Kuang I. Fu

MAGNIFYING OBSERVATION OF MICROVASCULAR ARCHITECTURE OF COLORECTAL LESIONS USING A NARROW-BAND IMAGING SYSTEM

We reviewed the magnifying observation of the microvascular architecture of colorectal lesions and discuss the utility of the detailed observation of the microvascular architecture for differential diagnosis during narrow‐band imaging (NBI) colonoscopy. Angiogenesis is critical to the transition of premalignant lesions in a hyperproliferative state to the malignant phenotype. Therefore, diagnosis based on angiogenic or vascular morphologic changes might be ideal for early detection or diagnosis of neoplasms. In this review, we propose the term ‘meshed capillary’ for the distinction between non‐neoplastic and neoplastic lesions and the capillary classification ‘capillary pattern’ for the differential diagnosis of colorectal lesions. We believe that the combined use of NBI optical chromoendoscopy and real chromoendoscopy decreases the time and cost of screening colonoscopy. To assess the feasibility and efficacy of using the NBI system, further studies are required for colorectal lesions and other lesions of the gastrointestinal tract.

Cyclooxygenase-2 is overexpressed in serrated adenoma of the colorectum.

PURPOSE: The aim of this study was to clarify whether cyclooxygenase-2 and cyclooxygenase-1 is expressed in hyperplastic polyps and serrated adenomas. METHODS: Forty-nine serrated adenomas and 25 hyperplastic polyps were immunostained using anticyclooxygenase-2 and anticyclooxygenase-1 antibodies. Cyclooxygenase-2 and cyclooxygenase-1 expression was investigated in all specimens. RESULTS: Cyclooxygenase-2 was expressed in dysplastic glands in the majority of serrated adenomas. Thirty-five of 49 (71.4 percent) serrated adenomas exhibited moderate to intense cyclooxygenase-2 immunoreactivity, and 8 of 25 hyperplastic polyps (32 percent) showed weak to moderate cyclooxygenase-2 immunoreactivity. Cyclooxygenase-1 immunoreactivity was very weak in all the hyperplastic polyps and serrated adenomas. CONCLUSIONS: These results suggest that cyclooxygenase-2 is overexpressed in serrated adenoma of the colorectum. Cyclooxygenase-2 inhibitors will reduce the incidence of serrated adenomas.

Etat actuel du diagnostic et du traitement endoscopique du cancer colorectal au Japon

RésuméLe cancer colorectal (CCR) est la troisième cause de décès au Japon, et depuis peu, son incidence augmente encore graduellement. A titre de prévention, la détection précoce associée à l’exérèse des lésions précancéreuses au début constitue un enjeu capital pour l’amélioration du pronostic des patients et la coloscopie est sans aucun doute la technique la plus performante tant au niveau de la détection que de la résection de ces lésions.La présente revue offre un panorama des techniques diagnostiques coloscopiques incluant la chromoendoscopie, la coloscopie à optique grossissante, et les nouveaux développements de l’imagerie NBI.SummaryColorectal cancer (CRC) is the third leading cause of death in Japan, and recently the incidence has still gradually increased. To prevent CRC, early detection in addition to removal of precancerous and early cancerous lesions is the most important to improve the prognosis of patients, and colonoscopy is definitely the most powerful tool for both detection and resection.This review is intended to provide an overview of colonoscopic diagnostic techniques including chromoendoscopy, magnified colonoscopy, and the newly developed narrow band imaging.

Depressed-type early invasive colon cancer in a patient treated with cyclooxygenase-2 inhibitor.

In vitro, nonsteroidal anti-inflammatory drugs (NSAIDs) have been well documented to suppress the occurrence of intestinal cancer in rodent models (1). In vivo, there is evidence that NSAIDs reduce the risk of colorectal cancer in humans (2, 3). Furthermore, NSAIDs have been associated with significant regression of adenomatous polyps in patients with familial adenomatous polyposis (FAP) (4‐6). We recently encountered a depressed-type submucosal cancer in a patient who had taken a preferential cyclooxygenase (COX-2) inhibitor, etodolac (Hypen, Nihon Shinyaku Co., Japan), for knee joint pain. Although regression of coexisting sporadic adenoma was identified, a depressed-type early invasive cancer was found on surveillance colonoscopy. We herein describe the first report of a depressed-type early invasive cancer in a patient receiving COX-2 inhibitor effective for sporadic adenoma.