IMMUNOHISTOCHEMICAL EXPRESSION OF C-MYC ONCOGENE, HEAT-SHOCK PROTEIN-70 AND HLA-DR MOLECULES IN MALIGNANT CUTANEOUS MELANOMA

The clinical course of malignant melanomas is frequently unpredictable , although a number of prognostically useful variables can be identifi ed. There is a need for additional markers of prognostic value. In a s eries of 60 malignant cutaneous melanomas, we analysed the immunohisto chemical expression of c-myc proto-oncogene, heat shock protein 70 (HS P70) and HLA-DR molecules in order to investigate their prognostic sig nificance. C-myc, HSP70 and HLA-DR were expressed in 43.3%, 56.6% and 38.3% of all melanoma cases, respectively. Advanced Clark levels (Clar k III-V) were significantly associated with c-myc expression rate (P<0 .05), HSP70 detection (P<0.01) and HLA-DR positivity (P<0.01). Increas ed Breslow thickness (>1.5 mm) was related to HLA-DR expression (P<0.0 5). High mitotic rate was closely associated with c-myc positivity (P< 0.05), while HSP70 and HLA-DR expression separately correlated to clin ical stage of the disease (P<0.05). The evaluation of these variables may be of immunological and prognostic significance. They were found t o be associated with melanocyte subpopulations of the vertical growth phase which are arguably characterized by an increased invasive potent ial.