Changes in Ultraviolet Radiation Exposure to the Ocular Region: A Population-Based Study

Abstract

In contrast to the well-established association between ultraviolet radiation (UVR) exposure and skin cancers, the relationship between UVR and uveal malignant melanoma (UM) remains controversial. To address this controversy, we evaluated the incidence rates of cutaneous malignancies in the eyelids as a proxy for UVR exposure in the ocular region using a population-based cancer registry. Overall, 74,053 cases of eyelid basal cell carcinoma (BCC) and 7890 cases of melanoma over a 26-year period (1982–2007) were analyzed. The incidence of eyelid basal cell carcinoma and uveal melanoma remained stable, whereas other cutaneous areas demonstrated an increase in the rates. A comparability test demonstrated that BCC incidence trends were significantly different between the eyelid versus both chronically exposed (males p = 0.001; females p = 0.01) and intermittently exposed skin (males and females, p = 0.0002), as well as the skin of the face (males p = 0.002; females p = 0.02). Similarly, melanoma trends were significantly different between the UM group versus both chronically exposed cutaneous melanoma (CM) (males p = 0.001; females p = 0.04) and intermittently exposed CM (males p = 0.005), as well as facial skin CM (males and females p = 0.0002). The discrepancy of cancer incidence between tumors in the peri-ocular region versus the rest of the body suggests that the peri-ocular region might have a different or unique exposure pattern to ultraviolet radiation.

The Impact of Ultraviolet Radiation on the Aetiology and Development of Uveal Melanoma

“…It is likely that data of UVR-related cancers especially before 2000 would show an increase in incidence, reflective of an increasing UVR. Analyses of cancer data from England and Wales [ 96 ], Denmark [ 22 ] and Canada [ 97 ], found an increase in CM incidence but not in UM. This strongly suggests that UVR does not play a role in UM.…”

“…This strongly suggests that UVR does not play a role in UM. However, this could potentially be an indication that ocular sites display different exposure patterns to UVR compared to skin [ 97 ], Additionally, in one of these studies there was an increase in the incidence of iris melanomas [ 22 ], with the iris the most likely to be influenced by UVR (see Section 2 ). Overall, changes in incidence over time suggests that changes in global UVR plays a great role in the development of CM, but little to no role in the development of UM.…”

Do Extracellular RNAs Provide Insight into Uveal Melanoma Biology?

“…While it is clear that UV radiation is the major risk factor for CM [ 57 ], its contribution to UM pathogenesis is not well-established [ 58 ]. Some studies showed a weak positive association between UV exposure and UM development [ 59 , 60 , 61 ], while others did not confirm this evidence [ 62 , 63 , 64 , 65 ]. On the contrary, it has been reported that increased UV exposure may have a protective effect, since outdoor workers showed a decreased risk of UM development compared to indoor workers [ 58 ].…”

Genetics and RNA Regulation of Uveal Melanoma

“…Although UV exposure is clearly a major risk factor for CM [20], the contribution of UV exposure to UM pathogenesis is not well established [21]. Several studies showed a weak positive association between UV exposure and the development of UM [22][23][24], but others did not confirm this evidence [25][26][27][28]. On the contrary, it has been reported that increased UV exposure may have a protective effect, as people who work outdoors have been shown to have a lower risk of developing UM compared to those who work indoors [21].…”