Limitations of the nested reverse transcriptase polymerase chain reaction on tyrosinase for the detection of malignant melanoma micrometastases in lymph nodes

The specificity and sensitivity of the nested reverse transcriptase polymer ase chain reaction (RT-PCR) on tyrosinase was studied, for the detection of micrometastases of malignant melanoma. The specificity was assessed in the blood of six healthy donors, four patients with non-melanoma cancers of wh ich one patient was treated with granulocyte-colony stimulating factor. Lym ph nodes of nine patients without malignant melanoma were tested and four c ell lines of various other tumours. Six of the nine non-melanoma lymph node s were positive in this assay. The sensitivity was tested in a spike experi ment in vitro, using a melanoma cell line. The detection limit was ten mela noma cells per 10(7) peripheral blood lymphocytes. (C) 2000 Cancer Research Campaign.