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A COMPARISON of LAPAROSCOPICALLY ASSISTED and OPEN COLECTOMY for COLON CANCER. The Clinical Outcomes of Surgical Therapy Study Group (Cost Study). NEJM, May 13, 2004. BACKGROUND METHODS RESULTS CONCLUSIONS EVIDENCE BASED MEDICINE Ranking of the Study. BACKGROUND.
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A COMPARISON of LAPAROSCOPICALLY ASSISTED and OPEN COLECTOMY for COLON CANCER The Clinical Outcomes of Surgical Therapy Study Group (Cost Study) NEJM, May 13, 2004
BACKGROUND • METHODS • RESULTS • CONCLUSIONS • EVIDENCE BASED MEDICINE • Ranking of the Study
Phillips, Ann, Surg, 1992 First to report laparoscopic approach to colectomy for colon cancer in 24 patients Berends, Lancet, 1994 Reported 3 of 14 patients developed trocar wound site recurrences in series of laparoscopically assisted resections for colon cancer.
Reilly, Disease Colon Rectum, 1996 Reported less than 1% wound site recurrences following laparoscopically assisted resections for colon cancer.
Questions Raised • Could a proper oncologic resection be performed with the laparoscopic approach? • Were there staging inaccuracies with the laparoscopic approach? • Were patterns of tumor cell dissemination altered by the laparoscopic approach?
Questions Raised • Were wound site recurrence rates truly higher with the laparoscopic approach? • Were overall recurrence rates higher with the laparoscopic approach? • Were disease free and overall survival rates lower with the laparoscopic approach?
Questions Raised • Were post operative complication rates higher with the laparoscopic approach? • Was post operative recovery faster with the laparoscopic approach?
COST STUDY • Initiated in 1994 to ensure that the laparoscopic approach to colon cancer was properly tested before its use became wide spread. • Surgeons generally adopted a virtual moratorium on laparoscopic resection for colon cancer outside of this trial.
Design • Noninferiority trial • Prospective randomized trial • Involved 66 credentialed surgeons from 48 institutions in the USA and Canada. • Compared laparoscopic vs open approach to colon cancer
Patients • Inclusion Criteria • 18 years of age or older • Diagnosed clinically with colon adenocarcinoma and had histologic confirmation at surgery • Right or left colon cancer
Patients • Exclusion Criteria • Pregnancy • Inflammatory bowel disease • Familial polyposis • Previous malignant tumor • Current malignant tumor • Severe medical illness • Prohibitive abdominal adhesions
Patients • Exclusion Criteria • Transverse colon cancer • Rectal cancer • Acute bowel obstruction • Perforation from cancer • Advanced local disease • Metastatic disease
Quality Control • 66 credentialed surgeons at 48 institutions • Each surgeon was required to have had performed at least 20 laparoscopically assisted colorectal surgeries prior to entry into the trial
Quality Control • Prior to entry into trial, each surgeon submitted a videotape of a laparoscopic colectomy that was reviewed for: • thoroughness of abdominal exploration • identification of critical adjacent structures • oncologic techniques • degree of avoidance of direct tumor handling • level of mesenteric ligation
Quality Control • Random audits of videotapes during trial • Assessment of bowel resection margins during trial
TECHNIQUE OF LAPAROSCOPIC COLON RESECTION • Pneumoperitoneal/ intracorporeal approach to: • abdominal exploration • mobilization of colon • identification of critical structures • ligation of vascular pedicles • Exteriorization of bowel through small incision for resection/ anastomosis
INDICATIONS FOR COVERSION FROM LAPAROSCOPIC TO OPEN SURGERY • Presence of associated conditions • Findings of advanced disease • Massive adhesions • Technical difficulties • Inadequate oncologic margins • Surgeons descretion for patient safety
Adjuvant chemotherapy was allowed at the physicians or patient’s descretion
RANDOMIZATION • Performed centrally at the North Central Cancer Treatment Group statistical office • Patients randomly assigned to: • laparoscopically assisted colectomy • open laparotomy and colectomy
RANDOMIZATION • Through use of minimization algorithm, treatment assignment was balanced with respect to three stratification variables: • surgeon • primary tumor site – right, left, sigmoid
RANDOMIZATION • American Society of Anesthesiologists Class • Class I – patient appears healthy • Class II – patient has systemic, well controlled disease • Class III – patient has multiple symptoms of disease, or well controlled major system disease
FOLLOW – UP: • COMPLICATIONS • Assessed by single reviewer • Reviewer unaware of patient’s treatment assignment • Assessed at date of discharge, 2 months, and 18 months
FOLLOW – UP: • TUMOR RECURRENCE • Physical exam including inspection of wound sites • CEA every 3 months for first year, then every 6 months for 5 years • CxR every 6 months for 2 years, then every year • Colonoscopy, or proctosigmoidoscopy and barium enema every 3 years • Recurrence had to be confirmed with imaging or endoscopy
STATISTICAL ANALYSIS • Designed to compare the following end points in the laparoscopic vs the open colectomy groups: • Primary end point • Time to tumor recurrence defined as the time from randomization to first confirmed recurrence • Secondary end points • Variables related to recovery • Complications • Disease free survival • Overall survival
Characteristics of Patients and Tumors • 872 patients underwent randomization from August 1994 to August 2001 over 7 years • 2 patients subsequently declined surgery • 7 patients subsequently were ineligible • This left 863 patients for final analysis
Characteristics of Patients and Tumors Grade of Differentiation
Characteristics of Patients and Tumors Depth of Invasion
SURGERY • Total Surgery Patients • Total patients 863 • Open colectomy 428 (49.6%) • Laparoscopic Colectomy 435 (50.4%) • Successful laparoscopic colectomy 345 (79%) • Converted to open colectomy 90 (21%)
SURGERY • Reasons for conversion# of patients • Advanced disease 22 (24%) • Other 21 (23%) • Adhesions 14 (16%) • No visualization 12 (13%) • of critical structures • Unable to mobilize colon 10 (11%) • Complicating disease 3 (3%) • Inadequate resection margins 4 (4%) • Intraoperative complications 4 (4%)
SURGERY Conversion Rates P Value High vs low volume surgeons >0.05 Early vs late trial entry surgeons >0.05
RECURRENCE (after median follow-up of 4.4 years)