The influence of hormone receptors and hormonal adjuvant therapy on disease-free survival in breast cancer: a multifactorial analysis.

The prognostic value of estrogen (ER) and progesterone (PgR) receptor status and the influence of hormonal adjuvant therapy on disease-free survival (DFS) in breast cancer were evaluated in 680 women after radical and modified radical mastectomy. The effect of 17 variables, including clinical data, TNM, hormone receptor status, histology and adjuvant therapy, on the DFS observed was analyzed, using a multivariate proportional hazard model. Multifactorial analysis revealed that DFS was strongly related to the number of positive axillary nodes (P less than 0.001) and the histological grade of the tumor (P = 0.05). Moreover, the DFS of ER-positive patients with node involvement was significantly improved by hormonal adjuvant therapy (tamoxifen). Combination of adjuvant chemotherapy with hormonal therapy did not enhance its effectiveness. Recurrence rates of either node-negative or ER-negative patients were not affected by either adjuvant therapy. When no systemic therapy was given, no significant relationship between ER or PgR content of the tumor and the DFS was observed. These findings suggest that hormone receptor status is not an independent prognostic factor but provides reliable information on responsiveness to adjuvant hormonal therapy which is very effective in patients selected on the basis of ER assay.