INTRODUCTION:Gastrointestinal metastasis from malignant pleural mesothelioma (MPM) is exceedingly rare and lacks a standardized diagnostic work-up. CASE PRESENTATION:An 87-year-old man with asbestos exposure and a 5-year history of left-sided MPM, radiographically stable on long-term nivolumab therapy, presented with melena and anemia. Contrast-enhanced CT revealed a circumferential jejunal lesion near the duodenojejunal flexure with enlarged mesenteric nodes. Double-balloon enteroscopy confirmed a 40-mm obstructive tumor, but biopsies were non-diagnostic. Partial jejunectomy with targeted mesenteric lymph-node dissection was performed. Histology with a mesothelioma-oriented immunohistochemical panel-negative for CEA and BerEP4 and positive for broad-spectrum cytokeratins-supported a diagnosis of metastatic MPM; nodal metastases were present. Given his age, no further systemic therapy was administered; the patient died 20 months postoperatively from progression of MPM. CONCLUSIONS:In MPM receiving immune-checkpoint inhibitor therapy, unexplained gastrointestinal bleeding should prompt comprehensive gastrointestinal evaluation, including small-bowel assessment. Surgery can secure symptom relief and a definitive diagnosis.

Adrenal metastasis from gastric cancer is often found as part of systemic metastasis, and is rarely an isolated tumor that requires resection.The patient was a 73-year-old man.Contrast CT scan performed to investigate anemia and positive stool for occult blood revealed a 5 cm mass in the left adrenal gland.Upper gastrointestinal endoscopy revealed gastric cancer in the lesser curvature of the gastric angle, and lower gastrointestinal endoscopy revealed rectal cancer.Laparoscopic left adrenalectomy was performed for the left adrenal mass, and a histopathological examination revealed that the tumor was adrenal metastasis from gastric cancer.After 3 courses of SOX therapy, robot-assisted distal gastrectomy, with D2 lymph node dissection, and Roux-en-Y reconstruction were performed.Postoperative pathological diagnosis was M, Less, ypType 4, 48×43 mm, por2>tub2>sig, ypT3(SS), INF c, Ly0, V0, ypPM0, ypDM0, ypN0, P0, CY0, H0, M1(ADR), ypStage Ⅳ.By appropriately combining systemic therapy(chemotherapy)and local therapy(surgical resection), it is expected that the prognosis can be improved even for isolated adrenal metastasis of gastric cancer.

INTRODUCTION: Spontaneous cancer regression is exceptionally rare, particularly in colorectal cancer. Tumor regression has been reported in some patients with autoimmune diseases or organ transplants, after cessation of immunosuppressive therapy; however, its underlying mechanisms remain unclear. We report a rare case of Stage IVA transverse colon cancer with synchronous liver metastasis that showed complete pathological regression in both sites after discontinuation of tocilizumab, an interleukin-6 receptor inhibitor. CASE PRESENTATION: A 79-year-old woman with a history of rheumatoid arthritis and interstitial pneumonia was treated with iguratimod, methotrexate, prednisolone, and tocilizumab. PET-CT images revealed an accumulation of fluorodeoxyglucose in the transverse colon and liver. Colonoscopy and biopsy findings confirmed a poorly differentiated adenocarcinoma in the transverse colon; liver biopsy findings confirmed metastatic disease. In preparation for surgery, and because the rheumatoid arthritis activity was stable, tocilizumab was discontinued. Three months after tocilizumab discontinuation, laparoscopic partial colectomy with lymph node dissection was performed. Histopathologic examination of the resected colon showed no viable tumor cells. Subsequently, laparoscopic partial hepatectomy of segments 2 and 3 revealed no viable tumor cells as well. The patient remained recurrence-free at the 2-year follow-up. CONCLUSIONS: The findings of this case suggest that tocilizumab discontinuation may have reactivated antitumor immune responses, resulting in spontaneous regression of both the primary colorectal cancer and liver metastasis. Notably, prior to regression, both masses were histologically confirmed as malignant lesions. This observation provides valuable clinical insight into the relationship between interleukin-6 receptor blockade, immune modulation, and tumor dynamics.

Background Six months of adjuvant S-1 is the standard treatment for resected pancreatic cancer in Japan. Metformin has demonstrated potential anticancer effects in preclinical and observational studies. This study aimed to evaluate whether adding metformin to S-1 improves 2-year survival after pancreatic cancer resection. Methods This multicenter, randomized, open-label Phase II trial enrolled patients with histologically confirmed Stage I–II invasive pancreatic ductal carcinoma who underwent curative resection. Patients were randomized to receive S-1 plus metformin (Group A) or S-1 alone (Group B). S-1 was administered for 6 months in both groups, and metformin for 2 years in Group A. The primary endpoint was 2-year overall survival; secondary endpoints were recurrence-free survival and safety. The sample size was calculated assuming a 2-year survival rate of 65% with S-1 alone and 78% with S-1 plus metformin (hazard ratio: 0.58), providing 80% power with a one-sided α of 0.20. Glycemia-related safety was monitored using Common Terminology Criteria for Adverse Events-defined hyperglycemia and hypoglycemia. Results Seventy-six patients were randomized (38 per group). The 2-year survival rate was 66.7% in Group A and 66.1% in Group B (hazard ratio 1.09; 95% confidence interval 0.55–2.16; p = 0.93). Median overall survival was 53.8 versus 58.0 months, and median recurrence-free survival was 17.9 versus 12.6 months ( p = 0.78). No grade ≥ 4 adverse events occurred; Grade 3 toxicities were infrequent and comparable between groups. Conclusions Adding metformin to adjuvant S-1 did not improve survival in patients with resected pancreatic cancer.

Background/Objectives: Postoperative recurrence is a critical issue in the treatment of resectable pancreatic ductal adenocarcinoma (rPDAC). Moreover, the prognosis after early recurrence is extremely poor. This study aimed to develop a recurrence prediction model and to define early recurrence after upfront surgery (UFS) for rPDAC. Methods: This multicenter retrospective study included patients who underwent UFS for anatomically rPDAC between January 2013 and December 2017. Multivariate analyses were conducted to identify the risk factors for recurrence-free survival and to construct a recurrence prediction model. Subsequently, a minimum p value approach was used to determine the optimal cutoff values for early and late recurrence. Results: The cohort included 603 patients (325 men and 278 women). During the median follow-up period of 25 months (interquartile range, 15-38 months), 381 patients (63.2%) experienced a recurrence. Multivariate analyses revealed carbohydrate antigen 19-9 ≥37 U/mL (hazard ratio [HR], 1.58; p < 0.001), tumor size ≥ 2.2 cm (HR, 1.59; p < 0.001), lymph node metastasis (HR, 1.86; p < 0.001), R1 resection (HR, 1.56; p = 0.002), and no adjuvant chemotherapy (HR, 1.54; p < 0.001) as independent predictors. The recurrence prediction model demonstrated an area under the curve of 0.72-0.75. The optimal threshold for early and late recurrences was a recurrence-free interval of five months. Carbohydrate antigen 19-9 ≥ 156 U/mL was a significant predictor of early recurrence (OR, 3.28; p < 0.001). Conclusions: This study identified the prognostic risk factors for recurrence and developed a recurrence prediction model for patients undergoing UFS for rPDAC. Moreover, a recurrence-free interval of five months was identified as the optimal threshold for distinguishing between early and late recurrences.

BACKGROUND:Although portal vein (PV) contact ≤ 180° in pancreatic body/tail ductal adenocarcinoma (PbtCa) is a criterion for resectable, adequate evidence has not been established yet. METHODS:This retrospective study analyzed 1693 patients with PbtCa who underwent distal pancreatectomy across 31 institutions in Japan. Clinicopathological factors, survival, and recurrence pattern were compared among non-PV contact, PV contact, and celiac axis (CeA) contact groups. RESULTS:Overall survival (MST: 28.3 months) and the positive surgical margin rate (23%) in the PV contact (n = 168) were worse than those of non-PV contact (n = 1353, 47.9 months [p < 0.001], 13% [p = 0.001]), and were comparable with CeA contact (n = 172, 26.4 months [p = 0.136], 26% [p = 0.447]). Incidence of local recurrence (26%) and peritoneal recurrence (20%) in the PV contact were comparable to those in the CeA contact (21%, p = 0.309, and 19%, p = 0.915). Cox proportional hazards analysis revealed PV contact (hazard ratio, 1.295; p = 0.003) as independent prognostic factors for overall survival. CONCLUSIONS:PbtCa with PV contact should be considered borderline resectable because of a high positive surgical margin rate and poor survival, similar to those in PbtCa with CeA contact. TRIAL REGISTRATION:This study was registered in the UMIN Clinical Trial Registry (UMIN-CTR: UMIN000041642).

Background/Objectives: Upfront surgery (UFS) remains the standard treatment for patients with resectable pancreatic ductal adenocarcinoma (PDAC). We aimed to investigate the prognostic factors for survival after UFS in patients with resectable PDAC and to develop a prognostic prediction model. Methods: This multicenter, retrospective study included 603 patients who underwent UFS for resectable PDAC between January 2013 and December 2017. Univariate and multivariate analyses were performed to identify prognostic factors for overall survival (OS). We constructed a prognostic prediction model for OS after UFS. An internal validation was performed to evaluate the discriminative performance of the model. Results: The 1-, 3-, and 5-year OS rates were 83.7%, 48.2%, and 37.5%, respectively. The Cox proportional hazards model showed that tumor size > 2 cm (hazard ratio [HR] 1.50, p = 0.001); tumor contact with the portal and superior mesenteric veins of ≤180° (HR 1.47, p = 0.003); carbohydrate antigen 19-9 levels of 40 to 500 U/mL (HR 1.59, p = 0.002) and ≥500 U/mL (HR 2.16, p < 0.001); and a modified Glasgow Prognostic Score of two (HR 1.56, p = 0.038) were predictors associated with OS. The prognostic prediction model for 5-year OS demonstrated an area under the curve of 0.68. The calibration plots indicate a concordance index of 0.63. Conclusions: We identified the preoperative prognostic factors for OS and developed a prognostic prediction model to estimate OS in patients undergoing UFS for resectable PDAC. Our model may be useful and internally validated for predicting OS.

BACKGROUND:In the context of Japan's rapidly aging population, establishing optimal treatment strategies for elderly patients with colorectal cancer(CRC)remains a pressing clinical concern. Colonic self-expandable metallic stent(SEMS) placement has gained recognition as a viable option for managing obstructive CRC, including in elderly individuals. METHODS:We conducted a retrospective analysis of 162 patients who underwent SEMS placement for primary obstructive CRC between 2015 and 2024. Patient demographics, clinical characteristics, and outcomes were compared between elderly and non-elderly cohorts. RESULT:Elderly patients were more likely to have poor performance status and a history of dementia; however, the outcomes of SEMS placement and subsequent surgical intervention were comparable to those observed in non-elderly patients. Primary tumor resection following bridge to surgery (BTS) was associated with improved overall survival. CONCLUSIONS:SEMS placement serves as a versatile and effective treatment strategy, particularly in elderly patients with diverse clinical profiles. Our findings suggest that primary tumor resection after BTS may contribute to improved survival, supporting the clinical significance of this treatment strategy.

INTRODUCTION:As the nonoperative management of acute appendicitis becomes more widespread, identifying patients at high risk of appendiceal tumors is increasingly important. This study aimed to clarify the predictive factors of appendiceal tumors before appendectomy. METHODS:We retrospectively analyzed 434 patients diagnosed with acute appendicitis who underwent emergency or interval appendectomy. RESULTS:Appendiceal neoplasms were found in 3.9% of patients. Patients with tumors were significantly older (64.4 vs. 49.6 years, p < 0.001). The tumor group exhibited a lower appendicolith incidence (48% vs. 12%, p = 0.011) and larger appendiceal diameters (18.0 vs. 12.3 mm, p < 0.001). Multivariate analysis demonstrated that age ≥60 years, absence of appendicolith, and an appendiceal diameter ≥12 mm were independent risk factors of appendiceal tumors. Among patients who underwent interval appendectomy, only the non-tumor group exhibited significant improvement in appendiceal diameter after nonoperative management (tumor, +1.6 mm vs. no tumor, -3.5 mm, p < 0.001). CONCLUSIONS:Advanced age, absence of appendicolith, and an enlarged appendiceal diameter may be significant predictive factors of appendiceal tumors. These factors will aid in the selection of appropriate appendicitis treatment strategies.

BACKGROUND:In Japan, the fastest aging country in the world, colorectal cancer(CRC)patients at least 90 years old are rapidly increasing. MATERIALS AND METHODS:Among CRC patients who received resection of primary lesions between 2014 and 2023, we retrospectively compared and examined 24 cases of CRC aged 90 years or older(SE group)with non-elderly patients aged 50 to 74 years(NE group). RESULTS:SE group had significantly poorer nutritional indexes and anemia. Right side colon cancer was more common in SE group. SE group patients were more frequently underwent laparotomy, and less D3 lymph node dissection. Therefore, operative time was significantly shorter in SE group. 3-year overall survival(OS)was significantly worse in SE group, but 3-year disease-specific survival(DSS)was comparable. Postoperative complication of Grade 2 or worse tended to occur more often in SE group, including cerebral infarction in 2 cases and heart failure in 1 case. The number of patients being discharged home was less frequent in SE group. CONCLUSIONS:Patients with colorectal cancer aged 90 years or older had anemia and poorer nutritional indexes, and their OS was poor. We should pay attention to the possibility of postoperative including cerebral infarction and heart failure.

AbstractAimLynch syndrome (LS) is a dominantly inherited syndrome characterized by an increased risk for LS associated tumors such as colorectal cancer (CRC) and gastric cancer (GC). However, the clinical benefit of surveillance for GC remains unclear while it has already been recommended for CRC. This study aimed to elucidate the clinical features of GC in Japanese individuals with LS, and the risk of developing multiple GCs to build regional‐tailored surveillance programs in LS patients with GC.MethodsData on Japanese individuals with LS were retrospectively collected from a single institution. The clinical features of GC, including the cumulative risk of multiple GCs, were analyzed.ResultsAmong 96 individuals with LS (MLH1/MSH2/MSH6, 75:20:1), 32 GC lesions were detected in 15 individuals with LS (male/female, 11:4). The median age at initial GC diagnosis was 52.7 y (range: 28–71). Histological examination revealed a predominance of intestinal type (19/24: 87.5%). Moreover, the majority of the GC lesions (82%) were determined to have high‐frequency of microsatellite instability. The cumulative risk of individuals with LS developing GC at 70 y was 31.3% (MLH1 36.1%, MSH2 18.0%). Notably, the cumulative risk of individuals with LS developing metachronous and/or synchronous GCs at 0, 10 and 20 y after initial diagnosis of GC was 26.7%, 40.7%, and 59.4%, respectively.ConclusionDue to a higher risk of developing multiple GCs, intensive surveillance might be especially recommended for Japanese individuals with LS associated initial GC.

In the clinical course of malignant melanoma, which can metastasize to multiple organs, gallbladder metastases are rarely detected. A 69-year-old man who underwent resection of a primary malignant melanoma was subsequently treated with nivolumab for lung metastases and achieved complete response. Seven years after surgery, multiple nodules were found in the gallbladder, and he underwent laparoscopic cholecystectomy. The postoperative diagnosis was metastases of malignant melanoma. He has been recurrence-free 8 months after surgery. If radical resection is possible, such surgery should be performed for gallbladder metastases found in patients with other controlled lesions of malignant melanoma.

We analyzed the clinicopathological features and prognosis of 9 patients with primary small bowel adenocarcinoma, excluding duodenal cancer, between January 2009 and February 2024 at our hospital. The mean age of the patients was 68.9(60-82)years, and the male to female ratio was 7 : 2. Seven patients were diagnosed with small bowel cancer preoperatively, and 5 out of 7 patients were diagnosed pathologically. We performed partial resection in 6 patients and laparoscopic partial resection, laparoscopic ileocecal resection and endoscopic mucosal resection in 1 patient respectively. The histological type was well-differentiated adenocarcinoma in 6 patients, moderately differentiated adenocarcinoma in 1 patient, poorly differentiated adenocarcinoma in 2 patients. The pathological Stage was 0 in 2 patients, Stage Ⅱ in 3 patients, Stage Ⅲ in 3 patients, Stage Ⅳ in 1 patient. The median duration of follow-up was 18(1-143)months. Six patients are alive without recurrence, 1 patient died of cancer, and 2 patients died of other diseases. It was assumed that proactive radical surgery and postoperative adjuvant chemotherapy were associated with improved prognosis.

This editorial discusses an article by Peng et al . This study reviewed the efficacy and safety of a new approach for treating obstructive jaundice. Although the pathophysiology of obstructive jaundice has not yet been fully elucidated, progress has been made in its management. There are two aspects of obstructive jaundice: Cholestatic status and absence of bile in the intestinal lumen. Internal biliary drainage resolved both the conditions. Clinically, endoscopic retrograde biliary drainage (ERBD) has replaced percutaneous transhepatic biliary drainage, and ERBD is transitioning to endoscopic ultrasound guided biliary drainage. This editorial briefly explains the mechanism and treatment of obstructive jaundice and the prospects of this new internal biliary drainage technique.

The prognosis of patients with gastric cancer and ovarian metastasis is extremely poor, with many studies reporting survival durations within 1-2 years after diagnosis. The patient in this study was a 64-year-old female who visited a local hospital with lower abdominal pain and was referred to our hospital's gynecology department for follow-up of uterine fibroids. MRI revealed a right ovarian tumor and upper gastrointestinal endoscopy revealed gastric cancer in the upper stomach. A total hysterectomy with bilateral adnexectomy was performed, and the pathological examination revealed that gastric cancer had metastasized to the uterus and right ovary. After SOX therapy, laparoscopic proximal gastrectomy with double-flap reconstruction was performed. Postoperative pathological diagnosis was U, Ant, pType 5, 38×21 mm, por-tub, ypT4a(SE), Ly1b, V0(VB), ypPM0, ypDM0, ypN0, P0, CY0, H0, M1(OTH), ypStage Ⅳ, R0. Two years and 10 months have passed since the surgery, and there have been no signs of recurrence. In this patient, both the ovarian metastasis and primary gastric lesion were completely resected, and chemotherapy was effective, resulting in a good prognosis. Considering that gastrectomy reduces chemotherapy tolerability, the timing of gastrectomy should be considered. In addition, avoiding total gastrectomy is important for postoperative adjuvant chemotherapy.

Spontaneous hemoperitoneum is a rare and potentially life-threatening condition with a wide differential diagnosis. Gastrointestinal stromal tumors (GIST) can present with spontaneous hemoperitoneum, although diagnosing GIST as the cause of hemoperitoneum is challenging due to its rarity. A 76-year-old Japanese man presented with sudden epigastric pain and was found to have a 10 cm space-occupying lesion and ascites on ultrasonography. Despite stable vital signs, computed tomography (CT) findings showed a 10×15 cm mass with heterogeneously enhanced solid and cystic lesions, and the patient opted for conservative treatment. Two months later, a contrast-enhanced CT scan revealed a high-density area within the hematoma, prompting further investigation with fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT), which showed FDG accumulation suggestive of malignancy. Exploratory laparotomy revealed a large encapsulated mass from the greater omentum, and histopathology confirmed a diagnosis of high-risk extraluminal gastric GIST. The patient was successfully treated with surgical resection. This case highlights two important clinical issues. First, follow-up CT and FDG-PET/CT are useful in detecting GIST when an unexplained intraperitoneal hematoma is identified. Second, surgical intervention is recommended in such cases to determine the cause. Contrast-enhanced follow-up CT and FDG-PET/CT are valuable in clarifying the presence of GIST, and surgical intervention is recommended to identify the causes of intraperitoneal hematoma. Further studies are needed to standardize the approach to spontaneous hematoma from GIST.

Background Celiac axis stenosis (CAS) is frequently observed in patients undergoing pancreaticoduodenectomy (PD). This poses challenges because of the potential disruption of the hepatic arterial blood flow. Case presentation We present the case of an 81-year-old woman diagnosed with pancreatic head cancer and severe CAS caused by calcification. The patient received neoadjuvant chemotherapy (NAC) and underwent preoperative endovascular stenting of the celiac axis to restore blood flow. After two cycles of NAC, subtotal stomach-preserving PD was performed. An intraoperative assessment of the hepatic arterial blood flow determined that it was well maintained. PD was performed using the standard technique; specialized techniques were not necessary. Importantly, no ischemic complications were encountered. Conclusion This case report describes the successful combination of preoperative celiac axis stenting, NAC, and surgical intervention for the management of CAS in an elderly patient with pancreatic cancer. This approach offers a potential solution for maintaining the hepatic arterial blood flow in the presence of CAS without vascular reconstruction, particularly in elderly individuals.

Background:Adult intussusception is a rare condition that is often associated with a high incidence of malignancy. The optimal management strategy remains controversial, particularly regarding the necessity for bowel reduction before resection. To date, there is a paucity of data on adult intussusception in the English literature. We present two cases of sigmoid colon cancer with intussusception prolapsing through the anus and highlight the different surgical approaches. Case Description:Case 1: an 84-year-old woman presented with sigmoid colon prolapse and biopsy-confirmed adenocarcinoma. Urgent surgery revealed intussusception. Despite unsuccessful manual reduction, the Hutchinson technique successfully resolved the intussusception. Resection with a temporary colostomy was performed. Histopathological examination revealed mucinous adenocarcinoma without metastasis; the patient recovered well. Case 2: a 76-year-old woman with sigmoid colon prolapse presented with abdominal pain and blood-streaked stools. Emergency surgery was performed because of failed reduction attempts and persistent symptoms. Intussusception resolution was achieved through transanal insertion of a circular sizer. Resection with temporary colostomy was performed, after which tubular adenocarcinoma was identified. The patient remains symptom-free 3 years post-surgery. Conclusions:Choice of the surgical approach depends on the ease of intussusception reduction. In cases wherein reduction is straightforward, routine preoperative examinations are preferred given the low risk of injury or cancer cell dissemination. Conversely, in situations such as ours, gentle reduction under general anesthesia might be crucial. In addition, laparoscopic surgery could be beneficial. Importantly, accumulation of reports on adult intussusception could contribute to the standardization of this approach.

The patient was a 73-year-old female with left lower abdominal pain. Colonoscopy revealed a tumor in the transverse colon, which was biopsied and diagnosed as a well-differentiated adenocarcinoma. Computed tomography revealed incomplete formation of the ligament of Treitz, with the small bowel located in the right abdomen and the ascending colon along the midline. The superior mesenteric vein(SMV)was positioned on the left side of the superior mesenteric artery(SMA). The tumor was located in the central part of the transverse colon. The patient was diagnosed with transverse colon cancer with intestinal malrotation before surgery. Laparoscopic partial colectomy(of the transverse colon)was performed. The lymph nodes were dissected from the right margin of the SMV. The middle and right colic arteries were severed, and D3 lymph node dissection was performed. The colon was found to have shifted to the left side, with extensive adhesions between the omentum and mesocolon. The postoperative pathological diagnosis was tub1, pT3, pN0, pM0, and pStage Ⅱ a. Intestinal malrotation was diagnosed preoperatively, and unusual vascular positioning was identified. Consequently, we were able to perform safe and adequate lymph node dissection during laparoscopic surgery.