Background: At 5 years, AT did not improve disease free survival or overall survival and RS was a more accurate predictor of relapse than standard clinicopathologic characteristics for patients with hormone receptor (HR) positive tumors. Methods: A Phase III Intergroup trial tested adjuvant AT vs. AC. Women with 1-3 N + or N - and T-size > 1cm were randomized to 4 cycles of AT (60 mg/m²/60 mg/ m²) or AC (60 mg/m²/600 mg/m²) q 3 wk x 4. Patients(pts) with ER + and/ or PR + tumors received tam for 5 yrs. Pts were stratified by nodal, HR (ER+ PR+, ER+PR-, ER-PR+, ER-PR-, ER/PR unk) and menopausal status. The primary endpoint was DFS. A sample of 465 pts with HR + breast cancer with 0 to 3 positive axillary nodes who did (N =116) or did not have a recurrence had tumor tissue evaluated using the 21- gene assay. Grade and HR expression were evaluated locally and centrally. Results: 2952 pts were randomized between 7/30/98 and 1/21/00. 2883 were eligible and analyzable. Arms were balanced for age, HR, menopause, nodes, surgery, grade and T-size: median age 51; 64% ER +; 65% LN-; grade: 10% low, 38% int., 46% high; and median T-size - 2.0 cm. At a median follow-up of 11.5 years the DFS/OS results are shown in the table below. RS was a highly significant predictor of recurrence including node negative and node positive disease (P < .0001) and predicted recurrence more accurately than clinical variables. Conclusions: At 11.5 yrs. median follow-up, there remains no difference in DFS or OS, although there continue to be fewer events in the AT arm in the prespecified ER/PR negative subgroup. At 10 years, the RS continues to be a more accurate predictor of relapse than standard clinical features.

	Hazard ratio (HR)*, 95Cl, p- value** 5 yr	5-yr DFS		Hazard ratio (HR)*, 95Cl, p value** 10 yr	10-yr DFS
		AT	AC		AT	AC
Overall DFS	1.02 (0.86-1.22), 0.78	85%	85%	1.02 (0.88-1.18), 0.83	77%	77%
ER+	0.89 (0.71-1.12), 0..32	87%	88%	0.91 (0.76-1.10), 0.34	78%	79%
ER-	1.24 (0.95-1.62), 0.12	81%	77%	1.22 (0.96-1.56), 0.11	76%	71%
OS	1.06 (0.85-1.31), 0.62	92%	91%	1.03 (0.86-1.23), 0.73	85%	84%

*HR>1 favors AT; **based on log-rank test.