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Background: Due to the coronavirus disease 2019 (COVID‐19) pandemic, cancer screening, diagnosis, and treatment have changed. This study aimed to investigate the impact of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection prior to gastroenterological cancer surgeries on postoperative complications using data from a nationwide database in Japan. Methods: Data on patients who underwent surgery for cancer including esophageal, gastric, colon, rectal, liver, and pancreatic cancer between July 1, 2019, and September 300, 2022, from real‐world sources in Japan were analyzed. The association between preoperative SARS‐CoV‐2 infection and short‐term postoperative outcomes was evaluated. A similar analysis stratified according to the interval from SARS‐CoV‐2 infection to surgery (<4 vs. >4 weeks) was conducted. Results: In total, 60 604 patients were analyzed, and 227 (0.4%) patients were diagnosed with SARS‐CoV‐2 infection preoperatively. The median interval from SARS‐CoV‐2 infection to surgery was 25 days. Patients diagnosed with SARS‐CoV‐2 infection preoperatively had a significantly higher incidence of pneumonia (odds ratio: 2.05; 95% confidence interval: 1.05–3.74; p = 0.036) than those not diagnosed with SARS‐CoV‐2 infection based on the exact logistic regression analysis adjusted for the characteristics of the patients. A similar finding was observed in patients who had SARS‐CoV‐2 infection <4 weeks before surgery. Conclusions: Patients with a history of SARS‐CoV‐2 infection had a significantly higher incidence of pneumonia. This finding can be particularly valuable for countries that have implemented strict regulations in response to the COVID‐19 pandemic and have lower SARS‐CoV‐2 infection‐related mortality rates. [ABSTRACT FROM AUTHOR]

Aim: The coronavirus disease 2019 (COVID‐19) pandemic greatly impacted medical resources such as cancer screening, diagnosis, and treatment given to people for various diseases. We surveyed the impacts of the pandemic on the incidence of complications and mortality following pancreaticoduodenectomy for pancreatic cancer in Japan. Methods: Data on patients who underwent pancreaticoduodenectomy for pancreatic cancer were extracted from the Japanese National Clinical Database (NCD) between 2018 and 2021. The number of the pancreaticoduodenectomy for pancreatic cancer were obtained and then the morbidity and mortality rates were evaluated using a standardized morbidity/mortality ratio (SMR), which is the ratio of the observed number of incidences to the expected number of incidences calculated by the risk calculator previously developed by the NCD. Results: This study included 22 255 cases. The number of pancreaticoduodenectomies exhibited an increasing trend even during the COVID‐19 pandemic. The mean observed incidence rates of Grade C pancreatic fistula and Clavien–Dindo grade ≥4 complications, and the 30‐day mortality and surgical mortality rates were 0.8%, 1.8%, 0.8% and 0.9%, respectively. The standardized morbidity ratios did not increase during the COVID‐19 pandemic. The standardized mortality ratios remained within the range of variations observed before the COVID‐19 pandemic. Conclusion: The increasing trend in the number of pancreaticoduodenectomies and favorable short‐term outcomes even in the COVID‐19 pandemic suggest the medical care for pancreatic cancer in Japan functioned well during the pandemic. [ABSTRACT FROM AUTHOR]

Aim: The coronavirus disease 2019 (COVID‐19) pandemic has significantly impacted the allocation of medical resources, including cancer screening, diagnosis, and treatment. We aimed to investigate the effects of the pandemic on morbidity and mortality following hepatectomy for hepatocellular carcinoma (HCC). Methods: We identified patients who underwent hepatectomy for HCC between 2018 and 2021 from the Japanese National Clinical Database (NCD). The number of surgical cases, the use of intensive care units, and the incidence of morbidity were assessed. The standardized morbidity / mortality ratio (SMR) was used to evaluate the rates of morbidity (bile leakage and pneumonia) and mortality in each month, which compares the observed incidence to the expected incidence calculated by the NCD's risk calculator. Results: The study included a total of 10 647 cases. The number of patients undergoing hepatectomy for HCC gradually decreased. The proportion of patients aged 80 years or older increased and that of cases with T1 stage decreased. The proportion of patients who were admitted to the intensive care unit did not change between the pre‐ and postpandemic period. The mean actual incidence rates of bile leakage, pneumonia, 30‐day mortality, and surgical mortality were 9.2%, 2.3%, 1.4%, and 2.1%, respectively. The SMR for the mortalities and morbidities in each month did not increase mostly throughout the COVID‐19 pandemic. Conclusions: The present study showed the decreasing number of resected cases for HCC, while the surgical safety for hepatectomy was enough to be maintained by managing medical resources in Japan. [ABSTRACT FROM AUTHOR]

Aim: Serum cholinesterase (ChE) levels are considered to reflect nutritional status. Although ChE has been well documented as a prognostic factor for some cancers, no clear consensus on its use for colorectal cancer (CRC) has been reached. The aim of this study was to investigate the relationship between preoperative serum ChE and postoperative long‐term prognosis in CRC patients. Methods: A total of 1053 CRC patients who underwent curative surgery were included in this study. The correlations between the preoperative ChE value and overall survival (OS) or cancer‐specific survival (CSS) were assessed. By dividing patients into two groups according to their ChE value, OS and CSS were compared between the groups. Results: Multivariate analysis revealed that the continuous ChE value was a significant predictor of OS (hazard ratio, 0.996; 95% CI, 0.993–0.998; p = 0.002) and CSS (hazard ratio, 0.994; 95% CI, 0.991–0.998; p = 0.001), independent of other variables. The low‐ChE (≤234 U/L) group had a significantly poorer prognosis than the high‐ChE (>234 U/L) group for both OS (5‐year OS for low ChE and high ChE: 79.8% and 93.3%, respectively; p < 0.001) and CSS (5‐year CSS for low ChE and high ChE: 84.8% and 95.6%, respectively; p < 0.001). Conclusions: Lower preoperative serum ChE levels are a predictive factor of poor prognosis for CRC patients. As serum ChE levels can be measured quickly and evaluated easily, ChE could become a useful marker for predicting the postoperative long‐term outcomes of CRC patients. [ABSTRACT FROM AUTHOR]

Author(s): Si Hui Tan [sup.1] , Yada Swathi [sup.1] , Shawna Tan [sup.1] , Jasmine Goh [sup.1] , Ryo Seishima [sup.1] , Kazuhiro Murakami [sup.2] , Masanobu Oshima [sup.3] , [...], LGR5 marks resident adult epithelial stem cells at the gland base in the mouse pyloric stomach.sup.1, but the identity of the equivalent human stem cell population remains unknown owing to a lack of surface markers that facilitate its prospective isolation and validation. In mouse models of intestinal cancer, LGR5.sup.+ intestinal stem cells are major sources of cancer following hyperactivation of the WNT pathway.sup.2. However, the contribution of pyloric LGR5.sup.+ stem cells to gastric cancer following dysregulation of the WNT pathway--a frequent event in gastric cancer in humans.sup.3--is unknown. Here we use comparative profiling of LGR5.sup.+ stem cell populations along the mouse gastrointestinal tract to identify, and then functionally validate, the membrane protein AQP5 as a marker that enriches for mouse and human adult pyloric stem cells. We show that stem cells within the AQP5.sup.+ compartment are a source of WNT-driven, invasive gastric cancer in vivo, using newly generated Aqp5-creERT2 mouse models. Additionally, tumour-resident AQP5.sup.+ cells can selectively initiate organoid growth in vitro, which indicates that this population contains potential cancer stem cells. In humans, AQP5 is frequently expressed in primary intestinal and diffuse subtypes of gastric cancer (and in metastases of these subtypes), and often displays altered cellular localization compared with healthy tissue. These newly identified markers and mouse models will be an invaluable resource for deciphering the early formation of gastric cancer, and for isolating and characterizing human-stomach stem cells as a prerequisite for harnessing the regenerative-medicine potential of these cells in the clinic. AQP5 is identified as a marker for pyloric stem cells in humans and mice, and stem cells in the AQP5.sup.+ compartment are shown to be a source of invasive gastric cancer in mouse models.

Colorectal mucinous adenocarcinoma (MAC) is one of the most lethal histological types of colorectal cancer, and its mechanism of development is not well understood. In this study, we aimed to clarify the molecular characteristics of MAC via in silico analysis using The Cancer Genome Atlas database. The expression of genes on chromosome 20q (Chr20q) was negatively associated with the expression of MUC2, which is a key molecule that can be used to distinguish between MAC and nonmucinous adenocarcinoma (NMAC). This was consistent with a significant difference in copy number alteration of Chr20q between the two histological types. We further identified 475 differentially expressed genes (DEGs) between MAC and NMAC, and some of the Chr20q genes among the DEGs are considered to be pivotal genes used to define MAC. Both in vitro and in vivo analysis showed that simultaneous knockdown of POFUT1 and PLAGL2, both of which are located on Chr20q, promoted MUC2 expression. Moreover, these genes were highly expressed in NMAC but not in MAC according to the results of immunohistological studies using human samples. In conclusion, POFUT1 and PLAGL2 are considered to be important for defining MAC, and these genes are associated with MUC2 expression. Significance statement: The pathogenesis of colorectal mucinous adenocarcinoma (MAC) is not well understood. In this study, in silico analysis revealed that the high expression of chromosome 20q (Chr20q) genes is specifically associated with low expression of MUC2, which is a key molecule of MAC. Among differentially expressed genes between MAC and nonmucinous adenocarcinoma, POFUT1 and PLAGL2 were the Chr20q genes that were considered to be important for defining the mucinous feature of cancer as these genes associated with MUC2 expression. Our findings will provide new insights into the mechanism of MAC development. [ABSTRACT FROM AUTHOR]

Aim: The Coronavirus Disease 2019 (COVID‐19) pandemic affected the allocation of various medical resources to several areas, including intensive care units (ICUs). However, currently, its impact on the short‐term postoperative outcomes of gastrointestinal cancer surgeries remains unclear. We aimed to evaluate the impact of the pandemic on the incidence of complications occurring after low anterior resection in patients with rectal cancer in Japan. Methods: Data from the Japanese National Clinical Database between 2018 and 2021 were retrospectively examined. The primary outcome of the study was the postoperative morbidity and mortality rates before and after COVID‐19 pandemic. Moreover, the postoperative ICU admission rate was assessed. Morbidity and mortality rates were also assessed using a standardized morbidity/mortality ratio (SMR, the ratio of the actual number of incidences to the expected number of incidences calculated by the risk calculator). Results: This study included 74 181 patients, including 43 663 (58.9%) from COVID‐19 epidemic areas. The mean actual incidences of anastomotic leakage (AL) and pneumonia during the study period were 9.2% and 0.9%, respectively. The SMRs of these complications did not increase during the pandemic but those of AL declined gradually. The mean 30‐day mortality and operative mortality rates were 0.3% and 0.5%, respectively. Moreover, SMRs did not change significantly in the pandemic or regional epidemic status. The ICU admission rate temporarily decreased, especially in the epidemic areas. Conclusion: Although the pandemic temporarily decreased the ICU admission rate, its impact on short‐term outcomes following low anterior resection in patients with rectal cancer was insignificant in Japan. [ABSTRACT FROM AUTHOR]

Background: The coronavirus disease 2019 (COVID‐19) pandemic had resulted in either failure to provide required medical resources or delayed treatment for gastric cancer patients. This study aimed to investigate the impact of COVID‐19 on the incidence of postoperative complications using a nationwide Japanese database of patients undergoing distal gastrectomy for gastric cancer. Methods: We collected the data of patients who underwent distal gastrectomy from January 2018 to December 2021 from the National Clinical Database (NCD), a web‐based surgical registration system in Japan. The number of surgical cases, the use of intensive care units, and the incidence of morbidity per month were analyzed. We also calculated the standardized mortality ratio (SMR), defined as the ratio of the number of observed patients to the expected number of patients calculated using the risk calculator established in the NCD, for several morbidities, including pneumonia, sepsis, 30‐day mortality, and surgical mortality. Results: A decrease of 568 gastrectomies was observed from April 2020 to May 2020. Although the absolute number of patients admitted to intensive care units had declined since 2020, the proportion of patients admitted to the ICU did not change before and after the pandemic. Mortality and critical morbidity (such as pneumonia and sepsis) rates were not worse during the pandemic compared to pre‐pandemic periods per the SMR. Conclusions: Surgical management was conducted adequately through the organized efforts of the entire surgery department in our country even in a pandemic during which medical resources and staff may have been limited. [ABSTRACT FROM AUTHOR]

Aim: The splenic flexure has variable vascular anatomy, and the details of the venous forms are not known. In this study, we report the flow pattern of the splenic flexure vein (SFV) and the positional relationship between the SFV and arteries such as the accessory middle colic artery (AMCA). Methods: This was a single‐centre study using preoperative enhanced CT colonography images of 600 colorectal surgery patients. CT images were reconstructed into 3D angiography. SFV was defined as a vein flowing centrally from the marginal vein of the splenic flexure visible on CT. AMCA was defined as the artery feeding the left side of the transverse colon, separate from the left branch of the middle colic artery. Results: The SFV returned to the inferior mesenteric vein (IMV) in 494 cases (82.3%), the superior mesenteric vein in 51 cases (8.5%) and the splenic vein in seven cases (1.2%). The AMCA was present in 244 cases (40.7%). The AMCA branched from the superior mesenteric artery or its branches in 227 cases (93.0% of cases with existing AMCA). In the 552 cases in which the SFV returned to the IMV, superior mesenteric vein or splenic vein, the left colic artery was the most frequent artery accompanying the SFV (42.2%), followed by the AMCA (38.1%) and the left branch of the middle colic artery (14.3%). Conclusions: The most common flow pattern of the vein in the splenic flexure is from the SFV to IMV. The SFV is frequently accompanied by the left colic artery or AMCA. [ABSTRACT FROM AUTHOR]

Background: The number of lymph node metastasis (LNM) is a strong prognostic factor in the treatment of colorectal cancer (CRC). However, the impact of the mesentery location on LNM remains unclear. We assessed the impact LNM location on the recurrence of stage III CRC. Methods: Subjects with CRC and pathologically positive LNM were enrolled retrospectively. We defined three groups: LNM adjacent to the tumour (group A), metastases with horizontal or vertical spread (group B), and metastases with both horizontal and vertical spread (group C). Recurrence‐free survival (RFS) was the primary outcome measure used for the study. Results: A total of 241 (Group A: 121, B: 90, and C: 30) patients were recruited for the study. Multivariate analysis by Cox regression model indicated LNM location to be an independent predisposing risk factor for recurrence [group B: Hazard ratio (HR) 2.01, 95% Confidential interval (CI) 1.12–3.60, P = 0.019; group C: HR 3.00, 95% CI 1.34–6.72, P = 0.008]. Addition of mesentery spread to the N classification was significant risk factor for recurrence (mN2a: HR 2.01, 95% CI 1.07–3.78, P = 0.029; mN2b: HR 3.96, 95% CI 2.12–7.40, P < 0.01). Comparison of Harrell's C‐index values was conducted, and the modified N staging risk was 0.6377, whereas the TNM N stage classification was 0.5869. Conclusion: Mesentery location of LNM was a risk factor and consideration of it might be beneficial for accurate prediction of CRC prognosis. [ABSTRACT FROM AUTHOR]

Imaging and measuring compression stresses secure a safe and healthy life. Compression stresses in kPa range are not easily detected by conventional mechanoresponsive materials because microscopic molecular motion of the chromophores is not induced by such weak stresses. Moreover, imaging of the stress distribution is not achieved so far. The present study shows a sponge device combining two stimuli‐responsive materials, a capsule releasing interior liquid and color‐changing polymer in responses to compression stress and chemical stimulus, respectively. The stimuli‐responsive capsule is dispersed on a melamine sponge comprised of the fibers with coating the layered polydiacetylene (PDA). The application of weak compression stresses induces collapse of the capsules, outflow of the interior liquid, and subsequent irreversible color change of PDA. The cascading response in the sponge device colorimetrically enables imaging of the distribution and measuring the strength of the compression stresses in kPa range. Furthermore, the device demonstrates imaging and measuring unknown weak compression stresses applied by the irregular‐shaped objects. A couple of clinical issues in surgical operation of intestine are studied using the stress‐imaging sponge device. The device and its design strategy can be applied to stress imaging in a variety of fields. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the significance of next-generation sequencing-based gene panel testing in surgically resectable colorectal cancer by analyzing real-world data. Materials & methods: A total of 107 colorectal cancer patients who underwent curative surgery were included, and correlations between next-generation sequencing data and clinicopathological findings were evaluated. Results: More combination patterns in gene alteration were identified in advanced-stage tumors than in early-stage tumors. The copy number alteration count was significantly lower in right-sided colon tumors and early-stage tumors. Homologous recombination deficiency was more often identified in advanced-stage tumors, and high homologous recombination deficiency status was useful for identifying high-risk stage II tumors. Conclusion: Homologous recombination deficiency was identified as a useful result of gene panel testing with novel utility in clinical practice. [ABSTRACT FROM AUTHOR]

Aim: Main lymph node (LN) metastasis dissected with a high vascular tie at the root of the feeding artery is a poor prognostic factor in colorectal cancer (CRC). However, the effects of horizontal spread on recurrence after curative resection remain unclear. The purpose of this study is to evaluate the relationship between the horizontal spread of LN metastasis and recurrence in CRC. Method: In this retrospective study, 189 CRC patients (98 men, 91 women) who underwent curative resection at our hospital from 2003 to 2018 and had only pericolic LN metastasis were divided into two groups: patients with LN metastasis beside the tumour only (T group, n = 121) and those with LN metastasis with horizontal spread (S group, n = 68) (mean follow‐up period 50.9 ± 34.1 months). The primary outcome was recurrence‐free survival (RFS). We investigated the correlation between clinicopathological background factors and recurrence using Cox regression analysis. Results: Fewer than three LN metastases (N1) were found in 157 patients (107 T group, 50 S group), and four or more metastases (N2a) were found in 32 patients (14 T group, 18 S group). Univariate analyses revealed significantly shorter RFS in the S group [hazard ratio (HR) 1.95, 95% CI 1.07–3.55; p = 0.03). Multivariate analyses revealed that horizontal spread is an independent risk factor for recurrence (HR 1.95, 95% CI 1.05–3.68; p = 0.03). Conclusion: Although further investigation is needed, horizontal spread of LN metastasis is a prognostic factor for recurrence in Stage III CRC. [ABSTRACT FROM AUTHOR]