Long-term relative survival in uveal melanoma: a systematic review and meta-analysis

Abstract

Background: A large proportion of patients with uveal melanoma develop metastases and succumb to their disease. Reports on the size of this proportion vary considerably.

Methods: PubMed, Web of Science and Embase were searched for articles published after 1980. Studies with ≥100 patients reporting ≥five-year relative survival rates were included. Studies solely reporting Kaplan-Meier estimates and cumulative incidences were not considered, due to risk for competing risk bias and classification errors. A meta-analysis was performed using random-effects and weighted averages models, as well as a combined estimate based on curve fitting.

Results: Nine studies and a total of 18 495 patients are included. Overall, the risk of selective reporting bias is low. Relative survival rates vary across the population of studies (I² 48 to 97% and Q p < 0.00001 to 0.15), likely due to differences in baseline characteristics and the large number of patients included (τ² < 0.02). The 30-year relative survival rates follow a cubic curve that is well fitted to data from the random-effects inverse-variance and weighted average models (R ² = 0.95, p = 7.19E^-7). The estimated five, ten, 15, 20, 25 and 30-year relative survival rates are 79, 66, 60, 60, 62 and 67%, respectively.

Conclusions: The findings suggest that about two in five of all patients with uveal melanoma ultimately succumb to their disease. This indicates a slightly better prognosis than what is often assumed, and that patients surviving 20 years or longer may have a survival advantage to individuals of the same sex and age from the general population.

Keywords: Cancer epidemiology; Eye cancer.

Fig. 1. Flow diagram of study selection process.

The selection of articles for analysis was performed in four steps: identification, abstract and full-text screening, eligibility assessment, and inclusion.

Fig. 2. Forest plots of relative survival rates at 5-year intervals between 5 and 30 years after uveal melanoma diagnosis in a random-effects inverse-variance model (IV).

Y years. RS relative survival, CI confidence interval. Error bars represent 95% CI.

Fig. 3. Uveal melanoma relative survival curves.

a Based on reported rates in each included study. b Based on meta-analysis in a random-effects inverse-variance model. c Based on meta-analysis in a weighted averages model. d Combined estimate based on curve fitting to random-effects inverse-variance and weighted averages models. Green areas represent 95% confidence intervals. The confidence interval of the combined estimate is based on the standard deviation between the random-effects and weighted average models.