Abstract
A major purpose with this thesis was to assess the incidence and mortality rates of uveal melanoma in Sweden during the period 1960 to 1998, using population-based registry data.
In total, 2,995 patients (1,541 males and 1,454 females) were diagnosed with uveal melanoma. The age-standardized incidence rate of uveal melanoma declined significantly among men from 11.7 cases/million to 8.4 cases/million (p=0.002) and was stable in females, 10.3 cases/million to 8.7 cases/million (p=0.108). The annual decrease in incidence rate was estimated to 1% (95% Cl: 0.81.2) in males and to 0.7% (95% Cl: 0-1.3) in females. The 5year observed and relative survival rates were 60% and 70% respectively, with better survival in younger age groups and later time periods.
The etiology of uveal melanoma is unknown. By analyzing the coexistence of uveal melanoma and other malignancies, possible associations with shared risk factors might give indications of common etiologies. A 13% increased risk of subsequent cancers was found in uveal melanoma patients compared to population controls. No significantly elevated risk was found for any specific cancer site, including cutaneous melanoma. Only two familial cases of uveal melanoma were identified in the Multigeneration Registry, indicating that hereditary factors are of minor importance in the causation of uveal melanoma.
The impact on survival and functional outcome following brachytherapy with 106-ruthenium plaques was evaluated in 579 patients, treated during the period 1979-2003. The 5-year observed and relative survival rates were estimated at 83% and 95% in this selected patient group. 5-year cumulative incidence of enucleation was 16.8%. In patients with a 5-year follow-up visual acuity of >=0.5 was retained in 31 %, and visual acuity of >1 in 49%.
In conclusion, the incidence rate of uveal melanoma in the Swedish population decreased in males and was stable in females during the period 1960-98. In the same population the incidence rates of skin melanoma increased 2-5% yearly, which indicates that mechanisms other than UV-exposure are to be considered in the pathogenesis of uveal melanoma.