HLA–A2 Expression in Uveal Melanoma: Implications for Adjuvant Immunotherapy

Abstract

Abstract: : Purpose: To evaluate HLA–A2 expression in a cohort of patients affected by uveal melanoma. Methods: A prospective study on 237 patients affected by choroidal and ciliary body melanoma was performed to quantify HLA–A2 expression. An analysis from the cytotoxic T lymphocytes (CTLs) in peripheral blood was made. Up regulation of HLA–A2 was related to: demographic characteristics, tumor dimensions, tumor recurrence and development of liver metastases. Results: Mean follow–up was 32 months (range 6–108 months). Mean large basal tumor diameter (LBD) was 8 mm (range 4–14 mm). HLA–A2 expression was positive in 110/237 cases (46%). HLA–A2 expression was negative in 127/237 cases (54%). Both groups were not statistically different as tumor characteristics (P>0.3, P>0.5). Eight patients HLA–A2+ (7.3%) developed liver metastases versus ten patients HLA A2– (7.9%). Conclusions: If HLA–A2 + is mandatory to treat patients affected by uveal melanoma with immunological adjuvant (i.e immunotherapy based on HLA class I restricted CTLs) more than 50% of patients are untreatable. Identification of more selective, individual cytogenetic prognostic markers is mandatory to improve patient selection for any adjuvant treatment.

Keywords: melanoma • immunomodulation/immunoregulation