There have been some reports that DAX-1 (Dosage-sensitive sex reversal, Adrenal hypoplasia critical region, on chromosome X, gene 1) can modify the estrogen receptor-β and the progesterone and androgen receptors. Therefore, the aims of this work were to evaluate the expression pattern of DAX-1 in human breast cancer and its relationship to the steroid hormone receptors and other prognostic factors.

A retrospective analysis was performed using the clinical records of 161 patients diagnosed with invasive breast cancer, and who underwent surgical treatment and hormonal therapy between 1994 and 2004. We evaluated the presence and distribution of DAX-1 expressions in breast cancers using immunohistochemical staining.

DAX-1 was expressed in 57 (35.4%) of the 161 cases. Also, the DAX-1 expression showed significant correlations with the size and nodal metastasis. In the androgen receptor positive cases (85 cases), the DAX-1 positive cases were statistically younger than the DAX-1 negative cases. In the progesterone receptor positive cases (81 cases), a statistical significance was noted between the DAX-1 expression and nodal metastasis.

We conclude that DAX-1 can modulate the steroid hormone receptors including the progesterone and androgen receptors, in breast cancer. It could also be assumed that the influence of DAX-1 on the prognosis of breast cancer is different according to the kind of steroid hormonal receptor expressed.