Estradiol receptor alone or estradiol and progesterone receptors (ER, PgR) have been measured in tumors from 307 women who were treated for primary breast adenocarcinoma. Patients received adjuvant therapy in relation to tumor stage independently of receptor status. Over a relatively short follow-up, more recurrences are recorded in patients with ER+ tumors, but at 7 years the same proportion of recurrences are registered in both groups of patients whose tumors were ER+ or ER-. Patients whose tumors were processed for both ER and PgR (148 cases) have now been evaluated after 5 years follow-up. Among 56 patients with PgR+ tumors 5 recurred, versus 22/92 in the PgR- group. 21/87 patients who had 1 to 4 invaded nodes at the time of surgery relapsed: 17/54 had PgR- tumors versus 4/33 PgR+. 6 recurrences were recorded in the 61 patients with negative nodes: 5 of them occurred in patients with PgR- tumors. In addition, recurrences observed in patients with negative receptor status occurred after a shorter disease-free interval. Analysis of the incidence of recurrences in relation to the combined ER/PgR status in patients who did not receive adjuvant therapy suggests that tumor PgR content is a more significant criterion than ER for long-term prognosis.