Detection of melanoma seeding during surgical procedures – an RT-PCR based model

Abstract

Aim: It has long been suggested that malignant cells may be shed into the blood stream during any given surgical procedure for cancer. A number of studies have now reported the detection of occult melanoma cells in peripheral blood using a reverse transcriptase polymerase chain reaction (RT-PCR) based assay. The principal aim of these studies has been to determine a prognostic value for the test and not to evaluate the influence of intervention upon results.Methods:In this pilot study we aimed to determine whether the assay could be used as a model to detect cells that are seeded during surgery. Peripheral blood samples were obtained pre- and post-operatively on twenty patients undergoing surgery for malignant melanoma – ten with primary disease and ten undergoing regional lymphadenectomy. A further ten patients undergoing surgery for non-melanoma conditions provided controls.Results: Using RT-PCR, it was possible to identify tyrosinase transcripts in the peripheral blood of one of ten patients undergoing excision of local disease and four of ten undergoing surgery for regional metastatic disease.Conclusion: It was concluded that this technique does enable detection of a greater percentage of RT-PCR findings post-operatively. This in turn may provide a means for optimizing or comparing surgical techniques and provides a potential guide in the use of adjuvant therapies.