POLYMERASE-CHAIN-REACTION DETECTION OF MELANOMA-CELLS IN THE CIRCULATION - RELATION TO CLINICAL STAGE, SURGICAL-TREATMENT, AND RECURRENCE FROM MELANOMA

Purpose: The detection of melanoma cells in the circulation by polymer ase chain reaction (PCR) assays has been shown by several investigator s to correlate with the stage of the disease and possibly with prognos is. Patients and Methods: We performed prospective studies on 276 pati ents with primary melanoma and regional lymph node (LN) metastases to assess the predictive value of PCR detection of tyrosinase and melanom a antigen recognized by T cells-1 (MART-1) in the blood for recurrence of melanoma. Results: PCR tests for gp 100, Muc-18, and p97 reacted w ith RNA in blood from healthy subjects and were considered unsuitable for patient monitoring. The tests were most frequently positive in the first 3 months after surgery. There were 47 recurrences in 123 patien ts who had been followed up for 18 months. Assays within 3 months of s urgery predicted recurrence from melanoma in 66% of the latter (tests for tyrosinase alone detected 51% and MART-1 alone 21% of the patients ). Hence, 34% of recurrences were not predicted by tests in the early postoperative period. This did not appear to be because of marker-nega tive melanoma because summation of tests over the first year identifie d 89% of those with recurrent disease. Conclusion: Positive tests were recorded in 35% of patients who remained disease free, but it is too early to assess whether these represent false positive results. The fa lse-negative results raise the question of whether the assays will pro vide a reliable basis for selection of patients for adjuvant therapy. (C) 1998 by American Society of Clinical Oncology.