Estrogen and progesterone receptor status in breast cancer can determine therapeutic options and may provide prognostic information. The purpose of this study is to compare the concordance of the primary breast cancer steroid hormone receptor status to that of the recurrent breast cancer and to determine whether the type of second lesion (local recurrence, second primary, or metatastic lesion) and adjuvant therapy received changed the receptor concordance. The records of eighty-three patients with estrogen receptor (ER) analysis available for primary (p) and recurrent (r) breast cancer for 1976-1990 were reviewed. In addition, 32 of these patients also had available progesterone receptor (PR) values for primary and recurrent breast cancers. Statistical evaluation was performed by chi-square, Stu- dent's t-test, and Wilcoxon signed-rank test. ER concordance (primary/ recurrent, p/r) was identified in 59/83 (7 1%) patients; PR concordance was identified in 18/32 (56%) patients. Whether the second lesion was a local recurrence, second primary, or a metastatic lesion did not affect ER concordance or PR concordance. Adjuvant chemotherapy, hormonal therapy, or radiation therapy, either alone or in combination, did not affect ER or PR concordance. The disease-free survival (DFS) for patients with ER (p+)/(r-) (primary receptor positive/recurrent receptor negative) was significantly shorter than those with ER (p-)/(r+)(27.6 * 7.4 months versus 50.6 k 7.6 mo, P = 0.04). The DFS for PR (p+)/(r-) patients was 28.8 k 7.9 months compared to the DFS of 46.8 2 1 1.8 months for PR (p-)/(r+) patients (P = NS). A significantly shorter DFS for ER (p+)/ (r-) patients compared to ER (p-)/(r+) patients and a trend towards a shorter DFS for PR (p+)/(r-) patients compared to PR (p-)/(r+) patients may reflect a loss of hormonal regulation or an increase in cancer aggressiveness.