Table 3.

Characteristics of the cases and controls

Arm AArm BOverall
CasesControlsCasesControlsCasesControls
N = 166N = 287N = 153N = 270N = 319N = 557
Age, y, median (range)66 (49–80)66 (48–80)69 (49–80)67 (47–79)68 (49–80)66 (47–80)
Treatment, n (%)
 BCS without RT29 (17.5)45 (15.7)25 (16.3)45 (16.7)54 (16.9)90 (16.2)
 BCS with RT95 (57.2)186 (64.8)90 (58.8)171 (63.3)185 (58.0)357 (64.1)
 Mastectomy without RT39 (23.5)52 (18.1)35 (22.9)47 (17.4)74 (23.2)99 (17.8)
 Mastectomy with RT3 (1.8)4 (1.4)3 (2.0)7 (2.6)6 (1.9)11 (2.0)
Tumor stage, n (%)
 I102 (61.4)181 (63.1)94 (61.4)165 (61.1)196 (61.4)346 (62.1)
 II/III64 (38.6)106 (36.9)59 (38.6)105 (38.9)123 (38.6)211 (37.9)
Node status, n (%)
 Positive66 (39.8)108 (37.6)56 (36.6)93 (34.4)122 (38.2)201 (36.1)
 Negative100 (60.2)179 (62.4)97 (63.4)177 (65.6)197 (61.8)356 (63.9)
Grade, n (%)
 I29 (18.7)64 (24.3)29 (20.9)65 (27.1)58 (19.7)129 (25.6)
 II126 (81.3)199 (75.7)110 (79.1)175 (72.9)236 (80.3)374 (74.4)
 Unknown112414302554
Her2 status, n (%)
 Positive13 (8.1)16 (5.8)9 (6.1)16 (6.1)22 (7.2)32 (5.9)
 Negative147 (91.9)262 (94.2)138 (93.9)248 (93.9)285 (92.8)510 (94.1)
 Unknown69661215