Posterior uveal melanoma in 321 Asian Indian patients: analysis based on the 8th edition of American Joint Committee Cancer classification.

Abstract

To evaluate the presenting features, treatment, and outcomes of posterior uveal melanoma (PUM) in Asian Indians based on the 8th edition of American Joint Committee on Cancer (AJCC) classification. Retrospective interventional case series of 321 Asian Indian patients with PUM. Based on AJCC, PUM was classified into categories T1 (n = 36; 11%), T2 (n = 74; 23%), T3 (n = 126; 39%), and T4 (n = 85; 27%). Regarding tumor features, T4 was more likely to have pre-equatorial epicenter (vs T1 and T2; p ≤ 0.011), iris abnormalities (vs T2 and T3; p ≤ 0.002), and extraocular tumor extension (vs T3; p = 0.001), whereas T1 was more likely to have macular epicenter (vs T2, T3, T4; p ≤ 0.013), lipofuscin deposits (vs T3 and T4; p ≤ 0.008), and amelanotic tumors (vs. T4; p = 0.003). On multivariate analysis, factors predictive of systemic metastasis were increasing tumor thickness (p = 0.002) and extraocular tumor extension (p = 0.009). The 5-, 10-, and 15-year melanoma-related metastases rates were 0%, 0%, and 0% in T1, 0%, 60%, and 60% in T2, 7%, 40%, and 70% in T3 and 13%, 36%, and 76% in T4, respectively. Risk for metastasis was 1.23 times more for every 1-mm increase in tumor thickness and 9 times more with extraocular tumor extension. The AJCC 8th edition provides prognostic classification for PUM in Asian Indian patients. The significant risk factors for metastasis were increasing tumor thickness and extraocular tumor extension.