Polymerase chain reaction detection of circulating tumour cells. EORTC Melanoma Cooperative Group, Immunotherapy...

Reverse transcriptase polymerase chain reaction (RT-PCR)-based assays to detect occult neoplastic cells offer the highest sensitivity for the study of tumour dissemination and minimal residual disease. The detection of small numbers of tumour cells in a clinical sample may result in a redefinition of what constitutes residual disease and relapse, affecting 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 standard quality control measures is pressing in order to facilitate meaningful assessment of the methodology and it's clinical value. A 2-day workshop organized by the immunotherapy subgroup of the EORTC Melanoma Cooperative Group was held on this topic at the Ludwig Institute in Epalinges-sur-Lausanne, Switzerland in January 1996, with Stefan Carrel as the local host. Many pertinent issues were discussed in great detail, covering every step from sample handling to quality control. This workshop resulted in a concerted action leading to the preparation of laboratory guidelines, which are summarized in this review.