Associating liver partition and portal vein ligation for staged hepatectomy as bridging therapy for liver transplantation in an infant with an advanced hepatic rhabdoid tumor.

BACKGROUND: Malignant rhabdoid tumors (MRTs) are rare, aggressive tumors that mainly affect children and currently lack effective chemotherapeutic regimens. Liver MRTs are particularly challenging to manage due to the difficulty of performing one-stage liver resection, and preemptive liver transplantation is associated with high recurrence rates. However, the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) technique offers a promising surgical approach for advanced-stage liver tumors where conventional liver resection is not feasible. CASE REPORT: A patient with a large liver rhabdoid tumor that had invaded the three main hepatic veins underwent four courses of cisplatin-pirarubicin chemotherapy. ALPPS was performed due to insufficient residual liver capacity, with hepatic parenchymal dissection between the anterior and posterior liver zones in the first stage of surgery. After confirming adequate remaining liver volume, the liver was resected except for S1 and S6 on postoperative day 14. LDLT was performed 7 months after ALPPS due to the gradual deterioration of liver function caused by chemotherapy. The patient was recurrence-free 22 and 15 months after ALPPS and LDLT, respectively. CONCLUSIONS: The ALPPS technique is a curative option for advanced-stage liver tumors that cannot be managed with conventional liver resection. In this case, ALPPS was used successfully to manage a large liver rhabdoid tumor. Then, liver transplantation was performed after chemotherapy. The ALPPS technique should be considered a potential treatment strategy for patients with advanced-stage liver tumors, particularly those who can undergo liver transplantation.

Mesothelin blockage by Amatuximab suppresses cell invasiveness, enhances gemcitabine sensitivity and regulates cancer cell stemness in mesothelin-positive pancreatic cancer cells.

BACKGROUND: Mesothelin is a 40-kDa glycoprotein that is highly overexpressed in various types of cancers, however molecular mechanism of mesothelin has not been well-known. Amatuximab is a chimeric monoclonal IgG1/k antibody targeting mesothelin. We recently demonstrated that the combine therapy of Amatuximab and gemcitabine was effective for peritonitis of pancreatic cancer in mouse model. METHODS: We discover the role and potential mechanism of mesothelin blockage by Amatuximab in human pancreatic cells both expressing high or low level of mesothelin in vitro experiment and peritonitis mouse model of pancreatic cancer. RESULTS: Mesothelin blockage by Amatuximab lead to suppression of invasiveness and migration capacity in AsPC-1 and Capan-2 (high mesothelin expression) and reduce levels of pMET expression. The combination of Amatuximab and gemcitabine suppressed proliferation of AsPC-1 and Capan-2 more strongly than gemcitabine alone. These phenomena were not observed in Panc-1 and MIA Paca-2 (Mesothelin low expression). We previously demonstrated that Amatuximab reduced the peritoneal mass in mouse AsPC-1 peritonitis model and induced sherbet-like cancer cell aggregates, which were vanished by gemcitabine. In this study, we showed that the cancer stem cell related molecule such as ALDH1, CD44, c-MET, as well as proliferation related molecules, were suppressed in sherbet-like aggregates, but once sherbet-like aggregates attached to peritoneum, they expressed these molecules strongly without the morphological changes. CONCLUSIONS: Our work suggested that Amatuximab inhibits the adhesion of cancer cells to peritoneum and suppresses the stemness and viability of those, that lead to enhance the sensitivity for gemcitabine.

An increase in the peripheral lymphocyte-to-monocyte ratio after primary site resection is associated with a prolonged survival in unresectable colorectal carcinoma.

PURPOSE: The prognostic benefits of primary tumor resection in patients with unresectable distant metastatic colorectal cancer remain unclear. A high pre-treatment lymphocyte-to-monocyte ratio (LMR) was previously shown to be associated with a better prognosis. We assessed whether or not primary tumor resection was associated with an improved survival if the peripheral lymphocyte-to-monocyte ratio increased after primary site resection. METHODS: The survival in 64 and 59 patients with and without primary tumor resection, respectively, was retrospectively compared. After resection, the survival in 39 patients with a postoperatively increased LMR (LMR-increase) and 25 patients with a decreased LMR (LMR-decrease) was compared. RESULTS: Primary tumor resection prolonged the median survival more frequently in cases of non-differentiated adenocarcinoma, obstructive symptoms, high serum albumin levels, and no lymph-node metastasis than in others. Cox regression showed that the potential independent prognostic variable was non-resection of the primary lesion. After resection, the median survival in the LMR-increase vs. LMR-decrease groups was significantly different (27.3 vs. 20.8 months). There were no marked differences in patient background characteristics between the groups, except for in the number of pre-operative peripheral blood lymphocytes. The resected specimens showed significantly lower CD8+:CD163+ invading leukocyte ratios in the LMR-increase group than in the LMR-decrease group. CONCLUSIONS: Primary tumor resection in patients with unresectable metastatic colorectal cancer may be associated with an improved survival, especially when the LMR is increased after primary tumor resection.

Chorionic Gonadotropin-ß Modulates Epithelial-Mesenchymal Transition in Colorectal Carcinoma Metastasis.

Ectopic production of free ß human chorionic gonadotropin (hCGß) has been associated with aggressive behavior in non-trophoblastic tumors. hCGß shares common evolutionary sequences with transforming growth factor-ß (TGF-ß), which represents a major driving force of epithelial-to-mesenchymal transition (EMT). In this study, we examined the biological roles of hCGß during EMT and its clinical significance in colorectal cancer (CRC) progression. Eighty CRC specimens and 54 preoperative serum samples were analyzed. hCGß-overexpressing human CRC cell lines were examined for invasiveness and tumorigenicity, and the expression of EMT-associated genes was investigated. In human CRC, histologic hCGß positivity [13/80 (16.3%)] was lower than serologic hCGß positivity [13/54 (24.1%)]. However, it was significantly correlated with several clinicopathological features and unfavorable outcome (P < 0.05). hCGß-overexpressing cell lines had increased invasiveness, migratory ability, and metastatic potential in mice (P < 0.01). Western blot, PCR, and microarray analyses showed hCGß altered expression of EMT-related genes, including E-cadherin, phosphorylated SMAD2, SNAIL, and TWIST. hCGß-induced SNAIL and TWIST overexpression levels were reversible by type I and type II TGF-ß receptor inhibitors (P < 0.05). hCGß thus induces EMT via the TGF-ß signaling pathway, and it may represent a molecular target in CRC treatment.

Preoperative FOLFOX in resectable locally advanced rectal cancer can be a safe and promising strategy: the R-NAC-01 study.

PURPOSE: The aim of this study was to assess the safety of rectal surgery after 5-fluorouracil-leucovorin-oxaliplatin chemotherapy (FOLFOX6). METHODS: This was a prospective, multicenter study in 11 Japanese hospitals. We included patients with rectal cancer who received 4 courses of modified FOLFOX6 (mFOLFOX6) before rectal surgery and examined the postoperative complication rate, the clinicopathological response, and the rate of chemotherapy-related adverse events (UMIN 000012559). RESULTS: The study population included 36 men and 5 women. The average age of the patients was 60.8 years and the average body mass index was 23.1 kg/m2. After 4 courses of chemotherapy, grade 2 peripheral nerve disorder and other grade 3 adverse events were seen in 3 patients each (7.3%). Twenty-eight (73.7%) and 8 (21.1%) patients underwent low anterior resection and abdominoperineal resection, respectively. The pelvic nerves were preserved in 35 patients. Surgical morbidity (grade ≥ 3) occurred in 4 patients (10.5%). Anastomotic leakage occurred after surgery in 2 patients (7.1%). No patients achieved pathologically complete remission. However, downstaging of the clinical stage and N stage was seen in 17 (41.5%) and 22 (53.7%) patients, respectively. CONCLUSIONS: Surgery after four courses of mFOLFOX6 chemotherapy can be a safe and promising strategy for patients with locally advanced rectal cancer.

MLH1-93 G/a polymorphism is associated with MLH1 promoter methylation and protein loss in dysplastic sessile serrated adenomas with BRAFV600E mutation.

BACKGROUND: Sessile serrated adenomas with BRAF mutation progress rapidly to cancer following the development of dysplasia (SSAD). Approximately 75% of SSADs methylate the mismatch repair gene MLH1, develop mismatch repair deficiency and the resultant cancers have a good prognosis. The remaining SSADs and BRAF mutant traditional serrated adenomas (TSA) develop into microsatellite stable cancers with a poor prognosis. The reason for this dichotomy is unknown. In this study, we assessed the genotypic frequency of the MLH1-93 polymorphism rs1800734 in SSADs and TSAs to determine if the uncommon variant A allele predisposes to MLH1 promoter hypermethylation. METHODS: We performed genotyping for the MLH1-93 polymorphism, quantitative methylation specific PCR, and MLH1 immunohistochemistry on 124 SSAD, 128 TSA, 203 BRAF mutant CRCs and 147 control subjects with normal colonoscopy. RESULTS: The minor A allele was significantly associated with a dose dependent increase in methylation at the MLH1 promoter in SSADs (p = 0.022). The AA genotype was only observed in SSADs with MLH1 loss. The A allele was also overrepresented in BRAF mutant cancers with MLH1 loss. Only one of the TSAs showed loss of MLH1 and the overall genotype distribution in TSAs did not differ from controls. CONCLUSIONS: The MLH1-93 AA genotype is significantly associated with promoter hypermethylation and MLH1 loss in the context of SSADs. BRAF mutant microsatellite stable colorectal cancers with the AA genotype most likely arise in TSAs since the A allele does not predispose to methylation in this context.

[Effectiveness of indocyanine green fluorescence in endoscopic marking in gastric cancer surgery:a feasibility study for replacing India ink].

When injected, indocyanine green (ICG) immediately combines with lipoproteins to fluoresce. Here, we studied whether ICG fluorescence is effective for endoscopic marking in gastric cancer surgery using a photodynamic eye (PDE) camera and fluorescent endoscope. An ICG solution was endoscopically injected into the submucosal layer of the gastric tumor 3 days before surgery. We observed the lesions using both a PDE camera and a fluorescent endoscope during laparotomy and laparoscopy, respectively;we also observed the fluorescent luminance and fluorescent size of the resected lesions. We could intraoperatively detect the size of the resected lesions in eight patients with early gastric cancer and six patients with advanced gastric cancer. We believe that the use of ICG fluorescence in endoscopic marking requires additional information, such as the volume of the ICG solution and the timing of the ICG injection.

Comparison of single-incision plus one additional port laparoscopy-assisted anterior resection with conventional laparoscopy-assisted anterior resection for rectal cancer.

BACKGROUND: Reduced-port laparoscopic surgery is the latest innovation in minimally invasive surgery. We performed single-incision plus one additional port laparoscopy-assisted anterior resection (SILS + 1-AR) starting in August 2010. This study aimed at evaluating the feasibility of SILS + 1-AR and comparing it with that of conventional laparoscopy-assisted anterior resection (C-AR). METHODS: Patients with preoperative clinical stage 0 to stage III rectal cancer were included. Demographic, intraoperative, and pathological examination data, as well as short-term outcome data, of 20 patients who underwent SILS + 1-AR were retrospectively compared with that of 20 patients who underwent C-AR. Invasiveness of the two procedures was also evaluated through a vital signs diary and hematological examination on postoperative days (POD) 1, 3, and 7. RESULTS: Operating time, mean estimated blood loss, the number of lymph nodes dissected, the number of lymph node metastases, and the mean distal resection margin length were not significantly different. However, postoperative neutrophil counts in the SILS + 1-AR group were lower than those in the C-AR group (P = 0.085). A significant difference in body temperature was observed in the SILS + 1-AR group on POD 1 (P = 0.028). No significant differences were observed in perioperative and overall morbidity between the two groups. Conversion to open surgery was required in 2 (10 %) of the 20 patients in the SILS + 1-AR group. The mean postoperative length of stay and recurrence rates were similar in the two groups. CONCLUSION: SILS + 1-AR for rectal cancer is similar to C-AR in safety, feasibility, and provision of oncological radicality.

Fatal acquired coagulation factor V deficiency after hepatectomy for advanced hepatocellular carcinoma as a possible immune checkpoint inhibitor-related adverse event: a case report.

BACKGROUND: Atezolizumab plus bevacizumab therapy was recently introduced as the first line for unresectable advanced hepatocellular carcinoma (HCC), but immune-related adverse events (IrAEs) due to atezolizumab are a great concern. Here, we report the case of a patient who developed fatal acquired coagulation factor deficiency after hepatectomy for HCC, treated with atezolizumab and bevacizumab before surgery. CASE PRESENTATION: A 70-year-old man received right trisegmentectomy of the liver with hepaticojejunostomy for advanced HCC with bile duct invasion, after atezolizumab and bevacizumab therapy. The patient suffered the sudden onset of severe multiple coagulation factor deficiency (II, V, VII, VIII, IX, X, XI and XII) immediately following reoperation for anastomotic leakage of hepaticojejunostomy, 7 days after hepatectomy. The coagulation factor deficiency did not reverse even with intensive treatment, and the patient died of uncontrollable bleeding 32 days after hepatectomy. An IrAE due to atezolizumab was suspected because the patient had developed the possible IrAE of enthesitis of the right gastrocnemius muscle before surgery, and specific inhibitors against factor V and anti-factor V autoantibodies were detected, leading to an ultimate diagnosis of autoimmune FV/5 deficiency (AiF5D). CONCLUSION: Severe acquired coagulopathy should be recognized as a possible life-threatening IrAE when using atezolizumab and bevacizumab for HCC.

Human chorionic gonadotropin-ß promotes pancreatic cancer progression via the epithelial mesenchymal transition signaling pathway.

Background: The human chorionic gonadotropin free beta-subunit (hCGß) is ectopically produced in various epithelial cancers and is associated with poor prognoses. However, its molecular mechanism remains unclear. In this study, we examined the biological role of hCGß in pancreatic cancer progression. Methods: Tissue specimens of 30 patients with pancreatic cancer were examined immunohistochemically to investigate the relationship between hCGß expression and clinicopathological features. We also evaluated the molecular effects of hCGß-downregulated pancreatic cell lines. Results: Total of 21 cases were positive for immunostaining, and 17 of 25 metastatic lymph nodes were positive. hCGß expression levels were correlated with pancreatic cancer T and N factors. hCGß expression was significantly associated with poor overall and recurrence-free survival (P<0.001). In a multivariate analysis, hCGß expression was independently associated with overall survival (HR 14.0; 95% CI: 1.5-130; P=0.019). The proliferative, invasive, and migratory abilities of hCGß-downregulated cell lines were reduced compared with the control cell lines. Moreover, downregulation of hCGß reduced vimentin, slug, and α-smooth muscle actin expression and increased E-cadherin expression. Conclusions: hCGß expression is related to cancer progression and poor prognoses via epithelial mesenchymal transition. hCGß is a potential prognostic marker and molecular target in pancreatic cancer.

[Usefulness of intraoperative fluorescent imaging using indocyanine green for repeated resection of hepatocellular carcinoma].

For recurrent hepatic tumors with treatment history or cirrhosis, small region including extrahepatic tumors that cannot be identified on routine ultrasonography, we used a fluorescent imaging with indocyanine green (ICG) for repeated resection of hepatocellular carcinoma. The patients were consisted of 4 men and 2 women with a mean age of 61.5 (37-66) years. Five cases of intra or extra hepatic tumors could be identified with fluorescent imaging system. Two cases were a local recurrence after TACE, 1 case was a small tumor exited in liver surface, 1 case could be identified the area of vascular invasion of subcutaneous recurrence, and 1 case was a mediastinal small lymph node metastasis of hepatocellular carcinoma. Fluorescent imaging using ICG was considered to be useful for identification of recurrent hepatocellular carcinoma that cannot be identified by a routine ultrasonography.

Proficiency Level of Novice Technically Qualified Surgeons in Laparoscopic Rectal Resection.

The actual proficiency levels of surgeons after their qualification by the Endoscopic Surgical Skill Qualification System have not been established. This study aimed to investigate whether technically qualified surgeons could safely perform laparoscopic low anterior resection and to evaluate the proficiency level at the time of certification acquisition. A total of 46 patients (mean age, 63.3 y; male to female ratio, 29:17) who underwent low anterior resection were included. Outcomes of 46 low anterior resections for rectal cancer performed by 3 novice surgeons certified by the Endoscopic Surgical Skill Qualification System from 2013 to 2018 at 2 hospitals were retrospectively assessed. The mean operative time and blood loss were 201 minutes and 12.9 mL, respectively. One patient (2.2%) required conversion to open surgery, and major postoperative complications occurred in 4 patients (8.6%), including anastomotic leakage in 2 patients (4.3%). Histologic R0 resection was achieved in all cases. The operative time moving average for the 3 surgeons gradually decreased from 233 to 158 minutes. In cumulative sum charts, the operative time values continuously decreased after the 12th case compared with the target operative time (180 min). In conclusion, surgeons can safely perform laparoscopic low anterior resection just after their qualification but have the potential to further attain proficiency.

EGFR and Prion protein promote signaling via FOXO3a-KLF5 resulting in clinical resistance to platinum agents in colorectal cancer.

Epidermal growth factor receptor (EGFR) supports colorectal cancer progression via oncogenic signaling. Anti-EGFR therapy is being investigated as a clinical option for colorectal cancer, and an observed interaction between EGFR and Prion protein has been detected in neuronal cells. We hypothesized that PrPC expression levels may regulate EGFR signaling and that detailed understanding of this signaling pathway may enable identification of resistance mechanisms and new actionable targets in colorectal cancer. We performed molecular pathway analysis following knockdown of PrPC or inhibition of EGFR signaling via gefitinib to identify changes in expression of key signaling proteins that determine cellular sensitivity or resistance to cisplatin. Expression of these proteins was examined in matched primary and metastatic patient samples and was correlated for resistance to therapy and progression of disease. Utilizing three colorectal cancer cell lines, we observed a correlation between high expression of PrPC and resistance to cisplatin. Investigation of molecular signaling in a resistant cell line revealed that PrPC contributed to signaling via colocalization with EGFR, which could be overcome by targeting p38 mitogen-activated protein kinases (p38 MAPK). We revealed that the level of Krüppel-like factor 5 (KLF5), a target downstream of p38 MAPK, was predictive for cell line and patient response to platinum agents. Further, high KLF5 expression was observed in BRAF-mutant colorectal cancer. Our study indicates that the EGFR to KLF5 pathway is predictive of patient progression on platinum-based therapy.

The anti-mesothelin monoclonal antibody amatuximab enhances the anti-tumor effect of gemcitabine against mesothelin-high expressing pancreatic cancer cells in a peritoneal metastasis mouse model.

Pancreatic cancer often has a very poor prognosis, even after complete resection. The recurrence of hepatic and peritoneal metastases is an important prognostic factor; therefore, the development of improved adjuvant therapy is urgently required. Mesothelin is a cell surface glycoprotein whose expression is restricted to a variety of cancer types, including pancreatic cancer. This expression pattern makes mesothelin an attractive target for cancer therapy, and several agents targeting mesothelin are currently in clinical trials. Here, we used the chimerized high-affinity anti-mesothelin monoclonal antibody amatuximab to investigate its effect on peritoneal metastasis. We used the AsPC-1 pancreatic cancer cell line engineered to express Gaussia luciferase (Gluc), (AsPC-1-Gluc) for in vivo experiments. Results showed that while amatuximab was not directly cytotoxic on an AsPC-1-Gluc tumor cells in a peritoneal metastasis model, it prevented the formation of tumor growth. In combination therapy with gemcitabine, amatuximab exhibited synergistic killing. Our results suggest that blockade of mesothelin by amatuximab may be a useful strategy for preventing the peritoneal dissemination of pancreatic cancer under an adjuvant setting.

RNF43 is mutated less frequently in Lynch Syndrome compared with sporadic microsatellite unstable colorectal cancers.

The WNT signaling pathway is commonly altered during colorectal cancer development. The E3 ubiquitin ligase, RNF43, negatively regulates the WNT signal through increased ubiquitination and subsequent degradation of the Frizzled receptor. RNF43 has recently been reported to harbor frequent truncating frameshift mutations in sporadic microsatellite unstable (MSI) colorectal cancers. This study assesses the relative frequency of RNF43 mutations in hereditary colorectal cancers arising in the setting of Lynch syndrome. The entire coding region of RNF43 was Sanger sequenced in 24 colorectal cancers from 23 patients who either (i) carried a germline mutation in one of the DNA mismatch repair genes (MLH1, MSH6, MSH2, PMS2), or (ii) showed immunohistochemical loss of expression of one or more of the DNA mismatch repair proteins, was BRAF wild type at V600E, were under 60 years of age at diagnosis, and demonstrated no promoter region methylation for MLH1 in tumor DNA. A validation cohort of 44 colorectal cancers from mismatch repair germline mutation carriers from the Australasian Colorectal Cancer Family Registry (ACCFR) were sequenced for the most common truncating mutation hotspots (X117 and X659). RNF43 mutations were found in 9 of 24 (37.5%) Lynch syndrome colorectal cancers. The majority of mutations were frameshift deletions in the G659 G7 repeat tract (29%); 2 cancers (2/24, 8%) from the one patient harbored frameshift mutations at codon R117 (C6 repeat tract) within exon 3. In the ACCFR validation cohort, RNF43 hotspot mutations were identified in 19/44 (43.2%) of samples, which was not significantly different to the initial series. The proportion of mutant RNF43 in Lynch syndrome related colorectal cancers is significantly lower than the previously reported mutation rate found in sporadic MSI colorectal cancers. These findings identify further genetic differences between sporadic and hereditary colorectal cancers. This may be because Lynch Syndrome cancers commonly arise in colorectal adenomas already bearing the APC mutation, whereas sporadic microsatellite unstable colorectal cancers arise from serrated polyps typically lacking APC mutation, decreasing the selection pressure on other WNT signaling related loci in Lynch syndrome.

Tumor budding and human chorionic gonadotropin-ß expression correlate with unfavorable patient outcome in colorectal carcinoma.

Tumor budding is thought to represent a manifestation of epithelial-to-mesenchymal transition (EMT) and it has been correlated with poor patient outcomes in colorectal cancer (CRC). Our group recently demonstrated that human chorionic gonadotropin-ß (hCGß) modulates EMT in CRC. In the current study, based on the likely relationships between tumor budding and hCGß expression, we examined their clinicopathologic significance in CRC. Twenty-eight of 80 (35.0%) CRC showed tumor budding. Tumor budding significantly correlated with lymph node metastasis (P < 0.01), pathologic stage (P < 0.01), lymphatic invasion (P = 0.044), and vascular invasion (P = 0.013). Thirteen of 80 (16.3%) CRC were hCGß positive on immunohistochemistry. More tumor buds were present in the hCGß-positive cases (P < 0.01), and tumor budding was significantly correlated with hCGß positivity (P < 0.01). Cases with both tumor budding and hCGß expression had the poorest prognosis compared with all other groups (P < 0.01). In conclusion, tumor budding and hCGß expression are closely associated with EMT, and they are independent prognostic factors in CRC. They identify patients with an "EMT phenotype" who may respond to targeted molecular therapies.

Copy number profiles of paired primary and metastatic colorectal cancers.

Liver metastasis is the major cause of death following a diagnosis of colorectal cancer (CRC). In this study, we compared the copy number profiles of paired primary and liver metastatic CRC to better understand how the genomic structure of primary CRC differs from the metastasis. Paired primary and metastatic tumors from 16 patients and their adjacent normal tissue samples were analyzed using single nucleotide polymorphism arrays. Genome-wide chromosomal copy number alterations were assessed, with particular attention to 188 genes known to be somatically altered in CRC and 24 genes that are clinically actionable in CRC. These data were analyzed with respect to the timing of primary and metastatic tissue resection and with exposure to chemotherapy. The genomic differences between the tumor and paired metastases revealed an average copy number discordance of 22.0%. The pairs of tumor samples collected prior to treatment revealed significantly higher copy number differences compared to post-therapy liver metastases (P = 0.014). Loss of heterozygosity acquired in liver metastases was significantly higher in previously treated liver metastasis samples compared to treatment naive liver metastasis samples (P = 0.003). Amplification of the clinically actionable genes ERBB2, FGFR1, PIK3CA or CDK8 was observed in the metastatic tissue of 4 patients but not in the paired primary CRC. These examples highlight the intra-patient genomic discrepancies that can occur between metastases and the primary tumors from which they arose. We propose that precision medicine strategies may therefore identify different actionable targets in metastatic tissue, compared to primary tumors, due to substantial genomic differences.

Oncogenic BRAF mutation induces DNA methylation changes in a murine model for human serrated colorectal neoplasia.

Colorectal cancer is a major cause of cancer death and approximately 20% arises within serrated polyps, which are under-recognized and poorly understood. Human serrated colorectal polyps frequently exhibit both oncogenic BRAF mutation and widespread DNA methylation changes, which are important in silencing genes restraining neoplastic progression. Here, we investigated whether in vivo induction of mutant Braf is sufficient to result in coordinated promoter methylation changes for multiple cancer-related genes. The BrafV637E mutation was induced in murine intestine on an FVB;C57BL/6J background and assessed for morphological and DNA methylation changes at multiple time points from 10 days to 14 months. Extensive intestinal hyperplasia developed by 10 days post-induction of the mutation. By 8 months, most mice had murine serrated adenomas with dysplasia and invasive cancer developed in 40% of mice by 14 months. From 5 months onwards, Braf mutant mice showed extensive, gene-specific increases in DNA methylation even in hyperplastic mucosa without lesions. This demonstrates that persistent oncogenic Braf signaling is sufficient to induce widespread DNA methylation changes. This occurs over an extended period of time, mimicking the long latency followed by rapid progression of human serrated neoplasia. This study establishes for the first time that DNA methylation arises slowly in direct response to prolonged oncogenic Braf signaling in serrated polyps; this finding has implications both for chemoprevention and for understanding the origin of DNA hypermethylation in cancer generally.

The Balance Between Surgical Resident Education and Patient Safety in Laparoscopic Colorectal Surgery: Surgical Resident's Performance has No Negative Impact.

OBJECTIVE: This study aimed to evaluate the feasibility and effectiveness of a comprehensive theoretical and hands-on training program in performing laparoscopic colonic resections under supervision of an expert surgeon. MATERIALS AND METHODS: Laparoscopic right colectomy was performed in 78 patients (10 with benign disease, 68 with carcinoma). Demographic, intraoperative, pathologic examination, and short-term outcome data were retrospectively compared between 25 patients operated by surgical residents (R group) and 53 patients operated by senior surgeons (S group). The residents who performed surgeries in the R group had between 1 and 6 years after graduation; no experience with open or laparoscopic colorectal surgery was necessary. The residents completed a training program under supervision of a single expert laparoscopic colorectal surgeon, which included 6 steps, from basic skills to certification. RESULTS: There were no differences in patient age, sex, and body mass index between the R and S groups. Significantly more patients in the R group had early cancer and benign lesions (P<0.05). Thirteen of the 16 residents (81.2 %) had not had prior experience with colonic resection. The time of suturing and knot tying in the dry box did not differ between residents and senior surgeons (68 and 69 s, respectively). All the residents performed laparoscopic right colectomy without intraoperative complications. There were no significant differences in operating time (R group: 173±34 min, S group: 172±52 min), mean estimated blood loss (50±111 vs. 49±100 mL), number of lymph nodes dissected (20.8±12.8 vs. 17.1±9.0), and mean postoperative hospital stay (9.1±3.3 vs. 10.7±4.1 d). On the basis of the year of their residency period, all 3 residents at 6 years after graduation had far greater experience than the other residents and therefore performed the surgery with minor verbal support from the expert. However, residents with 1 or 2 years after graduation had to receive guidance provision by the expert during surgery. CONCLUSIONS: When supervised and led by an expert laparoscopic surgeon, surgical residents are capable of performing laparoscopic surgery without negative effects on outcomes.

Does reduced-port laparoscopic surgery for medically uncontrolled ulcerative colitis do more harm than good?

INTRODUCTION: Reduced-port laparoscopic surgery is a novel minimally invasive surgery. However, reduced-port surgery for ulcerative colitis (UC) remains controversial. Here, we describe the clinical outcomes of single-incision plus one port laparoscopic surgery (SILS + 1) for medically uncontrolled UC. METHODS: Between May 2011 and September 2014, 10 UC patients underwent SILS + 1 port surgery. All procedures were performed with the use of a SILS port and either a 5-mm or a 12-mm port placed at the planned ileostomy site. RESULTS: The median age of patients was 32 years (range, 22-53 years). Six patients underwent two-stage SILS + 1 port restorative proctocolectomy with ileal pouch-anal anastomosis, two patients underwent SILS + 1 total proctocolectomy, and the remaining two patients underwent SILS + 1 subtotal colectomy with subsequent three-stage SILS + 1 ileal pouch-anal anastomosis. The median operative time was 363.1 min (range, 253-465 min) and the median estimated blood loss was 29 mL (range, 0-100 mL). There were no conversions or additional ports required. Two patients previously underwent SILS + 1 subtotal colectomy, and in one of those patients, SILS + 1 ileal pouch-anal anastomosis was performed successfully 6 months after the previous surgery. There were no intra-abdominal adhesions, and no extra wounds were necessary because the previous stoma site had been used to access the SILS port. The median postoperative period was 24 months, during which five patients had their ileostomies closed. No patients reported occasional minor daily soiling or the need to wear a pad. CONCLUSION: Reduced-port laparoscopic surgery for medically uncontrolled UC is a feasible and safe procedure when performed by skilled surgeons.