1. ¹Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
2. ²Department of Clinical Biochemistry, NBG, Aarhus University Hospital, Aarhus, Denmark
3. ³Department of Plastic Surgery, Aarhus University Hospital, Aarhus, Denmark
4. ⁴Department of Surgical Gastroenterology, Hvidovre University Hospital, Aarhus, Denmark

Correspondence: Dr Henrik Schmidt, Department of Oncology, Aarhus University Hospital, Norrebrogade 44, 8000 Aarhus C, Denmark. E-mail: hesch@as.aaa.dk

Received 1 September 2005; Revised 19 October 2005; Accepted 8 November 2005; Published online 12 January 2006.

Abstract

The detection of melanoma cells in peripheral blood has been proposed to select patients with a high risk of relapse. In this study, tyrosinase and melanoma antigen recognized by T cells 1 (MART-1) mRNA expression was evaluated in serial samples obtained before definitive surgery and during follow-up in patients with American Joint Committee on Cancer stage I–II melanoma. Serial samples (n=2,262) were collected from 236 patients from 1997 to 2002. Analyses of the RNA samples were performed with a calibrated reverse transcriptase-PCR assay. Gender, age, primary tumor site, ulceration, thickness, Clark level, and histological subtype were analyzed together with tyrosinase and MART-1 mRNA treated as updated covariates in a Cox proportional-hazard model. After a median follow-up time of 66 months, 42 out of 236 patients (18%) had relapsed. The following variables were significantly associated with relapse-free survival in the univariate analyses: tyrosinase, MART-1, gender, ulceration, thickness, Clark level, and histological subtype. Entering these covariates into a multivariate Cox analysis resulted in thickness as the single independent prognostic factor (P<0.0001), whereas MART-1 (P=0.07) approached significance at the 5% significance level. The serial measurements of tyrosinase and MART-1 mRNA in peripheral blood of stage I–II melanoma patients cannot be demonstrated to have independent prognostic impact on relapse-free survival.