Purpose: Paget's disease (PD) of the breast as well as the vulva is a rare condition that accounts for about 4% of breast neoplasms and 1% of vulvar malignancies. Recurrent disease after breast and vulvar surgery might be a challenge. To evaluate relevant molecules therapeutically, tissue from mammary and vulvar PD lesions was investigated immunohistochemically.
Methods: Histopathologic samples from 11 patients with mammary PD and eight patients with vulvar PD were stained with antibodies against estrogen and progesterone receptors, HER-2/neu and COX-2 followed by semiquantitative evaluation of the staining results.
Results: All tested mammary lesions as well as seven out of eight vulvar PD were negative for estrogen and progesterone receptors. Strong membranous staining for HER-2/neu (Score 3) was seen in all cases. Six out of 8 vulvar and 10 out of 11 mammary PD showed COX-2 overexpression.
Conclusions: PD of the breast and vulva are negative for estrogens and progesterons, therefore, anti-hormonal therapy is not indicated. The high frequency of Her-2/neu and COX-2 overexpression, however, suggests that these molecules could be therapeutically relevant in patients with PD. These results require further investigation.