Immunohistochemical evaluation of estrogen and progesterone receptors of pre and post-neoadjuvant chemotherapy for breast cancer.

OBJECTIVE To evaluate the immunoexpression of estrogen and progesterone receptors in biopsies and surgical specimens of patients with breast cancer before and after neoadjuvant chemotherapy and to correlate their changes with the pattern of response to chemotherapy and diagnosis of menopause. METHODS We selected 47 patients with histological diagnosis of locally advanced primary breast carcinoma. For each patient there were two blocks: the biopsy specimen and surgical resection one. From these blocks hormone receptor expression was assessed by immunohistochemistry using the technique of streptoavidin-biotin-immunoperoxidase and anti-ER and anti-PR primary antibodies. The statistical analysis used the Student's t test and the nonparametric Fisher's exact test, with significance level of 5%. RESULTS Of the 47 patients, 30 showed positive immunostaining for hormone receptors. There was significant reduction in the levels of both estrogen and progesterone receptors and in their immunoreactivity. In 53.3% we observed changes in levels of estrogen receptor expression, 56.6% in the progesterone receptor, 26.6% in the immunoexpression of estrogen receptor immunoreactivity and 33.3% in the immunoreactivity of the progesterone receptor. There was no statistical correlation between the influence of the response to chemotherapy and the diagnosis of menopause in women with variation in the expression of hormone receptors. CONCLUSION Neoadjuvant chemotherapy has significantly altered hormone receptor immunoreactivity in patients in the sample, reducing its positivity in tumor cells.