RELIABILITY OF REVERSE TRANSCRIPTION-POLYMERASE CHAIN-REACTION (RT-PCR)-BASED ASSAYS FOR THE DETECTION OF CIRCULATING TUMOR-CELLS - A QUALITY-ASSURANCE INITIATIVE OF THE EORTC MELANOMA COOPERATIVE GROUP

Reverse transcription-polymerase chain reaction (RT-PCR)-based assays detecting occult neoplastic cells are increasingly being used for the study of tumour dissemination and minimal residual disease. However, d ifferent methods are employed by various research groups and the resul ts are heterogenous. We prospectively assessed the results from nine l aboratories performing tyrosinase RT-PCR assays for the detection of m elanoma cells on a series of blind samples. After complete analysis, t he results were compared for sensitivity and specificity. All laborato ries reported correct results for cDNA standards. Five laboratories at tained acceptable specificity and a sensitivity detecting 10 cells in 10ml of whole blood. Four laboratories had unacceptable specificity an d/or sensitivity. This blind study highlights the difficulty of RT-PCR data interpretation and the need for quality assurance between labora tories. Measures to increase the reliability of RT-PCR assays are prop osed, which have to be prospectively evaluated in future studies. (C) 1998 Elsevier Science Ltd. All rights reserved.