Impact of loss-of-function mutations at the RNF43 locus on colorectal cancer development and progression.

RNF43 mutations are frequently detected in colorectal cancer cells and lead to a loss of function of the ubiquitin E3 ligase. Here, we investigated the clinical significance of RNF43 mutations in a large Japanese cohort and the role of RNF43 at various stages of colorectal cancer development and progression. Mutation analysis of the RNF43 gene locus with pyrosequencing technology detected RNF43 hotspot mutations in one (0.88%) of 113 colorectal polyp cases and in 30 (6.45%) of 465 colorectal cancer cases. Moreover, patients with colorectal cancer harbouring mutated RNF43 experienced a higher recurrence rate than those harbouring non-mutated RNF43. In addition, the growth of RNF43 wild-type colorectal cancer cell lines was significantly increased by RNF43 silencing. We generated Rnf43 knockout mice in a C57BL/6 N background by using the CRISPR-Cas9 system. Although intestinal organoids from Rnf43 knockout mice did not show continuous growth in the absence of R-spondin, an azoxymethane/dextran sodium sulphate mouse model demonstrated that tumours were markedly larger in Rnf43 knockout mice than in wild-type mice. These findings provide evidence that Wnt signalling activation by RNF43 mutations during the tumourigenic stage enhances tumour growth and promotes a high recurrence rate in colorectal cancer patients. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Colorectal Cancer Stem Cells Acquire Chemoresistance Through the Upregulation of F-Box/WD Repeat-Containing Protein 7 and the Consequent Degradation of c-Myc.

The cancer stem cell (CSC) paradigm suggests that tumors are organized hierarchically. Chugai previously established an LGR5+ human colorectal cancer (CRC) stem-cell-enriched cell line (colorectal CSCs) that expresses well-accepted colorectal CSC markers and that can dynamically switch between proliferative and drug-resistant noncycling states. We performed this study to elucidate the molecular mechanisms responsible for evading cell death in colorectal CSCs mediated by anticancer agents. During the cell cycle arrest caused by anticancer agents, we found that c-Myc expression was substantially decreased in colorectal CSCs. The c-Myc expression alterations were mediated by upregulation of F-box/WD repeat-containing protein 7 (FBXW7), as evidenced through FBXW7-small interfering RNA knockdown experiments that resulted in enhanced cell sensitivity to anticancer agents. Upregulation of FBXW7 following drug treatment was not evident in commercially available cancer cell lines. Colorectal CSCs were induced to differentiation by Matrigel and fetal bovine serum. Differentiated CSCs treated with anticancer agents did not show upregulation of FBXW7 and were more sensitive to irinotecan (CPT-11), highlighting the potential CSC-specific nature of our data. The FBXW7 over-expression was further validated in resected liver metastatic sites in CRC patients after chemotherapy. In conclusion, our study revealed that a CSC-specific FBXW7-regulatory mechanism is strongly associated with resistance to chemotherapeutic agents. Inhibition of FBXW7-upregulation in CSCs following chemotherapy may enhance the response to anticancer agents and represents an attractive strategy for the elimination of colorectal CSCs. Stem Cells 2017;35:2027-2036.

Controlling Nutritional Status (CONUT) score is a prognostic marker for gastric cancer patients after curative resection.

BACKGROUND: Controlling Nutritional Status (CONUT), as calculated from serum albumin, total cholesterol concentration, and total lymphocyte count, was previously shown to be useful for nutritional assessment. The current study investigated the potential use of CONUT as a prognostic marker in gastric cancer patients after curative resection. METHODS: Preoperative CONUT was retrospectively calculated in 416 gastric cancer patients who underwent curative resection at Kumamoto University Hospital from 2005 to 2014. The patients were divided into two groups: CONUT-high (≥4) and CONUT-low (≤3), according to time-dependent receiver operating characteristic (ROC) analysis. The associations of CONUT with clinicopathological factors and survival were evaluated. RESULTS: CONUT-high patients were significantly older (p < 0.001) and had a lower body mass index (p = 0.019), deeper invasion (p < 0.001), higher serum carcinoembryonic antigen (p = 0.037), and higher serum carbohydrate antigen 19-9 (p = 0.007) compared with CONUT-low patients. CONUT-high patients had significantly poorer overall survival (OS) compared with CONUT-low patients according to univariate and multivariate analyses (hazard ratio: 5.09, 95% confidence interval 3.12-8.30, p < 0.001). In time-dependent ROC analysis, CONUT had a higher area under the ROC curve (AUC) for the prediction of 5-year OS than the neutrophil lymphocyte ratio, the Modified Glasgow Prognostic Score, or pStage. When the time-dependent AUC curve was used to predict OS, CONUT tended to maintain its predictive accuracy for long-term survival at a significantly higher level for an extended period after surgery when compared with the other markers tested. CONCLUSIONS: CONUT is useful for not only estimating nutritional status but also for predicting long-term OS in gastric cancer patients after curative resection.

Risk factors for pulmonary morbidities after minimally invasive esophagectomy for esophageal cancer.

BACKGROUND: Pulmonary morbidities after esophagectomy are still common and are a major cause of surgery-related mortality. The relationship between minimally invasive esophagectomy (MIE) and pulmonary morbidities is not clear. The current study aimed to examine the incidence of pulmonary morbidities after MIE and to clarify the associated risk factors. METHODS: Between May 2011 and December 2016, 184 patients underwent MIE for esophageal cancer. Clinical data were prospectively collected and analyzed. Patient- and surgery-related factors, relating to pulmonary complications, were compared between the complicated and uncomplicated cases. RESULTS: The incidence of any pulmonary morbidity following MIE was 17.9%. Univariate analysis showed that past heavy smoking [Brinkman index (BI) ≥ 1000], presence of neoadjuvant therapy, advanced clinical stage (stage III, IV), and intraoperative bleeding ≥ 600 g were candidates for being postoperative pulmonary morbidity risk factors. Multivariate analysis suggested that BI ≥ 1000 and advanced clinical stage were independent risk factors for causing pulmonary morbidities. CONCLUSIONS: Past heavy smoking and advanced stage are independent risk factors for pulmonary morbidities after MIE. When performing MIE for such cases, various preoperative precautions and careful postoperative monitoring are necessary.

Total iron-binding capacity is a novel prognostic marker after curative gastrectomy for gastric cancer.

BACKGROUND: Patients with gastric cancer (GC) are affected by changes in iron status. Before surgery, GC patients are likely to have iron-deficiency anemia; and after gastrectomy, patients suffer from low nutritional status and low iron. This study investigated preoperative iron status associated with prognosis after curative gastrectomy for gastric cancer. METHODS: We evaluated preoperative serum hemoglobin (Hgb), Fe and total iron-binding capacity (TIBC) in 298 patients who underwent curative gastrectomy for GC without preoperative chemotherapy, and analyzed these factors' associations with prognosis after surgery. RESULTS: Of the 298 patients, 129 (43.2%) had low Hgb levels, and 33 (11.1%) had low TIBC (< 260 µg/dl) that was not associated with Hgb or Fe level. Patients with low TIBC were significantly associated with older age (≥ 65 years old; P = 0.0085), low albumin (< 3.9 g/dl; P = 0.0388) and high CRP (≥ 0.15 mg/dl; P = 0.0018) in multivariate analysis. Low Fe (< 60 µg/dl) was not associated with disease-free survival (DFS) or overall survival (OS); however, low Fe was associated with longer cancer-specific survival in Stage III GC patients (P = 0.0333). Both low Hgb and low TIBC were significantly associated with shorter DFS (Hgb: P = 0.0433; TIBC: P < 0.0001) and shorter OS (Hgb: P = 0.0352; TIBC: P < 0.0001). Low TIBC were significantly associated with shorter DFS (HR 2.167, 95% CI 1.231-3.639, P = 0.0086) and shorter OS (HR 2.065, 95% CI 1.144-3.570, P = 0.0173) in multivariate Cox hazard regression analysis. CONCLUSIONS: Preoperative serum TIBC level of GC patients who undergo curative gastrectomy is a novel prognostic marker in univariate and multivariate analyses.

The association of the lymph node ratio and serum carbohydrate antigen 19-9 with early recurrence after curative gastrectomy for gastric cancer.

PURPOSE: This study investigated the predictors associated with early recurrence (i.e. within 12 months) after curative gastrectomy for gastric cancer (GC). METHODS: We evaluated the clinicopathological factors in 429 patients who underwent curative gastrectomy for GC without preoperative chemotherapy and analyzed these factors' associations with early recurrence. RESULTS: Of 429 patients, 57 experienced recurrences, which were associated with gender, diameter, depth of invasion, lymph node (LN) metastasis, the LN ratio (LNr; LNs with metastasis/dissected LNs), lymphatic invasion, vascular invasion, carbohydrate antigen 19-9 (CA19-9) levels, C-reactive protein levels and the neutrophil/lymphocyte ratio. Twenty-one patients (36.8%) recurred within 12 months. Early recurrence was associated with a high LNr (P = 0.0020) and high CA19-9 levels (P = 0.0415). The other factors were not significantly associated with early recurrence. The 12-month recurrence rate was 33.9% in patients with a high LNr and 1.9% in those with a low LNr and 20.3% in patients with high CA19-9 levels and 3.5% in those with low CA19-9 levels. The 12-month recurrence rate was 62.5% in patients with a high LNr and high CA19-9 levels, 18.4% in those with a high LNr or high-CA19-9 levels, and 1.4% in those with a low LNr and low CA19-9 levels. CONCLUSION: LNr ≥ 0.15 and CA19-9 ≥ 37 U/ml were effective surrogate markers for predicting early recurrence.

Tuberculous peritonitis after conservative treatment for acute perforated appendicitis: a case report.

BACKGROUND: Interval appendectomy is widely recommended for patients with abscesses due to perforated appendicitis. A concomitant malignancy-related problem was reported after conservative treatment of acute appendicitis with abscess, but perforated appendicitis-associated tuberculous peritonitis was never reported. CASE PRESENTATION: A 67-year-old male patient with a laryngeal cancer history presented to our hospital with an acute appendicitis-associated ileal abscess. He was scheduled for an interval appendectomy after conservative treatment. Fortunately, the symptoms subsided, and the patient was discharged for a later scheduled appendectomy. However, after 3 months, he was readmitted to our hospital with fever and abdominal pain, and emergency surgery was performed, which was suspected to be peritonitis. Intraoperative results revealed numerous white nodules in the abdominal cavity. The condition was diagnosed as tuberculous peritonitis based on macroscopic results, later pathological findings, and positive T-SPOT.TB. The antituberculosis medications were effective, and the patient recovered and was discharged from the hospital 8 days thereafter. CONCLUSION: Patients, particularly those immunocompromised, may develop tuberculous peritonitis after conservative treatment for acute perforated appendicitis.

Efficacy of Staging Laparoscopy for Pancreatic Cancer.

BACKGROUND/AIM: Preoperative evaluation of resectability of pancreatic cancer (PC) is difficult, so that staging laparoscopy (SL) has come to be used for detecting occult metastases. We aimed to evaluate the prognostic impact of SL in comparison with exploratory laparotomy (EL) in unresectable PC. PATIENTS AND METHODS: Between 2010 and 2016, 57 patients with PC underwent SL after conventional tumor staging. Patient characteristics, operative findings and survival rates were compared between SL and EL group. RESULTS: Twenty patients (35%) were identified as having unresectable factors in SL group. In contrast, laparotomy showed unresectable factors in 8 patients who did not receive preoperative SL (EL group). The time between the surgery to the induction of chemotherapy was significantly shorter in the SL group (mean=6 days, range=2-17) than in the EL group (mean=10 days, range=6-15). There was no significant difference in overall survival between the two groups; however, EL was associated with shorter survival in the early postoperative period. CONCLUSION: SL was associated with a shorter time interval to chemotherapy and lead to the prevention of unnecessary laparotomy.