Endoscopic Removal of Premalignant Lesions Reduces Long-Term Colorectal Cancer Risk: Results From the Japan Polyp Study

BACKGROUND & AIMS

To date, no regional evidence of long-term colorectal cancer (CRC) risk reduction after endoscopic premalignant lesion removal has been established. We aimed to analyze this over a long-term follow-up evaluation.

METHODS

This was a prospective cohort study of participants from the Japan Polyp Study conducted at 11 Japanese institutions. Participants underwent scheduled follow-up colonoscopies after a 2-round baseline colonoscopy process. The primary outcome was CRC incidence after randomization. The observed/expected ratio of CRC was calculated using data from the population-based Osaka Cancer Registry. Secondary outcomes were the incidence and characteristics of advanced neoplasia (AN).

RESULTS

A total of 1895 participants were analyzed. The mean number of follow-up colonoscopies and the median follow-up period were 2.8 years (range, 1-15 y) and 6.1 years (range, 0.8-11.9 y; 11,559.5 person-years), respectively. Overall, 4 patients (all males) developed CRCs during the study period. The observed/expected ratios for CRC in all participants, males, and females, were as follows: 0.14 (86% reduction), 0.18, and 0, respectively, and 77 ANs were detected in 71 patients (6.1 per 1000 person-years). Of the 77 ANs detected, 31 lesions (40.3%) were laterally spreading tumors, nongranular type. Nonpolypoid colorectal neoplasms (NP-CRNs), including flat (<10 mm), depressed, and laterally spreading, accounted for 59.7% of all detected ANs. Furthermore, 2 of the 4 CRCs corresponded to T1 NP-CRNs.

CONCLUSIONS

Endoscopic removal of premalignant lesions, including NP-CRNs, effectively reduced CRC risk. More than half of metachronous ANs removed by surveillance colonoscopy were NP-CRNs. The Japan Polyp Study: University Hospital Medical Information Network Clinical Trial Registry: University Hospital Medical Information Network Clinical Trial Registry, C000000058; cohort study: UMIN000040731.

miR-144-3p/miR-451a promotes lymphovascular invasion through repression of PTEN/p19 in rectal neuroendocrine tumors

BACKGROUND AND AIM

Although rectal neuroendocrine tumor (NET-G1) have potential metastatic capability, even among small tumors, no predictive biomarker for invasion and metastasis has been reported. We analyzed microRNA (miRNA) expression profiles in rectal NET-G1 tissues with and without lymphovascular invasion (LVI). Moreover, we then investigated their target genes to clarify the mechanism of invasion/metastasis in NET-G1.

METHODS

miRNA array analysis was performed using seven rectal NET-G1 tissues with LVI and seven without LVI. miRNA expression was confirmed by quantitative real-time PCR. A NET cell line H727 was transfected with miRNA mimic or target gene small interfering RNA, and migration and invasion assays were performed.

RESULTS

The expression levels of miR-144-3p and miR-451a were significantly higher in NET-G1 with LVI versus without LVI, as determined by miRNA array analysis and RT-qPCR. A significant correlation was observed between miR-144-3p and miR-451a expression levels, strongly suggesting miR144/451 cluster overexpression in NET-G1 with LVI. Bioinformatic analysis of target genes revealed that miR-144-3p and miR-451a directly interact with PTEN and p19 mRNA, respectively. Immunohistochemistry revealed significantly lower expression of PTEN and p19 in NET-G1 tissues with LVI than in those without LVI. The miR-144-3p and miR-451a mimic significantly increased cell migration/invasion capability, respectively. Knockdown of PTEN and p19 induced significant augmentation of cell invasion and migration capability, respectively.

CONCLUSIONS

Our data suggest that overexpression of miR-144/miR-451 cluster promotes LVI via repression of PTEN and p19 in rectal NET-G1 cells. miR-144/451 cluster may be a novel biomarker for predicting invasion/metastasis in rectal NET-G1.

S100P Expression via DNA Hypomethylation Promotes Cell Growth in the Sessile Serrated Adenoma/Polyp-Cancer Sequence

BACKGROUND/AIMS

Sessile serrated adenomas/polyps (SSA/Ps) are a putative precursor lesion of colon cancer. Although the relevance of DNA hypermethylation in the SSA/P-cancer sequence is well documented, the role of DNA hypomethylation is unknown. We investigated the biological relevance of DNA hypomethylation in the SSA/P-cancer sequence by using 3-dimensional organoids of SSA/P.

METHODS

We first analyzed hypomethylated genes using datasets from our previous DNA methylation array analysis on 7 SSA/P and 2 cancer in SSA/P specimens. Expression levels of hypomethylated genes in SSA/P specimens were determined by RT-PCR and immunohistochemistry. We established 3-dimensional SSA/P organoids and performed knockdown experiments using a lentiviral shRNA vector. DNA hypomethylation at CpG sites of the gene was quantitated by MassARRAY analysis.

RESULTS

The mean number of hypomethylated genes in SSA/P and cancer in SSA/P was 41.6 ± 27.5 and 214 ± 19.8, respectively, showing a stepwise increment in hypomethylation during the SSA/P-cancer sequence. S100P, S100α2, PKP3, and MUC2 were most commonly hypomethylated in SSA/P specimens. The mRNA and protein expression levels of S100P, S100α2, and MUC2 were significantly elevated in SSA/P compared with normal colon tissues, as revealed by RT-PCR and immunohistochemistry, respectively. Among these, mRNA and protein levels were highest for S100P. Knockdown of the S100P gene using a lentiviral shRNA vector in 3-dimensional SSA/P organoids inhibited cell growth by >50% (p < 0.01). The mean diameter of SSA/P organoids with S100P gene knockdown was significantly smaller compared with control organoids. MassARRAY analysis of DNA hypomethylation in the S100P gene revealed significant hypomethylation at specific CpG sites in intron 1, exon 1, and the 5'-flanking promoter region.

CONCLUSION

These results suggest that DNA hypomethylation, including S100P hypomethylation, is supposedly associated with the SSA/P-cancer sequence. S100P overexpression via DNA hypomethylation plays an important role in promoting cell growth in the SSA/P-cancer sequence.

Randomised comparison of postpolypectomy surveillance intervals following a two-round baseline colonoscopy: the Japan Polyp Study Workgroup

OBJECTIVE

To assess whether follow-up colonoscopy after polypectomy at 3 years only, or at 1 and 3 years would effectively detect advanced neoplasia (AN), including nonpolypoid colorectal neoplasms (NP-CRNs).

DESIGN

A prospective multicentre randomised controlled trial was conducted in 11 Japanese institutions. The enrolled participants underwent a two-round baseline colonoscopy (interval: 1 year) to remove all neoplastic lesions. Subsequently, they were randomly assigned to undergo follow-up colonoscopy at 1 and 3 years (2-examination group) or at 3 years only (1-examination group). The incidence of AN, defined as lesions with low-grade dysplasia ≥10 mm, high-grade dysplasia or invasive cancer, at follow-up colonoscopy was evaluated.

RESULTS

A total of 3926 patients were enrolled in this study. The mean age was 57.3 (range: 40-69) years, and 2440 (62%) were male. Of these, 2166 patients were assigned to two groups (2-examination: 1087, 1-examination: 1079). Overall, we detected 29 AN in 28 patients at follow-up colonoscopy in both groups. On per-protocol analysis (701 in 2-examination vs 763 in 1-examination group), the incidence of AN was similar between the two groups (1.7% vs 2.1%, p=0.599). The results of the non-inferiority test were significant (p=0.017 in per-protocol, p=0.001 in intention-to-treat analysis). NP-CRNs composed of dominantly of the detected AN (62%, 18/29), and most of them were classified into laterally spreading tumour non-granular type (83%, 15/18).

CONCLUSION

After a two-round baseline colonoscopy, follow-up colonoscopy at 3 years detected AN, including NP-CRNs, as effectively as follow-up colonoscopies performed after 1 and 3 years.

Clinical and endoscopic evaluations of sessile serrated adenoma/polyps with cytological dysplasia

BACKGROUND AND AIM

Although sessile serrated adenoma/polyps (SSA/Ps) are considered to be premalignant lesions and rapidly progress to carcinomas after they develop cytological dysplasia (CD), a treatment strategy for SSA/Ps in Asian countries is still being debated and has not yet been established. The present study aimed to propose a treatment strategy for SSA/Ps.

METHODS

Histopathological data of patients, who underwent colonoscopy at our center between January 2011 and December 2016, were reviewed. Data of patients with ≥ 1 SSA/P were retrieved, and clinicopathological characteristics were retrospectively analyzed.

RESULTS

A total of 281 patients with 326 SSA/Ps, including 258 patients who had 300 SSA/Ps without CD (SSA/Ps-CD[-]) and 23 patients who had 26 SSA/Ps with CD (SSA/Ps-CD[+]), were evaluated in this study. Although SSA/Ps-CD(+) were often found in older female patients and in the proximal colon, there were no significant differences between SSA/Ps-CD(-) and SSA/Ps-CD(+). Endoscopic morphological findings, such as large or small nodules on the surface and partial protrusion of the lesions, were significantly more common in SSA/Ps-CD(+) than in SSA/Ps-CD(-). Although the diagnostic ability of nodule/protrusion in lesions to predict CD within SSA/Ps was very high with an accuracy of 93.9% and a negative predictive value of 95.4%, sensitivity was low at 46.2%. SSA/Ps-CD(+) were significantly larger than SSA/Ps-CD(-), and the rate of CD within SSA/Ps significantly increased with lesion size (≤ 5 mm, 0%; 6-9 mm, 6.0%; ≥ 10 mm, 13.6%).

CONCLUSION

The study proposes removing all SSA/Ps ≥ 6 mm in order to remove high-risk SSA/Ps-CD(+), with high sensitivity.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (Translated Version)

Hereditary colorectal cancer accounts for less than 5% of all colorectal cancer cases. Some of the unique characteristics that are commonly encountered in cases of hereditary colorectal cancer include early age at onset, synchronous/metachronous occurrence of the cancer, and association with multiple cancers in other organs, necessitating different management from sporadic colorectal cancer. While the diagnosis of familial adenomatous polyposis might be easy because usually 100 or more adenomas that develop in the colonic mucosa are in this condition, Lynch syndrome, which is the most commonly associated disease with hereditary colorectal cancer, is often missed in daily medical practice because of its relatively poorly defined clinical characteristics. In addition, the disease concept and diagnostic criteria for Lynch syndrome, which was once called hereditary non-polyposis colorectal cancer, have changed over time with continual research, thereby possibly creating confusion in clinical practice. Under these circumstances, the JSCCR Guideline Committee has developed the "JSCCR Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (HCRC)," to allow delivery of appropriate medical care in daily practice to patients with familial adenomatous polyposis, Lynch syndrome, or other related diseases. The JSCCR Guidelines 2016 for HCRC were prepared by consensus reached among members of the JSCCR Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR Guidelines 2016 for HCRC.

Prospective real-time evaluation of diagnostic performance using endocytoscopy in differentiating neoplasia from non-neoplasia for colorectal diminutive polyps (≤ 5 mm)

AIM

To clarify the diagnostic performance of endocytoscopy for differentiation between neoplastic and non-neoplastic colorectal diminutive polyps.

METHODS

Patients who underwent endocytoscopy between October and December 2016 at Sano Hospital were prospectively recruited. When diminutive polyps (≤ 5 mm) were detected, the lesions were evaluated by endocytoscopy after being stained with 0.05% crystal violet and 1% methylene blue. The diminutive polyps were classified into five categories (EC 1a, 1b, 2, 3a, and 3b). Endoscopists were asked to take a biopsy from any lesion diagnosed as EC1b (indicator of hyperplastic polyp) or EC2 (indicator of adenoma). We have assessed the diagnostic performance of endocytoscopy for EC2 and EC1b lesions by comparison with the histopathology of the biopsy specimen.

RESULTS

A total of 39 patients with 63 diminutive polyps were analyzed. All polyps were evaluated by endocytoscopy. The mean polyp size was 3.3 ± 0.9 mm. Among the 63 diminutive polyps, 60 were flat and 3 were pedunculated. The mean time required for EC observation, including the time for staining with crystal violet and methylene blue, was 3.0 ± 1.9 min. Histopathologic evaluation showed that 13 polyps were hyperplastic and 50 were adenomas. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of EC2 for adenoma compared with EC1b for hyperplastic polyp were 98.0%, 92.3%, 96.8%, 98.0% and 92.3%, respectively. There were only two cases of disagreement between the endoscopic diagnosis made by endocytoscopy and the corresponding histopathological diagnosis.

CONCLUSION

Endocytoscopy showed a high diagnostic performance for differentiating between neoplastic and non-neoplastic colorectal diminutive polyps, and therefore has the potential to be used for “real-time histopathology”.

Additional chromoendoscopy for colorectal lesions initially diagnosed with low confidence by magnifying narrow-band imaging: Can it improve diagnostic accuracy?

BACKGROUND AND AIM

Magnifying chromoendoscopy has been one of the most reliable diagnostic methods for distinguishing neoplastic from non-neoplastic lesions. The aim of this prospective study was to clarify the clinical usefulness of magnifying chromoendoscopy for colorectal polyps initially diagnosed with low confidence (LC) by magnifying narrow-band imaging (NBI).

METHODS

Consecutive adult patients who underwent total colonoscopic examination with magnifying NBI between July and December 2016 at Sano Hospital were prospectively recruited. Endoscopists were asked to carry out additional magnifying chromoendoscopy for cases that had been initially diagnosed as Japan NBI Expert Team (JNET) Type 1 or 2A with LC by magnifying NBI. We investigated the diagnostic performance of magnifying NBI for polyps diagnosed as JNET Type 1 or 2A with LC (first phase) and that of subsequent magnifying chromoendoscopy (second phase) in differentiating neoplasia from non-neoplasia.

RESULTS

In 50 patients, we analyzed 53 polyps classified as JNET Type 1 or 2A with LC prediction. Accuracy and negative predictive value of magnifying NBI (first phase) were 58.5% (95% CI, 44.1-71.9%) and 66.0% (95% CI, 36.6-77.9%), and those of magnifying chromoendoscopy (second phase) were 66.0% (95% CI, 51.7-78.5%) and 61.1% (95% CI, 43.5-76.9%), respectively.

CONCLUSION

Regardless of the findings of additional chromoendoscopy, all polyps should be resected and submitted for histopathological examination when the confidence level in differentiating adenomatous from hyperplastic polyps by magnifying NBI is low.

Analysis of gastrointestinal virus infection in immunocompromised hosts by multiplex virus PCR assay

Regarding viral infection of intestinal mucosa, there have been only a few studies on limited diseases, targeting a few herpes family viruses. In this study, we analyzed 12 kinds of DNA viruses including 8 species of herpes family viruses in the gastrointestinal mucosa of patients with hematologic malignancies, inflammatory bowel diseases, collagen diseases, or other miscellaneous forms of gastroenteritis using the multiplex virus PCR assay, which we recently developed. The virus PCR assay yielded positive results in 63 of 102 patients; Epstein-Barr virus (EBV) was the most frequently detected, followed by cytomegalovirus (CMV), human herpes virus 6 (HHV-6), HHV-7, parvovirus B19, and herpes simplex virus type 1. The frequencies of viral detection in the 4 diseases were similar involving these 6 viruses. Regarding CMV colitis, the multiplex virus PCR assay was superior to the immunohistopathologic method in detecting CMV. All viruses were more efficiently detected in the mucosa than in the blood in individual patients. These results suggest that CMV, EBV, and HHV-6 were commonly detected in the gastrointestinal mucosa of patients with these 4 diseases, and our multiplex virus PCR assay was useful for the early diagnosis of gastrointestinal virus infection, especially CMV colitis.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2016 for the treatment of colorectal cancer

Japanese mortality due to colorectal cancer is on the rise, surpassing 49,000 in 2015. Many new treatment methods have been developed during recent decades. The Japanese Society for Cancer of the Colon and Rectum Guidelines 2016 for the treatment of colorectal cancer (JSCCR Guidelines 2016) were prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment, and to deepen mutual understanding between health-care professionals and patients by making these Guidelines available to the general public. These Guidelines were prepared by consensus reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches, and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these Guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. As a result of the discussions held by the Guideline Committee, controversial issues were selected as Clinical Questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here we present the English version of the JSCCR Guidelines 2016.

The Improvement of the Hepatic Histological Findings in a Patient with Non-alcoholic Steatohepatitis with Type 2 Diabetes after the Administration of the Sodium-glucose Cotransporter 2 Inhibitor Ipragliflozin

The patient was a 67-year-old woman with type 2 diabetes and non-alcoholic steatohepatitis (NASH). The administration of the sodium-glucose cotransporter 2 (SGLT2) inhibitor, ipragliflozin improved her liver dysfunction clinically and histologically. The serum alanine aminotransferase (ALT) and ferritin levels decreased to normal limits after treatment for four months. Type IV collagen and hyaluronic acid, both of which were serum fibrotic markers, decreased after treatment. Ultrasonography and computed tomography showed a decrease in the fat deposits in her liver. Her liver sample showed marked improvement, especially in steatosis, inflammation, and ballooning. The SGLT2 inhibitor ipragliflozin may be useful as a specific therapeutic drug for NASH.

Intramucosal colorectal carcinoma with invasion of the lamina propria: a study by the Japanese Society for Cancer of the Colon and Rectum

Cancer invasion of the lamina propria is an important pathological finding. However, the clinicopathologic features and diagnostic accuracy of intramucosal carcinoma assessment in colorectal carcinoma (CRC) are unknown. In this study, intramucosal CRCs were reviewed in institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum, and 32 cases with invasion of the lamina propria were identified. Next, a consensus meeting was held to select cases with a high consensus about the presence of invasion, which were reviewed by one Western pathologist for confirmation. In addition to clinicopathologic evaluation, concordance was assessed for diagnosis and histologic findings. During the consensus meeting, 3 cases were found to show ambiguous features such that it was unclear whether there was intramucosal or submucosal invasion, and 7 cases were judged to have invasion of the lamina propria by more than 75% of the pathologists. A poorly differentiated adenocarcinoma and a signet ring cell carcinoma were diagnosed unanimously. Concordance in diagnosis and detection of characteristics of invasion of the lamina propria proved to be only poor to fair. Single or small clusters of cells and atypical or complex glandular arrangements that are beyond normal mucosal architecture were detected more frequently in the 7 high-consensus tumors. Desmoplasia and marked inflammation were detected more often in cases characterized as ambiguous. Intramucosal CRCs with invasion of the lamina propria constituted 5.1% of the surgically resected high-grade intramucosal epithelial dysplastic/neoplastic lesions, and stromal infiltration of single or small clusters of cells is the best objective criterion of invasion.

The microfluidic lighthouse: an omnidirectional gradient generator

Studies of chemotactic cell migration rely heavily on various assay systems designed to evaluate the ability of cells to move in response to attractant molecules. In particular, the development of microfluidics-based devices in recent years has made it possible to spatially distribute attractant molecules in graded profiles that are sufficiently stable and precise to test theoretical predictions regarding the accuracy and efficiency of chemotaxis and the underlying mechanism of stimulus perception. However, because the gradient is fixed in a direction orthogonal to the laminar flow and thus the chamber geometry, conventional devices are limited for the study of cell re-orientation to gradients that move or change directions. Here, we describe the development of a simple radially symmetric microfluidics device that can deliver laminar flow in 360°. A stimulant introduced either from the central inlet or by photo uncaging is focused into the laminar flow in a direction determined by the relative rate of regulated flow from multiple side channels. Schemes for flow regulation and an extended duplexed device were designed to generate and move gradients in desired orientations and speed, and then tested to steer cell migration of Dictyostelium and neutrophil-like HL60 cells. The device provided a high degree of freedom in the positioning and orientation of attractant gradients, and thus may serve as a versatile platform for studying cell migration, re-orientation, and steering.

Prospective evaluation of the proportion of sessile serrated adenoma/polyps in endoscopically diagnosed colorectal polyps with hyperplastic features

BACKGROUND AND STUDY AIMS

Sessile serrated adenoma/polyps (SSA/Ps) are considered precursors of colorectal cancers with microsatellite instability. However, it is still difficult to differentiate SSA/Ps from hyperplastic polyps endoscopically; therefore, the prevalence of SSA/Ps remains uncertain in clinical practice. This study aimed to clarify the proportion of SSA/Ps in endoscopically diagnosed colorectal polyps with hyperplastic features (E-HPs).

PATIENTS AND METHODS

Patients aged ≥ 40 years undergoing colonoscopy for standard clinical indications at our center were prospectively enrolled between June 2013 and May 2014. During colonoscopy, 0.05 % indigo carmine dye was sprayed throughout the colorectum to highlight lesions. All detected lesions were diagnosed by high definition magnifying narrow-band imaging and were resected endoscopically or surgically, apart from rectosigmoid E-HPs ≤ 5 mm. The number of rectosigmoid E-HPs ≤ 5 mm was recorded, and some were resected for use as tissue samples.

RESULTS

A total of 343 patients (male: 42.9 %; mean age: 61.5 years) were included. Among 3838 E-HPs (distal: 96.4 %) detected in 294 patients, 792 were resected and analyzed. All of 21 SSA/Ps identified in 17 patients were included in E-HPs, and the overall proportion of SSA/Ps in E-HPs was 2.7 %. However, this proportion increased with the size of E-HPs (≤ 5 mm: 0.7 %; 6 - 9 mm: 29.0 %; ≥ 10 mm: 70 %) and was higher in the proximal colon than in the distal colorectum (10.9 % vs. 0.9 %). In addition, no SSA/P was found in the rectum, and no SSA/P had cytological dysplasia.

CONCLUSIONS

The overall proportion of SSA/Ps in E-HPs was 2.7 %, although this proportion was higher in the proximal colon and increased with the size of E-HPs. SSA/Ps were common in routine colonoscopy, with a prevalence of at least 5.0 %.

STUDY REGISTRATION

UMIN000010832.

The addition of high magnifying endoscopy improves rates of high confidence optical diagnosis of colorectal polyps

BACKGROUND AND STUDY AIMS

The real-time optical diagnosis of colorectal polyps with high confidence predictions can achieve high levels of accuracy. Increasing the rates of high confidence optical diagnosis can improve the clinical application of real-time optical diagnosis in routine practice. The primary aim of this prospective study was to evaluate whether high magnifying endoscopy improves the rates of high confidence narrow-band imaging (NBI) - based optical diagnosis for differentiating between neoplastic and non-neoplastic colorectal lesions according to the NBI international colorectal endoscopic (NICE) classification.

PATIENTS AND METHODS

Consecutive adult patients undergoing colonoscopy with a high magnifying (maximum, × 80) colonoscope between April and August 2012 were recruited. The optical diagnosis for each polyp was evaluated during colonoscopy in two consecutive stages by the same endoscopist, who first used NBI with non-magnifying endoscopy (NBI-NME), then NBI with magnifying endoscopy (NBI-ME). A level of confidence was assigned to each prediction.

RESULTS

The analysis included 124 patients (mean age, 56.4 years; male-to-female ratio, 72:52) with 248 polyps smaller than 10 mm. Of the 248 polyps, 210 were 1 to 5 mm in size and 38 were 6 to 9 mm in size; 77 polyps were hyperplastic, 4 were sessile serrated adenomas/polyps, 160 were low grade adenomas, 5 were high grade adenomas, and 2 were deep submucosal invasive carcinomas. The rate of high confidence optical diagnosis when NBI-ME was used was significantly higher than the rate when NBI-NME was used for diminutive (1 - 5 mm) polyps (92.9 % vs 79.5 %, P < 0.001) and for small (6 - 9 mm) polyps (94.7 % vs 84.2 %, P = 0.048).

CONCLUSION

High magnifying endoscopy significantly improved the rates of high confidence NBI-based optical diagnosis of diminutive and small colorectal polyps.

STUDY REGISTRATION

UMIN 000007608.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2014 for treatment of colorectal cancer

Colorectal cancer is a major cause of death in Japan, where it accounts for the largest number of deaths from malignant neoplasms among women and the third largest number among men. Many new methods of treatment have been developed during recent decades. The Japanese Society for Cancer of the Colon and Rectum Guidelines 2014 for treatment of colorectal cancer (JSCCR Guidelines 2014) have been prepared as standard treatment strategies for colorectal cancer, to eliminate treatment disparities among institutions, to eliminate unnecessary treatment and insufficient treatment, and to deepen mutual understanding among health-care professionals and patients by making these guidelines available to the general public. These guidelines have been prepared as a result of consensuses reached by the JSCCR Guideline Committee on the basis of careful review of evidence retrieved by literature searches and taking into consideration the medical health insurance system and actual clinical practice in Japan. They can, therefore, be used as a guide for treating colorectal cancer in clinical practice. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. As a result of the discussions of the Guideline Committee, controversial issues were selected as clinical questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories, on the basis of consensus reached by Guideline Committee members. Here we present the English version of the JSCCR Guidelines 2014.

Effect of REG Iα protein on angiogenesis in gastric cancer tissues

Regenerating gene (REG) Iα is not only overexpressed in a subset of gastric cancers, but also involved in tumor progression. However, the mechanism by which (REG) Iα promotes tumor growth is not fully understood. In the present study, we investigated whether REG Iα plays a role in angiogenesis during the progression of gastric cancers. Expression of REG Iα and its receptor (EXTL3; exostoses like-3) was examined using immunohistochemistry in specimens of human gastric cancer. Microvessel density (MVD) in gastric cancer tissues was evaluated using an image analysis system after CD34 immunostaining. Relationships among clinicopathological features, REG Iα expression and MVD in gastric cancer tissues were analyzed. Effects of REG Iα protein on HUVEC cells in terms of proliferation and anti-apoptosis were assessed by WST-1 assay and FACS, respectively. Furthermore, the intracellular signaling by which REG Iα exerts its biological roles was examined in vitro. REG Iα expression was significantly related to lymph node metastasis and its receptor EXTL3 was ubiquitously expressed in not only the tumor cells, but also the tumor vessel cells in the gastric cancer tissues. MVD was significantly higher in gastric cancers that were REG Iα-positive than in those that were negative. Treatment with REG Iα protein promoted growth and anti-apoptosis through activation of the ERK and Akt signaling pathways in HUVEC cells, whereas these effects were attenuated by treatment with anti-REG Iα -antibody. REG Iα protein may play a role in angiogenesis during progression of gastric cancer.

Primary non-gestational pure choriocarcinoma arising in the ovary: A case report and literature review

Pure non-gestational choriocarcinoma is a primary germ cell neoplasm that has been defined as a tumor without other germ cell elements. The current study presents an extremely rare case of non-gestational pure choriocarcinoma in a postmenarcheal young female and describes details of the tumor, including the clinicopathological findings. The patient was a 10-year-old female who underwent salpingo-oophorectomy. Histologically, the extensive hemorrhagic tumor was composed of choriocarcinoma without additional germ cell tumor components. The tumor cells were immunohistochemically positive for epithelial markers, including cytokeratins and epithelial membrane antigens, and there was a positive cytoplasmic reaction for β-human chorionic gonadotropin in the syncytiotrophoblasts. Furthermore, numerous tumor cells were immunohistochemically positive for the β2-microglobulin antibody. The patient received adjuvant cisplatin, etoposide and bleomycin chemotherapy, and is currently disease-free without evidence of recurrence or metastasis subsequent to 62 months of follow-up.

The Axl receptor tyrosine kinase is a discriminator of macrophage function in the inflamed lung

Much of the biology surrounding macrophage functional specificity has arisen through examining inflammation-induced polarizing signals, but this also occurs in homeostasis, requiring tissue-specific environmental triggers that influence macrophage phenotype and function. The TAM receptor family of receptor tyrosine kinases (Tyro3, Axl and MerTK) mediates the non-inflammatory removal of apoptotic cells by phagocytes through the bridging phosphatidylserine-binding molecules growth arrest-specific 6 (Gas6) or Protein S. We show that one such TAM receptor (Axl) is exclusively expressed on mouse airway macrophages, but not interstitial macrophages and other lung leukocytes, under homeostatic conditions and is constitutively ligated to Gas6. Axl expression is potently induced by granulocyte-macrophage colony-stimulating factor expressed in the healthy and inflamed airway, and by type I interferon or Toll-like receptor-3 stimulation on human and mouse macrophages, indicating potential involvement of Axl in apoptotic cell removal under inflammatory conditions. Indeed, an absence of Axl does not cause sterile inflammation in health, but leads to exaggerated lung inflammatory disease upon influenza infection. These data imply that Axl allows specific identification of airway macrophages, and that its expression is critical for macrophage functional compartmentalization in the airspaces or lung interstitium. We propose that this may be a critical feature to prevent excessive inflammation because of secondary necrosis of apoptotic cells that have not been cleared by efferocytosis.

Narrow-band imaging observation of colorectal lesions using NICE classification to avoid discarding significant lesions

AIM: To assess the risk of failing to detect diminutive and small colorectal cancers with the “resect and discard” policy.

METHODS: Patients who received colonoscopy and polypectomy were recruited in the retrospective study. Probable histology of the polyps was predicted by six colonoscopists by the use of NICE classification. The incidence of diminutive and small colorectal cancers and their endoscopic features were assessed.

RESULTS: In total, we found 681 cases of diminutive (1-5 mm) lesions in 402 patients and 197 cases of small (6-9 mm) lesions in 151 patients. Based on pathology of the diminutive and small polyps, 105 and 18 were non-neoplastic polyps, 557 and 154 were low-grade adenomas, 18 and 24 were high-grade adenomas or intramucosal/submucosal (SM) scanty invasive carcinomas, 1 and 1 were SM-d carcinoma, respectively. The endoscopic features of invasive cancer were classified as NICE type 3 endoscopically.

CONCLUSION: The risk of failing to detect diminutive and small colorectal invasive cancer with the “resect and discard” strategy might be avoided through the use of narrow-band imaging observation with the NICE classification scheme and magnifying endoscopy.

IL-22 produced by cancer-associated fibroblasts promotes gastric cancer cell invasion via STAT3 and ERK signaling

BACKGROUND

Interleukin-22 (IL-22) has been recently highlighted owing to its biological significance in the modulation of tissue responses during inflammation. However, the role of IL-22 in carcinogenesis has remained unclear. Here, we investigated the pathophysiological significance of IL-22 expression in gastric cancer tissues and examined the mechanism by which IL-22 promotes gastric cancer cell invasion.

METHODS

Human gastric cancer specimens were analysed by immunohistochemistry for expression of IL-22 and IL-22 receptor 1 (IL-22R1). The effects of IL-22-induced STAT3 and ERK signalling on invasive ability of gastric cancer cells were examined using a small-interfering RNA system and specific inhibitors. AGS cells were co-cultured with cancer-associated fibroblasts (CAFs) from human gastric cancer tissues and assessed by invasion assay.

RESULTS

Interleukin-22 and its receptor were expressed in α-smooth muscle actin-positive stromal cells and tumour cells at the invasive front of gastric cancer tissues, respectively. The expression of IL-22 and IL-22R1 was significantly related to lymphatic invasion. Interleukin-22 treatment promoted the invasive ability of gastric cancer cells through STAT3 and ERK activation. The invasive ability of gastric cancer cells was significantly enhanced by co-culture with IL-22-expressing CAFs.

CONCLUSIONS

Interleukin-22 produced by CAFs promotes gastric cancer cell invasion via STAT3 and ERK signalling.

Digestive disease management in Japan: a report on the 6th diagnostic pathology summer fest in 2012

The 6th Diagnostic Pathology Summer Fest, held in Tokyo on August 25-26, 2012, opened its gates for everyone in the medical profession. Basic pathology training can contribute to the improvement of algorithms for diagnosis and treatment. The 6th Summer Fest with the theme 'Pathology and Clinical Treatment of Gastrointestinal Diseases' was held at the Ito International Research Center, The University of Tokyo. On August 25, 'Treatment of Early Gastrointestinal Cancer and New Guidelines' was discussed in the first session, followed by 'Biopsy Diagnosis of Digestive Tract: Key Points of Pathological Diagnosis for Inflammation and Their Clinical Significance' in the second session. On August 26, cases were discussed in the third session, and issues on pathological diagnosis and classification of neuroendorcrine tumor in the fourth session. The summaries of speeches and discussions are introduced along with the statements of each speaker. This meeting was not a formal evidence-based consensus conference, and 20 experts gave talks on their areas of specialty. Discussion was focused on how the management strategy should be standardized on the algorithm of patient care.

Histological assessment of intra- and inter-institutional reliabilities in detection of desmoplastic reaction in biopsy specimens of early colorectal carcinomas

We previously reported a relationship between depth of submucosal invasion of early colorectal carcinomas and desmoplastic reaction (DR). However, poor inter-observer agreement on the histopathological diagnosis of DR in biopsy specimens with hematoxylin and eosin (H&E) staining has been the major critique of this tool. In this study, reproducibility of the histopathological diagnosis of DR was evaluated. Furthermore, we investigated the possible improvement of the reproducibility after education about histological characteristics and tried to identify histological characteristics that are most important in the recognition of DR. A total of 34 H&E stained slides were included in this study and analyzed by three pathologists. Slides were reviewed before and after education about histological characteristics of DR. Kappa statistics were used to compare the inter-observer variability. We investigated the relationship between DR and histopathological factor. The inter-observer agreement during the first session varied between 0.30 and 0.63, which improved during the second session toward an agreement between 0.58 and 0.71. Myofibroblast proliferation associated with cancer invasion was found to be the most useful in the diagnosis of DR. In conclusion, the correct detection of myofibroblasts may facilitate the standardization of diagnosis of DR.

Immunohistochemical assessment of a unique basal pattern of p53 expression in ulcerative-colitis-associated neoplasia using computer-assisted cytometry

Background

The basal pattern of p53 expression, defined as its immunoreactivity confined to the basal half of the glands, is associated with early neoplastic lesions in ulcerative colitis (UC). However, their clinical utility of this finding is limited by the use of “visual estimation” (approximate immunoreactivity on the basis of scanning the stained slide, without formal counting). This study was designed to analyze the basal pattern of p53 using computer-assisted cytometry and to identify the optimal cutoff value for discriminating between UC-associated early-stage neoplasia and regenerative atypia.

Methods

The specimens were obtained from eight UC patients undergoing colectomy and were classified according to the criteria by the Research Committee of Inflammatory Bowel Disease of the Ministry of Health and Welfare in Japan. Patients with classes UC-IIa (indefinite for dysplasia, probably regenerative), UC-IIb (indefinite for dysplasia, probably dysplastic), and UC-III (definitive dysplasia) were enrolled in the study. Based on the percentage of immunoreactive cells in the basal half of the crypt with visual estimation, basal positivity of p53 was classified into three categories: grade 1 (1 - 9%), grade 2 (10 - 19%), and grade 3 (≥20%). Next, crypts classified as grade 3 by visual estimation were analyzed by computer-assisted image analysis.

Results

Using visual estimation, grade-3 p53 basal positivity was observed in 46.0% of UC-IIa crypts (128 of 278), 61.9% of UC-IIb crypts (39 of 63), and 94.2% of UC-III crypts (81 of 86). Using image analysis, the median p53 basal positivities were 30.3% in UC-IIa, 52.3% in UC-IIb, and 65.4% in UC-III (P ≤0.002). A receiver operating characteristics curve was generated to determine the method’s diagnostic utility in differentiating UC-IIa from UC-III. In this cohort, the sensitivity was 0.78; the specificity was 0.98; the negative predictive value was 87.4%; the positive predictive value was 95.5%, and the accuracy was 90.2% with a cutoff value for p53 basal positivity of 46.1%.

Conclusions

Our findings indicate that assessing p53 basal positivity by image analysis with an optimal threshold represents an alternative to visual estimation for the accurate diagnosis of UC-associated early-stage neoplasia.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3588120501252608

Analysis of KRAS mutations in cases of metastatic colorectal cancer at a single institution in Tochigi, Japan

OBJECTIVE

Colorectal cancer patients bearing wild-type KRAS benefit from anti-epidermal growth factor receptor (EGFR) antibody treatment. Since clinical studies showed the efficacy of anti-EGFR antibody treatment for metastatic colorectal cancer (mCRC), we analyzed KRAS mutations in mCRC to gain insight into the association between these mutations and clinicopathological characteristics.

METHODS

KRAS mutations were analyzed in 109 tissue samples of mCRC using amplification refractory mutation system-Scorpion (ARMS/S) assay (68 samples) and direct sequencing (41 samples).

RESULTS

In the ARMS/S assay, 36.5 and 7.4% of mCRCs harbored mutations at codons 12 and 13, respectively. In direct sequencing, corresponding values were 24.4 and 19.5%. Overall, 37.6% (codon 12/13, 25.7/11.9%) of mCRCs harbored KRAS mutations. No significant differences were found between KRAS mutations and clinicopathological variables. Among mCRC patients <65 years of age, the incidence of KRAS mutations at codon 13 was significantly higher in female than male patients (p = 0.035).

CONCLUSION

The incidence of KRAS mutations in mCRC was similar to that of non-mCRC as previously reported. KRAS codon 13 mutations might be associated with younger female patients with mCRC, but further investigation is necessary to clarify the association between this type of mutation and metastatic potential in female CRC patients.

Malignant transformation of hyperplastic gastric polyps: An immunohistochemical and pathological study of the changes of neoplastic phenotype

In spite of the evidence that the malignant transformation of gastric hyperplastic polyps (HPs) is a rare event, it must always be taken into account during diagnosis. The aim of the current study was to clarify the mechanism of the malignant transformation of gastric hyperplasia polyps, with focus on phenotypic expression, cell proliferation and p53 overexpression. Immunohistochemistry for mucin phenotypic markers, including MUC1, MUC2, MUC5AC, MUC6, tight junction factors (claudin-3, -4 and -18), an intestinal phenotypic marker [caudal type homeobox 2 (Cdx2)], Ki-67 proliferative index and p53 overexpression, was performed on archival specimens of gastric polyps excised from six patients. Histologically, the intermingled components of several lesions were present in these polyps. Furthermore, the cancer components were predominantly differentiated adenocarcinoma. Immunohistochemically, all hyperplastic components expressed MUC5AC, but did not exhibit positivity for MUC2. Additionally, the majority of hyperplastic components were immunonegative for claudin-3, while claudin-3 positivity was observed in the majority of areas of dysplasia and carcinoma. Expression of claudin-4 was also observed in the majority of cases and claudin-18 was preserved in the hyperplastic, dysplastic and adenocarcinomatous lesions of all cases. Nuclear accumulation of Cdx2 was detected in almost all the samples with dysplasia and carcinoma, while nuclear p53 was detected in 24-80% of the dysplastic areas and >85% of the cancer components. The Ki-67 labeling index appeared to correlate with neoplastic progression. The observations provided evidence that the mechanism underlying malignant transformation of gastric HPs may occur by multistep carcinogenesis, such as the hyperplasia-adenoma (dysplasia)-adenocarcinoma sequence, and these neoplastic cells may acquire various phenotypes during this process.

Manganese superoxide dismutase plays an important role in the inflammatory process and predicts disease severity and activity in patients with ulcerative colitis

The aim of this study was to investigate the expression pattern of manganese superoxide dismutase (MnSOD) in relation to inflammatory factors in ulcerative colitis (UC) and characterize this enzyme as a newly identified biomarker potentially linked to disease pathogenesis of UC. MnSOD expression was analyzed immunohistochemically in 48 formalin-fixed and paraffin-embedded specimens from patients with UC who had undergone endoscopical biopsy. MnSOD expression was observed in vascular endothelium, macrophages, and polymorphonuclear leukocytes within lamina propria of inflamed mucosa. The patients who did not express MnSOD tended to have stabilization of symptoms, but accompanied with status of inflammation. The MnSOD expression pattern was strongly correlated with disease type. MnSOD was expressed in polymorphonuclear leukocytes of all disease types, but cases of chronically counting and exacerbation type had particularly high frequency of immunopositive cells. MnSOD expression in macrophages was frequently observed in cases of symptom remaining type. The cases with MnSOD expression in the vascular endothelium showed a tendency to express in relapse-remission and exacerbation of symptoms. Immunohistochemical evaluation for MnSOD expression may be useful for predicting disease severity and activity in patients with UC.

[The brand new trend of colorectal carcinoma pathology]

Japanese classification of colorectal carcinoma continues to develop several decades. In 2015, the Japanese Society for Cancer of the Colon and Rectum published the eighth edition of the general rules for clinical and pathological studies on cancer of the colon, rectum, and anus. The new Japanese classification of colorectal carcinoma based on new evidences including sessile serrated adenoma/polyp (SSA/P) of serrated polyp, budding, desmoplastic reaction, head/stalk invasion, submucosal invasion depth for early cancer, EX (extramural cancer deposit), and PN (perineural invasion) for advanced cancer. And recently molecular targeted therapy for anti EGFR has made rapidly progress in refractory advanced cancer. However, some issues still remain to be resolved in pathological diagnosis. We describe and discuss about assessment of pathological diagnosis for new therapy for colorectal carcinoma.

Overexpression of regenerating gene Iα appears to reflect aberration of crypt cell compartmentalization in sessile serrated adenoma/polyps of the colon

Background

Colorectal sessile serrated adenoma/polyps (SSA/Ps) are characterized by asymmetrical distribution of Ki67-positive cells, which varies among crypts and involves the crypt length to a variable extent; the pattern has been designated as aberration of crypt cell compartmentalization. The regenerating gene (REG) Iα is a cell growth and/or anti-apoptotic factor and its overexpression might be associated with aberration of crypt cell compartmentalization in SSA/Ps. We investigated REG Iα expression in SSA/Ps in comparison to hyperplastic polyps (HPs).

Methods

A total of 64 cases of serrated polyps (≥10 mm in size), including 53 SSA/Ps and 11 HPs, were included in the present study. Immunostaining was performed using a labeled streptavidin-biotin method. REG Iα expression was classified as follows: (i) expression of endocrine cells: grade 0 (a few positive cells) to 3 (marked increase in positive cells); (ii) expression of goblet cells: grade 0 (negative) to 2 (positive for crypts and surface epithelial cells); (iii) staining intensity of goblet cells: grade 0 (negative) to 2 (strong); (iv) staining intensity of crypt (absorptive) cell membranes: grade 0 (negative) to 2 (strong). The presence of aberration of crypt cell compartmentalization was assessed using Ki67 immunostaining.

Results

With regard to the REG Iα expression of endocrine cells, 8 out of 11 HPs (73%) were grade 0, whereas 51 of 53 SSA/Ps (96%) were grade 1 or higher (p < 0.001). With regard to the distribution of REG Iα-immunoreactive goblet cells, 10 of 11 HPs (91%) were grade 1, whereas 50 of 53 SSA/Ps (94%) were grade 2 (p < 0.001). A similar trend was found in the staining intensity of goblet cells or crypt cell membranes (p = 0.011). Aberration of crypt cell compartmentalization was more frequently identified in SSA/Ps (72%) than in HPs (18%; p = 0.002). A significant association was observed between REG Iα overexpression and the aberration of crypt cell compartmentalization in serrated polyps (p = 0.037).

Conclusions

REG Iα overexpression is a characteristic of SSA/Ps, which appears to reflect aberration of crypt cell compartmentalization.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7240956081100040

Immunohistochemical analysis of the DNA methyltransferase 3b expression is associated with significant improvements in the discrimination of ulcerative colitis-associated neoplastic lesions

PURPOSE

Making a clinicopathological diagnosis of dysplasia is crucial. We herein assess the significance of the DNA methyltransferase 3b (DNMT3b) expression as a diagnostic marker of ulcerative colitis (UC)-associated neoplasia.

METHODS

Thirty-one patients with long-standing and extensive UC were included in this study. The expression of DNMT3b in non-neoplastic rectal epithelium (non-dysplasia in 31 patients) and colorectal neoplasia (dysplasia in 43 patients and invasive cancer in 34 patients) was determined using immunohistochemistry. The presence of immunoreactive DNMT3b was assessed in the areas with the highest density of cells with positively staining nuclei. DNMT3b was expressed as the percentage of positive cells relative to the total number of cells counted under high power magnification.

RESULTS

The DNMT3b expression in neoplastic rectal epithelium (0.76, range 0.59-0.84) was increased compared to that observed in non-neoplastic epithelium (0.32, range 0.18-0.67, P < 0.001). A ROC curve analysis confirmed 0.68 to be the best diagnostic cut-off value for the DNMT3b expression in neoplastic epithelium (area under the curve = 0.810). The sensitivity of the diagnostic test was 66.2 %, the specificity was 86.7 %, the positive predictive value was 95.7 % and the negative predictive value was 36.1 %. The positive likelihood ratio was 4.98 and the negative likelihood ratio was 0.20. The accuracy was 69.9 %.

CONCLUSIONS

An immunohistochemical analysis of the DNMT3b expression was associated with significant improvements in the discrimination of UC-associated neoplastic lesions.

Immunohistochemical analysis of chromogranin A and p53 expressions in ulcerative colitis-associated neoplasia: neuroendocrine differentiation as an early event in the colitis-neoplasia sequence

Pancellular dysplasia involving neuroendocrine cells has been shown to be comparatively rare but crucially implicated in the development of neuroendocrine tumors in ulcerative colitis (UC). We attempted to clarify the prevalence of chromogranin A expression as a marker of neuroendocrine differentiation in UC-associated neoplasia by immunohistochemical analyses of 26 lesions of low-grade dysplasia (LGD), 32 high-grade dysplasias (HGDs) and 27 invasive cancers (INVs), along with p53 expression. We additionally assessed the utility of these proteins for differential diagnosis between LGD and HGD. Chromogranin A was considered positive when immunoreactive cells were more than 5% of neoplastic lesions, and the positivity tended to be higher in HGDs (57.7%) or INVs (46.7%) than LGDs (32.0%). Focal or diffuse nuclear staining for p53 was defined as positive. The positive rate for p53 was also higher in HGDs (59.4%; P = 0.037) or INVs (59.3%) than LGDs (30.8%). A similar trend was found in co-positivity for both proteins (HGDs, 30.7%/INVs, 26.7% versus LGDs, 12.0%). No positivity for both proteins was identified in the non-neoplastic mucosa. The combination of the two proteins improved the sensitivity (66.7%), specificity (80.0%), positive predictive value (72.7%) and negative predictive value (75.0%) for HGD as compared to p53 alone (sensitivity, 57.7%; specificity 68.0%; positive predictive value, 65.2%; negative predictive value, 60.7%). In conclusion, we show here that neuroendocrine differentiation is relatively common and represents an early event in the UC-neoplasia pathway in which p53 and chromogranin A are coordinately up-regulated. Immunohistochemical assessment of their expression might provide a useful adjunct tool for grading dysplasia in UC.

A large-scale multicenter study of long-term outcomes after endoscopic resection for submucosal invasive colorectal cancer

BACKGROUND AND STUDY AIMS

Patients with submucosal invasive colorectal cancer (SM-CRC) treated with endoscopic resection who are at low risk of lymph node metastasis and local recurrence may be followed up with observation alone, while additional surgery is recommended for those with high risk features. However, the long-term outcomes that these strategies offer are still unclear. The objective of our study was to retrospectively evaluate the long-term outcomes of patients with SM-CRC managed with endoscopic resection.

PATIENTS AND METHODS

We retrospectively analyzed all patients with SM-CRC treated by endoscopic resection at six institutions between 2000 and 2007. SM-CRCs with (i) negative vertical margin, (ii) well or moderately differentiated adenocarcinoma, (iii) absence of lymphovascular invasion, and (iv) invasion depth < 1000 µm were classified as low risk. Patients with SM-CRCs without these characteristics were classified as high risk. Outcomes were assessed by 5-year recurrence-free survival (RFS) and recurrence rate.

RESULTS

During the study period, 428 patients with SM-CRC (low risk, 126; high risk, 302) who underwent endoscopic resection as their first treatment were enrolled (median follow-up 61 months). Among the 120 patients with low risk features treated by endoscopic resection alone, the 5-year RFS and recurrence rates were 98 % and 0.8 %, respectively. Of the 302 patients with high risk features, 196 underwent additional surgery and 106 were managed with endoscopic resection alone. For those who underwent additional surgery, the 5-year RFS and recurrence rates were 97 % and 3.6 %, respectively. Among the 106 patients managed with endoscopic resection alone, RFS and recurrence rates were 89 % (P < 0.05 vs. low risk patients treated by endoscopic resection alone) and 6.6 % (P < 0.05), respectively.

CONCLUSIONS

Endoscopic resection alone is adequate for the management of patients with SM-CRC and low risk features. However, in those patients with SM-CRC and high risk features, surgery should be considered in addition to endoscopic resection.

Clinical validation of the gastrointestinal NET grading system: Ki67 index criteria of the WHO 2010 classification is appropriate to predict metastasis or recurrence

BACKGROUND

In the WHO 2010 classification, the neuroendocrine tumors (NETs) are subdivided by their mitotic index or Ki67 index into either G1 or G2 NETs. Tumors with a Ki67 index of <2% are classified as G1 and those with 3-20% are classified as G2. However, the assessment of tumors with Ki67 index of greater than 2% and less than or equal to 3% is still unclear. To resolve the problem, we validated the Ki67 index criteria of gastrointestinal NETs of the WHO 2010 classification.

METHODS

The medical records of 45 patients who were pathologically diagnosed as having NET G1/G2 of the gastrointestinal tract were analyzed retrospectively. According to the WHO 2010 classification, Ki67 index were calculated. Computer-assisted cytometrical analysis of Ki67 immunoreactivity was performed using the WinRooF image processing software. Receiver operating characteristic (ROC) curves were generated to determine the best discriminating Ki67 index. To clarify the assessment of tumors with Ki67 index between 2-3%, the calculated cutoff of Ki67 index was evaluated using Fisher's exact test.

RESULTS

ROC curve analysis confirmed that 2.8% was the best Ki67 index cutoff value for predicting metastasis or recurrence. The sensitivity of the new Ki67 index cutoff was 42.9%, and the specificity was 86.8%.

CONCLUSIONS

Division of NETs into G1/G2 based on Ki67 index of 3% was appropriate to predict metastases or recurrences. The WHO grading system may be the most useful classification to predict metastases or recurrences.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1553036118943799.

Long-term outcomes after resection for submucosal invasive colorectal cancers

BACKGROUND & AIMS

Little is known about the long-term outcomes of patients with submucosal invasive colorectal cancer who undergo endoscopic or surgical resection. We performed a retrospective analysis of long-term outcomes of patients treated for submucosal colon and rectal cancer.

METHODS

We collected data on 549 patients with submucosal colon cancer and 209 patients with submucosal rectal cancer who underwent endoscopic or surgical resection at 6 institutions over a median follow-up period of 60.5 months. Patients were classified into one of 3 groups: low-risk patients undergoing only endoscopic resection (group A), high-risk patients undergoing only endoscopic resection (group B), and high-risk patients undergoing surgical resection that included lymph node dissection (group C). We assessed recurrence rates, 5-year disease-free survival, and 5-year overall survival. Cox regression analysis was used to compare recurrences.

RESULTS

The rates of recurrence, disease-free survival, and overall survival in group A for submucosal colon and rectal cancer were 0% versus 6.3% (P < .05), 96% versus 90%, and 96% versus 89%, respectively. For group B, these values were 1.4% versus 16.2% (P < .01), 96% versus 77% (P < .01), and 98% versus 96%, respectively; local recurrence was observed in 5 patients (one with submucosal colon cancer and 4 with submucosal rectal cancer). Tumor location was the only factor that contributed significantly to disease recurrence and death (hazard ratio, 6.73; P = .045). For group C, these values were 1.9% versus 4.5%, 97% versus 95%, and 99% versus 97%, respectively.

CONCLUSIONS

The risk for local recurrence was significantly higher in high-risk patients with submucosal rectal cancer than in patients with submucosal colon cancer when treated with only endoscopic resection. The addition of surgery is therefore recommended for patients with submucosal rectal cancer with pathologic features indicating a high risk of tumor progression; University Hospital Medical Network Clinical Trials Registry, Number: UMIN 000008635.

Analysis of the anatomic subsites, gender and age in unresectable advanced colorectal carcinomas in Tochigi, Japan suggests a shift in location towards the right side colon in elderly patients treated with cetuximab

Colorectal cancer is a frequently occurring cancer whose incidence has shown a marked increase in recent years. Additionally, an increase in right side colon in elderly patients has been identified. Therefore, a clinicopathological study was conducted in 49 patients with unresectable advanced colorectal carcinomas to elucidate the association of clinicopathological characteristics and K-ras mutation. Of the 49 patients included in this study, 24 were aged <60 years with a male/female (M/F) ratio of 16/8 and 25 patients were aged ≥60 years with a M/F ratio of 16/9. Of the patients aged ≥65 years, 15 patients were enrolled as controls and the M/F ratio was 9/6. Results revealed that with regard to the subsite of cancer, unresectable advanced colorectal carcinomas developed in the right-sided colon in 13 patients, left-sided colon in 19 patients and rectum in 17 patients. Right-sided colon carcinomas were commonly identified in the elderly patients aged ≥65 years, with a marked tendency in the female patients (P=0.024). Immunostaining was performed for the epidermal growth factor receptor (EGFR) antibody in 40 patients to determine whether the K-ras gene would yield positive results. The mutant K-ras gene was identified in 8 patients (20%) and the frequency was lower compared with that of the normal colorectal carcinomas. Anti-EGFR antibody (cetuximab) is considered to be a molecularly targeted agent for unresectable advanced colorectal carcinomas. The increase in incidence of right-sided colon carcinomas as well as the increase in the number of patients presenting with colorectal carcinomas means this issue should be addressed. Sessile serrated adenoma/polyp (SSA/P) with b-raf mutation and CIMP (CpG island methylator phenotype) abnormality as a precursor lesion of right-sided colon carcinoma is common and since cetuximab refractory wild-type K-ras/mutant b-raf colorectal carcinoma may increase in elderly patients and patients with right-sided colon carcinoma, a simultaneous examination for the K-ras and b-raf gene abnormalities for the treatment of colorectal cancer using anti-EGFR antibody (cetuximab) is crucial. In addition, the multidisciplinary assessments regarding the effect of such treatments is likely to be determined based on cumulative results, such as the duration of patient survival.

Differentiation between sessile serrated adenoma/polyp and non-sessile serrated adenoma/polyp in large hyper plastic polyp: A Japanese collaborative study

A hyperplastic polyp (HP) >10 mm is described as a large hyperplastic polyp (LHP). Previous studies have considered LHP and sessile serrated adenoma/polyp (SSA/P) as synonymous. Although HP and SSA/P have previously been morphologically distinguished, differences between LHP and SSA/P have not yet been reported. The present study aimed to define the differences between SSA/P and non-SSA/P in LHP using immunohistochemistry for Ki67. Colorectal serrated lesions (>10 mm) that were completely resected by endoscope and derived from 11 institutions in Japan [Dokkyo Medical University School of Medicine (Mibu), Takahiro Fujii Clinic (Tokyo), Sano Hospital (Kobe), Oda GI Clinic, Hattori GI Endoscopy and Oncology Clinic (Kumamoto), Ohta Clinic (Nagoya), Hiroshima University (Hiroshima), Iwate Medical University (Morioka), Juntendo and Kyorin Universities (Tokyo) as well as Toyama University (Toyama)] affiliated with the Japanese Society for Cancer of the Colon and Rectum (JSCCR) between January 2003 and December 2010 were selected. The histological criteria of the Japanese Society for Cancer of the Colon and Rectum (JSCCR, project meeting; editor-in chief, Takashi Yao) were used to distinguish SSA/P and non-SSA/P from LHP. Non-SSA/P comprises both incomplete SSA/P and HP. A total of 154 samples diagnosed as SSA/P or non-SSA/P from 148 patients were used. This study comprised 107 SSA/P and 47 non-SSA/P cases, whereby lesions were located on the right side of the colon (73.2 and 26.8%, respectively). Ki67-positivity in SSA/Ps was significantly higher compared to non-SSA/Ps. A greater number of SSA/Ps in LHP were located on the right side of the colon compared to the left side. SSA/Ps occurring on the right side of the colon may be precursor lesions of colorectal carcinoma in serrated neoplasia pathways. In conclusion, LHPs and SSA/Ps limited to the right side of the colon are suggested to be clinically treated as the same type of lesions.

Irregular arrangement of collecting venules (IRAC) provides a critical endoscopic insight in Helicobacter pylori-induced gastritis: A secondary publication

The aim of this study was to evaluate the significance of an endoscopic atrophic border and irregular arrangement of collecting venules (IRAC) in the diagnosis of Helicobacter pylori (H. pylori)-induced gastritis. Upper gastrointestinal tract endoscopy was performed on 723 patients, who were screened them for H. pylori infection. Any patients who had undergone H. pylori eradication therapy were excluded from the study. The endoscopic atrophic border and IRAC in each patient were assessed. The H. pylori status was determined in the patients by combination of a serological test and/or histopathological examination. The H. pylori infection rates were 95.4% (455/477) in the group with an endoscopic atrophic border and 22.3% (55/246) in the group without an endoscopic atrophic border. In the diagnostic validity check, presence of an endoscopic atrophic border had a sensitivity of 89.2% and a specificity of 89.7%. Furthermore, the H. pylori infection rates were 95.5% (506/530) in the IRAC group and 2.1% (4/193) in the regular arrangement of collecting venules (RAC) group. In the diagnostic validity check, IRAC had a sensitivity of 99.2% and a specificity of 88.7%. In conclusion, the presence of an endoscopic atrophic border and IRAC are highly indicative of an H. pylori-infected gastric mucosa.

Laminin-5 is a biomarker of invasiveness in cervical adenocarcinoma

BACKGROUND

Glandular lesions are often problematic for diagnostic cervical pathology. The survival of patients with adenocarcinoma is significantly poorer than that of patient with squamous cell carcinoma. One reason for this increased risk is the aggressive invasiveness of adenocarcinoma. Therefore additional biomarkers, to supplement morphological diagnosis of adenocarcinoma, are necessary. We have assessed the diagnostic utility of Laminin-5 (Laminin γ2 chain): Lam-5 in the diagnosis of the invasiveness of cervical adenocarcinoma and related glandular lesions.

METHODS

Lam-5 immunohistochemistry was performed on archival specimens from 8 patients with uterine leiomyoma as a negative control group, 6 patients with endocervical gland hyperplasia, 6 patients with adenocarcinoma in situ, 6 patients with microinvasive adenocarcinoma and 24 patients with invasive adenocarcinoma.

RESULTS

The expression of Lam-5 was not detected in normal mucosa, but was seen along the basement membrane in endocervical gland hyperplasia and adenocarcinoma in situ and was observed in the cytoplasm of tumor cells in microinvasive and invasive adenocarcinoma.

CONCLUSION

We conclude that Lam-5 is a useful biomarker in the evaluation of invasiveness in cervical adenocarcinoma.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7316562925827381.

Desmoplastic reaction in biopsy specimens of early colorectal cancer: a Japanese prospective multicenter study

We previously reported that detection of desmoplastic reaction (DR) in pretreatment biopsy specimens was useful for predicting the depth of submucosal invasion (SM depth) in nonpedunculated early colorectal cancers (ECRCs) in a retrospective study. Here, we performed a prospective multicenter study for verification of our previous findings. Subjects were diagnosed with ECRC by endoscopy, and with adenocarcinoma from the biopsy specimens. Eleven institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum participated in this collaborative study. A total of 112 patients with ECRC were enrolled. For nonpedunculated ECRCs, presence of DR was significantly correlated with SM depth. The sensitivity and specificity of detection of DR for prediction of pSM2 (tumor invasion ≥1000 µm) in nonpedunculated ECRCs were 68.6% and 92.0%, respectively. Evaluation of DR in pretreatment biopsy specimens may be useful for the clinicopathological diagnosis of colorectal carcinoma with massive invasion into the submucosal layer.

An assessment of the diagnostic criteria for sessile serrated adenoma/polyps: SSA/Ps using image processing software analysis for Ki67 immunohistochemistry

Background

Serrated polyps belong to a heterogeneous group of lesions that are generally characterized morphologically. This type of lesion is thought to be the precursor of sporadic carcinomas with microsatellite instability, and probably also the precursor for CpG island-methylated microsatellite-stable carcinomas. For practical purposes, according to the 2010 WHO classification, the diagnostic criteria for sessile serrated adenomas/polyps (SSA/Ps) was established by the research project “Potential of Cancerization of Colorectal Serrated Lesions” led by the Japanese Society for Cancer of the Colon and Rectum. The aim of this study was to evaluate the validity of the morphologic characteristics established in Japan by using immunohistochemical staining for Ki-67.

Methods

To calculate the target cells, 2 contiguous crypts which could be detected from the bottom of the crypt to the surface of the colorectal epithelium were selected. To validate the proliferative activity, we evaluated the percentage and the asymmetrical staining pattern of Ki67 positive cells in each individual crypt. To examine the immunoreactivity of Ki67, computer-assisted cytometrical analysis was performed.

Results

SSA/Ps had a higher proliferative activity as compared to hyperplastic polyps (HPs) based on the difference in incidence of Ki67 positive cells, and the former also exhibited a significantly higher asymmetric distribution of these cells as compared to HPs, even in lesions with a diameter <10 mm.

Conclusion

We conclude that assessment of the pathological findings of SSA/Ps, including crypt dilation, irregularly branching crypts, and horizontally arranged basal crypts (inverted T- and/or L-shaped crypts) is appropriate to show a significantly higher proliferative activity as compared to HPs. Further, the use of two-dimensional image analysis software is an objective and reproducible method for this type of histological examination.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6718091416698112

Matched case-control study comparing endoscopic submucosal dissection and endoscopic mucosal resection for colorectal tumors

BACKGROUND AND AIM

For large colorectal tumors, the en bloc resection rate achieved by endoscopic mucosal resection (EMR) is insufficient, and this leads to a high rate of local recurrence. As endoscopic submucosal dissection (ESD) has been reported to achieve a higher rate of en bloc resection and a lower rate of local recurrence in the short-term, it is expected to overcome the limitations of EMR. We conducted a matched case-control study between ESD and EMR to clarify the effectiveness of ESD for colorectal tumors.

METHODS

Between April 2005 and February 2009, a total of 28 colorectal tumors in 28 patients were resected by ESD and were followed up by colonoscopy at least once. As a control group, 56 EMR cases from our prospectively completed database were matched. En bloc resection, complication and recurrence rates were compared between the two groups.

RESULTS

The mean sizes of the lesions were 27.1 mm in the ESD group and 25.0 mm in the EMR group. The en bloc resection rate was significantly higher in the ESD group (92.9% vs 37.5% with ESD vs EMR), and the rate of perforation was also significantly higher (10.7% vs 0%). All cases of perforation were managed conservatively. No recurrence was observed in the ESD group, whereas local recurrences were detected in 12 EMR cases (21.4%). Eleven of the 12 recurrences (91.7%) were managed endoscopically, and one required surgical resection.

CONCLUSIONS

Endoscopic submucosal dissection is a promising technique for the treatment of colorectal tumors, giving an excellent outcome in comparison with EMR.

Clinicopathological features of serrated adenocarcinoma defined by Mäkinen in dukes' B colorectal carcinoma

OBJECTIVE

Serrated adenocarcinoma (SAC), proposed as a new pathologic type, arises predominantly in the right side of the colon and has a poorer prognosis than conventional colorectal carcinoma. The prognosis of colorectal carcinoma is variable in Dukes' B, so the aim of this study was to determine whether or not SAC has a poor prognosis in Dukes' B.

METHODS

The study group comprised 64 patients who underwent surgery for colorectal carcinoma. We undertook a statistical analysis of the association of SAC and non-SAC with sex, age, histologic type, depth of tumor, location of tumor, venous invasion and lymphatic invasion.

RESULTS

SACs were encountered in 17.5% of cases (n = 11). SAC had a less favorable 5-year survival than non-SAC (p = 0.0396 log-rank, Kaplan-Meier). The factors that achieved statistical significance in the univariate analysis were subsequently included in a multivariate analysis and we found that SAC was an independent factor (p = 0.027).

CONCLUSIONS

SAC has a poor prognosis and is not affected by other factors confirming that SAC is an independently less favorable prognostic factor.