1. SENTINEL LYMPH NODE BIOPSY IN COLORECTAL CARCINOMA E Leung*, J Francombe*, S Chew, PR Douglas, GL Newstead Prince of Wales Hospital, Sydney, Australia *Warwick Hospital, Warwickshire, UK INTRODUCTION 50% PATIENTS WITH CURATIVE SURGERY DIE WITHIN 5YEARS CHEMOTHERAPY INEFFECTIVE IN DUKES B (IMPACT B2 TRIAL) (But would benefit those 30% destined to relapse) NEED TO IDENTIFY THOSE DUKES B PATIENTS DESTINED TO RELAPSE ? INACCURATE STAGING, ? DETECTION OF MICROMETASTASES INTRODUCTION 50% PATIENTS WITH CURATIVE SURGERY DIE WITHIN 5YEARS CHEMOTHERAPY INEFFECTIVE IN DUKES B (IMPACT B2 TRIAL) (But would benefit those 30% destined to relapse) NEED TO IDENTIFY THOSE DUKES B PATIENTS DESTINED TO RELAPSE ? INACCURATE STAGING, ? DETECTION OF MICROMETASTASES SENTINEL LYMPH NODE THE FIRST NODE THAT RECEIVES LYMPH FROM THE PRIMARY TUMOUR. THE NODE ALSO HAS THE HIGHEST POTENTIAL TO CONTAIN TUMOUR CELLS WHEN THEY ARE PRESENT. (Morton et al Arch Surg 1992) SENTINEL LYMPH NODE THE FIRST NODE THAT RECEIVES LYMPH FROM THE PRIMARY TUMOUR. THE NODE ALSO HAS THE HIGHEST POTENTIAL TO CONTAIN TUMOUR CELLS WHEN THEY ARE PRESENT. (Morton et al Arch Surg 1992) STUDY AIMS COULD WE IDENTIFY SLN? COMPARE ROUTINE H&E TO IMMUNOHISTOCHEMICAL STAINING OF SLN COULD THE SLN ACCURATELY STAGE THE LYMPH NODE BASIN? MATERIALS AND METHODS PATIENTS PROSPECTIVELY STUDIED BETWEEN JAN – DEC 2001 2ML BLUE V DYE INJECTED INTRAOPERATIVELY PERITUMOUR STANDARD COLORECTAL RESECTION PERFORMED SLN IDENTIFIED BY SURGEON AND HISTOPATHOLOGIST H&E STAINING ALL NODES H&E AND IMMUNOHISTOCHEMICAL STAINING OF SLN NUMBER41 SLN DEMONSTRATED 38 (92.6%) SLN POSITIVE11(28.9%) SLN NEG H&E, POS HIS1 (3.7%) IHS=IMMUNOHISTOCHEMICAL STAINING NUMBER41 SLN DEMONSTRATED 38 (92.6%) SLN POSITIVE11(28.9%) SLN NEG H&E, POS HIS1 (3.7%) IHS=IMMUNOHISTOCHEMICAL STAINING SLN POS: NSLN NEG4 SLN POS: NSLN POS7 SLN NEG: NSLN POS8 SLN NEG: NSLN NEG19 SLN NI : NSLN POSITIVE 2 SLN NI : NSLN NEGATIVE 1 NI=Not identified SLN POS: NSLN NEG4 SLN POS: NSLN POS7 SLN NEG: NSLN POS8 SLN NEG: NSLN NEG19 SLN NI : NSLN POSITIVE 2 SLN NI : NSLN NEGATIVE 1 NI=Not identified SENSITIVITY(True positive rate)46.6% (How good is SLN at picking up patients with positive nodes) SPECIFICTY(True negative rate)82.6% (How good is SLN at correctly excluding patients without positive nodes) FALSE NEGATIVE RATE53.3% SENSITIVITY(True positive rate)46.6% (How good is SLN at picking up patients with positive nodes) SPECIFICTY(True negative rate)82.6% (How good is SLN at correctly excluding patients without positive nodes) FALSE NEGATIVE RATE53.3% POSITIVE PREDICTIVE VALUE63.6% (If patient SLN positive, probability node basin will be positive) NEGATIVE PREDICTIVE VALUE 70.3% (If patient SLN negative, probability node basin will be negative) POSITIVE PREDICTIVE VALUE63.6% (If patient SLN positive, probability node basin will be positive) NEGATIVE PREDICTIVE VALUE 70.3% (If patient SLN negative, probability node basin will be negative) FEASIBLESLN ID RATE 92.6% SLN NOT ID2 BULKY TUMOURS WITH LOCAL SPREAD 1 NODE NEG IHSINCREASES MM DETECT 3.7%(?WORTHWHILE) SLN BIOPSY ALONE IS NOT SUFFICIENT TO ACCURATELY STAGE DISEASE. SLN DOES NOT ALTER EXTENT OF RESECTION SLN IS A USEFUL ADJUVANT. IF A POSITIVE SLN IDENTIFIED THEN FURTHER EXAMINATION OF THE NODE BASIN IS NOT REQUIRED IF A POSITIVE SLN IDENTIFIED THEN FURTHER EXAMINATION OF THE NODE BASIN IS NOT REQUIRED. SLN IF POSITIVE IS A TIME AND COST EFFECTIVE SCREENING TOOL TO THE HISTOPATHOLOGIST. NEGATIVE SLN DOES NOT EXCLUDE POSITIVE BASIN NODES, FURTHER NODE EXAMINATION MANDATORY. A NEGATIVE SLN ADDS NO FURTHER INFORMATION. RESULTS NON SENTINEL NODES SENTINEL NODES CONCLUSIONS