRNAs in the proliferation and invasion of pancreatic cancer cells. RESULTS: Based on the microarray data, we found frequent and marked overexpression of miR-10a, miR-92, and miR-17-5p in pancreatic cancer cell lines. Microdissection analyses revealed that miR-10a was overexpressed in pancreatic cancer cells isolated from a subset of primary tumors (12 of 20, 60%) compared with precursor lesions and normal ducts (P<.01). In vitro experiments revealed that miR-10a inhibitors decreased the invasiveness of pancreatic cancer cells (P<.01), but had no effect on their proliferation. Inhibition of HOXA1, a target of miR-10a, promoted the invasiveness of pancreatic cancer cells (P<.01). CONCLUSIONS: The present data suggest that miR-10a is overexpressed in a subset of pancreatic cancers and is involved in the invasive potential of pancreatic cancer cells partially via suppression of HOXA1.