Trends in incidence and survival for uveal melanoma in Norway, 1993-2021

Understanding uveal melanoma incidence and survival trends is crucial for improving patient outcomes and allocating healthcare resources. We aimed to investigate the incidence and survival for uveal melanoma in Norway, 1993-2021, including information on tumour site, tumour (T) category and summary stage.

The Cancer Registry of Norway provided data on all patients diagnosed with a first primary uveal melanoma in Norway between 1 January 1993 and 31 December 2021. We calculated age-standardised incidence rates using the European standard population and estimated net survival and crude probability of death. Net survival estimates were obtained using the Pohar-Perme estimator, period approach and cohort approach.

Altogether, 1497 patients (49.6% men) were diagnosed with a primary uveal melanoma in 1993-2021. The age-standardised incidence rate increased from 6.8 (95% CI 5.7 to 7.9) per million person-years in 1993-1997 to 9.8 (95% CI 8.8 to 11.0) per million person-years in 2017-2021, with an overall rate of 9.0 (95% CI 8.6 to 9.5). This increase was primarily driven by localised, T1 and T2 choroidal melanomas. Ten-year net survival for patients with uveal melanoma remained relatively stable between 57.2% (95% CI 36.2% to 73.5%) in 1993-1997 and 65.5% (95% CI 53.8% to 74.9%) in 2017-2021. Over the same periods, there was a notable net survival improvement in patients with choroidal melanoma from 53.4% (95% CI 27.9% to 73.4%) to 74.8% (95% CI 59.8% to 84.9%).

The increased uveal melanoma incidence in Norway was mainly due to localised choroidal tumours. Improved detection of choroidal tumours is likely to have contributed to both the increased incidence and long-term net survival, highlighting the potential benefits of early detection strategies.