WIO 2024: Conditional metastasis-free survival of uveal melanoma based on tumor size category
In this study, the investigators retrospectively analyzed the incidence of metastasis in 8,034 patients with uveal melanoma over a 35-year period based on tumor size category.
(Image credit: AdobeStock/artegorov3@gmail)
Rolika Bansal, MD, and colleagues reported that the smaller the uveal melanoma tumor, the better the prognosis and the longer the patient lives, the risk of metastasis decreases across all the tumor size categories with lower likelihood of long-term metastasis. She is from the Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, and reported the findings of their project at the Women In Ophthalmology annual meeting in Carlsbad, CA.
The study rationale, according to the authors, is that tumor size is measurable and available for most patients with known information about a correlation between tumor size category and patient prognosis; however, the long-term conditional metastasis-free survival remains unknown and may provide insights for patient counseling.
The investigators retrospectively analyzed the incidence of metastasis in 8,034 patients with uveal melanoma over a 35-year period based on tumor size category; the tumors were defined as small when ranging from 0.0 to 3.0 mm, medium from 3.1 to 8.0 mm, and large exceeding 8.1 mm.
The primary outcome was the cumulative incidence of metastasis at 5-, 10-, 15-, 20-, 25-, and 30-years, using non-conditional and conditional survival at 3-, 5-, and 10-years of metastasis-free survival, the investigators explained.
The study is statistically strengthened by non-conditional and conditional analysis. Non-conditional analysis, they explained, provides information to the patient at the time of presentation regarding a prediction about their probability of metastasis in the future at a particular timeframe. However, conditional analysis is a powerful statistical tool that provides the patients with information about their probability of developing metastasis after specific future timeframes, provided the patient survives a certain additional number of years.
Analysis results
The mean thicknesses of the small, medium, and large tumors were, respectively, 2.5, 5.0, and 10.2 mm.
The investigators reported that when they compared small vs. medium vs. large melanoma, the small tumors were more likely to be found in female patients and younger patients(p < 0.001). Large tumors were likely to be associated with rupture of Bruch’s membrane and extraocular extension (p < 0.001).
The 25-year non-conditional percentages of metastasis were, respectively, 5% vs. 12% vs. 21%, and for those who survived 5 years without metastasis, the 25-year incidence rates of metastasis were 6% vs. 12% vs. 20%. For patients who maintained 3-, 5-, and 10-year metastasis-free-survival, the hazard ratios of large vs. medium uveal tumors were 2.22, 2.22, and 2.52 (p <0.001 for all comparisons); the hazard ratios for medium vs. small uveal tumors were 2.19,2.24, and 2.24 (p <0.001 for all comparisons).
Based on their results, the authors concluded that this long-term analysis of uveal melanoma metastasis based on the tumor size categories showed “that larger melanomas are more likely to have poorer prognosis and have a higher tendency to develop metastasis over time. The patients achieving 3-, 5-, and 10-years of metastasis-free survival have significantly reduced subsequent risk of metastasis, with hazard ratios demonstrating a marked decrease in risk across all tumor sizes,” Bansal and colleagues said.
They concluded, “This study adds a new dimension to patient prognosis and considers an individual's history of metastasis-free survival, providing insight into ultimate survival. Such prognostic insights are critical for advising patients about their impending prognosis beyond genetic profiling.”
