Abstract
Purpose :
Uveal melanoma (UM) is the most common primary intraocular malignancy in adults and has a high risk of metastasis (50%). Previous studies have correlated nuclear BRCA1- associated protein 1 immunohistochmical (BAP1-IHC) staining of UM in enucleated eyes with patient outcome. The correlation between BAP1-IHC and gene expression profiling (GEP) and their relative utility as prognostic tests have not been investigated.
Methods :
We performed a retrospective chart review and prospective follow-up of 30 patients with primary UM who underwent enucleation from 2008-2018. The clinical history, histopathological findings, GEP classification, and BAP1-IHC of the formalin-fixed paraffin-embedded (FFPE) tissues and follow-up data for metastasis were collected and statistically analyzed. The BAP1-IHC was graded in a masked fashion by two independent obstervers (HEG, GS). Grade 0-1 was considered low BAP1 expression and Grade 2-3 was considered high BAP1 expression.
Results :
The mean follow-up was 30 (SD 23) months. Thirteen of 14 patients (93%) who had metastasis had low nuclear BAP1 expression, of which 11 (79%) were GEP class 2 and 2 (14%) were class 1b. One patient with a class 1a tumor and high nuclear BAP1 expression had metastasis. Positive and negative predictive values for BAP1-IHC were 68% and 91% respectively compared to 73% and 80% for GEP. Both tests had an accuracy rate of 77%.
Conclusions :
Nuclear BAP1-IHC correlated strongly with GEP classification and was equally accurate in prediction of metastasis. Evaluation of nuclear BAP1-IHC in enucleated eyes with UM is a reasonable alternative to GEP for predicting metastasis.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.