Influence of Robotic Rectal Resection Versus Laparoscopic Rectal Resection on Postoperative Ileus: A Single-center Experience.

AIM: This study was performed to clarify the relationship between robotic rectal resection and postoperative ileus (POI) by comparing robotic surgery with laparoscopic surgery. MATERIALS AND METHODS: We retrospectively reviewed 238 patients who underwent robotic (n=41) or laparoscopic (n=197) rectal resection for rectal cancer in our institution from January 2013 to June 2020. First, we compared the background factors and short-term surgical outcomes between robotic and laparoscopic surgery. Next, we investigated the postoperative complications of robotic and laparoscopic rectal resection. Finally, we identified the risk factors for POI following rectal cancer resection. RESULTS: The percentages of patients with an Rb tumor location, treatment by abdominoperitoneal resection/intersphincteric resection/low anterior resection, a temporary diverting ileostomy, and a long operation time were significantly higher in robotic than laparoscopic surgery ( P <0.0001, P =0.0002, P =0.0078, and P =0.0001, respectively). There was no significant difference in any individual postoperative complication between robotic and laparoscopic surgery. Risk factors for POI were male sex ( P =0.0078), neoadjuvant chemoradiotherapy ( P =0.0007), an Rb tumor location ( P =0.0005), treatment by abdominoperitoneal resection/intersphincteric resection/low anterior resection ( P =0.0044), a temporary diverting ileostomy ( P <0.0001), and operation time of ≥240 minutes ( P =0.0024). Notably, robotic surgery was not a risk factor for POI following rectal resection relative to laparoscopic surgery. CONCLUSION: Although patients who underwent robotic surgery had more risk factors for POI, the risk of POI was similar between robotic and laparoscopic rectal resection.

RAD51 Expression as a Biomarker to Predict Efficacy of Preoperative Therapy and Survival for Esophageal Squamous Cell Carcinoma: A Large-cohort Observational Study (KSCC1307).

OBJECTIVE: The aim of this study is to identify biomarkers that predict efficacy of preoperative therapy and survival for esophageal squamous cell carcinoma (ESCC). BACKGROUND: It is essential to improve the accuracy of preoperative molecular diagnostics to identify specific patients who will benefit from the treatment; thus, this issue should be resolved with a large-cohort, retrospective observational study. METHODS: A total of 656 patients with ESCC who received surgery after preoperative CDDP + 5-FU therapy, docetaxel + CDDP + 5-FU therapy or chemoradiotherapy (CRT) were enrolled. Immunohistochemical analysis of TP53, CDKN1A, RAD51, MutT-homolog 1, and programmed death-ligand 1 was performed with biopsy samples obtained before preoperative therapy, and expression was measured by immunohistochemistry. RESULTS: In all therapy groups, overall survival was statistically separated by pathological effect (grade 3 > grade 2 > grade 0, 1, P < 0.0001). There was no correlation between TP53, CDKN1A, MutT-homolog 1, programmed death-ligand 1 expression, and pathological effect, whereas the proportion of positive RAD51 expression (≥50%) in cases with grade 3 was lower than that with grade 0, 1, and 2 (P = 0.022). In the CRT group, the survival of patients with RAD51-positive tumor was significantly worse than RAD51-negative expressors (P = 0.0119). Subgroup analysis of overall survival with respect to positive RAD51 expression indicated preoperative chemotherapy (CDDP + 5-FU or docetaxel + CDDP + 5-FU) was superior to CRT. CONCLUSIONS: In ESCC, positive RAD51 expression was identified as a useful biomarker to predict resistance to preoperative therapy and poor prognosis in patients who received preoperative CRT. Administration of preoperative chemotherapy may be warranted for patients with positive RAD51 expression.

Circulating Tumor DNA Analysis Detects FGFR2 Amplification and Concurrent Genomic Alterations Associated with FGFR Inhibitor Efficacy in Advanced Gastric Cancer.

PURPOSE: FGFR2 amplification is associated with poor prognosis in advanced gastric cancer and its subclonal heterogeneity has been revealed. Here, we examined whether circulating tumor DNA (ctDNA) was useful for detecting FGFR2 amplification and co-occurring resistance mechanisms in advanced gastric cancer. EXPERIMENTAL DESIGN: We assessed genomic characteristics of FGFR2-amplified advanced gastric cancer in a nationwide ctDNA screening study. We also analyzed FGFR2 amplification status in paired tissue and plasma samples with advanced gastric cancer. In addition, we examined patients with FGFR2-amplified advanced gastric cancer identified by ctDNA sequencing who received FGFR inhibitors. RESULTS: FGFR2 amplification was more frequently detected by ctDNA sequencing in 28 (7.7%) of 365 patients with advanced gastric cancer than by tissue analysis alone (2.6%-4.4%). FGFR2 amplification profiling of paired tissue and plasma revealed that FGFR2 amplification was detectable only by ctDNA sequencing in 6 of 44 patients, which was associated with a worse prognosis. Two patients in whom FGFR2 amplification was detected by ctDNA sequencing after tumor progression following previous standard chemotherapies but not by pretreatment tissue analysis had tumor responses to FGFR inhibitors. A third patient with FGFR2 and MET co-amplification in ctDNA showed a limitation of benefit from FGFR inhibition, accompanied by a marked increase in the MET copy number. CONCLUSIONS: ctDNA sequencing identifies FGFR2 amplification missed by tissue testing in patients with advanced gastric cancer, and these patients may respond to FGFR inhibition. The utility of ctDNA sequencing warrants further evaluation to develop effective therapeutic strategies for patients with FGFR2-amplified advanced gastric cancer.

Identification of SLC38A7 as a Prognostic Marker and Potential Therapeutic Target of Lung Squamous Cell Carcinoma.

BACKGROUND: No effective molecular targeted therapy has been established for SCC. We conducted a comprehensive study of SCC patients using RNA-sequencing and TCGA dataset to clarify the driver oncogene of SCC. METHOD: Forty-six samples of 23 patients were totally analyzed with RNA-sequencing. We then searched for candidate-oncogenes of SCC using the TCGA database. To identify candidate oncogenes, we used the following 2 criteria: (1) the genes of interest were overexpressed in tumor tissues of SCC patients in comparison to normal tissues; and (2) using an integrated mRNA expression and DNA copy number profiling analysis using the TCGA dataset, the DNA copy number of the genes was positively correlated with the mRNA expression. RESULT: We identified 188 candidate-oncogenes. Among those, the high expression of SLC38A7 was a strong prognostic marker that was significantly associated with a poor prognosis in terms of both overall survival (OS) and recurrence-free survival in the TCGA dataset (P < 0.05). Additionally, 202 resected SCC specimens were also subjected to an immunohistochemical analysis. Patients with the high expression of SLC38A7 (alternative name is sodium-coupled amino acid transporters 7) protein showed significantly shorter OS in comparison to those with the low expression of SLC38A7 protein [median OS 3.9 years (95% confidence interval, 2.4-6.4 years) vs 2.2 years (95% confidence interval, 1.9-4.1 years); log rank test: P = 0.0021]. CONCLUSION: SLC38A7, which is the primary lysosomal glutamine transporter required for the extracellular protein-dependent growth of cancer cells, was identified as a candidate therapeutic target of SCC.

Expression of CD44 variant 9 induces chemoresistance of gastric cancer by controlling intracellular reactive oxygen spices accumulation.

BACKGROUND: CD44 variant 9 (CD44v9) has been reported to suppress reactive oxygen spices (ROS) in association with antioxidant factors such as glutathione (GSH) and glutathione peroxidase 2 (GPx2), resulting in promoted tumor growth. METHODS: CD44v9 and GPx2 expression were investigated by immunohistochemistry in resected specimens from 193 gastric cancer (GC) patients without preoperative chemotherapy and in pretreatment biopsy specimens from 29 GC patients with preoperative chemotherapy. We analyzed the relationship between CD44v9 expression and clinicopathological factors, prognosis, and pathological response to chemotherapy. In GC cell lines, we examined the relationship between CD44v9 expression and chemotherapeutic sensitivity. RESULTS: In patients without preoperative chemotherapy, CD44v9 expression was significantly associated with depth of invasion, lymphatic permeation, vascular invasion, distant metastasis and GPx2 expression. In multivariate analysis, CD44v9 expression was an independent poor prognosis factor for overall survival and recurrence-free survival. In patients with preoperative chemotherapy, CD44v9 expression was significantly associated with worse pathological response and GPx2 expression. In GC cell lines, downregulation of CD44v9 expression enhanced chemotherapeutic sensitivity to 5-fluorouracil with changing GSH and ROS levels. CONCLUSIONS: CD44v9-positive expression was associated with chemotherapeutic resistance by controlling intracellular accumulated ROS, suggesting that CD44v9 may be a predictive biomarker for chemotherapy in GC.

[The Efficacy of topo â -pS10 Expression in Gastric Cancer as a Predictive Biomarker for Irinotecan Use].

BACKGROUND: Though irinotecan is commonly used for treating advanced gastric cancer, there is no predictive biomarker to date. We have studied the resistant mechanism for irinotecan and found that phosphorylation of serine 10 residue of topoisomerase Ⅰ(topo Ⅰ)is an important step for irinotecan resistance. We have developed an immunohistochemical staining-based biomarker; topo Ⅰ-pS10, for predicting irinotecan efficacy. PURPOSE: The purpose of this study is to test the accuracy of topo Ⅰ-pS10 immunohistochemical staining in gastric cancer clinical samples. METHODS: In this study we performed 2 sets of tests. In the training set, we stained 79 gastric cancer clinical samples which efficacy of irinotecan was measured by succinate dehydrogenase inhibition(SDI)test. In the validation set, we used 27 gastric cancer clinical samples which irinotecan was used and the efficacy was known. RESULTS: Training set: From the ROC curve the cut-off point was set at 35% positive nuclei. Sixty three cases were positive with topo Ⅰ-pS10 in the nuclei. With the result of irinotecan SDI, the sensitivity was 76.6% and the positive predictive value was 92.5%. This result showed that topo Ⅰ-pS10 positive case does not respond to irinotecan. Validation set: In this set, the sensitivity was 82.4% and the positive predictive value was 82.4%. CONCLUSION: topo Ⅰ-pS10 staining can be used as a predictive biomarker for irinotecan for gastric cancer patients.

Cytolytic activity score as a biomarker for antitumor immunity and clinical outcome in patients with gastric cancer.

BACKGROUND: A simple measure of immune cytolytic activity (CYT) base on mRNA expression levels of two genes, GZMA and PRF1, was recently reported. Here, we aimed to evaluate the CYT score's potential as a measure of antitumor immunity and predictor of clinical outcome in gastric cancer (GC) patients. MATERIALS AND METHODS: We evaluated the correlations between tumor-infiltrating immune cells and the CYT score in 238 GC samples from The Cancer Genome Atlas (TCGA). Next, we investigated CYT score associations with molecular subtypes, somatic mutation load, and immune checkpoint molecules in GC samples from TCGA and Asian Cancer Research Group (ACRG). Moreover, we evaluated the clinical significance of the CYT score calculated by reverse transcription (RT)-quantitative PCR (qPCR) data in 123 GC samples and the association of the CYT score with the response to anti-PD-1 therapy in 7 GC samples from Kyushu University Hospital. RESULTS: The CYT score positively correlated with the proportions of tumor-infiltrating CD8+ T cells and macrophages and negatively correlated with the proportion of regulatory T cells in GC tissues. A high CYT score was associated with common immune checkpoint molecules, a high mutation, the Epstein-Barr virus subtype, and the microsatellite instability subtype in GC. Moreover, a low CYT score was a poor prognosis factor in patients with GC. Finally, the CYT score was higher in a responder to anti-PD-1 therapy compared to nonresponders. CONCLUSION: The CYT score reflects antitumor immunity and predicts clinical outcome in GC patients.

Radiomics Texture Analysis for the Identification of Colorectal Liver Metastases Sensitive to First-Line Oxaliplatin-Based Chemotherapy.

OBJECTIVE: The aim of this study was to develop a radiomics-based prediction model for the response of colorectal liver metastases to oxaliplatin-based chemotherapy. METHODS: Forty-two consecutive patients treated with oxaliplatin-based first-line chemotherapy for colorectal liver metastasis at our institution from August 2013 to October 2019 were enrolled in this retrospective study. Overall, 126 liver metastases were chronologically divided into the training (n = 94) and validation (n = 32) cohorts. Regions of interest were manually segmented, and the best response to chemotherapy was decided based on Response Evaluation Criteria in Solid Tumors (RECIST). Patients who achieved clinical complete and partial response according to RECIST were defined as good responders. Radiomics features were extracted from the pretreatment enhanced computed tomography scans, and a radiomics score was calculated using the least absolute shrinkage and selection operator regression model in a trial cohort. RESULTS: The radiomics score significantly discriminated good responders in both the trial (area under the curve [AUC] 0.8512, 95% confidence interval [CI] 0.7719-0.9305; p < 0.0001) and validation (AUC 0.7792, 95% CI 0.6176-0.9407; p < 0.0001) cohorts. Multivariate analysis revealed that high radiomics scores greater than - 0.06 (odds ratio [OR] 23.803, 95% CI 8.432-80.432; p < 0.0001), clinical non-T4 (OR 6.054, 95% CI 2.164-18.394; p = 0.0005), and metachronous disease (OR 11.787, 95% CI 2.333-70.833; p = 0.0025) were independently associated with good response. CONCLUSIONS: Radiomics signatures may be a potential biomarker for the early prediction of chemosensitivity in colorectal liver metastases. This approach may support the treatment strategy for colorectal liver metastasis.

Quadruple gastrointestinal cancer with discordance of mismatch repair protein deficiency and microsatellite instability suggesting Lynch syndrome.

A 65-year-old woman with prior personal and family histories of cancer was admitted to our hospital for quadruple cancer. Preoperative endoscopy revealed a type 0-II gastric cancer (GC; gastric body), advanced type-II colon cancer (ascending colon), and early-stage recto-sigmoid colon cancers. We diagnosed her with Lynch syndrome (LS) per Amsterdam criteria, and performed distal gastrectomy, ileocecal resection and high anterior resection. Her pathological diagnoses were GC: well-to-poorly differentiated adenocarcinoma (AD, por2 > tub2) with signet-ring cells, ypT1b SM2; ascending colon cancer: AD with focal mucin products (tub2 > muc), SS; sigmoid colon cancer: AD (tub1), M; recto-sigmoid cancer: AD (tub1 > tub2), SM. Immunohistochemical tests revealed that all cancers lacked the MLH1/PMS2 protein. However, the three colon cancers were found to have high microsatellite instability (MSI); the GC was microsatellite stable (MSS). No recurrence or other cancers were observed for 30 months after surgery without adjuvant chemotherapy. As patients with LS may also develop MSS cancers, we should check for MSI in all LS cancers for proper treatment.

Impact of a Long Linear Staplers on the Incidence of Stricture after Triangulating Esophagogastric Anastomosis.

BACKGROUND: Various techniques have been reported for esophagogastric anastomosis to prevent anastomotic leakage. Recently, not only postoperative anastomotic leakage but also anastomotic stricture is considered important because stricture contributes to the patient's postoperative quality of life. However, the best procedure for anastomosis has not been established. MATERIALS AND METHODS: The authors divided 101 patients with thoracic or abdominal esophageal cancer who underwent cervical triangulating esophagogastric anastomosis using a linear stapler between May 2017 and May 2020 into 2 groups: surgery with a short (45 mm) linear stapler (SS group, n=59) or a long (60 mm) stapler (LS group, n=42). The frequencies of anastomotic leakage and stricture were compared between the 2 groups. RESULTS: The incidence of anastomotic leakage and stricture without leakage were significantly lower in the LS versus SS group (respectively: leakage: 15% vs. 0%, P=0.01; stricture: 36% vs. 7%, P=0.01). A short linear stapler and anastomotic leakage were independent risk factors for anastomotic stricture in the multivariate analysis (short stapler: odds ratio, 3.27; 95% confidence interval, 1.08-9.9; P=0.03; anastomotic leakage: odds ratio, 2.78; 95% confidence interval, 1.02-8.5; P=0.04). CONCLUSION: A long linear stapler is preferable for cervical triangulating esophagogastric anastomosis.

Indications for laparoscopic surgery for older rectal cancer patients with comorbidities.

PURPOSE: Given the lack of safety studies concerning laparoscopic surgery for rectal cancer in patients ≥ 80 years old with comorbidities, we sought to investigate this in the current study. METHODS: Between 2012 and 2019, 24 patients ≥ 80 years old underwent laparoscopic surgery for rectal cancer without preoperative treatment. These patients were divided into those with [comorbidity(+) group, n = 13] and without [comorbidity(-) group, n = 11] comorbidities. The preoperative nutritional status and ASA classification, postoperative complications, time to oral diet, and length of hospital stay were evaluated in each group. RESULTS: In the comorbidity(+)/comorbidity(-) groups, the average age was 85.9/84.1 years old, respectively. The major comorbidities were heart disease including atrial fibrillation and valvular disorder. The average PNI and CONUT scores in the comorbidity(+)/comorbidity(-) groups were 44.7/44.2 an 3.1/2.2, respectively. Planned surgical procedures were completed in all patients. Postoperative complications occurred in 2/3 cases in the comorbidity(+)/comorbidity(-) groups, respectively, and the average time to oral diet was 3.8/3.7 days, while the average length of hospitalization after surgery was 15.2/16.5 days, respectively. In the comorbidity(+) group, there was no exacerbation of comorbidities in any cases. CONCLUSION: The safety of laparoscopic surgery is acceptable among older rectal cancer patients with comorbidities.

New Anastomosis Technique to Prevent Anastomotic Leakage in Laparoscopic Anterior Resection for Rectal Cancer, Especially Upper Rectal Cancer.

BACKGROUND/AIM: Anastomotic leakage (AL) is a major problem in rectal cancer surgery. To prevent AL, we developed a side-to-side anastomosis technique using a circular stapler and termed it the circular side stapling technique (CST). We herein report the method and outcome of the CST. PATIENTS AND METHODS: In this study, we analyzed 154 patients with stage 0 to III rectal cancer who underwent curative laparoscopic low anterior resection. Perioperative factors and complications were compared between the CST and usual double stapling technique (DST). RESULTS: The CST was performed in 110 of the 154 patients. When comparing the outcomes of patients with upper rectal cancer. AL occurred in no patients in the CST group and in three patients in the DST group (p=0.011). The CST prevented AL in all patients with upper rectal cancer. CONCLUSION: The CST is a safe and useful procedure in laparoscopic anterior resection. This technique can prevent AL, especially in patients with upper rectal cancer.

A rare case of esophageal adenocarcinoma with urinary bladder metastasis.

A 75-year-old man was admitted to our hospital for treatment of esophageal cancer (EC) in March 2017. Esophagogastroduodenoscopy revealed Barrett's esophagus and superficial, distal EC (type 0-IIc). Tumor biopsy showed esophageal adenocarcinoma. Computed tomography revealed no lymph node metastasis but did reveal a 19-mm tumor on the right side of the urinary bladder. Bladder cancer (BC) was also suspected, and the patient underwent endoscopic submucosal dissection for EC and transurethral resection of the bladder tumor. The pathological diagnosis of EC was moderately to poorly differentiated adenocarcinoma (tub2), pT1b (SM), ly0, v0. The pathological horizontal margin was negative and the vertical margin was positive. Additional esophagectomy and lymph node dissection were indicated for curability. Esophagectomy was difficult because the patient had severe cardiovascular disease, so follow-up observation was adopted. BC was classified as urothelial carcinoma Ta, ly0, v0. After 32 months, multiple tumors were found in the bladder, and BC recurrence was suspected. Transurethral resection of the bladder was performed again for seven tumors, and pathological diagnosis was poorly differentiated adenocarcinoma (tub2). The immunohistochemical features matched those of EC. We diagnosed EC metastasis in the urinary bladder. Bladder adenocarcinoma is difficult to distinguish from metastasis from other organs, especially the upper gastrointestinal tract, and cytomorphological features and appropriate clinical history are required.

Obstructive rectal endometriosis treated by robot-assisted laparoscopic surgery: a case report.

BACKGROUND: Rectal endometriosis is a rare disease. A definitive diagnosis prior to surgery is often difficult. We encountered a patient with rectal sub-obstructive endometriosis that was treated by robot-assisted laparoscopic low anterior resection. CASE PRESENTATION: A 43-year-old woman visited our hospital with suspected stenosis caused by upper rectal cancer. She had a 2-year history of constipation. We were unable to confirm the diagnosis through detailed examinations, including laparoscopy. Robot-assisted laparoscopic low anterior resection with D3 lymph node dissection was performed for both diagnosis and treatment. The postoperative specimen showed a submucosal tumor. The pathological examination confirmed rectal endometriosis. CONCLUSIONS: We herein describe a rare case of obstructive rectal endometriosis that we were unable to diagnose preoperatively. Robotic surgery was useful in this case, which involved extensive pelvic adhesion.

Primary anorectal malignant melanoma with laparoscopic abdominoperineal resection: a case study and review of the relevant literature.

ARMM is a disease with a poor prognosis. ARMM is often diagnosed at an advanced stage, and the 5-year survival rate of ARMM is < 20%. Although the number of case reports on ARMM is gradually increasing, the optimal treatment strategy for ARMM remains controversial. We report the case of an 81-year-old woman who had experienced bloody stool for 6 months before her diagnosis and who had been initially diagnosed with hemorrhoids. The pathological diagnosis of a biopsy specimen was malignant melanoma. Other examinations showed no evidence of lymph node or distant metastasis. Based on these results, laparoscopic abdominoperineal resection was performed. Three months later on her first follow-up examination, distant metastasis to the lung and liver was detected. Immunotherapy using Nivolumab was initiated to treat the recurrent disease. We reviewed the characteristics of a total of 1834 ARMM patients described in previous reports on ARMM for which the full text was available on PubMed. We experienced a case of ARMM. The prognosis of ARMM is still poor, regardless of the surgical procedure. Previous studies and our case report suggest that systemic therapy, such as immunotherapy using an anti-PD-1 ligand may be more important than reinforcement of local control for improving the prognosis of ARMM patients.

Expression of PD-L1, PD-L2, and IDO1 on tumor cells and density of CD8-positive tumor-infiltrating lymphocytes in early-stage lung adenocarcinoma according to histological subtype.

PURPOSE: This study examined the expression of programmed cell death-ligand 1 (PD-L1), programmed cell death-ligand 2 (PD-L2), and indoleamine 2,3-dioxygenase-1 (IDO1) in tumor cells and cluster of differentiation 8 (CD8)-positive tumor-infiltrating lymphocytes (TILs) in early-stage lung adenocarcinoma according to histological subtypes. METHODS: We evaluated PD-L1, PD-L2, and IDO1 expression in tumor cells and CD8-positive TILs in surgically resected specimens from 196 stage 0 or I lung adenocarcinoma patients by immunohistochemical staining. We also examined the relationships between the expression of PD-L1, PD-L2, and IDO1 in tumor cells and the density of CD8-positive TILs and clinical factors. Patients were divided into three groups: A, adenocarcinoma in situ and minimally invasive adenocarcinoma (N = 32); B, lepidic predominant invasive adenocarcinoma (IAD; LPA; N = 66); and C, IAD except for LPA (N = 98). RESULTS: PD-L1 was expressed only in Group C, but not in Groups A or B. The positive ratio of PD-L2 was significantly higher in Group C (63.3%), and that of IDO1 was also significantly higher in Group C (65.3%). The density of CD8-positive TILs was significantly higher in Group C (45 ± 2.4). There was no significant difference between the positive ratios of PD-L2 and IDO1 and the density of CD8-positive TILs in Group A (50.0%, 21.9%, and 36 ± 4.1, respectively) or Group B (60.6%, 25.8%, and 44 ± 3.0, respectively). CONCLUSIONS: No cases in Groups A and B expressed PD-L1. The expression of immune-related factors, especially PD-L1 and IDO1, was significantly associated with Group C. This is the first report of the detailed examination of PD-L1, PD-L2, IDO1, and CD8 expression in lung adenocarcinoma subtypes with lepidic predominant components. Our results could help identify patients who would benefit from perioperative immunotherapy.