Abstract
Purpose :
To investigate the incidence of other primary cancers in patients with ciliary body and choroidal melanomas
Methods :
This is a retrospective register based cohorte study on all ciliary body and choroidal melanoma patients diagnosed in the period 1968 - 2014.
Data were collected from the Danish Cancer registry and The Danish nationwide civil registry. A total of 2272 cases with posterior uveal melanoma was identified in the Danish Cancer registry. These cases were paired 1:10 according to age and gender with 21632 cases from the Danish nationwide registry. New cancers were identified in the cancer registry for both groups.
Results :
A new cancer was identified in 421 cases (18.5%) of the 2272 patients with posterior uveal melanoma. In the control group 3871 cases (17.9%) with new cancer were identified. The follw-up time was 17412.02 persons years for the posterior uveal melanoma group and 265088.94 persons years for the control group. This gave an incidence rate of IR=2.4 (95%CI: 2.2-2.7) for the uveal melanoma group and IR=1.4 (95%CI: 1.4-1.5) for the control group. The ratae ratio was RR 0=1.7 (95%CI: 1.5-1.8) and the hazard ratio was HR=1.5 (95%CI: 1.4-1.9) p<0.001
Conclusions :
In this Danish register based cohorte study, patients with posterior uveal melanoma had 50% higher risk of developing a second primary cancer in the follow-up period, compared to an age and gender matched control group. The strength of this study is the very high quality of the registers in Denmark and the link to the civil registration system, that accounts for all residents in Denmark. The weakness is the also the registers, that cannot assure under-reporting of cancers or mis-registration of diagnoses. The high hazard ratio of new primary cancer reported in this study mandates carefully work-up of patients with uveal melanoma with signs of dissiminated disease, as this could be a new cancer and not metastasis.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.