Risk factors for residual and recurrent uveal melanoma after trans-scleral local resection

Aims-The aims of this study were to report local tumour control after transscleral local resection of uveal melanoma and to identify risk factors for (i) clinical residual tumour recognised immediately after surgery, and (ii) delayed tumour recurrence from subclinical microscopic deposits. Methods-The sample included 310 patients, treated by choroidectomy (188), cyclochoroidectomy (87), or iridocyclectomy (35), with follow up ranging from 42 days to 20.9 years (median 36 months), a mean basal largest tumour diameter of 13.2 mm, and a mean tumour thickness of 7.4 mm. Results-There were 24 patients with residual tumour. Forward stepwise logistic regression indicated that posterior extension to within 1 disc diameter of the optic disc or fovea was the sole best indicator of the risk of residual disease (p<0.001). After excluding these cases, 286 patients were studied for the development of delayed local recurrence, which occurred in 57 cases. Forward stepwise multivariate analysis showed the statistically significant predictors for recurrent tumour to be epithelioid cellularity (p=0.002), posterior tumour extension to <1 disc diameter of disc of fovea (p=0.002), large tumour diameter greater than or equal to 16 mm (p=0.019) and lack of adjunctive plaque radiotherapy (p=0.018). Conclusions-The recurrence rate at 4 years varied from 6% if no risk factors were present to 57% if there were more than two risk factors.