Endoscopy

Introduction
The Endoscopy Division covers three fields of interest: the gastrointestinal (GI) tract,respiratory systemand head and neck. A total of 9,201 endoscopic examinations were　performed in 2001, of which 8,159 were GIendoscopy, 691 bronchoscopy, and 291 laryngoscopy. Recently, a remarkable increase has been noted in thenumber of endoscopic treatments, such as endoscopic mucosal resection (EMR), percutaneous endoscopicgastrostomy (PEG), endoscopic dilatation, and metallic stenting. A high detection rate foresophageal carcinomaat GI endoscopy is a characteristic of our hospital, which is explained by the fact that the large number ofpatients with head and neck cancer who have high risks of combining esophageal cancers are examined at ourdivision.
We have operated a digital filing system for endoscopic images since 1997. The filing system makes it prompt to compare new images with older ones of the same patients. The digital images have advantages of high quality resolution and the possibility of long-term preservation using EVIS 240 system. In addition, we have introduced a new operating system for endoscopy called Miracle, which connect with the local area network in the National Cancer Center Hospital East. We have newly operated a Miracle system for endoscopy since October 2001.

Routine Activities　
An electronic laryngoscope is routinely used in the pretreatment and postoperative evaluations of head and neck cancer patients. We also find it useful in patient education. Recent developments of instruments and techniques include metallic stenting for malignant esophageal stenosis, PEG for palliation, ultrathin cholangiopancreatoscopy, and adaptive enhancement by image processing. An endoscopic ultrasonography (EUS) provides important information in staging and determining resectability. EUS-guided fine-needle aspiration or biopsy is being conducted in patients with submucosal tumor or nodes adjacent to GI tract wall.
Therapeutic frontiers are also being explored by the use of EMR for early gastrointestinal The percentage of cases treated with EMR has been increasing, and this increase iscaused by expansion of indications. New techniques, such as endoscopic resection using an insulating-tipped diathermic needle knife (IT knife) for early gastro-intestinal cancer has overcome the limitation in size of the tumors. On colonoscopy, we have used a magnifying endoscope (CF240ZI, Olympus Optical Co., Ltd. Japan) routinely since December 1993. Endoscopic day surgery such as polypectomy and EMR, are now performed in one tenth of all examinations.
For diagnosis of early lung cancer, lung biopsy under real-time CT fluoroscopic guidance has been performed in a large number of cases, and has yielded promising results. Brachytherapy is applied to relapsed cases of lung cancer with a high response rate.

New Developments
Correct assessment of gastrointestinal mucosal color is extremely important in the endoscopic diagnosis ofdigestive tract diseases. New diagnostic method using endoscopic spectroscopy system (ESS) and narrow band imaging system (NBI) has been developed for the examination of the spectral characteristics of tissue in the GI tract and head and neck area. In our study, each lesion in GI tract had its own peculiar spectral characteristics,which suggested that ESS and NBI might become a useful modality for clarifying the spectral characteristics of　malignant lesions in comparison with any other benign lesions. It has been clarified that adaptive enhancement　by image processing is effective for the diagnosis of crypt pattern of colonic tumors, extent of cancerous　invasion in early gastric cancer and ulcer staging. Image analysis of the fine mucosal network pattern by　magnifying endoscopy is also being studied. These studies along with progress in electronic video endoscopy are thought to be the most promising concepts in endoscopic diagnosis. Furthermore, it is very important to develop them for making objective and quantitative diagnosis.
Genetic and immunohistochemical analyses using endoscopic biopsy specimens have allowed the prediction of chemosensitivity and survival in patients with advanced esophageal and gastric cancers. We have also adopted these methods to study the growth and development of hyperplastic polyp (hMLH1 and hMSH2 expression), serrated adenoma, superficial type lesions and synchronous/ metachronous cancers of the colon and rectum. In addition, we have investigated the correlation between bacterial infection and upper GI carcinogenesis. We found that mutant ALDH2-2 allele is strongly associated with multiple dysplastic or cancerous changes in the upper aerodigestive tract and that exhalation of high levels of acetaldehyde and normal oral microflora might be a regional source of this carcinogenic compound upon drinking.

T. SHINKAI
Y. SANO

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