Risk factors for metastatic uveal melanoma after trans-scleral local resection

Aims-This study reports the metastatic death rate after trans-scleral local resection of uveal melanoma and identifies relevant risk factors. Methods-Local resection was performed in 332 patients (mean. age 51 years), with follow up ranging to 20.9 years (median for living patients 33 months). The tumours had a mean largest basal diameter of 13.1 mm and mean thickness of 7.5 mm, with 135 containing epithelioid cells. Risk factors were identified by Cox analysis and metastatic rates demonstrated using Kaplan-Meier curves. Results-There were 52 deaths from metastatic melanoma. The significant risk factors were (i) age more than 60 years at treatment (p=0.001), (ii) mixed/epithelioid tumours (p=0.003), (iii) superior location of mixed/epithelioid tumours (over and above (ii)) (p=0.001), (iv) largest basal tumour diameter of 16 mm or more (p<0.001), (v) lack of adjunctive radiotherapy (p=0.031), (vi) secondary enucleation for bulky residual/recurrent tumour (p=0.002), and (vii) secondary enucleation for small residual/recurrent tumour extraocularly (p=0.019). Metastatic death was not significantly associated with (i) incomplete tumour excision (p=0.163), and (ii) small residual/recurrent tumour treated by enucleation (p=0.855). Conclusions-Survival diminished from 92% at 15 years if less than two risk factors were present to less than 30% in 3.5 years if more than three risk factors were present.