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Updated: May 31, 2026
In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
Published on: July 25, 2019
Prognostic value of BAP1 expression in uveal melanoma: a comparative study with histopathological factors in a large
Patricia Valencia Nieto1,2, Ciro García Álvarez1,3, María Elena García Lagarto1,4
1Intraocular Tumours Unit, Valladolid University Clinical Hospital, Valladolid, Spain.
Purpose:
To evaluate the prognostic significance of BRCA1-associated protein 1 (BAP1) nuclear expression in enucleated eyes with uveal melanoma (UM), and to compare its predictive value with classical clinicopathological factors in a large Spanish cohort.
Design:
Prospective, single-center, observational-cohort study.
Subjects:
A total of 150 consecutive patients diagnosed with posterior uveal melanoma and treated with primary enucleation at a national reference center between 2006 and 2024.
Methods:
Immunohistochemical analysis of BAP1 expression was performed on formalin-fixed, paraffin-embedded tumor sections. Nuclear staining was classified as low grade (<33% positive tumor nuclei) or high grade (≥33%). Clinicopathological features and survival outcomes were assessed, and multivariate Cox regression was used to identify independent prognostic factors for melanoma-specific survival.
Main Outcome Measures:
Melanoma-specific survival and its association with BAP1 nuclear expression and classical prognostic variables.
Results:
Low grade nuclear BAP1 expression was detected in 50% of tumors and was significantly associated with worse melanoma-specific survival (hazard ratio [HR] = 2.72; 95% confidence interval [CI]: 1.04-7.11; p = 0.041). Additional independent predictors of poor prognosis included vortex vein invasion (HR = 4.55; p = 0.028), extrascleral extension (HR = 4.73; p = 0.004), and epithelioid cell type (HR = 4.12; p = 0.019). No significant association was observed between BAP1 expression and sex, mitotic index, or Ki-67 proliferation rate.
Conclusions:
Low grade nuclear BAP1 immunostaining is a strong, independent predictor of poor prognosis in uveal melanoma, comparable to established histopathological features. Immunohistochemical assessment of BAP1 is a cost-effective tool for risk stratification in routine clinical practice.
