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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]