1235 - Incidence and survival of Uveal Melanoma occurring as single cancer versus its occurrence as a first or second primary neoplasm

Background

Uveal Melanoma (UVM) is the most common ocular malignancy. Many mutations were identified in affected patients defining genetic predisposition syndromes. Previous studies discussed separately the incidence of single or second primary ocular melanomas. However, understanding the genetic background, and relation to other tumors requires further investigation for defining the UVM subgroups, their shared developmental and, hence, the targeting mechanisms.

Methods

We used Surveillance Epidemiology and End Results program of the National Cancer Institute, United States, to review patients diagnosed with UVM, either as single primary or combined with other malignancies, between 1973 and 2015. We have calculated standardized incidence ratios (SIR) and measured risk in the form of Observed/Expected ratios (O/E) and Hazard Ratios (HR).

Results

We have identified 7,386 patients diagnosed with single primary UVM, besides 646 with UVM followed by another malignancy and 437 patients diagnosed with a primary UVM after other malignancies. SIR of developing another malignancy following UVM was significant and increased most within the first 5 years following UVM following choroid uveal melanoma (1.198, 95%CI=1.056-1.353). The risk of developing melanomas of the skin, thyroid cancers, and kidney cancers, increased significantly within the first 5 years following UVM, with SIRs (3.763, 95%CI=2.539-5.372), (3.158, 95%CI=1.270-6.506), and (2.618, 95%CI=1.465-4.317), respectively. SIR of developing a second UVM following another malignancy was significant between the 5^th and 10^th years following the first cancer diagnosis (O/E=1.204, 95% CI = 1.007-1.428), where the increase of UVM risk was highest among patients with primary prostate cancer (1.404, 95%CI=1.024-1.878) or leukemia (2.915, 95%CI=1.070-6.345). Cox models did not show a significant difference between the overall survival of single UVM and second UVM, but females showed better overall survival outcomes. In addition, Ciliary body tumors, and dark-skinned people were associated with worse survival outcomes.

Conclusions

The three groups of uveal melanoma showed different behaviors that may represent diverse underlying developmental mechanisms.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.