Uveal melanoma is characterized by an unpredictable clinical course, d
uring which metastatic disease may occur after a prolonged and, at pre
sent, undefinable disease-free interval. Because of its relative rarit
y and the dispersion of cases, the possible genetic alterations implic
ated in the invasive and metastatic behaviour of this ocular neoplasm
have not yet been characterized. The aim of this immunohistochemical r
etrospective study was to assess the expression of nm23 gene product,
proposed to be a metastasis-suppressor gene, in uveal melanoma and to
analyse its prognostic significance in relation to the various convent
ional histopathological parameters, currently considered the major pro
gnostic indicators in this intra-ocular neoplasm. We analysed formalin
-fixed paraffin-embedded samples excised from 33 patients with uveal m
elanoma. Of these, 22 (67%) were positive for monoclonal antibody nm23
. This nm23 positivity was inversely associated with scleral invasion
level (P = 0.001) and largest tumour diameter (P = 0.02), which repres
ent the two most significant prognostic factors for metastasis. On the
other hand, there was no correlation between nm23 expression and othe
r prognostic markers such as cell type, intraocular location or clinic
al characteristics. These results may suggest a close relationship bet
ween nm23 gene expression and metastatic potential of uveal melanomas.
In addition, analysis of nm23 gene expression on bioptic tissue may r
epresent an extreme useful prognostic tool for metastatic progression
of uveal melanomas.