Purpose
To characterize the clinical features and intraocular radiation treatment response of class 1 and class 2 uveal melanomas based on gene expression profiling assay.
Methods
The charts of one hundred thirty patients who diagnosed uveal melanoma by tumor biopsy from a single institution were reviewed. The medical records of the ninety patients who underwent intraocular radiation treatment were analyzed for clinical characteristics and radiation response based upon molecular pattern of uveal melanomas.
Results
Fifty-eight patients (64.4%) had class 1 tumors and thirty-two patients (35.6%) had class 2 tumors. The mean age of patients at the time of diagnosis was significantly greater in patients with class 2 tumors (68.8±15.3 years) as compared to patients with class 1 tumors (60.1±15.2 years) (P=0.047). There was no difference in fundus findings and fluorescein angiographic features (presence of orange pigment, drusen, and subretinal fluid) (P=0.197, 0.285, 0.334) and statistically borderline difference in the rate of enucleation between 2 classes during follow-up periods (P=0.052). Mean pretreatment ultrasound thickness was significantly greater for class 2 patients (6.61±3.0 mm) as compared to class 1 patients (4.80±2.4 mm) (P=0.003). Moreover, there was significant difference between class 1 and class 2 tumors based on the extent of change in ultrasound thickness at approximately 6, 12 months after intraocular radiation treatment (P=0.018).
Conclusions
Age and ultrasound tumor thickness were pretreatment findings to predict molecular pattern, but there was a large variability in most clinical parameters (gender, tumor location, chorioretinal findings, metastasis and adjunctive treatments) in both classes in determination of molecular characteristics of the uveal melanomas. This study demonstrated that class 2 uveal melanomas are generally greater in tumor thickness at diagnosis and had significantly greater decrease in thickness after intraocular radiation treatment than class 1 uveal melanomas.