Aims Vulvar squamous-cell carcinoma (SCC) is a rare gynaecological cancer. Vulvar SCC has been shown to develop from vulvar intraepithelial neoplasias, which are related to lichen sclerosus (LS). Most studies to date have compared vulvar SCC with LS only morphologically, but no detailed molecular analysis has been performed. The objective was to compare claudin and p53 expression in these diseases and determine if there was any association with expression and vulvar SCC progression.

Methods Immunohistochemical analysis was performed in order to determine expression of p53 and claudin 1, 2, 3, 4, 5, 7 and 11 in human vulvar tissue samples from LS, SCC and control patients.

Results Claudin 1, 2, 3, 4 and 5 were expressed comparably in the three groups. Claudin 7 and 11 expression was significantly decreased in LS and SCC samples compared with the control group. Expression of p53 was significantly increased in SCC and LS patient samples compared with the control group.

Conclusions Claudin 7 and 11 were not expressed in LS and SCC. However, there was no significant difference in expression of any of the claudins between the LS and SCC samples. Furthermore, p53 expression is the highest in SCC patients and lowest in the control group. However, expression of p53 did not vary between samples from isolated LS and LS associated SCC patients, suggesting that increased p53 expression is not the determining factor in the progression of LS lesions to SCC.