Abstract
Purpose: :
There is limited population-based epidemiologic data published in the field of ocular oncology to date. This branch of medicine is comprised of multiple rare diseases; however, the vision- and life-threatening nature of these malignancies amplifies their importance from a population health perspective. As Alberta has a single provincial cancer agency, and universal government sponsored health insurance system, we identified a unique opportunity to construct an accurate report of the epidemiology of ocular oncology in our province.
Methods: :
Population-based, retrospective case-series: 1979-2004. The Alberta Cancer Registry was used to identify all patients diagnosed with intra-ocular and ocular-adnexal malignancies. Incidence rates were age-standardized to the USA 2000 Standard Population and a Joinpoint Regression was utilized to calculate statistical significance in yearly incidence trends.
Results: :
Alberta's (2008) population was estimated at 3,512,368. During our study period, a total of 4601 Albertans were diagnosed with an intra-ocular or ocular-adnexal malignancy. Of these, 2171 (47.2%) were female and 2430 (52.8%) were male. The average age at diagnosis was 59.8 yrs (female) and 60.9 yrs (male). Topographically, eyelid malignancies accounted for the greatest proportion of cancers (84.7%); the remaining distribution was: choroid (6.9%), conjunctiva (2.3%), orbit (1.7%), retina (1.5%) and ciliary body (1.1%); cornea, iris, and lacrimal gland cancers each accounted for <1% of total cases. The age-standardized average incidence rate for all ocular cancer morphologies was 8.46 cases/100,000 Albertans; there was no statistically significant increase in this overall incidence rate over the 25-year timespan of the study (p=0.07). Basal cell carcinoma of the eyelid occurred most frequently (6.16 cases/100,000) and had a statistically significant rise in incidence (p=0.017); in contrast, malignant uveal melanoma (0.70 cases/100,000), squamous cell carcinoma of the eyelid (0.60 cases/100,000), and orbital lymphomas (0.20 cases/100,000) were statistically stable.
Conclusions: :
We are the first research team to provide a comprehensive picture of the epidemiology of ocular oncology in Canada. Our findings will allow for future assessment the impact of these diseases. Additionally, our reported incidence rates are in agreement with literature published from countries with populations comparable to our own.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • oncology • tumors