Conditional Survival of Patients With Uveal Melanoma
Factoring in years of metastasis-free survival may lead to an improved prognosis.
Harrison S. Fellheimer, BA; Madison M. Woods, BA; Joseph D. DeSimone, BS; and Carol L. Shields, MD
Retina Today
Uveal melanoma is a rare, life-threatening malignancy that leads to systemic metastasis by 10 years in approximately 25% to 40% of patients.1,2 Until recently, prognostication has relied on nonconditional analysis, a static method that estimates survival based on the time of diagnosis. One limitation of this method is that it cannot be used to estimate the prognosis of patients who have accrued a certain number of metastasis-free years since their initial diagnosis. In contrast, conditional analysis accounts for the increased survival probability that comes with accrued years of survival and, thus, can provide patients with a better idea of future risk. In this overview, we explore three studies that use both conditional and nonconditional analyses and discuss how these analytical methods influence disease prognostication. METASTASIS-FREE SURVIVAL AND FUTURE RISK Zabor et al reported on the conditional and nonconditional metastasis-free survival of 6,863 patients with uveal melanoma 5 and 10 years after diagnosis using the online Surveillance, Epidemiology, and End Results database (Table).3 These data highlight that conditional survival estimates of uveal melanoma improve with time from primary diagnosis to provide the patient with more personalized prognostic information. Relevance of TCGA Group Conditional survival analysis can also be calculated for cytogenetic variations. The Cancer Genome Atlas (TCGA) serves as a four-category prognostic classification for uveal melanoma metastatic risk based on the tumor’s genetic profile. Using this classification, uveal melanoma is classified into Group A (disomy 3, disomy 8), Group B (disomy 3, 8q gain), Group C (monosomy 3, 8q gain possible), and Group D (monosomy 3, 8q gain multiple).4 Shields et al studied nonconditional and conditional metastatic rates in patients with uveal melanoma based on genetic testing in 1,001 cases over a period of 22 years (Figure 1).5 This analysis included TCGA Groups A (49%), B (14%), C (26%), and D (11%).5 The nonconditional metastatic rate (ncMR) at presentation revealed 5- and 10-year metastatic rates of 4% and 6% (Group A), 12% and 20% (Group B), 33% and 49% (Group C), and 60% and 68% (Group D), respectively.5 The conditional metastatic rate (cMR) after 2 years of metastasis-free survival yielded 5- and 10-year metastatic rates of 2% and 5% (Group A), 8% and 18% (Group B), 21% and 40% (Group C), and 38% and 50% (Group D), respectively.5 These findings further suggest that longer survival without metastasis correlates with a reduction in metastatic risk. In addition, the researchers found that this decreased risk was most prominent in TCGA Group D.5 Figure 1. Comparison of cMR and ncMR of patients with uveal melanoma based on the TCGA classification system.