Search

Abstract Adjuvant oxaliplatin plus capecitabine (XELOX) therapy is recommended for patients with curatively resected colon cancer. However, prospective data on its practical application in Japanese patients are limited. Therefore, we aimed to conduct a long-term clinical evaluation of the efficacy and safety of adjuvant XELOX in patients with curatively resected stage III colon cancer (MCSCO-1024). This prospective, multi-center, open-label, single-arm, phase II study enrolled patients with curatively resected stage III colon cancer. The treatment protocol consisted of a 120-minute intravenous infusion of oxaliplatin (130 mg/m2) on day 1 and two divided doses oral capecitabine (2000 mg/m2/day) for 14 days in a 3-week cycle, totaling eight cycles (24 weeks). The primary endpoint was 3-year disease-free survival (DFS), and the secondary endpoints were 5-year overall survival and long-term prognosis of peripheral sensory neuropathy. A total of 196 patients were enrolled between November 2011 and August 2014 (34 months). The 3-year DFS rate was 73%, and the 5-year overall survival rate was 87%. The overall incidence of peripheral sensory neuropathy was 17%, with a 1% rate of grade 3 neuropathy after 5 years. Adjuvant XELOX demonstrated utility and safety in the clinical management of Japanese patients with stage III colon cancer.

Abstract We developed a novel clamping device for laparoscopic surgery, free from conventional pinch structure, capable of uniformly occluding any ductal organ. This study aimed to evaluate performance of the new clamper compared to the pinch-type clamper. The new clamper consists of two metal bars with ties at each end, which enables parallel clamping. A resected porcine stomach was used, with an infusion tube at the anal end to increase intra-luminal pressure. The oral side of the stomach was clamped with either the new clamper or the pinch-type clamper, and their performances were evaluated in qualitative and semi-quantitative manner. Qualitative evaluation involved imaging the clamping site at intra-gastric pressures from 0 to 15 mmHg using microfocus computed tomography. The new clamper showed no gap even under increased intra-luminal pressure, while the pinch-type clamper showed a gap on the distal side. Quantitative evaluation measured bursting pressure under continuous air insufflation. Air leakages were observed in the new clamper at higher intra-luminal pressures than in the pinch-type clamper (46.1 mmHg vs. 13.6 mmHg, P

Abstract Purpose Postoperative venous thromboembolism (VTE) risk is pronounced after abdominal cancer surgery. Enoxaparin shows promise in preventing VTE in gastrointestinal, gynecological, and urological cancers, but its application after surgery for hepatobiliary‐pancreatic malignancy has been under‐evaluated due to bleeding concerns. We confirmed the safety of enoxaparin administration in patients undergoing curative hepatobiliary‐pancreatic surgery for malignancies in a prospective, multi‐center, phase I study. Methods The study was conducted from April 2015 to May 2021 across eight specialized centers. Patients (n = 262) were randomized to enoxaparin prophylaxis given postoperatively for 8 days (n = 131) or control (n = 131). The primary endpoint was the efficacy in reducing VTE. Secondary endpoints examined safety. Results The full analysis set included 259 patients (131 control, 129 enoxaparin). The per‐protocol population included 233 patients (117 control, 116 enoxaparin). Most cases were hepatic malignancies (111 control, 111 enoxaparin). The median administration duration of enoxaparin was 7 days, with 92% receiving 4000 units/day. Despite a reduction in the relative risk (RR) of VTE due to postoperative enoxaparin administration, the results were not significant (control: four cases, 3.4% vs. treatment: two cases, 1.7%; RR 0.50, 95% CI 0.09–2.70; p = 0.6834). No significant difference was found in the incidence of bleeding events (control: five cases, 4.3% vs. treatment: five cases, 4.3%, RR 1.00, 95% CI 0.53–1.89; p = 1.0000). Conclusions The perioperative administration of enoxaparin in hepatobiliary‐pancreatic malignancies is feasible and safe. However, further case accumulation and investigation are necessary to assess its potential in reducing the occurrence of VTE.

Abstract Background Local recurrence is common after curative resections of rectal cancer. Surgical resection is considered a primary curative treatment option for patients with locally recurrent rectal cancer (LRRC). LRRC often requires a combined resection of other organs, especially in the case of posterior recurrence, which requires a combined resection of the sacrum, making the surgery highly invasive. Venous thromboembolism (VTE) is one of the lethal complications in the postoperative period, particularly in the field of pelvic surgery. We found no reports regarding the risks of postoperative VTE in surgery for LRRC, a typical highly invasive procedure in the field of colorectal surgery. This study aims to evaluate the risk of postoperative VTE in surgery for LRRC patients. Methods From April 2010 to March 2022, a total of 166 patients underwent surgery for LRRC in the pelvic region at our institutions. Clinicopathological background and VTE incidence were compared retrospectively. Results Among the 166 patients included in the study, 55 patients (33.1%) needed sacral resection. Pharmacological prophylaxis for prevention of VTE was performed in 121 patients (73.3%), and the incidence of VTE was 9.09% (5/55 patients) among those who underwent surgery for LRRC with sacral resection, while it was 1.8% (2/111 patients) in those without sacral resection. In univariate analysis, the combination with sacral resection was identified as a risk factor for VTE in surgery for LRRC (p = 0.047). Conclusions This study demonstrates that surgery for LRRC combined with sacral resection could be a significant risk factor for VTE.

Abstract Background Conversion surgery (CS) is a highly anticipated strategy for stage IV advanced gastric cancer (AGC) with a good response to chemotherapy. However, prognostic factors limiting R0 resection remain unclear. In this multi‐institutional study, we investigated the clinical outcomes of CS for stage IV AGC and the prognostic factors of CS‐limiting R0 resection and analyzed them according to metastatic patterns. Methods Clinical data on 210 patients who underwent CS for stage IV AGC at six institutions between 2007 and 2017 were retrospectively retrieved. The patient background, preoperative treatment, operative outcomes, and survival times were recorded. Prognostic factors for overall and recurrence‐free survival were investigated using univariate and multivariate analyses for patients who underwent R0 resection. Results R0 resection was achieved in 146 (70%) patients. The median survival time was 32 months, and the 3‐year survival rate was 45%. Patients who achieved R0 resection had significantly longer survival than those with R1/2 resection (median survival time: 41.5 months vs. 20.7 months). Multivariate analysis identified pathological N positivity for overall and relapse‐free survival and pathological T4 for relapse‐free survival as significant independent poor prognostic factors of R0 resected patients. There was no significant difference in survival among the peritoneum, liver, and lymph node groups regarding the initial metastatic sites. Conclusions CS with R0 resection for patients with stage IV AGC can lead to longer survival. Patients with pathological T4 and pathological N positivity were eligible for intensive adjuvant therapy after CS with R0 resection.

Abstract Aim The number of elderly patients with liver cancer is increasing with the aging society. The Geriatric Prognostic Scoring System is useful in predicting the postoperative prognosis for elderly patients with gastrointestinal cancer. The aim of the present study was to assess the predictive ability of the geriatric prognostic scoring system for postoperative survival in elderly patients with liver cancer. Methods Eighty‐eight patients aged ≥75 years who were treated for primary liver cancer and metastatic liver tumor were retrospectively analyzed. The Geriatric Prognostic Score (GPS) was created by several clinical parameters such as age, sex, type of cancer, stage, performance status, body mass index, and comprehensive geriatric assessment. Each patient was divided into two groups of high‐risk to low‐risk according to their GPS: ≧30 high‐risk group and

Abstract Purpose The NY‐ESO‐1 antigen is highly immunogenic and often spontaneously induces an immune response in patients with cancer. We conducted a large‐scale multicenter cohort study to investigate the utility of serum NY‐ESO‐1 and p53 antibodies as predictive markers for the postoperative recurrence of gastric cancer. Here, we examined the usefulness of pre‐treatment NY‐ESO‐1 and p53 antibodies as tumor markers for the diagnosis of gastric cancer in combination with carcinoembryonic antigen (CEA) and carbohydrate antigen 19‐9 (CA19‐9). Methods A total of 1031 patients with cT3‐4 gastric cancer were enrolled in the study. NY‐ESO‐1 and p53 antibodies were assessed prior to treatment. The positivity of NY‐ESO‐1 and p53 antibodies, CEA, and CA19‐9 was evaluated before treatment. Results Serum NY‐ESO‐1 and p53 antibodies were positive in 12.6% and 18.1% of the patients, respectively. Positive NY‐ESO‐1 antibody response was correlated with male gender, higher cStage, and upper tumor location. However, a positive p53 antibody response was not associated with tumor factors. The combination of NY‐ESO‐1 or p53 antibody response with CEA and CA19‐9, or the 4‐factors, was positive in 45.1%, 49.6%, and 53.8% of patients, respectively. Moreover, the 4‐factor combination was able to detect >60% of cStage III‐IV diseases, which was 14% higher than that with the combination of CEA and CA19‐9. Conclusion The combination of NY‐ESO‐1 and p53 antibody responses to CEA and CA19‐9 increases the diagnostic accuracy of gastric cancer. Serum NY‐ESO‐1 and p53 antibodies may be useful tumor markers for gastric cancer.

Abstract Background Liver transplant recipients (LTRs) are at a high risk of severe COVID-19 owing to immunosuppression and comorbidities. LTRs are less responsive to mRNA vaccines than healthy donors (HDs) or other immunosuppressed patients. However, the disruption mechanism in humoral and cellular immune memory responses is unclear. Methods We longitudinally collected peripheral blood mononuclear cells and plasma samples from HDs (n = 44) and LTRs (n = 54) who received BNT162b2 or mRNA-1273 vaccines. We measured the levels of anti-receptor-binding domain (RBD) antibodies and spike-specific CD4+ and CD8+ T-cell responses. Results Here, we show that the induction of anti-RBD IgG was weaker in LTRs than in HDs. The use of multiple immunosuppressive drugs is associated with lower antibody titers than only calcineurin inhibitor, and limits the induction of CD4+ T-cell responses. However, spike-specific CD4+ T-cell and antibody responses improved with a third vaccination. Furthermore, mRNA vaccine-induced spike-specific CD8+ T cells are quantitatively, but not qualitatively, limited to LTRs. Both CD4+ and CD8+ T cells react to omicron sublineages, regardless of the presence in HDs or LTRs. However, there is no boosting effect of spike-specific memory CD8+ T-cell responses after a third vaccination in HDs or LTRs. Conclusions The third mRNA vaccination improves both humoral responses and spike-specific CD4+ T-cell responses in LTRs but provides no booster effect for spike-specific memory CD8+ T-cell responses. A third mRNA vaccination could be helpful in LTRs to prevent severe COVID-19, although further investigation is required to elicit CD8+ T-cell responses in LTRs and HDs.

Abstract Aim To compare the effects of open (OG) and laparoscopic gastrectomy (LG) on body composition and muscle strength. Methods This study performed a propensity score matching analysis using cases from a large‐scale, multicenter, phase III randomized controlled trial concerning oral nutritional supplements after gastrectomy and analyzed both the whole and matched cohorts. Measurements of body composition and hand grip strength (HGS) were performed at baseline (preoperatively) and at 1, 2, 3, 6, and 12 months after gastrectomy. Results Of 835 patients, 275 and 560 underwent OG and LG, respectively. Skeletal muscle mass (SMM) and HGS loss were significantly lesser in the LG group than in the OG group. The propensity score‐matched analysis, including 120 pairs of patients, confirmed that the % SMM loss values at 1, 2, 3, 6, and 12 POM were −4.5%, −4.0%, −4.7%, −4.6%, and −5.8% in the OG group and −3.0%, −1.9%, −2.4%, −2.2%, and −2.7% in the LG group, respectively. The % SMM loss was significantly lesser in the LG group than in the OG group (repeated measures ANOVA p

Abstract Aim Postoperative small bowel obstruction (SBO) is one of the major complications that is mainly caused by postoperative adhesion. Recently, the antiadhesion membrane has become popular for postoperative SBO prevention. However, its efficacy is yet to be confirmed in the gastric cancer surgery field. Here, we conducted the supplemental analysis of the randomized controlled trial JCOG1001 to investigate the efficacy of the antiadhesion membrane on SBO prevention in patients with open gastrectomy for gastric cancer. Methods Of the 1204 patients enrolled in JCOG1001, 1200 patients were included. The development of SBO of Grade ≥ IIIa according to the Clavien–Dindo classification was recorded. Univariable and multivariable analyses were performed using the Fine and Gray model to determine the risk factors for SBO. Results Fifty‐one patients developed SBO (median follow‐up duration: 5.6 years). Total gastrectomy, combined resection, and blood loss significantly increased the risk for SBO development in the univariable analysis. Large amount of blood loss was independently associated with SBO development in the multivariable analysis (hazard ratio [HR], 3.089; 95% confidence interval [CI], 1.562–6.109, p = 0.0012). Antiadhesion membrane did not reduce the risk for SBO (HR, 1.299; 95% CI 0.683–2.470; p = 0.4246). In the patients belonging to subgroup analyses who received distal and total gastrectomy, the antiadhesion membrane was not associated with the incidence of SBO. Conclusions Antiadhesion membrane did not decrease SBO occurrence rate after open gastrectomy. Therefore, the use of antiadhesion membrane would not be effective for preventing SBO in gastric cancer surgery.

Abstract Background A diaphragmatic hernia is a prolapse of the abdominal organs into the thoracic cavity through a hole in the diaphragm. Traumatic diaphragmatic injuries are rare and usually occur after blunt or penetrating thoracic or abdominal traumas. Blunt diaphragmatic rupture rarely accounts for immediate mortality and may go clinically silent until complications occur which can be life threatening. It usually present late with intrathoracic herniation of abdominal viscera and carry a high mortality rate. We experienced a very rare case who showed repeated colon incarcerations 7 years after injury. And, we operated laparoscopically. Case presentation A 64-year-old man presented with multiple left rib fractures that occurred during an accident. After 7 years, he visited the emergency department with the chief complaint of left shoulder pain and epicardial pain after eating. He was diagnosed with transverse colon incarceration due to a left diaphragmatic hernia by computed tomography (CT) and X-ray imaging. Surgical repair was recommended, but he refused as the symptoms improved. Fourteen months later, the patient revisited the hospital in similar symptoms and improved spontaneously. He consulted our hospital for the surgical indication. We recommended that he undergo surgery, showing images of the X-ray and CT when his transverse colon was obstructed and he felt pain and when symptoms improved. Finally, he decided to undergo surgery. We performed diaphragmatic hernia repair with laparoscopic direct suturing in good view. The patient experienced an uneventful postoperative recovery period. The absence of diaphragmatic herniation recurrence was confirmed seven months after surgery. Conclusions We experienced a traumatic diaphragmatic hernia with repeated colon incarcerations 7 years after injury and performed surgical repair laparoscopically.

Abstract Background First‐line nivolumab plus chemotherapy and nivolumab plus ipilimumab both demonstrated significant overall survival (OS) benefit versus chemotherapy in previously untreated patients with advanced esophageal squamous cell carcinoma (ESCC) in the CheckMate 648 trial, leading to approvals of both nivolumab‐containing regimens in many countries. We report longer‐term follow‐up data. Methods This open‐label, phase III trial (NCT03143153) enrolled adults with previously untreated, unresectable, advanced, recurrent, or metastatic ESCC. Patients were randomized 1:1:1 to nivolumab plus chemotherapy, nivolumab plus ipilimumab, or chemotherapy. Primary endpoints were OS and progression‐free survival (PFS) by blinded independent central review. Hierarchical testing was performed first in patients with tumor cell programmed death ligand 1 (PD‐L1) expression of ≥1% and then in the overall population. Results A total of 970 patients were randomly assigned. After 29 months of minimum follow‐up, nivolumab plus chemotherapy continued to demonstrate improvement in OS versus chemotherapy (hazard ratio [HR] = 0.59 [95% CI: 0.46–0.76]) in patients with tumor cell PD‐L1 expression of ≥1% and in the overall population (HR = 0.78 [95% CI: 0.65–0.93]) and with nivolumab plus ipilimumab versus chemotherapy (HR = 0.62 [95% CI: 0.48–0.80]) in patients with tumor cell PD‐L1 expression of ≥1% and in the overall population (HR = 0.77 [95% CI: 0.65–0.92]). In patients with tumor cell PD‐L1 expression of ≥1%, nivolumab plus chemotherapy demonstrated PFS benefit versus chemotherapy (HR = 0.67 [95% CI: 0.51–0.89]); PFS benefit was not observed with nivolumab plus ipilimumab versus chemotherapy (HR = 1.04 [95% CI: 0.79–1.36]). Among all treated patients (n = 936), Grade 3–4 treatment‐related adverse events were reported in 151 (49%, nivolumab plus chemotherapy), 105 (32%, nivolumab plus ipilimumab), and 110 (36%, chemotherapy) patients. Conclusions Nivolumab plus chemotherapy and nivolumab plus ipilimumab continued to demonstrate clinically meaningful OS benefit versus chemotherapy with no new safety signals identified with longer follow‐up, further supporting use as first‐line standard treatment options for patients with advanced ESCC.

Abstract Objectives Flexible endoscopy does not have a system that can automatically evacuate surgical smoke generated in the gastrointestinal lumen. We aimed to investigate the feasibility and potential usefulness of automatic smoke evacuation systems in flexible endoscopy. Methods [Bench] After surgical smoke generated in the stomach was evacuated by the evacuator, the degree of residual smoke and gastric luminal collapse were evaluated to optimize the evacuator settings. [Animal] Insufflation, suction, and total operation time to complete the protocol of 10 cauterizations of the gastric mucosa were measured in three groups: “manual suction only,” “manual suction with automatic evacuation (50% force),” and “manual suction with automatic evacuation (70% force).” The stability of endoscopic visualization and operability was evaluated by 10 endoscopists blinded to those suction settings, and the number of manual suctions, insufflations, and total operation time were measured. Results [Bench] The degree of residual smoke and gastric luminal collapse were inversely correlated. [Animal] When the automatic evacuator was partially used, there was no difference in the insufflation time, but the suction time (vs 50%; p = 0.011, vs. 70%; p = 0.011) and total operation time (vs. 50%; p = 0.012, vs. 70%; p = 0.036) were significantly reduced compared to manual operation only. Furthermore, manual suction with automatic evacuation (50% force) significantly improved the stability of endoscopic visualization and operability compared to manual operation only (p = 0.041, p = 0.0085). Conclusions The automatic smoke evacuation in flexible gastrointestinal endoscopy was potentially feasible and useful by improving the device setting.

Abstract Background and aims In our previous study, we visualized and systematically evaluated gas leakage from the forceps plug of the gastrointestinal endoscope system using the Schlieren system. In order to minimize the potential risk of infection from gas leakage from the gastrointestinal endoscope, the development of a new forceps plug was considered urgent. In this study, we analyzed the structure of commercially available forceps plugs and attempted to develop new forceps plugs with improvements. Methods Microfocus computed tomography was used to nondestructively analyze the structural changes that occur when forceps are inserted into a commercially available forceps plug. Based on the findings, the basic structure of the newly developed forceps plug was set. We examined the airtightness of these newly developed plugs using the Schlieren system and also compared their fractional resistance with those of commercially available plugs. Results As a result of the nondestructive analysis, all of the commercially available plugs had a single valve, and the cleavage created in the valve during forceps, insertion was large in the case of plugs with slit‐type entrances. In the newly developed forceps plugs, all four types of plugs showed less gas leakage and similar or better usability compared to the commercially available plugs. Conclusions The structural weaknesses of the existing gastrointestinal endoscopic forceps plugs were identified. Based on the findings, we froze the design of a prototype of a new forceps plug that was airtight and not inferior in usability compared to commercially available plugs.

CD8+ T cells affect the outcomes of pancreatic ductal adenocarcinoma (PDAC). Using tissue samples at pre-treatment to monitor the immune response is challenging, while blood samples are beneficial in overcoming this limitation. In this study, we measured peripheral antigen-specific CD8+ T cell responses against four different tumor-associated antigens (TAAs) in PDAC using flow cytometry and investigated their relationships with clinical features. We analyzed the optimal timing within the treatment course for effective immune checkpoint inhibition in vitro. We demonstrated that the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells was correlated with a fold reduction in CA19-9 before and after neoadjuvant therapy. Moreover, patients with TAA-specific IFNγ+4-1BB+ CD8+ T cells after surgery exhibited a significantly improved disease-free survival. Anti-PD-1 treatment in vitro increased the frequency of TAA-specific IFNγ+4-1BB+ CD8+ T cells before neoadjuvant therapy in patients, suggesting the importance of the timing of anti-PD-1 inhibition during the treatment regimen. Our results indicate that peripheral immunophenotyping, combined with highly sensitive identification of TAA-specific responses in vitro as well as detailed CD8+ T cell subset profiling via ex vivo analysis, may serve as peripheral biomarkers to predict treatment outcomes and therapeutic efficacy of immunotherapy plus neoadjuvant chemotherapy.

Abstract Circulating tumor cells (CTCs) play an important role in metastasis and recurrence. However, which cells comprise the complex tumor lineages in recurrence and are key in metastasis are unknown in colorectal cancer (CRC). CRC with high expression of POU5F1 has a poor prognosis with a high incidence of liver metastatic recurrence. We aim to reveal the key cells promoting metastasis and identify treatment-resistant lineages with established EGFP-expressing organoids in two-dimensional culture (2DOs) under the POU5F1 promotor. POU5F1-expressing cells are highly present in relapsed clinical patients’ blood as CTCs. Sorted POU5F1-expressing cells from 2DOs have cancer stem cell abilities and abundantly form liver metastases in vivo. Single-cell RNA sequencing of 2DOs identifies heterogeneous populations derived from POU5F1-expressing cells and the Wnt signaling pathway is enriched in POU5F1-expressing cells. Characteristic high expression of CTLA4 is observed in POU5F1-expressing cells and immunocytochemistry confirms the co-expression of POU5F1 and CTLA4. Demethylation in some CpG islands at the transcriptional start sites of POU5F1 and CTLA4 is observed. The Wnt/β-catenin pathway inhibitor, XAV939, prevents the adhesion and survival of POU5F1-expressing cells in vitro. Early administration of XAV939 also completely inhibits liver metastasis induced by POU5F1-positive cells.

Abstract Background Severe scoliosis can cause reflux esophagitis, and is a risk factor for Barrett's adenocarcinoma of the esophagus. Severe scoliosis is associated with respiratory dysfunction, impaired operative tolerance, and anatomical difficulty in surgical manipulation, and is, therefore, considered a high surgical risk. In this report, we describe the case of a young patient with Barrett's esophageal adenocarcinoma with severe scoliosis who underwent salvage surgery after radical chemoradiotherapy. Case presentation The patient was a 39-year-old male. Although he had severe scoliosis and paraplegia of both lower limbs since childhood, he was independent in activities of daily living. His previous doctor, who diagnosed the esophageal cancer, determined that surgery was not indicated due to the coexistence of severe scoliosis, so he underwent chemoradiotherapy with curative intent. After chemoradiotherapy, the patient was referred to our hospital for a second opinion because of a tumor remnant. After various additional examinations, thoracoscopic and laparoscopic subtotal esophagectomy for esophageal cancer was performed, along with ante-thoracic route reconstruction using a narrow gastric tube. Although the patient had symptoms associated with postoperative reflux, he recovered well overall and was discharged home about 4 weeks after surgery. Conclusions We report the case of an esophageal cancer patient with severe scoliosis at high surgical risk who underwent successful minimally invasive esophagectomy.

Abstract Background Anorectal fistula cancer is often diagnosed in an advanced state, and radical resection is difficult when invasion of the pelvic wall is observed. In addition, there is currently no clear evidence for perioperative treatment of locally advanced cases. We report a case of anorectal fistula cancer with widespread infiltration diagnosed during the course of Crohn’s disease, which was curatively resected after preoperative chemoradiotherapy. Case presentation A 49-year-old man who had been diagnosed with Crohn’s disease (ileocolonic type) at the age of 25 and was found to have an anorectal fistula and perianal abscess at the age of 44 was referred to our department with complaints of abdominal pain and diarrhea. Computed tomography (CT) showed anal stenosis due to a pelvic mass. Pathological analysis of a biopsy taken under general anesthesia indicated mucinous carcinoma. Magnetic resonance imaging (MRI) revealed infiltration into the prostate, seminal vesicles, levator ani muscle, and left internal obturator muscle, and the patient was diagnosed with cT4N0M0 cStage IIIB anorectal fistula cancer (UICC TNM classification 8th edition). After performing a laparoscopic sigmoid colostomy, chemoradiation therapy (capecitabine + oxaliplatin, 50.4 Gy/28fr) was initiated. The patient then underwent laparoscopic total pelvic exenteration, colonic conduit diversion, extensive perineal resection, and reconstruction using bilateral gluteus maximus flaps and a right rectus abdominis musculocutaneous flap. The pathological diagnosis was mucinous adenocarcinoma, pT4, and all margins were negative. No recurrence was evident 6 months after the operation without adjuvant chemotherapy. Conclusion We described a case of curative resection after preoperative chemoradiotherapy for anorectal fistula cancer with extensive invasion that was diagnosed during the course of Crohn’s disease.An accumulation of cases is needed to determine the usefulness of preoperative chemoradiation therapy for local control of anorectal fistula cancer associated with Crohn’s disease.

Abstract Background Familial gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the digestive tract caused by germline gain-of-function mutations in the KIT gene or platelet-derived growth factor receptor alpha gene (PDGFRA). These mutations cause not only multiple GISTs but also diffuse hyperplasia of interstitial cells of Cajal (ICCs), which is related to esophageal motility disorder. Case presentation A 53-year-old man was referred to our hospital because of anemia and dysphagia. Fifteen years earlier, he had undergone a laparoscopic partial gastrectomy for multiple gastric GISTs with a germline mutation in exon 17 of the KIT gene. An upper gastrointestinal endoscopy revealed that the patient had multiple gastric GISTs and a large esophageal diverticulum directly above the esophagogastric junction. The largest gastric tumor was 7 cm, with a delle that might cause bleeding. Because the patient presented with dysphagia, we performed video-assisted thoracic esophagectomy and laparoscopic-assisted proximal gastrectomy simultaneously. The patient had survived without metastasis for 4 years after surgery and dysphagia had improved. Conclusions This is the first report of successful laparoscopic–thoracoscopic surgery for a patient with familial gastric GISTs accompanied with a large esophageal diverticulum.

Abstract In recent years, important clinical trials for gastric cancer (GC) and esophagogastric junction cancer (EGJC) have been reported, changing the strategies of surgical and perioperative treatment. Although laparoscopic gastrectomy has already been shown to be effective for early‐stage cancer, recent evidence from both Asia (JLSSG0901, CLASS‐01 and KLASS‐02) and Europe (LOGICA and STOMACH trials) has demonstrated that it is useful for advanced GC. Robotic surgery has been rapidly gaining popularity in recent years, and randomized controlled trials are ongoing to evaluate its efficacy. A prospective nationwide multicenter study mapped sites with frequent metastasis and revealed lymphatic flow specific to EGJC, thus establishing the optimal lymph node dissection area and surgical approach based on esophageal involvement. Perioperative chemotherapy, the mainstay of treatment in Europe, also has been established in Asia by the PRODIGY and RESOLVE studies. New clinical trials have been conducted to evaluate the efficacy of combining immunotherapy or molecular‐targeted therapy with perioperative chemotherapy or chemoradiotherapy. In this review, we present important recent clinical trials regarding the treatment of GC and EGJC published in 2021 or 2022.

Gastrointestinal cancers, which include a variety of esophageal and colorectal malignancies, present a global health challenge and require effective treatment strategies. In the evolving field of cancer immunotherapy, tissue-resident memory T cells (Trm cells) have emerged as important players in the immune response within nonlymphoid tissues. In this review, we summarize the characteristics and functions of Trm cells and discuss their profound implications for patient outcomes in gastrointestinal cancers. Positioned strategically in peripheral tissues, Trm cells have functions beyond immune surveillance, affecting tumor progression, prognosis, and response to immunotherapy. Studies indicate that Trm cells are prognostic markers and correlate positively with enhanced survival. Their presence in the tumor microenvironment has sparked interest in their therapeutic potential, particularly with respect to immune checkpoint inhibitors, which may improve cancer treatment. Understanding how Trm cells work will not only help to prevent cancer spread through effective treatment but will also contribute to disease prevention at early stages as well as vaccine development. The role of Trm cells goes beyond just cancer, and they have potential applications in infectious and autoimmune diseases. This review provides a thorough analysis of Trm cells in gastrointestinal cancers, which may lead to personalized and effective cancer therapies.

Abstract Background After orthotopic liver transplantation (OLT), complications such as hepatic artery stenosis, thrombosis, and bleeding are possible. Hepatic artery pseudoaneurysms (HAP) are prone to rupture, rupture hemorrhage, and increased mortality risk. Endovascular treatment of HAP may result in recurrence, even after successful embolization with thrombin. Formation of a HAP in the common hepatic artery (CHA) is challenging because the CHA is the only artery in the liver graft after OLT. Therefore, CHA embolization in HAP is not an initial option. We report a case of HAP at the CHA after OLT that was treated with endovascular therapy, resulting in the occlusion of the CHA with coil embolization, achieving a radical cure. Case presentation A 59-year-old man with decompensated hepatitis C virus cirrhosis underwent deceased donor whole-liver transplantation after graft failure of a living donor liver transplantation. After the second transplantation, the patient developed infectious narrow-necked HAP at the CHA associated with postoperative pancreatic fistula. Repeated transcatheter arterial embolization with thrombin and n-butyl-2-cyanoacrylate was unsuccessful, as confirmed by postprocedure angiography, which revealed recanalization and regrowth of the HAP. Eight months after the first transcatheter arterial embolization, the patient presented with a chief complaint of abdominal pain due to an enlarged HAP. Angiography of the superior mesenteric artery (SMA) revealed a collateral bypass around the bile duct from the SMA to the liver graft. Coil embolization of the HAP in the CHA completely occluded the HAP without complications. More than 2 years after coil embolization, the liver graft function test results remained within normal limits without HAP recurrence. Conclusions HAP at the CHA after liver transplantation can be fatal if ruptured. Because the liver is a highly angiogenic organ, even if initial treatment is not successful, radical treatment to occlude the CHA with HAP is possible if sufficient collateral vessels are developed.

Here we report a case of locally advanced rectal cancer with vaginal invasion, which was successfully resected via laparoscopic surgery using intraoperative indocyanine green (ICG) navigation to determine the vaginal cut line. Based on preoperative examinations, an 81-year-old female was diagnosed with locally advanced rectal cancer with vaginal invasion. After preoperative chemoradiotherapy, the lesion was judged to be resectable. During surgery, the gynecologist transvaginally injected ICG into the vaginal submucosa to determine the caudal margin of the vaginal invasion, and laparoscopically dissected under the near-infrared image of the stained area. Pathological analysis of the resection specimen revealed negative resection margins. One year after surgery, there has been no recurrence.

Abstract Integrating genomic data of multiple cancers allows de novo cancer grouping and elucidating the shared genetic basis across cancers. Here, we conduct the pan-cancer and cross-population genome-wide association study (GWAS) meta-analysis and replication studies on 13 cancers including 250,015 East Asians (Biobank Japan) and 377,441 Europeans (UK Biobank). We identify ten cancer risk variants including five pleiotropic associations (e.g., rs2076295 at DSP on 6p24 associated with lung cancer and rs2525548 at TRIM4 on 7q22 nominally associated with six cancers). Quantifying shared heritability among the cancers detects positive genetic correlations between breast and prostate cancer across populations. Common genetic components increase the statistical power, and the large-scale meta-analysis of 277,896 breast/prostate cancer cases and 901,858 controls identifies 91 newly genome-wide significant loci. Enrichment analysis of pathways and cell types reveals shared genetic backgrounds across said cancers. Focusing on genetically correlated cancers can contribute to enhancing our insights into carcinogenesis.

Abstract Background Metastatic testicular cancer is rare. In particular, primary colorectal cancer rarely metastasizes to the testes. This study reports a case of testicular metastasis recurrence 9 years after the resection of a primary colorectal cancer and a simultaneous metastatic lung tumour. Case presentation A 69-year-old man underwent a laparoscopic left hemicolectomy for descending colon cancer. Preoperative computed tomography revealed a solitary left lung mass. Postoperative chemotherapy reduced the size of the lung mass, and 6 months after the primary resection, the patient underwent a left upper segmentectomy. Based on the pathological examination, he was diagnosed with pulmonary metastasis from colorectal cancer. After four courses of adjuvant chemotherapy, the patient was recurrence-free. However, 9 years and 6 months after the primary resection, he complained of discomfort in his left testicle. Physical examination revealed a left testicular mass. Since a malignancy was not excluded via imaging, left testicular resection was performed to confirm the diagnosis. The pathological diagnosis was testicular metastasis from colorectal cancer. The patient was followed up without medication, and remained healthy, without recurrence, 11 months postoperatively. Conclusions It is important to follow up with testicular metastasis in mind, although it is rare.

Pancreatic ductal adenocarcinoma (PDAC) has a high recurrence rate even after radical resection because of subclinical tumors. To manage them, a reliable biomarker that can indicate the presence of subclinical tumors and predict their chemosensitivity is required. This study aimed to identify a miRNA as a biomarker that can be used to individualize postoperative adjuvant chemotherapy using postoperative peripheral blood samples. Integrating miRNA microarray data from the blood of 18 patients with PDAC and the in vitro results regarding the phenotypes of chemoresistant PDAC cells, a candidate miRNA was identified. The relationships between candidate miRNA expression and chemosensitivity were examined in vitro and in clinical samples from other cohorts of 33 patients with recurrence. Comprehensive analyses of blood samples detected 5 candidate miRNAs. Of these, miR-26a-5p was considered a candidate biomarker of chemosensitive phenotypes. In validation experiments, chemosensitivity was inversely correlated with miR-26a-5p expression in vitro. Moreover, the ability of miR-26a-5p to predict chemosensitivity was clinically evaluated using blood samples. Patients with high miR-26a-5p expression in the blood after radical resection exhibited a significantly longer survival time after recurrence. Thus, we concluded that miR-26a-5p is a potentially useful biomarker for managing patients with PDAC, especially those undergoing adjuvant chemotherapy.

Islet transplantation (ITx) is an established and safe alternative to pancreas transplantation for type 1 diabetes mellitus (T1DM) patients. However, most ITx recipients lose insulin independence by 3 years after ITx due to early graft loss, such that multiple donors are required to achieve insulin independence. In the present study, we investigated whether skeletal myoblast cells could be beneficial for promoting angiogenesis and maintaining the differentiated phenotypes of islets. In vitro experiments showed that the myoblast cells secreted angiogenesis-related cytokines (vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and stromal-derived factor-1α (SDF-1α)), contributed to maintenance of differentiated islet phenotypes, and enhanced islet cell insulin secretion capacity. To verify these findings in vivo, we transplanted islets alone or with myoblast cells under the kidney capsule of streptozotocin-induced diabetic mice. Compared with islets alone, the group bearing islets with myoblast cells had a significantly lower average blood glucose level. Histological examination revealed that transplants with islets plus myoblast cells were associated with a significantly larger insulin-positive area and significantly higher number of CD31-positive microvessels compared to islets alone. Furthermore, islets cotransplanted with myoblast cells showed JAK-STAT signaling activation. Our results suggest two possible mechanisms underlying enhancement of islet graft function with myoblast cells cotransplantation: “indirect effects” mediated by angiogenesis and “direct effects” of myoblast cells on islets via the JAK-STAT cascade. Overall, these findings suggest that skeletal myoblast cells enhance the function of transplanted islets, implying clinical potential for a novel ITx procedure involving myoblast cells for patients with diabetes.

Abstract Background Studies have shown that cancer stemness and the endoplasmic reticulum (ER) stress response are inversely regulated in colorectal cancer (CRC), but the mechanism has not been fully clarified. Long noncoding RNAs (lncRNAs) play key roles in cancer progression and metastasis. In this study we investigated lncRNA 01534 (LINC01534) as a possible modulator between cancer stemness and ER stress response. Methods In vitro experiments using CRC cell lines were performed to explore a possible role of LINC01534. The expression of LINC01534 in clinical CRC samples was assessed by quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR) and in situ hybridization. Results Silencing LINC01534 led to suppression of cell proliferation, invasiveness, and cell cycle progression at the G2‐M phase, and promoted apoptosis. Moreover, we found that silencing LINC01534 suppressed cancer stemness, while it activated the ER stress response, especially through the PERK/eIF2α signaling pathway. In situ hybridization revealed LINC01534 was expressed in tumor cells and upregulated in CRC tissues compared with normal epithelium. A survival survey indicated that high LINC01534 expression was significantly associated with shorter overall survival in 187 CRC patients. Conclusion This is the first report on LINC01534 in human cancer. Our findings suggest that LINC01534 may be an important modulator of the maintenance of cancer stemness and suppression of the ER stress response, and that it could be a novel prognostic factor in CRC.

Abstract Aims Risk‐scoring systems for colorectal liver metastasis (CRLM) after hepatectomy allow prognoses to be predicted preoperatively. We investigated the clinical outcomes of neoadjuvant chemotherapy for resectable CRLM according to patient risk status, aiming to determine the subgroup of patients who could benefit from neoadjuvant chemotherapy. Methods In this multi‐institutional retrospective analysis, the preoperative risk score was calculated from six previously reported factors: synchronous metastases, primary lymph node positivity, tumor number, largest tumor diameter, extrahepatic metastasis, and the preoperative carbohydrate antigen 19–9 level. Patients were divided into three groups according to their risk scores: low risk (score = 0), intermediate risk (score 1–10), and high risk (score ≥11). Overall and recurrence‐free survival curves were calculated using the Kaplan–Meier method. After propensity‐score matching in the intermediate‐risk group, we compared clinicopathological features and outcomes. Results There were 318 cases, from 20 institutions. The preoperative risk score could be calculated in 277 cases. There were 34, 192, and 51 patients in the low‐, intermediate‐, and high‐risk groups, respectively. Intermediate‐risk group patients who received neoadjuvant chemotherapy had significantly better recurrence‐free survival than that of patients without neoadjuvant chemotherapy (P = .0453). After propensity‐score matching in the intermediate‐risk group, the recurrence‐free survival rate was better in patients who received neoadjuvant chemotherapy (P = .0261). But the overall survival rate was not improved after the matching. Conclusion Neoadjuvant chemotherapy for resectable CRLM might prolong the recurrence‐free survival period for intermediate‐risk patients with preoperative risk scores in the range of 1–10, but the overall survival was not improved by neoadjuvant chemotherapy.

Abstract To assess the potential clinical utility of cell-free DNA (cfDNA)-based biomarkers for identifying gastric cancer (GC) patients who benefit from nivolumab. From 31 GC patients treated with nivolumab monotherapy (240 mg/body, Bi-weekly) in 3rd or later line setting, we prospectively collected blood samples at baseline and before the 3rd dose. We compared cfDNA-based molecular findings, including microsatellite instability (MSI) status, to tissue-based biomarkers. We assessed the clinical value of blood tumor mutation burden (bTMB) and copy number alterations (CNA) as well as the cfDNA dynamics. The concordance between deficient-MMR and cfDNA-based MSI-high was 100% (3/3). Patients with bTMB ≥ 6 mut/Mb had significantly better progression-free survival (PFS) and overall survival (OS); however, such significance disappeared when excluding MSI-High cases. The combination of bTMB and CNA positivity identified patients with survival benefit regardless of MSI status (both PFS and OS, P

Abstract Background Exon 18 D842V, which is a point mutation from aspartic acid to valine at codon 842, is the most frequent mutation in Platelet-Derived Growth Factor Receptor alpha (PDGFRA)-mutated gastrointestinal stromal tumor (GIST). In the Japanese GIST guidelines, no standard systematic therapy is available for this type of GIST, which is refractory after recurrence. Recently, pimitespib (PIMI), a novel heat shock protein 90 (HSP90) inhibitor, was approved for the treatment of advanced GIST in a phase III study. This report presents a case of a long-term response to PIMI in GIST with PDGFRA D842V mutation. Case presentation A 55-year-old woman was diagnosed with primary GIST of the stomach and underwent partial gastrectomy. Eight years after the operation, recurrent GISTs were identified as multiple recurrent peritoneal GISTs in the upper right abdomen and pelvic cavity. We administered tyrosine kinase inhibitors, but they achieved poor effects. After failure of the standard treatment, PIMI was administered and achieved a partial response in the patient. The highest reduction rate was 32.7%. After PIMI failed, we performed multiplex gene panel testing, which revealed the PDGFRA D842V mutation. Conclusions We report the first case of long-term response to PIMI in PDGFRA D842V mutant GIST. Pimitespib may be effective for treating GIST harboring this mutation by inhibiting HSP90.

Abstract Background Although perioperative treatment has been the standard of care for resectable gastric cancer in the West, postoperative adjuvant chemotherapy is still the standard in Japan. We conducted the first phase 2 trial to investigate the efficacy and safety of neoadjuvant docetaxel, oxaliplatin, and S‐1 (DOS) chemotherapy for cStage III gastric or esophagogastric junction (EGJ) adenocarcinoma in Japan. Methods Eligibility criteria included cStage III adenocarcinoma of the stomach or EGJ. Patients received docetaxel (40 mg/m2, day 1), oxaliplatin (100 mg/m2, day 1), or S‐1 (80 mg/m2, days 1–14) during a 3‐week cycle. After two or three cycles of DOS, patients underwent surgical resection. The primary endpoint was progression‐free survival (PFS). Results Between June 2015 and March 2019, 50 patients were enrolled from four institutions. Of 48 eligible patients (37 gastric and 11 EGJ adenocarcinoma), 42 (88%) completed two or three DOS cycles. Grade 3–4 neutropenia and diarrhea occurred in 69% and 19% of patients, respectively, but there were no treatment‐related deaths. R0 resection was achieved in 44 (92%) patients, and the pathological response rate (≥ grade 1b) was 63% (30/48). The 3‐year PFS, overall survival, and disease‐specific survival rates were 54.2%, 68.7%, and 75.8%, respectively. Conclusion Neoadjuvant DOS chemotherapy had a sufficient antitumor effect and tolerable safety profile in patients with gastric or EGJ adenocarcinoma. The survival benefit of a neoadjuvant strategy using our DOS regimen should be validated in phase 3 trials.

Abstract Regorafenib has shown significant survival benefit as a salvage therapy for colorectal cancer; however, its starting dose has been controversial in recent studies. Therefore, we conducted a prospective study on the efficacy and safety of the dose reduction of regorafenib to 120 mg. Patients received 120 mg regorafenib once per day for 3 weeks, followed by a 1-week off-treatment period. The primary endpoint was the investigator-assessed disease control rate (DCR). Sixty patients were registered, and the DCR was 38.3% with a median progression-free survival of 2.5 months (95% confidence interval [CI] 1.9–3.7) and median overall survival of 10.0 months (95% CI 6.9–15.2). Common grade 3–4 adverse events were hand-foot skin reaction and hypertension (20.0% each). The results of administration of 120 mg regorafenib as the starting dose are consistent with reports from prior phase III trials, which used starting doses of 160 mg. This lower initiating dose of regorafenib may be beneficial to certain patient populations. This clinical trial was registered in the UMIN Clinical Trials Registry (UMIN-CTR number UMIN000018968, registration date: 10/09/2015).

Abstract Approximately 10% of patients with colorectal cancer with submucosal invasion have lymph node metastasis. Pathological risk factors for lymph node metastasis have varying sensitivities and specificities. To predict the risk of lymph node metastasis, the identification of new risk factors is vital. Tumor-infiltrating T cells have been reported to improve the prognosis of many solid tumors. Therefore, the purpose of this study was to examine the relationship between lymph node metastasis and tumor-infiltrating T cells in patients with colorectal cancer with submucosal invasion. We examined CD8+ tumor-infiltrating T cells level as a risk factor for lymph node metastasis in patients with colorectal cancer with submucosal invasion. Using immunohistochemical staining, we identified CD8 + T cells in surgically resected specimens from 98 patients with SM-CRC. We showed that low CD8+ tumor-infiltrating T cells levels are positively correlated with lymph node metastasis. Furthermore, by combining the number of CD8+ tumor-infiltrating T cell and the number of CD103+ tumor-infiltrating T cells, the results showed a high positive predictive value for lymph node metastasis in cases with low numbers of both types of tumor-infiltrating T cells and a high negative predictive value in cases with high numbers of both types of tumor-infiltrating T cells.

Abstract Background Rendu–Osler–Weber disease (Osler disease) is a genetic disease with an autosomal dominant inheritance pattern. It is characterized by widespread telangiectasia in multiple organs. Liver involvement of FNH is relatively common, but liver cancer is very rare, and there are few reports on hepatectomy or postoperative complications. We report a very rare case in which hepatectomy was performed for a patient with Osler disease. Case presentation The patient was a 39-year-old man with Osler disease who had been previously diagnosed with multiple FNH and who had been followed for 8 years. During follow-up, the diameter of an S6 lesion gradually increased from 30 to 50 mm; no other lesions increased in size. We decided to perform partial liver resection as total biopsy for the growing tumor, due to the possibility that the growing tumor lesion included malignant components. The pathological examination revealed no obvious malignancy, which was finally diagnosed FNH. The postoperative course was uneventful and he was discharged on the 14th day after surgery. In the second month after discharge, he was transferred to our hospital with sudden abdominal pain in the right hypochondrium with severe tenderness. CT showed extravasation of contrast medium from the hepatic dissection surface in S6, and the hematoma extended to the pelvic floor. Emergency IVR was performed and revealed leakage of the contrast medium from the A6 branch. We embolized the A6 with Lipiodol. After embolization, there were no major problems, and the patient was discharged on the 9th day after the treatment. Conclusions Postoperative hemorrhage often occurs within 24 h after surgery, and 2 months after surgery is considered to be the late stage of the wound healing process, and postoperative hemorrhage at this timepoint is considered rare. This unexpected delayed postoperative hemorrhage may have been related to the etiology and pathology of Osler disease, nevertheless, case reports of hepatectomy for patients with Osler disease are limited. We, therefore, report the present case with a review of the relevant literature.

Abstract Purpose Addition of perioperative multi‐agent chemotherapy to the treatment strategy for locally advanced rectal cancer (LARC) may be a promising option. We conducted a phase II study to evaluate the safety and efficacy of capecitabine combined with oxaliplatin and irinotecan (XELOXIRI) as triplet neoadjuvant chemotherapy in patients with LARC. Methods Patients received neoadjuvant irinotecan and oxaliplatin and capecitabine and then underwent total mesorectal excision. The primary study endpoint was the pathological complete response (pCR) rate. Results Between June 2013 and December 2016, 55 patients were enrolled in the study. Forty‐two (77.8%) of 54 completed the study protocol. The pCR rate was 7.7% (95% CI 3.0% to 18.2%). The 3‐year local recurrence rate was 3.9%, the 3‐year disease‐free survival (DFS) rate was 77.3, and the 3‐year overall survival rate was 96.0%. Conclusion XELOXIRI neoadjuvant chemotherapy appears to be feasible and efficacious for patients with LARC. Although neoadjuvant XELOXIRI alone did not yield our expected pCR rate, the local recurrence rate, 3‐year DFS, and measures of safety met current standards.

Abstract Aim Due to the overwhelming spread of SARS‐CoV‐2 and its disruption of the healthcare system, delays and reduced numbers were reported for colorectal cancer screening, colonoscopies, and surgery during the COVID‐19 pandemic. This multicenter retrospective study investigated the still poorly understood impact of the COVID‐19 pandemic on colorectal cancer treatment in Japan. Methods This study was organized by the Clinical Study Group of Osaka University, which comprised 32 major institutions in Osaka. We retrospectively analyzed the number of surgeries and colonoscopies performed and the characteristics of patients who underwent surgery for colorectal cancer between March 2019 and February 2021. We compared data collected before and during the COVID‐19 pandemic. We also assessed the methods used for detecting colorectal cancer, including fecal occult blood test, abdominal symptoms, and anemia. Results The COVID‐19 pandemic caused reductions in the annual numbers of surgeries (3569 vs 3198) and colonoscopies (67 622 vs 58 183) performed in the 2020 fiscal year, compared to the 2019 fiscal year. During the COVID‐19 pandemic, a significantly lower proportion of patients were treated for clinical stages ≤I (24.2% vs 26.9%; P = .011), compared to the proportion treated before the pandemic. Fecal occult blood tests for detecting colorectal cancer were used significantly less frequently during the COVID‐19 pandemic (26.2% vs 29.6%; P = .002). These trends were more significant in larger institutions. Conclusion The COVID‐19 pandemic reduced the number of colonoscopies and surgeries performed for colorectal cancer and hindered the detection of asymptomatic early‐stage cancers, and its impact varied by hospital size.

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has rapidly and dramatically influenced healthcare across Japan. However, the influence of the COVID-19 pandemic on the number of newly diagnosed cancer, surgical treatment, and diagnostic examination for cancer types have not been completely investigated all over Japan. This study aimed to analyze the number of cases before and during the COVID-19 pandemic. Methods This retrospective study was a survey that asked to provide the number of cases diagnosed with gastric, colorectal, lung, breast, and cervical cancer between January 2019 and December 2020. The survey was sent to tertiary healthcare hospitals, including national cancer institutions, university hospitals, and general hospitals, all over Japan. Data obtained from 105 of 486 surveyed hospitals were evaluated, and the number of cases in each quarter in 2020 was compared with that in the equivalent quarter in 2019. Results In the second quarter (Q2), significant reductions were observed in the median number of newly diagnosed cases from 2019 to 2020: gastric cancer, 26.7% (43 vs. 32, p

Abstract In cases after pancreas transplantation (PTx), the pancreas graft might be lost for various reasons, including a pancreatoduodenal graft-related complication or patient death with a functioning graft. Although the causes seem to have distinct characteristics, the causes of pancreas graft loss have not been characterized. This study aimed to characterize the causes of pancreas graft loss by analyzing data from a Japanese nationwide registry. This study included 391 patients who received simultaneous pancreas-kidney transplantation among 461 patients with PTx during the study period in approved institutions in Japan. We characterized each cause in terms of the timing of the cause-specific graft loss and preoperative factors associated with graft loss based on nationwide data from a Japanese nationwide registry. Among the 391 cases, 113 lost the pancreas graft due to patient death with a functioning graft (DWFG; n = 34, 44.2%), graft thrombus (n = 22, 28.6%), or chronic rejection (CR; n = 7, 9.1%). Average (± standard deviation) time from PTx to graft loss due to DWFG, graft thrombus, and CR was 3.70 ± 4.36, 0.02 ± 0.01, and 2.37 ± 2.08 years, respectively. Duration of type 1 diabetes mellitus and donor body mass index were significantly associated with pancreas graft loss due to DWFG and graft thrombus, respectively. This characterization showed that the timing and preoperative factors associated with pancreas graft loss were significantly different for different causes of graft loss. These results may inform PTx follow-up protocols to ensure that appropriate care is based on the cause of graft loss.

Abstract Background SMAD4 is a key mediator of TGFβ signaling and one of the mutated genes in extrahepatic bile duct cancer (eBDC). It has been also reported that SMAD4 has dual functions, in carcinogenesis via silencing and in tumor invasion/metastasis via signaling, depending on tumor stage. We previously visualized more nuclear transitioning functional SMAD4 at the tumor invasion front than the central lesion. So, we investigated the localization of functional SMAD4 (e.g., invasion area or metastasis lesion) and its association with chemotherapy and chemo-radiation therapy. Methods We performed SMAD4 immunostaining on 98 resected eBDC specimens and evaluated the presence of the functional form of nuclear SMAD4 at the central lesion, invasion front, and metastatic lymph node. We also examined the influence on chemotherapy after recurrence (n = 33) and neoadjuvant chemo-radiation therapy (NAC-RT, n = 21) and the prognostic value of using retrospective data. Results In 73 patients without NAC-RT, 8.2% had loss of SMAD4 expression and 23.3% had heterogeneous expression. Patients without SMAD4 expression at any site had significantly poorer overall survival (OS) than other patients (P = 0.014). Expression of SMAD4 at the invasion front was related to better survival (recurrence-free survival [RFS] P = 0.033; OS P = 0.047), and no SMAD4 expression at the metastatic lymph node was related to poorer OS (P = 0.011). The patients who had high SMAD4 expression had poorer prognosis after recurrence (RFS P = 0.011; OS P = 0.056). At the residual cancer in the resected specimen, SMAD4 was highly expressed after NAC-RT (P = 0.039). Conclusions Loss of SMAD4 protein expression was a poor prognostic factor in eBDC at resectable stage. However, the intensity of functional SMAD4 in eBDC is a marker of resistance to chemo-radiotherapy and malignant potential at advanced stages.

Abstract Background Esophageal squamous cell carcinoma (ESCC) is one of the most severe cancers and is characterized by chemotherapy resistance and poor prognosis associated with epithelial-mesenchymal transition (EMT). In a previous study, a low mitochondrial DNA (mtDNA) copy number was associated with poorer prognosis and induced EMT in ESCC. However, the detailed mechanism related to mtDNA copy number and EMT is unclear. The aim of this study was to clarify the mechanism by which a change in mtDNA copy number contributes to EMT and to examine treatment of chemotherapy resistance in ESCC. Methods The association between low mtDNA copy number and chemotherapy resistance was investigated using specimens from 88 patients who underwent surgery after neoadjuvant chemotherapy. Then, the mtDNA content of human ESCC cell lines, TE8 and TE11, was depleted by knockdown of mitochondrial transcription factor A expression. The present study focused on modulation of mitochondrial membrane potential (MMP) and DNA methylation as the mechanisms by which mtDNA copy number affects EMT. mRNA and protein expression, chemotherapy sensitivity, proliferation, MMP and DNA methylation were evaluated, and in vitro and in vivo assays were conducted to clarify these mechanisms. Results ESCC patients with decreased mtDNA copy number who underwent R0 resection after neoadjuvant chemotherapy had significantly worse pathological response and recurrence-free survival. Additionally, low mtDNA copy number was associated with resistance to chemotherapy in vitro and in vivo. mtDNA controlled MMP, and MMP depolarization induced EMT. Depletion of mtDNA and low MMP induced DNA methylation via a DNA methylation transcription factor (DNMT), and a DNMT inhibitor suppressed EMT and improved chemotherapy sensitivity in mtDNA-depleted ESCC cells, as shown by in vitro and in vivo assays. Conclusion This study showed that decreased mtDNA copy number induced EMT via modulation of MMP and DNA methylation in ESCC. Therapeutic strategies increasing mtDNA copy number and DNMT inhibitors may be effective in preventing EMT and chemosensitivity resistance.

Objectives: The cornerstone of treating colorectal cancer (CRC) is generally a surgical resection with lymph node (LN) dissection. The tools for predicting lymph node metastasis (LNM) in submucosal (SM) CRC are useful to avoid unnecessary surgical resection. Methods: Retrospectively, we analyzed 526 consecutive patients with SM CRC who underwent surgical resection at the Osaka International Cancer Institute, Osaka University Hospital, and Minoh City Hospital, Japan, between 1984 and 2012. The Osaka International Cancer Institute group and the Osaka University Hospital group were randomly divided into a training set and a test set of 2:1. The prediction model was validated in Minoh City Hospital. Results: We partitioned patients using three risk factors involved in the presence or absence of LNM in SM CRC: lymphatic invasion (Ly), budding grade (BD) and the depth of submucosal invasion (DSI) (cut-off value 2789 μm) that were significantly different in the multivariate analysis. As a result, a predictive model of “LNM

Abstract Background Agents targeting the programmed cell death‐1 pathway have demonstrated encouraging activity across multiple solid tumor types. The dose expansion phase of this phase I study evaluated the safety, tolerability, and antitumor activity of durvalumab monotherapy, and durvalumab plus tremelimumab (an anti‐cytotoxic T‐lymphocyte‐associated antigen 4 monoclonal antibody) combination therapy, in patients from Asia with biliary tract cancer (BTC), esophageal squamous cell carcinoma (ESCC), or head and neck squamous cell carcinoma (HNSCC). Methods Patients with advanced BTC, ESCC, or HNSCC with disease progression during or following ≥1 platinum‐based therapy received durvalumab monotherapy (10 mg/kg every 2 weeks) or durvalumab plus tremelimumab (durvalumab 20 mg/kg every 4 weeks [Q4W] plus tremelimumab 1 mg/kg Q4W for 4 doses, followed by durvalumab 20 mg/kg Q4W). The primary objective was safety and tolerability. Secondary objectives included antitumor activity. Results Durvalumab monotherapy was assessed in 116 patients (median age 63.5 years, 75.9% male) of whom, 42, 42, and 32 had BTC, ESCC, or HNSCC, respectively. Grade ≥3 treatment‐related adverse events (TRAEs) were reported in 19.0%, 9.5%, and 25.0% of patients with BTC, ESCC, and HNSCC, respectively. Objective response rate (ORR) was 4.8%, 7.1%, and 9.4% in BTC, ESCC, and HNSCC. Durvalumab plus tremelimumab was evaluated in 124 patients (median age 62.0 years, 79.8% male) of whom 65 had BTC and 59 had ESCC. Grade ≥3 TRAEs were reported in 23.1% and 13.6% of patients with BTC and ESCC. ORR was 10.8% and 20.3% in BTC and ESCC. There were two complete responses and 10 partial responses in ESCC, and seven partial responses in BTC. Conclusion In general, durvalumab monotherapy and durvalumab plus tremelimumab combination therapy displayed acceptable safety profiles consistent with published literature, and also demonstrated clinical benefit, in patients from Asia with BTC, ESCC, or HNSCC with disease progression on ≥1 prior treatment. ClinicalTrials.gov Identifier: NCT01938612.

Abstract In pancreatic cancer, methyltransferase-like 3 (METTL3), a N(6)-methyladenosine (m6A) methyltransferase, has a favorable effect on tumors and is a risk factor for patients’ prognosis. However, the details of what genes are regulated by METTL3 remain unknown. Several RNAs are methylated, and what genes are favored in pancreatic cancer remains unclear. By epitranscriptomic analysis, we report that polo-like kinase 1 (PLK1) is an important hub gene defining patient prognosis in pancreatic cancer and that RNA methylation is involved in regulating its cell cycle-specific expression. We found that insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2) binds to m6A of PLK1 3′ untranslated region and is involved in upregulating PLK1 expression and that demethylation of this site activates the ataxia telangiectasia and Rad3-related protein pathway by replicating stress and increasing mitotic catastrophe, resulting in increased radiosensitivity. This suggests that PLK1 methylation is essential for cell cycle maintenance in pancreatic cancer and is a new therapeutic target.

Summary: Somatic cell reprogramming using the microRNAs miR-200c, miR-302s, and miR-369s leads to increased expression of cyclin-dependent kinase inhibitors in human colorectal cancer (CRC) cells and suppressed tumor growth. Here, we investigated whether these microRNAs inhibit colorectal tumorigenesis in CPC;Apc mice, which are prone to colon and rectal polyps. Repeated administration of microRNAs inhibited polyp formation. Microarray analysis indicated that c-MAF, which reportedly shows oncogene-like behavior in multiple myeloma and T cell lymphoma, decreased in tumor samples but increased in microRNA-treated normal mucosa. Immunohistochemistry identified downregulation of c-MAF as an early tumorigenesis event in CRC, with low c-MAF expression associated with poor prognosis. Of note, c-MAF expression and p53 protein levels were inversely correlated in CRC samples. c-MAF knockout led to enhanced tumor formation in azoxymethane/dextran sodium sulfate–treated mice, with activation of cancer-promoting genes. c-MAF may play a tumor-suppressive role in CRC development.

Abstract Background The standard treatment for locally advanced rectal cancer (LARC) is preoperative chemoradiotherapy (CRT) followed by surgery and adjuvant chemotherapy. However, it has been suggested that intensification of neoadjuvant treatment with polychemotherapy in addition to CRT instead of as an adjuvant chemotherapy is better tolerated and associated with a higher pathological complete response (pCR) rate. This concept is known as total neoadjuvant therapy (TNT). Recently, the addition of immunotherapy to preoperative CRT has been reported to be useful in LARC patients with mismatch-repair-deficiency and high levels of microsatellite instability (MSI-H), but there are no reports showing the therapeutic effect of nivolumab in combination with TNT. Case presentation A 23-year-old man had frequent diarrhea. Preoperative examination revealed two adenocarcinomas in the rectum. His maternal grandmother had a rectal cancer patient who developed the disease at age 70s. The larger tumor was located at the peritoneal reflection, and its anterior border close to the prostate (

Abstract Background Low anterior resection syndrome (LARS) is the most common complication after rectal cancer resection. We aimed to identify LARS' predictive factors and construct and evaluate a predictive model for LARS. Methods This retrospective study included patients with rectal cancer more than 1 year after laparoscopic or robotic-assisted surgery. We administered a questionnaire to evaluate the degree of LARS. In addition, we examined clinical characteristics with univariate and multivariate analysis to identify predictive factors for major LARS. Finally, we divided the obtained data into a learning set and a validation set. We constructed a predictive model for major LARS using the learning set and assessed the predictive accuracy of the validation set. Results We reviewed 160 patients with rectal cancer and divided them into a learning set (n = 115) and a validation set (n = 45). Univariate and multivariate analyses in the learning set showed that male (odds ratio [OR]: 2.88, 95% confidence interval [95%CI] 1.11–8.09, p = 0.03), age

Abstract Background Despite advances in medical treatments, most patients with Crohn's disease (CD) will still require surgery, with 20%‐50% needing redo surgery within 10 years after the primary procedure. There is no consensus on the application of laparoscopic redo surgery for recurrent CD. Methods This study included 107 patients with CD who underwent surgery from 2012 to 2020 at Osaka University Hospital. All procedures were laparoscopic. Patients were grouped based on whether the surgery was redo or primary for evaluation of the safety and feasibility of laparoscopic redo surgery. Results The study included 40 patients undergoing redo surgery and 67 having primary surgery. The median age at the time of the procedure was higher for those undergoing redo surgery (43 years vs 34 years, P

Abstract Aim Early detection of surgical site infection (SSI) allows for appropriate management after Crohn's disease (CD) surgery. The aim of this study was to evaluate the usefulness of bacterial culture of postoperative drainage fluid after CD surgery. Methods This study included 110 patients with CD who underwent surgery with bowel resection between January 2010 and March 2020 at Osaka University Hospital. Patients with only perianal surgery or incomplete records were excluded. Risk factors for SSI were evaluated in the context of clinical findings, including bacterial culture of postoperative drainage fluid, and bacterial species related to SSI were also examined. Results Of 110 patients, 18 (16.4%) developed SSI. Organ/space SSI developed in six, and a positive bacterial culture of drainage fluid (D‐Posi) was found in five (83.3%). Of 104 patients without organ/space SSI, 31 (29.8%) were D‐Posi (P = .027). Similarly, 68.8% with incisional SSI were D‐Posi, whereas 26.6% without incisional SSI were D‐Posi (P = .0021). Multivariate analysis revealed that D‐Posi was an independent risk factor in both organ/space and incisional SSI. Bacterial examination showed that Pseudomonas aeruginosa and Enterococcus faecalis were significantly detected in patients with SSI. Conclusion This study suggests the usefulness of postoperative drainage fluid bacterial culture for early diagnosis of SSI after CD surgery.