Table A5.

Multivariate Cox Regression Analysis of Predictors of Locoregional Recurrence in the Cohort of Tamoxifen-Treated Patients in the NSABP B-20 Trial (n = 655)

Variable	Hazard Ratio	95% CI	Wald Test P*
Age (≥ 50 v < 50 years)	0.26	0.12 to 0.55	< .001
Mastectomy v L + XRT	0.23	0.1 to 0.5	< .001
Clinical tumor size (> 2 v ≤ 2 cm)	1.58	0.89 to 2.8	.004
Tumor grade
Moderate v well	0.91	0.39 to 2.14
Poor v well	2.34	1 to 5.49	.05
Interaction: initial LR treatment and age*	4.03	1.21 to 13.41	.023

Abbreviations: NSABP, National Surgical Adjuvant Breast and Bowel Project; L, lumpectomy; XRT, radiation therapy; LR, locoregional recurrence.

^*The P value for the likelihood ratio test for the interaction between type of initial treatment and age is .021.