OSSN Incidence on the Rise in Recent Years

The incidence of OSSN appears to be on the rise in the US, accompanying the increasing global incidence of cutaneous skin cancer. Topical immuno-chemotherapy IFN remained the most popular intervention for OSSN from 2014 to 2021. Photo: Christine Sindt, OD. Click image to enlarge. Researchers recently sought to analyze the incidence and demographic characteristics of ocular surface squamous neoplasia (OSSN) in the United States. Given the rising global incidence of cutaneous squamous cell carcinoma (SCC), the team hypothesized a similar increase in OSSN cases. Indeed, their analysis confirmed that the frequency of OSSN in 2021 had escalated compared to the previous eight years.The study used ICD 9th and 10th revision codes to identify eyes with OSSN from patients in the Intelligence Research in Sight (IRIS) Registry. The final analysis included 13,924 unique eyes from 13,383 patients in the US. From 2014 to 2021, the annual occurrence rate of OSSN documented in the IRIS® Registry was 3.4 per 100,000 patient-years. Within the registry, the incidence of OSSN surged by 2.9 times from the start to the end of this period. The researchers reported in their paper for Ophthalmology that “as of 2021, there are at least 2,100 new OSSN cases per year in the US.” They cautioned that this is likely an underestimation of the true OSSN incidence, given that “only about 25% of academic institutions, many of which may manage OSSN referrals, participate in the registry.”The average age of OSSN patients was 67, with 87% being older than 50 years and 62% exceeding 65 years of age. As previous literature reflects, the demographics of those affected were predominantly 63% male, 65% white and 10% Hispanic. Additionally, 40% of the OSSN patients were smokers, and 39% resided in the southern United States, according to US Census designations.Treatment patterns were also analyzed. Less than half of OSSN patients underwent surgical removal (44%). Among those undergoing primary topical treatment, 61% received interferon alfa-2b (IFN).“IFN grew in popularity as the treatment of choice, because of its tolerability and reduced side effects, with 5-fluorouracil and mitomycin-C also being used but with greater risk of side effects,” the researchers noted in their paper. “Our study is consistent with past studies showing that IFN has been the preferred topical therapy, and continued to increase in use, compared to 5-fluorouracil and mitomycin-C.” For example, they cited a recent survey that found the use of mitomycin-C as primary monotherapy fell from 76% in 2003 to 19% in 2022, while the use of IFN rose from 14% to 55%.While the study methods used in this analysis differ from those in previous incidence studies, the researchers concluded that the incidence of OSSN reported here is higher than prior estimates and “parallels the overall increase in the global burden of cutaneous skin cancer.” Click here for the journal source.  Meide EVH, Ferguson TJ, Karp CL, Lum F, Terveen DC. U.S. incidence and demographics of ocular surface squamous neoplasia in the IRIS® Registry (Intelligent Research in Sight) 2014-2021. Ophthalmol. April 18, 2025. [Epub ahead of print].