Keisuke Hata

Patients with extraintestinal manifestations have a higher risk of developing pouchitis in ulcerative colitis: multivariate analysis

Background: Restorative proctocolectomy and ileal pouch‐anal anastomosis (IPAA) have been the surgical treatments of choice for ulcerative colitis (UC). However, the IPAA is sometimes complicated with pouchitis. Furthermore, the cumulative risk and risk factors for developing pouchitis in patients with UC undergoing IPAA have not been reported in any Asian population. The aim of our study is to clarify the cumulative risk and risk factors for developing pouchitis in Japanese patients with UC undergoing IPAA. Methods: Fifty‐eight patients with UC undergoing IPAA were retrospectively evaluated for the presence of pouchitis, gender, age of onset, history of smoking, presence of extraintestinal manifestations (EIMs) and type of operation. The diagnosis of pouchitis was based on the pouchitis disease activity index. The cumulative risk and risk factors for developing pouchitis were assessed. Results: The cumulative risks for developing pouchitis at 1 and 5 years were 9.0% and 14.4%, respectively. The estimated risks of pouchitis at 5 years was 48.1% in patients with EIMs and 4.6% in those without. Both univariate and multivariate analyses revealed that the presence of EIMs is a significant risk factor (hazard ratio 16.85, 95% confidence interval 3.12–91.00; P = 0.001). Conclusions: The presence of EIMs is a significant risk factor for the development of pouchitis in Japanese patients with UC undergoing IPAA.

Gene Expression Signature and the Prediction of Ulcerative Colitis–Associated Colorectal Cancer by DNA Microarray

Purpose: Ulcerative colitis (UC) is associated with a high risk of colorectal cancer. To identify genes that could predict the development of cancer in UC, we conducted a DNA microarray analysis using nonneoplastic rectal mucosa of UC patients. Experimental Design: Gene expression in nonneoplastic mucosa of 53 UC patients were examined. Gene expression profiles were examined using human Genome U133 Plus 2.0 gene chip array (Affymetrix). Among 53 UC patients, 10 had UC-associated cancer (UC-Ca group) whereas 43 did not (UC-NonCa group). Results: By comparing gene expression profiles of nonneoplastic rectal mucosae between the UC-Ca and UC-NonCa groups, we could identify 40 genes that were differentially expressed between two groups. The list of discriminating genes included low-density lipoprotein receptor–related protein (LRP5 and LRP6). Previous studies suggested that LRP5 and LRP6 expression promotes cancer cell proliferation and tumorigenesis and are considered as candidate oncogenes. In the present study, both LRP5 and LRP6 showed significantly higher expression in the UC-Ca group, which suggests the importance of these genes in the development of UC-associated colorectal cancers. With the 40 selected discriminating genes, we did class prediction of the development of colorectal neoplasms in UC patients. Using the k-nearest neighbor method and the support vector machine, we could predict the development of UC-associated neoplasms with an accuracy of 86.8% and 98.1%, respectively. Conclusions: These findings have important implications for the early detection of malignant lesions in UC and may provide directions for future research into the molecular mechanisms of UC-associated cancer.

Cytomegalovirus infection in ulcerative colitis

Objective. Cytomegalovirus (CMV) infection has been reported as an exacerbating factor in inflammatory bowel disease but the relationship between CMV infection and ulcerative colitis (UC) remains unclear. There has been no detailed research to elucidate the clinicopathologic features of CMV infection in UC using surgical specimens. The aim of this study was to investigate the clinicopathologic features of CMV infection in UC patients who had undergone colectomy. Material and methods. Surgical specimens taken from UC patients were examined for CMV infection. The patients were divided into three groups: severe, refractory, and UC-associated dysplasia or cancer according to the operative indications. CMV infection rates were evaluated and a comparison of clinical parameters was made between CMV-positive and CMV-negative patients, and the risk factors for CMV infection were analyzed using multivariate analyses. Results. It was found that 25% of 32 patients were positive for CMV in the severe UC group; 8.3% of 72 patients were positive for CMV in the refractory UC group. None of the 22 patients was positive for CMV in the UC-associated dysplasia or cancer group. The CMV-positive rate in the severe UC group was significantly higher than that in the other groups (p<0.05). Patients’ age at the time of operation was higher in the CMV-positive group than in the CMV-negative group among the patients with severe UC (p<0.01), and age at operation was an independent risk factor for CMV infection. Conclusions. CMV is found more frequently in severe UC than refractory UC and UC-associated cancer or dysplasia. Higher age can be a risk factor for CMV infection in patients with severe UC. However, a high steroid dose may not always be a risk factor for CMV infection.

Early appendiceal adenocarcinoma. A review of the literature with special reference to optimal surgical procedures

A rare case of early colonic adenocarcinoma of the appendix confined to the mucosa is reported. The patient remained well 5 years after simple appendectomy. We also review the Japanese literature on early colonic adenocarcinoma of the appendix. Twenty-seven cases of early colonic adenocarcinoma of the appendix, including ours, have been reported in Japan. In 20 of these patients, right hemicolectomy or ileocecal resection was performed. Eighteen patients were available for lymph node evaluation. Lymph nodes were negative for metastasis in 17 of the 18. Only one patient, with poorly differentiated adenocarcinoma invading the submucosa, had lymph node metastases. Our study shows that well-differentiated adenocarcinoma invading the submucosa, or adenocarcinoma of any differentiation confined to the mucosa, may be feasibly treated with simple appendectomy.

Detection of APC mosaicism by next-generation sequencing in an FAP patient

Familial adenomatous polyposis (FAP) of the colon is characterized by multiple polyps in the intestine and extra-colonic manifestations. Most FAP cases are caused by a germline mutation in the tumor-suppressor gene APC, but some cases of adenomatous polyposis result from germline mutations in MUTYH, POLD1 or POLE. Although sequence analysis of APC by the Sanger method is routinely performed for genetic testing, there remain cases whose mutations are not detected by the analysis. Next-generation sequencing has enabled us to analyze the comprehensive human genome, improving the chance of identifying disease causative variants. In this study, we conducted whole-genome sequencing of a sporadic FAP patient in which we did not find any pathogenic APC mutations by the conventional Sanger sequencing. Whole-genome sequencing and subsequent deep sequencing identified a mosaic mutation of c.3175G>T, p.E1059X in ~12% of his peripheral leukocytes. Additional deep sequencing of his buccal mucosa, hair follicles, non-cancerous mucosa of the stomach and colon disclosed that these tissues harbored the APC mutation at different frequencies. Our data implied that genetic analysis by next-generation sequencing is an effective strategy to identify genetic mosaicism in hereditary diseases.

Laparoscopic surgery for ulcerative colitis: a review of the literature

Despite the development of new therapies, including anti-TNF alpha antibodies and immunosuppressants, a substantial proportion of patients with ulcerative colitis (UC) still require surgery. Restorative proctocolectomy with ileal-pouch anal anastomosis is the standard surgical treatment of choice for UC. With the advent of laparoscopic techniques for colorectal surgery, ileal-pouch anal anastomosis has also been performed laparoscopically. This paper reviews the history and current trends in laparoscopic surgery for UC. The accumulation of experience and improvement of laparoscopic devices have shifted the paradigm of UC surgery towards laparoscopic surgery over the past decade. Although laparoscopic surgery requires a longer operation, it provides significantly better short and long-term outcomes. The short-term benefits of laparoscopic surgery over open surgery include shorter hospital stays and fasting times, as well as better cosmesis. The long-term benefits of laparoscopy include better fecundity in young females. Some surgeons favor laparoscopic surgery even for severe acute colitis. More efforts are being made to develop newer laparoscopic methods, such as reduced port surgery, including single incision laparoscopic surgery and robotic surgery.

Level of arterial ligation in sigmoid colon and rectal cancer surgery.

BackgroundCurative resection of sigmoid colon and rectal cancer includes “high tie” of the inferior mesenteric artery (IMA). However, IMA ligation compromises blood flow to the anastomosis, which may increase the leakage rate, and it is unclear whether this confers a survival advantage. Accordingly, the IMA may be ligated at a point just below the origin of the left colic artery (LCA) “low tie” combined with lymph node dissection (LND) around the origin of the IMA (low tie with LND). However, no study has investigated the detailed prognostic results between “high tie” and “low tie with LND.” The aim of this study was to assess the utility of “low tie with LND” on survival in patients with sigmoid colon or rectal cancer.MethodsA total of 189 sigmoid colon or rectal cancer patients who underwent curative operation from 1997 to 2007 were enrolled in this study. The patient’s medical records were reviewed to obtain clinicopathological information. Overall survival (OS) and relapse-free survival (RFS) rates were calculated using the Kaplan-Meier method, with differences assessed using log-rank test.ResultsForty-two and 147 patients were ligated at the origin of the IMA (high tie) and just below the origin of the LCA combined with LND around the origin of the IMA (low tie with LND), respectively. No significant differences were observed in the complication rate and OS and RFS rates in the two groups. Further, no significant difference was observed in the OS and RFS rates in the lymph node-positive cases in the two groups.Conclusions“Low tie with LND” is anatomically less invasive and is not inferior to “high tie” with prognostic point of view.

Prognostic impact of tumor location in stage IV colon cancer: A propensity score analysis in a multicenter study

BACKGROUND Right-sided colon cancer is considered to be biologically different from left-sided colon cancer; however, conflicting results have been reported regarding differences in prognosis. We aimed to clarify the prognostic impact of tumor location in stage IV colon cancer. METHODS Stage IV colon cancer treated from January 1997 to December 2007 (n = 2208) were retrospectively studied. Clinical and pathological features were compared between right-sided colon cancer (cecum, ascending, and transverse colon) and left-sided colon cancer (descending, sigmoid, and rectosigmoid colon). The impact of tumor location on cancer-specific survival (CSS) was analyzed in a multivariate analysis and propensity score analysis to mitigate the differences in background features. RESULTS Right-sided colon cancer was associated with older age, female sex, larger tumor size, poorly differentiated adenocarcinoma, mucinous adenocarcinoma, and signet-ring cell carcinoma, a more advanced state within stage IV disease, and a worse CSS. In the cohort matched by propensity scores for background clinicopathological features, tumor location in the right-sided colon was associated with a significantly worse CSS (hazard ratio 1.2, 95% confidence interval 1.1-1.4, p = 0.008) in patients treated with palliative primary tumor resection, but not in those treated with R0 resection or no resection. CONCLUSION Right-sided colon cancer were diagnosed at a more advanced state within stage IV disease and showed a significantly worse prognosis than left-sided colon cancer, suggesting that stage IV right-sided colon cancer is oncologically more aggressive than left-sided colon cancer.

LINE-1 hypomethylation status of circulating cell-free DNA in plasma as a biomarker for colorectal cancer

Colorectal cancer (CRC) is a serious public health problem and non-invasive biomarkers improving diagnosis or therapy are strongly required. Circulating cell-free DNA (cfDNA) has been a promising target for this purpose. In this study, we evaluated the potential of long interspersed nuclear element-1 (LINE-1) hypomethylation as a blood biomarker for CRC. LINE-1 hypomethylation level in plasma cfDNA in 114 CRC patients was retrospectively examined by absolute quantitative analysis of methylated alleles real-time PCR, and was expressed using LINE-1 hypomethylation index (LHI) [unmethylated copy number/ (methylated copy number + unmethylated copy number)]. Greater LHI values indicated enhanced hypomethylation. In our clinicopathological analysis, CRC patients with large tumors (≥6.0 cm), advanced N stage (≥2), and distant metastasis (M1) had statistically significantly higher cfDNA LHI than other CRC patients, suggesting cfDNA LHI as a disease progression biomarker for CRC. Furthermore, early stage I/II (n = 57) as well as advanced stage III/IV (n =57) CRC patients had significantly higher cfDNA LHI than healthy donors (n=53) [stage I/II: median 0.369 (95% confidence interval, 0.360–0.380) vs. 0.332 (0.325–0.339), P < 0.0001; stage III/IV: 0.372 (0.365–0.388) vs. 0.332 (0.325–0.339), P < 0.0001]. The receiver operating characteristic analysis showed that cfDNA LHI had the detection capacity of CRC with area under the curve(AUC) of 0.79 and 0.83 in stage I/II and stage III/IV CRC patients, respectively. The present study demonstrated for the first time the potential of plasma cfDNA LHI as a novel biomarker for CRC, particularly for early stage detection.

Oncological Outcomes of Lateral Pelvic Lymph Node Metastasis in Rectal Cancer Treated With Preoperative Chemoradiotherapy

BACKGROUND: Oncological outcomes of lateral pelvic lymph node metastasis in rectal cancer treated with preoperative chemoradiotherapy remain to be elucidated. OBJECTIVE: The purpose of this study was to clarify the therapeutic effect of chemoradiotherapy on lateral pelvic lymph node metastasis, the risk factors of lateral pelvic lymph node metastasis, and oncological outcomes of lateral pelvic lymph node dissection after chemoradiotherapy. DESIGN: This was a nonrandomized, retrospective study. SETTINGS: The study was conducted at a tertiary referral university hospital. PATIENTS: Patients with rectal cancer treated with chemoradiotherapy and radical surgery from 2003 to 2015 (N = 222) were included. INTERVENTIONS: Radiation (total, 50.4 Gy in 28 fractions) with concomitant fluorouracil-based chemotherapy was administered. Lateral pelvic lymph nodes with a diameter of ≥8 mm before chemoradiotherapy were selectively dissected. MAIN OUTCOME MEASURES: Frequency and risk factors of lateral pelvic lymph node metastasis were examined. RESULTS: Lateral pelvic lymph node dissection was performed in 31 patients (14.0%), and 16 (51.6%) of these patients were pathologically diagnosed as positive for metastasis. Among the patients treated with total mesorectal excision alone (n = 191), 2 (0.9%) had recurrence in the lateral pelvic lymph node area, which was pathologically confirmed after salvage R0 resection. T category downstaging (73.3% vs 12.5%; p < 0.01) and high histological regression of the primary lesion (73.3% vs 18.8%; p < 0.01) were more frequent in patients with pathologically negative lateral pelvic lymph nodes than in those with positive lateral pelvic lymph nodes. Young age, short distance from the anal verge, and enlarged lateral pelvic lymph node before chemoradiotherapy were associated with lateral pelvic lymph node metastasis. LIMITATIONS: The study was limited by its retrospective nature and small study population. CONCLUSIONS: The incidence of lateral pelvic lymph node metastasis after chemoradiotherapy was estimated to be 8.1% (18/222). Young age, short distance from the anal verge, and enlarged lateral pelvic lymph node before chemoradiotherapy were risk factors of lateral pelvic lymph node metastasis after chemoradiotherapy.