ER as a predictor of early breast cancer (EBC) outcomes in patients

590 Background: Some ER-negative (ER-) breast cancers express low levels of estrogen receptors and approximately 12% express androgen receptors (Traina, T, et al. ASCO, 2012). Whether young premenopausal women (age 40yrs and by ER status. Results: In the two studies combined, ER- patients ≤40 had a superior DFS (84%) than ER- patients >40 (80%), while ER+ patients ≤40 had a worse 5-yr DFS (83%) than ER+ patients >40 (89%), although these findings were of borderline significance (see Table below). In 99-016, omitting C did not adversely affect outcomes in either age group, regardless of ER status. Conclusions: We did not observe worse outcomes in ER- patients ≤40 years compared to those >40 years in 2 US Oncology adjuvant chemotherapy trials, suggesting no adverse impact of assumed greater ovarian function following adjuvant chemotherapy in patients ≤40yrs. ER+ patients ≤40 had a worse DFS than ER+ patients >40. Omitting C in ER- patients ≤40 or >40 did not adversely affect outcome. [Table: see text]