THE PROGNOSTIC-SIGNIFICANCE OF C-MYC ONCOGENE EXPRESSION IN UVEAL MELANOMA

The role of the c-myc oncogene has been little investigated in uveal m elanoma. In this study an analysis of c-myc oncoprotein expression was undertaken using flow cytometry in 71 patients with posterior uveal m elanoma. Nuclear c-myc oncoprotein was detected in all of the tumours, and survival analysis revealed a significant association between high oncoprotein positivity and improved survival (log rank test: chi(2) = 6.47, P = 0.01). Multifactorial analysis using Cox's proportional haz ards model revealed nuclear c-myc oncoprotein to be an independent pro gnostic marker more accurate than other clinicopathological parameters (log rank test: chi(2) = 6.61, P = 0.01). However, this result of hig h oncoprotein expression correlating with improved outcome is surprisi ng and in contrast to our previous studies using the same method on cu taneous melanoma, where high levels of nuclear c-myc expression have b een found to correlate with poor outcome both in primary and secondary disease. This study suggests that the pattern of oncogene expression in uveal melanoma is distinct from cutaneous melanoma and that the und erlying biology of these tumours is different. (C) 1998 Lippincott-Rav en Publishers.