Androgen receptor and 5α-reductase immunohistochemical profiles in extramammary Paget disease

摘要

Background Extramammary Paget disease is an uncommon skin tumour occurring mostly in the genitoperineal region. Previous reports have shown frequent expression of androgen receptor, suggesting a tumour-proliferative effect of androgens on Paget cells. Androgen-converting enzymes such as 5α-reductase, which locally produces a bioactive androgen, have recently gained attention in studies of the intratumoral actions of androgens. Objectives We investigated correlations between the androgenic microenvironment and invasiveness in extramammary Paget disease, particularly in terms of sex differences. Methods We examined 58 cases of extramammary Paget disease (32 men, 26 women; 42 noninvasive, 16 invasive) using immunohistochemistry for androgen receptor and 5α-reductase. Results In all 58 cases, expression rates were 57% for androgen receptor and 55% for 5α-reductase, with 38% double-positivity for androgen receptor and 5α-reductase. Only 5α-reductase expression rate was significantly higher in invasive cases (81%) than in noninvasive cases (45%; P = 0·042). For invasive cases, numbers of double-positive results for androgen receptor and 5α-reductase were significantly higher in men (70%) than in women (17%; P = 0·039). Conclusions Double positivity for androgen receptor and 5α-reductase in Paget cells suggests autocrine synthesis of androgens in extramammary Paget disease. The different hormonal microenvironments in male and female cases and intratumoral androgen levels affect the invasiveness of extramammary Paget disease. © 2010 British Association of Dermatologists.