Colorectal Surgery


Introduction
Since July, 1992, when our clinical activities were launched, the number of major operations done by the Colorectal Surgery Division has gradually been increasing on an annual basis. In 1997, we operated on 310 cases with gastrointestinal malignancies. Of these 310 cases, 195 had colorectal cancer and the remaining 115 other abdominal malignancies such as gastric cancer. The number of colorectal cancer cases has actually been increasing, and our approach to patients with this malignancy involves various therapeutic modalities in close cooperation with the gastrointestinal oncology group of the center.

Routine Activities
1. Outpatient activities: The outpatient clinic is open 5 days a week and about 250 new patients were accepted last year. All outpatients who have undergone curative colorectal surgery are followed closely using various diagnostic modalities to detect early recurrence. The function care clinic for postoperative patients with lower rectal cancer is also open every Friday to evaluate these cases objectively employing the urodynamic scanner or rigiscan.
2. Treatment system: The Colorectal Surgery Division consistis of four consultants and two to three residents. Five to seven operations a week are carried out under general anesthesia. We have three conferences a week; (l) an image diagnosis conference with radiologists and endoscopists on Monday, (2) a case conference on Friday and (3) the integral clinical conference with the gastroenterology group on Wednesday, where we make therapeutic decisions on all new cases with GI malignancies based on discussions with medical oncologists, endoscopists and surgeons. The surgical pathology conference is held monthly with attending surgeons and pathologists.
3. Treatment modalities: In early cancer cases, many modalities have been introduced, including as endoscopic mucosal resection (EMR) and transanal endoscopic microsurgery (TEM). In addition, the laparoscopy-assisted operation (Lap-Op) was introduced in 1994 and has since been used as a minimally invasive surgical technique. In our understanding, it is indicated for patients with early cancer with submucosal invasion diagnosed histologically after EMR or those who have unresectable metastatic lesions, because with this technique the extent of lymph node dissection is limited to parabolic nodes (D l). Until last year, about 10% of our surgical cases were treated with Lap-Op. Recently, we have adopted the new technique of wider lymph node dissection up to D2, such that its indications have been extended. (see research activities.)

Research Activities
1. IORT for rectal cancer patients: To clarify the efficacy of limited surgery for lower rectal advanced cancer, a one arm prospective study on nerve sparing operation + IORT (intraoperative radiotherapy) is now ongoing.
2. Adjuvant chemotherapy (NSAS-CC trial): To clarify the efficacy of adjuvant chemotherapy using oral 5-FU derivatives (UFT: Tegafur+uracil), a randomized controlled trial for those with Dukes C colorectal cancer comparing the 2 arms, i.e. surgery alone vs. with adjuvant chemotherapy, is now ongoing.
3. Early feeding trial: To evaluate whether or not early feeding can shorten the patientÕs postoperative hospital stay, a prospective controlled trial to clarify the feasibility of shortening the hospital stay, as compared with historical controls, is ongoing.
4. The extension of indications for Lap-Op: A prospective trial for extending Lap-Op indications was started for patients with the following eligibility criteria, 1) tumor diameter within 5 cm, 2) no mass lesions over 7 mm in diameter around the main tumor on CT image, 3) without histological component of poorly differentiated adenocarcinoma. These criteria are based on the results of a retrospective analysis of preoperative conditions in our past operative cases. In this trial we anticipate curability exceeding 99%, and about 40% of patients with operable colon cancer are considered to be treatable by this technique.

Statistics
Number of Operative Cases in Colorectal Surgery Division in 1992-1996
yearTotal no.
of cases
Colorectal casesStomach
cases
colonrectumtotal
1993196633810177
19942386641107105
1995270756113688
19962958468152122
199731012075195115
Total1,307406283689516
Survival rate by pathological stage

1-yr2-yr3-yr4-yr5-yr
stage I9999979797
II9896929288
IIIa9591919183
IIIb8473734747
IV6438383828
Kaplan-Meier method (%)

(M. Ono)


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