Table 6.

Cox regression of potential prognostic factors in patients over 70 (P values).

Variable	Local recurrence	Distant recurrence
Histopathology	0.043	0.702
Tumor differentiation	0.855	0.571
Tumor size (cm)	0.520	0.006
Involved nodes†	0.306	<0.001
Estrogen receptor positive	<0.001	0.008
Postoperative chemotherapy	0.517	0.198
Tamoxifen	0.091	0.375
Radiation therapy	0.620	0.375
Undertreatment	0.150	0.818

^†Invasive tumors.