Table 3.

Multivariate Cox Regression Analysis of Predictors of Locoregional Recurrence in the Cohort of 895 Tamoxifen-Treated Patients From NSABP Trials B-14 and B-20

Variable	Hazard Ratio	95% CI	Wald Test P
Age (≥ 50 v < 50)	0.40	0.25 to 0.65	.0002
Mastectomy v L + XRT	0.62	0.39 to 0.99	.047
Clinical tumor size (> 2 v ≤ 2 cm)	0.98	0.61 to 1.59	.933
Tumor grade (moderate v well)	1.10	0.54 to 1.92	.113
Tumor grade (poor v well)	1.76	0.89 to 3.48
Recurrence score*	2.16	1.26 to 3.68	.005

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

^*Recurrence score was a continuous variable, with the hazard ratio for LRR calculated relative to an increment of 50 units (chosen to dichotomize the recurrence score and thus improve comparability of the hazard ratio with the hazard ratios based on the clinical covariates). The P value for the likelihood ratio test on RS is .007.