Objectives: The aim of this study was to evaluate the expression of GCDFP15 and GATA-binding protein 3 (GATA-3) in extramammary Paget's disease (EMPD) skin and serum samples and to assess their availability as tumor markers for the diagnosis and assessment of disease severity in primary EMPD.

Methods: Skin samples and serum samples were obtained from 16 patients with pri- mary EMPD (10 cases from male, six cases from female; stage IA six cases, stage IB seven cases, stage III one case, stage IV two cases). By immunohistochemistry, the ex- pression of GCDFP15 and GATA3 was examined in skin specimens. The serum levels of GCDFP15 and GATA3 were quantified by ELISA.

Results: In our study, eight out of 16 patients showed positive staining for GCDFP15. In contrast, all 16 patients showed positive staining for GATA-3. Immunohistochemical staining of EMPD skin samples showed that GATA-3 had a higher positivity rate than GCDFP15. However, there was no correlation between serum levels of GCDFP15 or GATA-3 and the disease stage.

Conclusion: Our results indicate that GCDFP15 and GATA-3 are useful for the diag- nosis of primary EMPD, but not for monitoring disease progression, and suggest that GATA-3 is a more reliable marker than GCDFP15 for the diagnosis of primary EMPD.

Authors: Soichiro Kado, Koji Kamiya, Meijuan Jin, Miho Kimura, Md Razib Hossain, Takeo Maekawa, Mayumi Komine and Mamitaro Ohtsuki.