Estrogen receptor (ER) levels were measured in 280 breast cancer patients (mean age 54.5 years). Progesterone receptor (PR) levels were assayed in 101 of them. 61.4% of cases were at stages I and IIa. No significant difference in 2-year survival was established between ER-negative and ER-positive patients (96.7 and 96.0%, respectively). Two-year survival rate and recurrence--free survival for PR-positive cases were significantly higher than those for PR-negative ones (p greater than 0.05).