POLYMERASE CHAIN-REACTION DETECTION OF CIRCULATING TUMOR-CELLS

Reverse transcriptase polymerase chain reaction (RT-PCR)based assays t o detect occult neoplastic cells offer the highest sensitivity for the study of tumour dissemination and minimal residual disease. The detec tion of small numbers of tumour cells in a clinical sample may result in a redefinition of what constitutes residual disease and relapse, af fecting future patient management. However, there remains disparity in the published data on the clinical value of RT-PCR for the detection of circulating tumour cells. This most likely reflects differences in the methods for sample preparation, RNA extraction, and cDNA synthesis among laboratories. Consequently the need for implementation of stand ard quality control measures is pressing in order to facilitate meanin gful assessment of the methodology and it's clinical value. A 5-day wo rkshop organized by the immunotherapy subgroup of the EORTC Melanoma C ooperative Group was held on this topic at the Ludwig Institute in Epa linges-sur-Lausanne, Switzerland in January 1996, with Stefan Carrel a s the local host. Many pertinent issues were discussed in great detail , covering every step from sample handling to quality control. This wo rkshop resulted in a concerted action leading to the preparation of la boratory guidelines, which are summarized in this review.