Abstract
Purpose:
To determine whether any conventional clinical prognostic factors for metastasis from uveal melanoma retain prognostic significance in multivariate models that includes gene expression profile (GEP) class of the tumor cells.
Methods:
Prospective IRB-approved clinical study of GEP testing and other conventional prognostic factors for metastasis and metastatic death in 299 patients with primary posterior uveal melanoma evaluated by fine-needle aspiration biopsy (FNAB) of the tumor at the time of or shortly prior to initial treatment with GEP testing of some of the aspirated tumor cells. Univariate prognostic significance of all evaluated potential prognostic variables (patient age, largest basal diameter of tumor, thickness of tumor, intraocular location of tumor, cytopathological class of tumor cells, and GEP class) was performed by comparison of Kaplan-Meier event rate curves and univariate Cox proportional hazards modeling. Multivariate prognostic significance of combinations of significant prognostic factors identified by univariate analysis was performed using step-up and step-down Cox proportional hazards modeling.
Results:
GEP class of the tumor cells was the strongest prognostic factor for metastatic death in this series. However, largest basal diameter of the tumor, thickness of the tumor and intraocular tumor location also proved to be significant individual prognostic factors in this study. On multivariate analysis, a two-term model that incorporated GEP class and largest basal diameter was associated with strong independent significance of each of the factors.
Conclusions:
Although the currently available GEP test for prognostic testing of uveal melanoma samples has asserted that recognized clinical prognostic factors for metastasis do not modify the metastatic risk of a patient with a GEP class 2 tumor, our single center study that included a substantial proportion of smaller tumors showed that both GEP class and LBD of the tumor are independent prognostic factors for metastasis and metastatic death in multivariate analysis.