Risk factors for conjunctival squamous cell neoplasia: a matched case-control study

Aims: To identify roles of human papillomavirus (HPV) infection and solar elastosis as the risk factors for conjunctival squamous cell neoplasia (CSCN). Methods: 30 consecutive pathological specimens, ranging from conjunctival intraepithelial neoplasia, carcinoma in situ, to invasive squamous cell carcinoma were retrieved from tissue archives. 30 controls were disease free conjunctiva from age and sex matched patients undergoing extracapsular cataract extraction. Two masked pathologists studied haematoxylin and eosin stains on paraffin embedded conjunctival tissues. Elastic stain for solar elastosis was blindly interpreted in comparison with negative and positive controls. HPV infection was studied by polymerase chain reaction and dot hybridisation. Results: The mean age of CSCN patients was 54.9 years. The male to female ratio was 1:1. Solar elastosis was seen in 53.3% of CSCN and in 3.3% of controls with an odds ratio of 16.0 (95% CI, 2.49 to 670.96; p value = 0.0003). HPV DNA were not detected in any of the specimens. Conclusion: Solar elastosis is much more frequently found in CSCN cases than in their matched controls and is a risk factor for CSCN. These data are insufficient to conclude that HPV infection is a risk factor for CSCN.