Effect of body fat mass loss on prognosis of radical resection for pancreatic ductal adenocarcinoma based on bioelectrical impedance analysis.

BACKGROUND: Few reports have performed a prognostic analysis based on bioelectrical impedance analysis in patients with radical resection of pancreatic ductal adenocarcinoma (PDAC), and its usefulness in prognostic analysis remains unclear. This study aimed to evaluate body composition changes in patients undergoing radical resection for PDAC and analyze its impact on prognosis. METHODS: The medical records of radical resection for patients with PDAC were retrospectively reviewed, and the parameters of body composition, including body weight, skeletal muscle mass, body fat mass (BFM), and extracellular water-total body water ratio, from preoperatively to 12 months postoperatively, for each surgical procedure were measured based on direct segmental multifrequency bioelectrical impedance analysis with an InBody 770 (InBody Inc., Tokyo, Japan) device. The clinicopathological and prognostic factors were analyzed. RESULTS: Among 79 patients who underwent radical resection for PDAC, 36 (46%), 7 (8%), and 36 (46%) underwent pancreatoduodenectomy, total pancreatectomy, and distal pancreatectomy, respectively. The multivariate overall survival analysis demonstrated that BFM loss percentage at 1 month postoperatively ≧14% (p = 0.021), lymph node metastasis (p = 0.014), and non-adjuvant chemotherapy (p <  0.001) were independent poor prognostic factors. Multivariate analysis revealed that preoperative BFM < 12 kg and preoperative albumin < 3.5 g/dL were independently associated with BFM loss percentage at 1 month postoperatively ≧14% (p = 0.021 and p = 0.047, respectively). CONCLUSIONS: Loss of BFM in the early postoperative period may have a poor prognosis in radical resection of PDAC.

Analysis of Acquisition of COVID-2019 Neutralizing Antibodies in Organ Transplant Recipients.

BACKGROUND: This study confirmed the kinetics of antibodies acquired by SARS-CoV-2 vaccination in solid-organ transplant recipients and examined their association with the development of COVID-19 and immunosuppressive status in organ transplant recipients. METHODS: We measured COVID-19 neutralizing antibody titer in 21 organ transplant recipients vaccinated with the COVID-19 vaccine and 14 nontransplant recipients (control group) 3 times before and at 1 and 6 months after the third dose of vaccine. By confirming the kinetics of the acquired antibodies, we examined the relevance of the background characteristics of organ transplant recipients, such as the development of infectious diseases and immunosuppressive status. RESULTS: The proportion of patients with neutralizing antibodies was significantly higher in the nontransplant group than in the transplant group. Neutralizing antibody titers were significantly lower in transplant recipients when they were compared before the third dose and 1 month later. In the transplant recipient group, 11 patients were positive, and 10 were negative for neutralizing antibodies. When the causal relationship between the neutralizing antibody titer and background was examined, a positive correlation was found between the antibody titer and the number of years since transplantation, and a negative correlation was found between the tacrolimus trough values, amount of mycophenolate mofetil or steroids taken internally, and antibody titer. CONCLUSION: This study suggests that the effectiveness of vaccination in transplant recipients is associated with the post-transplant period before vaccination and the dose of immunosuppressive agents.

Micro-lymph node metastasis in intrahepatic cholangiocarcinoma showing pathological complete response to primary tumor and intrahepatic metastasis treated by gemcitabine plus cisplatin chemotherapy and radical surgery.

Surgical resection is the only curative treatment option for achieving long-term survival in biliary tract cancer patients. However, regional lymph node dissection in intrahepatic cholangiocarcinoma (ICC) is controversial. Herein, we document our experience with a 76-year-old man who had a 70 mm mass in liver segments 6 and 7 and a 10 mm mass in liver segment 3, which were diagnosed as poorly differentiated adenocarcinomas by needle biopsy. Lymphadenopathy was not evident on multidetector computed tomography scanning. Twenty courses of gemcitabine plus cisplatin chemotherapy were administered to the patient. The tumor masses shrunk and exhibited a partial response to chemotherapy as per the Response Evaluation Criteria in Solid Tumors version 1.1. Although tumor markers were all within normal limits, renal function parameters showed deterioration due to systemic chemotherapy. Therefore, continuing systemic chemotherapy was deemed unfeasible and we decided to perform a radical resection using extended posterior segmentectomy and partial liver resection with regional lymph node dissection. Postoperative histopathological examination revealed complete response of primary tumor and intrahepatic metastases; however, a micro-lymph node metastasis was found. The patient is still alive, without recurrence, more than 30 months after treatment initiation and 15 months after surgery. Even if remarkably effective pathological findings may be observed in the primary tumor, there are cases in which a micro-lymph node metastasis remains that are not identified on imaging examinations. Thus, regional lymphadenectomy may be useful in obtaining the exact state of disease progression and evaluation of chemotherapeutic effect in radical surgery.

[Surgical Resection and Adjuvant Chemotherapy for Early Multiple Peritoneal Recurrence after Rejection of Hepatocellular Carcinoma-A Case Report].

Thus far, no consensus has been reached regarding the treatment of peritoneal dissemination of hepatocellular carcinoma (HCC). Here, we report a case of surgical resection and postoperative adjuvant chemotherapy for early multiple peritoneal recurrences of HCC. A 74-year-old man was found to have hepatic mass of 80 mm in size in S7 and 57 mm in S8, and was diagnosed with HCC. The patient underwent an open anterior segmentectomy and S7 subsegmentectomy of the liver. Peritoneal washing cytology revealed the presence of malignant cells. The tumor strongly adhered to the diaphragm, necessitating partial resection of the diaphragm. Six months after surgery, multiple disseminated recurrences were found on the CT scan. Atezolizumab plus bevacizumab combination therapy was initiated, but tumor size enlargement and elevation of tumor markers were observed after 3 courses. Resection of the dissemination(2 on the surface of the lung right lower lobe, 1 on the right renal superior retroperitoneum, 1 on the omentum, and 1 invading the jejunum)was performed. Considering the high risk of recurrence, postoperative adjuvant chemotherapy with lenvatinib was administered for 1 year. No recurrence has been found for 16 months after the resection. Although more cases are needed to conclude, this case report suggests that surgical resection and postoperative administration of lenvatinib may be effective in the treatment of disseminated HCC lesions at a high risk of recurrence.

[Unresectable Esophageal Cancer on the Elderly Woman Which Was Treated Effectively with Ipilimumab plus Nivolumab-A Case Report].

Until now, the standard treatment regimen was cisplatin plus 5-FU as the chemotherapy for unresectable advanced esophageal cancer. Immune checkpoint inhibitors have brought about changes to the cancer treatment. Ipilimumab plus nivolumab was approved in June 2022 for unresectable advanced esophageal cancer. An 86-year-old woman who was normal ADL and cognitive function was diagnosed with unresectable esophageal cancer with multiple lymph node metastasis. We thought surgery or chemotherapy is impossible because of her age and health status, so we treated with ipilimumab plus nivolumab. After 2 cycles, tumor became reduced in size on endoscopic examination and accumulation in primary lesion and lymph node metastases was decreased considerably on positron emission tomography/computed tomography(PET-CT). Though the cycle after initiation of chemotherapy was uneventful, tumor regrowth on the examinations at 5 months. The patient's condition of the disease was improved temporarily after change chemotherapy to paclitaxel as the second-line therapy, but she died due to disease progression at 11.4 months from initiation of treatment. Ipilimumab plus nivolumab can become one of the effective treatments for patients who are impossible to treat with conventional chemotherapy.

[A Case of Sclerosing Angiomatoid Nodular Transformation Resected for Suspected Relapse of Diffuse Large B-cell Lymphoma].

We report a case of sclerosing angiomatoid nodular transformation(SANT)5 years after remission of diffuse large B-cell lymphoma(DLBCL). A 64-year-old woman was diagnosed a nodular mass at the spleen by a contrast-enhanced CT scan 5 years after the relief for DLBCL. The mass showed accumulation of FDG. Because the possibility of the recurrence of malignant lymphoma could not be ruled out, laparoscopic splenectomy was performed for diagnosis and treatment. Immunohistologically, the resected mass revealed 3 different vascular components pattern(CD31, CD34 and CD8), so we diagnosed SANT. It is difficult to distinguish from malignant lymphoma or cancer even with various examination, so laparoscopic splenectomy is useful for diagnosis and treatment.

[A Case of Lynch Syndrome with Repeated Asynchronous Colorectal Cancer in a Short Period].

This case was a 73-year-old woman who previously underwent a partial colectomy for ascending colon cancer at the age of 70. She had a history of cancer of the uterus, descending colon, bladder, and left ureter. She had a family history of colorectal cancer and met the Amsterdam Ⅱ criteria for Lynch syndrome. She was diagnosed as Lynch syndrome with a MSH2 germline mutation by genetic analysis. One year later, a partial colectomy was performed for sigmoid colon cancer. Six months later, colonofiberscopy revealed early-stage cancer in the rectum, and EMR was performed. Despite adequate surveillance, she had frequent recurrences of advanced colorectal cancer within a short period of time. We report here risk factors of colorectal cancer in Lynch syndrome and indications for prophylactic total colectomy.

Transcriptomic Analysis of Annexin A10 and Chemosensitivity in Gastric Adenocarcinoma Cells.

BACKGROUND/AIM: Gastric cancer (GC) is the third-leading cause of cancer-related deaths worldwide; thus, novel diagnostic and therapeutic biomarkers are needed. Annexin A10 (ANXA10) is a calcium- and phospholipid-binding protein. As far as we are aware, there are no reports describing the detailed functions of ANXA10 in GC. Therefore, we investigated the downstream mRNA variation and the effects of ANXA10 on chemoresistance in GC cell lines. MATERIALS AND METHODS: ANXA10 knockout GC cell lines were generated, and we performed functional analyses, chemosensitivity drug testing, and microarray analyses. Additionally, immunohistochemistry for ANXA10 was performed on 40 patients with GC who had received 5-fluorouracil (5-FU)-based chemotherapy to compare their prognosis and clinicopathological factors. RESULTS: ANXA10 knockout GC cells showed significantly increased proliferation, invasion, and sensitivity to 5-FU. The overall survival of ANXA10-positive cases was considerably lower than that of ANXA10-negative cases in GC patients who received 5-FU-based chemotherapy. Microarray analysis revealed candidate pathways regulated by ANXA10 and claudin 1 (CLDN1), keratin 80 (KRT80), RANBP2-type and C3HC4-type zinc finger containing 1 (RBCK1), and solute carrier family 7 member 5 (SLC7A5) genes. CONCLUSION: ANXA10 knockout increased the susceptibility of GC cell lines to 5-FU; ANXA10 may be a predictive indicator for response to 5-FU treatment in GC cases. ANXA10 may be involved in the pathogenesis of GC, in collaboration with CLDN1, KRT80, RBCK1, and SLC7A5.

[A Case of Pancreatoduodenectomy for Multiple Nonfunctioning Neuroendocrine Tumors of the Duodenum].

A 42-year-old woman was referred to our hospital because of incidentally discovered multiple neoplastic lesions of the duodenum. Upper gastrointestinal endoscopy showed there were more than 10 submucosal tumors and less than 10 mm in diameter. Histological examination of the biopsy specimen revealed nonfunctioning neuroendocrine tumor(NET). Enhanced computed tomography(CT)showed neither regional lymph node nor distant metastasis, so we performed pancreatoduodenectomy with regional lymph node dissection. Pathological examination showed multiple NET G2 less than 5 mm in size with invasion to muscularis propria and 3 lymph node metastases, so diagnosed as pT2(m)N1M0, Stage Ⅲ. She is alive without tumor recurrence for 14 months after surgery. In general, sporadic nonfunctioning NET of the duodenum less than 10 mm in diameter has low possibility of lymph node metastasis. However, our case suggested the possibility of lymph node metastasis in patients with multiple NETs of the duodenum, in spite of small size. Therefore, pancreatoduodenectomy with regional lymph node dissection should be considered for multiple nonfunctioning NETs of the duodenum.

Distal Gastrectomy for Symptomatic Stage IV Gastric Cancer Contributes to Prognosis with Acceptable Safety Compared to Gastrojejunostomy.

BACKGROUND: The prognostic prolongation effect of reduction surgery for asymptomatic stage IV gastric cancer (GC) is unfavorable; however, its prognostic effect for symptomatic stage IV GC remains unclear. We aimed to compare the prognosis of gastrectomy and gastrojejunostomy for symptomatic stage IV GC. METHODS: This multicenter retrospective study analyzed record-based data of patients undergoing palliative surgery for symptomatic stage IV GC in the middle or lower-third regions between January 2015 and December 2019. Patients were divided into distal gastrectomy and gastrojejunostomy groups. We compared clinicopathological features and outcomes after propensity score matching (PSM). RESULTS: Among the 126 patients studied, 46 and 80 underwent distal gastrectomy and gastrojejunostomy, respectively. There was no difference in postoperative complications between the groups. Regarding prognostic factors, surgical procedures and postoperative chemotherapy were significantly different in multivariate analysis. Each group was further subdivided into groups with and without postoperative chemotherapy. After PSM, the data of 21 well-matched patients with postoperative chemotherapy and 8 without postoperative chemotherapy were evaluated. Overall survival was significantly longer in the distal gastrectomy group (p = 0.007 [group with postoperative chemotherapy], p = 0.02 [group without postoperative chemotherapy]). CONCLUSIONS: Distal gastrectomy for symptomatic stage IV GC contributes to prognosis with acceptable safety compared to gastrojejunostomy.

Utility of TMPRSS4 as a Prognostic Biomarker and Potential Therapeutic Target in Patients with Gastric Cancer.

BACKGROUND: Transmembrane serine protease 4 (TMPRSS4) belongs to the family of type II transmembrane serine proteases that are known to be upregulated in many malignant tumors. However, there is a paucity of studies documenting the clinical impact and biological effects of TMPRSS4 on gastric cancer (GC) patients who underwent surgery. METHODS: Tissues samples were obtained from 105 patients with GC who underwent gastrectomy followed by adjuvant chemotherapy, excluding those at stage I. The expression of TMPRSS4 was examined through immunohistochemical analysis. The association between TMPRSS4 expression and clinico-pathological features as well as prognosis was assessed. Moreover, the effects of TMPRSS4 expression on cell migration and sensitivity to 5-FU were investigated. RESULTS: The expression rate of TMPRSS4 was 56.3% (59/105) in GC cases. The expression of TMPRSS4 was positively correlated with the depth of tumor (T) and venous (V) invasion. The 5-year overall survival (OS) and recurrence-free survival (RFS) rates of the TMPRSS4-positive group was significantly lower than that of the TMPRSS4-negative group (p=0.0001 and p=0.005, respectively). Especially, there was significant differences in OS and RFS of patients with stage III cancer between the two groups (p=0.0064 and 0.012, respectively). Multivariate analysis demonstrated that TMPRSS4 expression and the stage of cancer were crucial prognostic factors for RFS. TMPRSS4-silenced GC cells exhibited increased sensitivity to 5-FU when compared with the non-specific control siRNA-transfected cells. CONCLUSION: TMPRSS4 can be considered as a potential prognostic biomarker, especially for stage III, and a promising therapeutic target for GC.

[A Case of Laparoscopic Surgery for Colon Metastasis of Renal Cancer].

A 67-year-old man underwent laparoscopic partial left nephrectomy for renal cell carcinoma 2.5 years ago. CT showed a well-defined 3 cm mass with contrast effect bordering on the descending colon, and PET-CT showed an accumulation of SUVmax 6.01 in the same area. Colonoscopy revealed a submucosal tumor-like mass in the descending colon. The patient was diagnosed with a local recurrence of renal cell carcinoma and invasion of the descending colon, and laparoscopic colectomy was performed. The excised specimen was a pale yellowish submucosal tumor measuring 4.5×3.8 cm, which was histologically diagnosed as metastasis of clear cell renal cell carcinoma. Surgical resections for metastases of renal carcinoma have been reported and expected prolong survival. We report a case of laparoscopic colon resection for recurrence of descending colon metastasis of renal cell carcinoma.

[A Case of Anal Canal Cancer with Pagetoid Spread and a Significant Response to Preoperative Chemoradiotherapy].

Perianal Pagetoid spread is a rare condition for which there is no proven therapy. We experienced a case of anal canal cancer with Pagetoid spread which exhibited a significant response to preoperative chemoradiotherapy(CRT). A 76-year-old man with anal stenosis was referred to our hospital. He was diagnosed with anal canal cancer with Pagetoid spread. No infiltration into the surrounding tissue was observed, but metastasis to the left inguinal lymph node was noted. The patient received preoperative CRT(oral S-1, 1.8 Gy×25 Fr, a total dose of 45 Gy)including the bilateral inguinal region. After CRT, the main tumor size was reduced and PET-CT showed disappearance of the abnormal accumulation in the left inguinal lymph nodes. Laparoscopic abdominoperineal resection and left inguinal trans lymphadenectomy were performed. The macroscopic findings of the surgical specimen confirmed no residual carcinoma or lymph node metastasis. Although more proof is needed, this case suggested that CRT may be effective for anal canal cancer with pagetoid spread.

Clinical complete response after nivolumab administered as a third-line treatment for unresectable advanced gastric cancer with peritoneal dissemination: A case report.

INTRODUCTION AND IMPORTANCE: Nivolumab, which is a fully human IgG4 PD-1 immune checkpoint inhibitor antibody, has been recommended as a third-line treatment based on the results of the ATTRACTION-2 study involving patients with unresectable advanced gastric cancer. CASE PRESENTATION: A 69 year-old woman was referred to our department with a diagnosis of gastric cancer based on an upper gastrointestinal endoscopy during a medical examination. The endoscopy, along with various tests, helped establish a diagnosis of unresectable advanced gastric cancer (cT4aN3aM1P1c, cStage IV) with peritoneal dissemination. The first and second-line chemotherapy administered was S-1 plus oxaliplatin followed by ramucirumab and nab-paclitaxel, respectively. In this case, the disease was evaluated as progressive disease due to increased peritoneal dissemination. Nivolumab was administered as the third-line treatment. The patient developed interstitial pneumonia after nine courses of nivolumab, for which chemotherapy was discontinued and prednisolone treatment was initiated. The patient had a complete response to treatment endoscopically, 9 months after the last administration of nivolumab. After that, there was no recurrence of the cancer, despite there being no treatment for 5 months. CLINICAL DISCUSSION: It was suggested that the therapeutic effect of nivolumab could be maintained for a long period after discontinuation of its administration. In addition, a correlation has been reported between the treatment efficacy and immune-related adverse events associated with nivolumab. CONCLUSIONS: The synergistic effect of the sustained effect of nivolumab and later-line treatment may contribute to the prolongation of survival after discontinuation of nivolumab in patients who are refractory or intolerant to treatment.

Laparoscopic resection for a large gastrointestinal stromal tumor (GIST) with diaphragm invasion following preoperative imatinib treatment: A case report.

INTRODUCTION: Neoadjuvant imatinib for large GISTs may prevent tumor rupture and the need for extended surgery by reducing tumor size. In this study, we present a case of large gastric GIST with diaphragm invasion, due to the patient receiving laparoscopic resection following preoperative imatinib treatment. PRESENTATION OF CASE: A 72-year-old woman was hospitalized with left hypochondriac pain for a month. Examinations revealed a large heterogeneous gastric mass measuring 80 mm in size, arising from the greater curvature of the corpus. The mass invaded the left thoracic diaphragm. Treatment with imatinib at an initial dosage of 400 mg/day was initiated. After a further two months of follow-up, the lesion had sustained reduction to 50 mm in size, however, the invasion to the diaphragm remained. The patient eventually underwent laparoscopic partial gastrectomy and partial resection of the diaphragm with curative intent. Adjuvant chemotherapy was initiated at one month after the surgery, however, was discontinued due to nausea. After one-year follow-up, no recurrence was noted. DISCUSSION: Neoadjuvant imatinib may shrink tumor size remarkably and prevent tumor rupture during surgery, and thus lead to increased rates of complete resection. To date, several publications have directly compared the oncologic results between laparoscopic and open resection for GISTs. In the present case, the tumor was movable, and moderately fixed on diaphragm. It was favorable condition for laparoscopic surgery. CONCLUSIONS: This is the first report of a large gastric GIST invading the diaphragm that was successfully treated by laparoscopic resection after tumor reduction by neoadjuvant imatinib.

Negative pressure wound therapy for broncho-pleural fistula with collapsed lung.

We present a case of the broncho-pleural fistula with a collapsed lung that was developed 2 weeks after right lower lobectomy. The patient urgently underwent open-window thoracostomy. However, the residual lung remained collapsed. To expand the lung and close the broncho-pleural fistula, negative pressure wound therapy was initiated 20 days after the procedure. The lung expanded within a few days, and the residual thoracic cavity gradually contracted. Subsequently, 2.5 months later, the remaining thoracic cavity was successfully closed using omentoplasty. No recurrence of the broncho-pleural fistula was observed for 1 year. If the lung could be inflated to reduce dead space in the thoracic cavity, broncho-pleural fistula with collapsed lung may be treated with bronchial stump coverage and negative pressure wound therapy.

A case of Turcot's syndrome type 1 with loss of immunoexpression of MSH6 in colon cancer and liver metastasis due to secondary somatic mutation in coding mononucleotide (C)8 tract: a case report.

BACKGROUND: Lynch syndrome (LS), which is known as a hereditary cancer syndrome, is distinguished by microsatellite instability, represented by the altered number of repetitive sequences in the coding and/or non-coding region. Immunohistochemical staining (IHC) of DNA mismatch repair (MMR) proteins (e.g., MLH1, MSH2, MSH6, and PMS2) has been recognized as an useful technique for screening of LS. Previous study has shown that the assessment of IHC, however, requires specific caution due to variable staining patterns even without germline mutations in MMR genes. CASE PRESENTATION: A 48-year-old man, who had been treated for anaplastic astrocytoma, was referred to our department for the precise examination of progressing anemia. Whole-body examination revealed two advanced carcinomas in descending colon and stomach. A hypo-vascular mass lesion was detected in liver as well. Pathological diagnosis (on surgical specimens) was poorly differentiated adenocarcinoma in descending colon, moderately differentiated tubular adenocarcinoma in stomach, and liver metastasis, which is possibly from colon. It was suspected that this case would be Turcot's syndrome-type-1 due to its specific family history having two cases of colon cancer within the second relatives. Pathogenic frameshift mutations in codon 618 of MLH1 gene was identified. Immunohistochemical analyses (IHC) demonstrated complete loss of MLH1 immuno-expression as well as of PMS2 except for those in brain tumor. Although frameshift mutation was not found in MSH6 gene, histological expression of MSH6 was patchy in primary colon carcinoma and was completely lost in the metastatic site in liver. MSH6 expression in gastric carcinoma, a coincidental cancer in this case, was intact. An abnormal (C)8 region was identified by the cloned PCR of colon and liver tumors but not from gastric cancer. Frameshift mutation in a (C)8 tract in exon 5 of the MSH6 gene was also detected in liver metastasis. CONCLUSION: This case supports a plausible mechanism, proposed by a previous literature, for the reduced expression of MSH6 in a somatic mutation manner, which might preferentially happen in colon cancer rather than in stomach carcinoma in MLH1/PMS2-deficient type of Turcot's syndrome type 1.

Gastric adenocarcinoma appearance in leiomyoma: A case report.

INTRODUCTION: We experienced an extremely rare case of gastric adenocarcinoma wrapped by leiomyoma. PRESENTATION OF CASE: A 65-year-old man had an abnormality (filling defect) of the upper gastrointestinal series in his first medical checkup five years prior. Esophagogastroduodenoscopy detected a 10 mm submucosal tumor-like lesion in the greater curvature of the upper gastric remnant body. Despite repeated biopsy from the lesion, there was no sign of malignancy. A delle was observed on the top of the tumor at another visit five year after the first and a biopsy specimen revealed poorly differentiated adenocarcinoma. Therefore, laparoscopic gastrectomy was performed. Histological assessment revealed a 28 × 22 mm elevated lesion with a slight depression. Microscopically, papillary adenocarcinoma was observed at the submucosa with a solitary heterotopic gastric gland adjacent to the lesion. The final diagnosis was papillary adenocarcinoma arising from a solitary heterotopic gastric gland in the leiomyoma. No recurrence has occurred during a follow-up of two and a half years after surgery. CONCLUSIONS: This is the first report of gastric adenocarcinoma arising from a submucosal tumor.

[A Case of Sigmoid Colon Cancer Recurrence at the Hand-Sewn Anastomosis Site Originated from Tumor Implantation].

We report a case of anastomotic recurrence following laparoscopic sigmoidectomy with hand-sewn anastomosis, which was attributable to the implantation of exfoliated cancer cells. A 78-year-old man diagnosed with early colon cancer underwent endoscopic submucosal dissection(ESD); however, ESD was suspended due to infiltrated muscle fibers. Subsequently, he underwent laparoscopic sigmoidectomy with hand-sewn anastomosis, accompanied by D3 lymph node dissection. Histopathological findings revealed a well-differentiated tubular adenocarcinoma, pT2(MP), tub1>tub2>por2, ly0, v1, PM0, DM0, RM0, N0M0, pStage Ⅰ. The follow-up CT 6 months after surgery, showed enhanced wall thickening and irregular surface of the sigmoid colon. Colonoscopy revealed a type 2 tumor located on the anastomotic line. Based on the diagnosis of anastomotic recurrence, the patient underwent partial colectomy. Histopathological findings were similar to those of the primary tumor and suggested implantation of exfoliated cancer cells as the origin of anastomotic recurrence. Cancer cells had infiltrated all layers. In conclusion, we recommend the performance of appropriate operative procedures to prevent anastomotic recurrence, such as the cleaning of the anastomosed intestinal tract. Careful follow-up in colon cancer patients is of the utmost importance and the risk of anastomotic recurrence should always be considered.

[MSI-H Small Bowel Cancer with Peritoneal Dissemination Successfully Treated with Pembrolizumab-A Case Report].

A 52-year-old man was diagnosed with small bowel adenocarcinoma(T4aN1M0, Stage ⅢA, according to the Japanese colorectal cancer classification)and treated with partial resection of the small bowel in June 2014. He also received adjuvant chemotherapy(XELOX: 8 courses)after surgery. Three and a half years after the operation, peritoneal dissemination recurred, and he received bevacizumab plus XELOX therapy. The regimen was adjusted to a total of 11 courses because of the disease progression. The primary lesion showed MSI-H. The patient was started on pembrolizumab therapy in April 2019. The tumor responded well to pembrolizumab(maximum therapeutic effect: PR, 31% reduction), but a new lesion appeared 6 months after the start of this regimen. He continued pembrolizumab therapy for 14 months without adverse events since it appeared to be clinically effective. Although MSI-H small bowel cancers are rare, accurate screening is essential to not miss the opportunity to administer pembrolizumab.