Development of a laparoscopic sigmoidectomy simulator: Sigmaster.

The sigmoid colon simulator was designed to accurately reproduce the anatomical layer structure and the arrangement of characteristic organs in each layer, and to have conductivity so that energy devices can be used. Dry polyester fibers were used to reproduce the layered structures, which included characteristic blood vessels, nerve sheaths, and intestinal tracts. The adhesive strength of the layers was controlled to allow realistic peeling techniques. The features of the Sigmaster are illustrated through a comparison of simulated sigmoidectomy using Sigmaster and actual surgery. We developed a laparoscopic sigmoidectomy simulator called Sigmaster. Sigmaster is a training device that closely reproduces the membrane structures of the human body and allows surgeons to experience the entire laparoscopic sigmoidectomy process.

Laparoscopic transabdominal approach for resection of presacral epidermoid cyst in an obese man: a case report.

BACKGROUND: Complete resection of presacral epidermoid cysts is recommended due to the potential for infection or malignancy. Transsacral and transabdominal approaches have been used to treat presacral tumors. However, there are no standard surgical approaches to resection. We present the case of a presacral epidermoid cyst in an obese male patient who underwent laparoscopic transabdominal resection. CASE PRESENTATION: A 44-year-old man was referred to our hospital for treatment of a cystic tumor on the pelvic floor. Contrast-enhanced computed tomography revealed a 45 × 40-mm tumor on the left ventral side of the rectum, right side of the ischial spine, dorsal side of the seminal vesicles, and in front of the 5th sacrum. Enhanced magnetic resonance imaging revealed a multilocular cystic tumor with high and low signal intensities on T2-weighted images. The tumor was diagnosed as an epidermoid cyst. We considered the transsacral or laparoscopic approach and decided to perform a laparoscopic-assisted transabdominal resection since the tumor was in front of away from the sacrum, and a transsacral approach would result in a larger scar due to poor visibility from the thickness of the buttocks. The entire tumor was safely resected under laparoscopic guidance, because the laparoscopic transabdominal approach can provide a good and magnified field of view even in a narrow pelvic cavity with small skin incisions, allowing safe resection of the pelvic organs, vessels, and nerves while observing the tumor contour. CONCLUSIONS: The laparoscopic transabdominal approach is an effective method for treating presacral tumors in obese patients.

Simplified and Optimized Immune Score for Colorectal Cancer Microenvironment.

BACKGROUND/AIM: Immunoscore (IS) is an important evaluation method for the tumor immune microenvironment (TIME); however, formal IS analysis requires designated reagents and a specific digital pathology software and image data analysis. This study aimed to investigate whether simplified IS (s-IS) can substitute formal IS upon modifying the location of the assessment of the numbers of immune cells and verify that the addition of T cell subset markers to s-IS can enhance the prognostic impact in patients with colorectal cancer (CRC). PATIENTS AND METHODS: A total of 82 CRC cases were included in this study. Immunohistochemical analysis was performed using CD3/CD8/CD45RO/FOXP3 on tissue specimens; the expression levels were calculated in the center and perimeter of the tumors using digital pathology. The clinical prognostic significance of the expression of these markers was investigated by concordance index comparison according to their location of assessment and combinations. RESULTS: In the univariate analysis, the CD3, CD8, and FOXP3 levels were significant prognostic factors. Moreover, for each T cell subset marker, the assessment of each T cell subset marker at the tumor perimeter had a stronger prognostic power than that in the tumor center. The modified s-IS (s-IS plus FOXP3 evaluation) was an independent prognostic factor for recurrence-free survival and overall survival through multivariate analysis and demonstrated the best prognostic power compared to other T subset marker combinations. CONCLUSION: In CRC, TIME evaluation could be simplified by assessing CD3- and CD8-positive T cells in the perimeter of the tumor, and additional FOXP3 evaluation would empower the ability of s-IS evaluation in prognostic assessment.

Comparison of long-term quality of life based on surgical procedure in patients with rectal cancer.

Introduction: Reports on the long-term quality of life (QOL) over 3 years after surgery in patients who have undergone surgery for rectal cancer are limited. Therefore, we aimed to evaluate the long-term QOL of patients who underwent high anterior resection (HAR), low anterior resection (LAR), internal sphincter resection (ISR), or abdominoperineal resection (APR) for rectal cancer. Methods: A questionnaire regarding QOL was sent to 360 patients with rectal cancer who underwent curative resection by HAR, LAR, ISR, or APR between January 2005 and December 2015. QOL was assessed using the short-form 36 (SF-36) and modified fecal incontinence QOL (mFIQL) questionnaire. QOL between surgical procedures was analyzed using a multivariate model adjusted for age, sex, and postoperative time. Results: A total of 144 patients responded with a median follow-up period of 94 months (range 38-233 months). According to surgical procedure, HAR was performed in 26 patients, LAR in 80 patients, ISR in 32 patients, and APR in 6 patients. Patients who underwent HAR had significantly better mFIQL scores than those who underwent LAR and ISR (p=0.013 and p=0004, respectively) and significantly better role/social component summary scores on the SF-36 subscales (p=0.007). No difference was observed in the mFIQL scores between patients who underwent ISR and those who underwent APR (p=0.8423). In addition, postoperative anastomotic leakage sutures did not influence the mFIQL and SF-36 scores after surgery. Conclusion: The QOL of patients who underwent anus-preserving surgery was best in the HAR group, with the QOL of other groups similar to the APR group. These results suggest that anus- preserving surgery is acceptable from a QOL standpoint. However, a colostomy may be a more satisfactory procedure in some patients.

Mismatch repair proteins expression and tumor-infiltrating T-cells in colorectal cancer.

Microsatellite instability (MSI) and tumor mutational burden (TMB) are indicators of the tumor mutational load, which can lead to immune cell recruitment. By contrast, the number of tumor-infiltrating T cells (TITs) is indicative of the host immune response to tumor cells. The present study evaluated if the expression of mismatch repair (MMR) proteins can be used as a precise tool to assess immunogenicity in the tumor microenvironment. A total of 73 colorectal cancer cases were enrolled in the present study. MMR protein expression was assessed using four-antibodies immunohistochemistry (IHC) targeting MLH1, MSH2, MSH6 and PMS2. TIT was assessed through IHC by counting CD3+ and CD8+ cells in tumor. The enrolled cases were classified into four groups according to MMR and TIT status i) Mismatch repair-proficient (pMMR) and a high number of TITs (pMMR/TIT-H); ii) pMMR and a low number of TITs (pMMR/TIT-L); iii) mismatch repair-deficient (dMMR) and TIT-H (dMMR/TIT-H); and iv) dMMR/TIT-L]. The present study evaluated the clinicopathological characteristics of the four groups, in addition to the difference of TMB. TMB analysis was counted the number of the somatic mutations through multi-genes panel using next-generation sequencing. Clinicopathological characteristics, including age, sex, pathological depth of invasion and lymph node metastasis, were not found to be statistically different between dMMR/TIT-H and dMMR/TIT-L groups. Tumors among pMMR/TIT-H group were associated with poorly differentiation compared with those in pMMR/TIT-L group (P=0.025). The median TMB among the dMMR/TIT-H group was the highest in four groups but the median TMB was <10 muts/Mb in dMMR/TIT-L, pMMR/TIT-H and pMMR/TIT-L groups, respectively. However, one tumor in the pMMR/TIT-H group showed high TMB. The present findings suggest that assessing MMR status alone may not be sufficient to precisely evaluate the antitumor immune response in the tumor microenvironment.

Trans-anal surgery with the taTME technique for rectal gastrointestinal stromal tumors: a retrospective study.

PURPOSE: Rectal gastrointestinal stromal tumors (GISTs) surgery is often challenging owing to the anatomical constraints of the narrow pelvis and tumor hugeness. Despite the increasing number of patients undergoing trans-anal total mesorectal excision (taTME) globally, the feasibility of trans-anal surgery with the taTME technique for rectal GISTs remains unclear. We aimed to evaluate the feasibility of trans-anal surgery with the taTME technique for rectal GISTs. METHODS: Using a prospectively collected database, we retrospectively analyzed the clinical findings, surgical outcomes, pathological outcomes, urinary and anal functions, and prognoses of patients who underwent trans-anal surgery with the taTME technique for primary rectal GISTs at the National Cancer Center Hospital East from September 2014 to March 2020. RESULTS: Twenty-one patients with primary rectal GISTs were included in this study. The median distance from the anal verge to the lower edge of the tumor was 40 mm (range, 15-60 mm), and the median tumor size was 59 mm (range, 11-175 mm). Moreover, seven and 14 patients underwent one-team and two-team surgeries, respectively, with curative intent. Nineteen patients (90.5%) underwent anus-preserving surgery, and the urinary tracts were preserved in all cases. Two-team surgery showed a significantly lower blood loss volume and shorter operation time than one-team surgery (58 vs. 222 mL, P = 0.017; 184 vs 356 min, P = 0.041, respectively). The pathological negative-margin resection rate was 100%. During the follow-up period, no patient developed local GIST recurrence and one (4.8%) developed distant metastasis. CONCLUSION: Trans-anal surgery with the taTME technique is feasible for rectal GISTs, and two-team surgery may be more advantageous than one-team surgery in terms of operation time and blood loss.

[Retrospective Analysis of Treatment Strategies for Local Recurrence following Radical Resection of Rectal Cancer].

We report the findings from a retrospective study to determine the optimum treatment strategy for local recurrence following radical resection of rectal cancer. In our department, among all 430 patients that underwent radical resection of rectal cancer from 2012 to 2018, there were 28 patients that developed local recurrence. Of those patients, 12 underwent surgical treatment(Op group)and 16 did not(N-Op group). In the Op group, 8 patients underwent radical resection, of which 2 patients remained recurrence-free, and the other 6 patients developed recurrence. In the N-Op group, 6 patients were treated with systemic chemotherapy alone, a further 6 patients had palliative irradiation in addition to systemic chemotherapy, and the other 4 selected best supportive care(2 patients were treated with palliative irradiation). In the 8 patients who had palliative irradiation, 7 showed a decrease in numerical rating scale(NRS)after irradiation. The adverse events of palliative irradiation were scrotal dermatitis in 1 patient and perianal inflammation in another 3 patients. Our surgical results for local recurrence of rectal cancer in our department were worse in terms of recurrence rate, so these findings suggest that the preoperative surgical strategy could be reviewed, as well as the actual surgical methods such as the optimal circumferential resection margin. Palliative irradiation was found to be useful for pain control. However, the occurrence of adverse events remains a concern.

Mesocolic hernia following retroperitoneal laparoscopic radical nephrectomy: A case report.

INTRODUCTION: Small bowel obstruction (SBO) caused by an internal hernia through a mesocolon after retroperitoneal laparoscopic nephrectomy (RLN) is rare. PRESENTATION OF CASE: A 66-year-old man who had undergone RLN with bladder cuff excision for a left renal pelvic cancer. After the surgery, he experienced SBO repeatedly. Contrast-enhanced computed tomography (CT) and gastrografin contract radiography through a long tube showed an internal hernia through the mesocolon to the retroperitoneal space where the resected left kidney had been located. We performed a subsequent surgery for the internal hernia. Postoperative course was uneventful and currently he has no recurrence of herniation 6 months post-operatively. DISCUSSION: Mesenteric defects that cause an internal hernia can be created inadvertently during RLN when the colon is mobilized medially, and the kidney is being detached from retroperitoneum. The removal of a kidney leads to a potential retroperitoneal space to which small intestine can migrate. While there is no absolute necessity in mobilizing the colon during the retroperitoneal laparoscopic approach, there is still a risk of making mesocolic defects directly in the retroperitoneal space. CONCLUSION: We need to perform operations with sufficient anatomical knowledge of retroperitoneal fascia and careful surgical techniques. The critical thing to prevent an internal hernia following RLN is to close the mesenteric defects intraoperatively. It is also important to suspect an internal hernia and do proper examinations promptly when patients had the symptoms of SBO after nephrectomy.

Mixed ductal-acinar cell carcinoma of the pancreas: A case report.

Mixed carcinoma of the pancreas is defined as the concurrent existence of pancreatic ductal carcinoma, acinar cell carcinoma, and/or islet cell carcinoma within the same neoplasm. We herein report a rare case of mixed ductal-acinar cell carcinoma in a 74-year-old man who was undergoing treatment for hypertension and diabetes at another hospital. After an abrupt worsening of his blood glucose control, the patient was referred to our hospital for further evaluation. Abdominal contrast-enhanced computed tomography and magnetic resonance imaging revealed a tumor with a multilocular cystic lesion in the head of the pancreas. Endoscopic retrograde cholangiopancreatography revealed obstruction of the main pancreatic duct and dilation of the dorsal pancreatic duct; in addition, adenocarcinoma was detected in the pancreatic juice cytology. Based on the abovementioned findings, the patient was diagnosed with carcinoma of the pancreatic head and underwent subtotal stomach-preserving pancreaticoduodenectomy. Based on the histopathological and immunohistochemical findings, the patient was diagnosed with mixed ductal-acinar cell carcinoma. The patient was prescribed TS-1 as postoperative adjuvant chemotherapy upon discharge. However, treatment was discontinued 2 months later due to marked general malaise, and the patient succumbed to tumor recurrence in the residual pancreas 12 months after the surgery.

Y­box­binding protein 1 inhibits apoptosis and upregulates EGFR in colon cancer.

Y­box­binding protein 1 (YB­1) is a DNA/RNA­-binding protein and an important transcription and translation factor in carcinogenesis. However, the biological function and molecular correlation of YB­1 in colorectal cancer are not fully understood. The aim of the present study was to determine the significance of YB­1 expression and its biological role in colorectal cancer. Cell proliferation, migration and apoptosis were examined upon knockdown of YB­1 expression in different colon cancer cell lines that had different genetic backgrounds. Since the properties of different colon cancer cell lines with specific RAS/RAF gene mutations downstream epidermal growth factor receptor (EGFR) may differ from wild­type colorectal cancer, it is critical to study the role of YB­1 with respect to the mutational status of RAS. The results indicated that the suppression of YB­1 decreased cell proliferation (P<0.05) and migration (P<0.05) regardless of the status of RAS/RAF in the HT29, HCT116 and CaCo2 cell lines. In contrast, YB­1 knockdown altered the expression of apoptosis­related genes and the expression of EGFR was detected in the cell lines expressing wild­type RAS/RAF but not in those expressing mutated RAS/RAF. These results indicated that YB­1 plays an important role in cell proliferation, migration, apoptosis and EGFR expression in colorectal cancer. Furthermore, apoptosis and EGFR expression may be affected by the mutational status of RAS/RAF and controlled through YB­1.

Correction to: The Immunoscore is a Superior Prognostic Tool in Stages II and III Colorectal Cancer and is Significantly Correlated with Programmed Death-Ligand 1 (PD-L1) Expression on Tumor-Infiltrating Mononuclear Cells.

In the original article, Akihiko Kawahara's first name is incorrect. It is correct as reflected here.

[Endocrine cell carcinoma of the esophagus without recurrence for more than 7 years after chemoradiotherapy].

We report a case of endocrine cell carcinoma (ECC) of the esophagus with long term survival after chemoradiotherapy. The patient had a complete response and remains without any recurrence. A 69-year-old woman visited our hospital because of progressive dysphagia. The patient was diagnosed by computed tomography and histology examination of biopsy specimens with small cell ECC of the esophagus, cT2N1M0, cStage II based on the Classification of Esophageal Carcinoma. She was treated with chemoradiotherapy comprising 45Gy of irradiation and four courses of cisplatin and etoposide chemotherapy. After completion of the treatment, she was found to have a complete response. She remains alive to date without evidence of any recurrence after 7 years. This case suggests that chemoradiotherapy is an effective treatment for ECC of the esophagus.

The Immunoscore is a Superior Prognostic Tool in Stages II and III Colorectal Cancer and is Significantly Correlated with Programmed Death-Ligand 1 (PD-L1) Expression on Tumor-Infiltrating Mononuclear Cells.

BACKGROUND: In colorectal cancer (CRC), the indication for immune checkpoint inhibitors is determined by the microsatellite instability status of the tumors. However, an optimal biomarker for their indication has not been fully identified to date. This study aimed to establish the clinicopathologic importance of the Immunoscore (IS) in CRC and to clarify the relationships between the IS, programmed death-ligand 1 (PD-L1) expression, and tumor-associated macrophages. METHODS: In 132 cases, CRC was diagnosed and surgically treated in our department from 2009 to 2010. Immunohistochemical staining using primary antibodies PD-L1, CD3, CD8, CD68, and CD163 was performed. The IS was determined according to the proposal of an international task force. Statistical analyses were performed to investigate the correlation between the IS, clinicopathologic variables, and expression of immune checkpoint molecules. RESULTS: The overall survival (OS) and relapse-free survival (RFS) in the high-IS group (I3-4) were significantly better than in the low-IS group (I0-2) (OS: P = 0.0420; RFS: P = 0.0226). The positivity rate for PD-L1 on tumor cells (tPD-L1) was only 0.8%, whereas that for PD-L1 on interstitial tumor-infiltrating mononuclear cells (iPD-L1) was 18.2%. The iPD-L1-positive group showed significantly better survival in terms of both OS and RFS than the iPD-L1-negative group (OS: P = 0.0278; RFS: P = 0.0253). The findings showed significant correlation between the IS and iPD-L1 expression (P < 0.0001). CONCLUSIONS: The study found that a high IS was a good indicator of a better prognosis and significantly correlated with iPD-L1 expression in CRC.

PD-L1 expression in pancreatic adenosquamous carcinoma: PD-L1 expression is limited to the squamous component.

AIM: We examined the programmed death-ligand 1 (PD-L1) expression in surgically resected pancreatic adenosquamous carcinoma (PASC) samples. Furthermore, the detection rate was also assessed using biopsy cases obtained from endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). METHODS: Fifteen cases of PASC (six resected and nine EUS-FNA biopsied) from the Kurume University Hospital between 2009 and 2016 were used for the evaluation of PD-L1 expression. As a control group, 34 cases of pancreatic ductal adenocarcinomas (PDACs) were selected. To compare　the positivity and intensity of PD-L1, two types of clones (SP263, E1L3N) were examined for immunostaining. Only the membrane expression of PD-L1 was regarded as positive. The PD-L1 expressions in the squamous cell carcinoma component (SCc), adenocarcinoma component (ACc), and immune cells were assessed separately. The ratio of PD-L1 expression was calculated by counting the positive tumor cells, and tumor proportion score (TPS) was applied (TPS; Null < 1%, low expression; 1 ≤ TPS ≤ 49% and high expression; ≥ 50%). RESULTS: PD-L1 expression was observed in five surgical PASC samples (83%). This shows that SCc presented a high expression in these cases. However, the overall TPS indicated a low expression. In contrast, only one case (3%) was positive for PD-L1 in PDACs, and the TPS indicated a low expression. No differences in PD-L1 expression were observed between the two clones, SP263 and E1L3N. High PD-L1 expression in the EUS-FNA sample was found in only one case (11%). DISCUSSION: Although assessment using the tumor cells of PASC samples obtained from EUS-FNA was difficult, this study suggests the selective expression of PD-L1 in the SCc of PASC. Furthermore, it was considered that immune checkpoint inhibitors could provide therapeutic effects selectively on the SCc for the entire range of TPSs, though the PD-L1 expression was low.