Table 1.

Association of patient/tumor characteristics with PIK3CA mutation status

Wild-type (n = 523)Mutant (n = 206)
CharacteristicTotal (n)n (%)n (%)Pa
Age
 ≤50 years395293 (56.0)102 (49.5)0.11
 >50 years334230 (44.0)104 (50.5)
Tumor size
 ≤2 cm233173 (33.1)60 (29.1)0.30
 >2 cm496350 (66.9)146 (70.9)
Tumor grade
 I4934 (6.7)15 (7.4)0.11
 II545382 (74.9)163 (80.7)
 III11894 (18.4)24 (11.9)
 Unknown17134
Lymph nodes status
 Negative377263 (50.7)114 (55.9)0.21
 Positive346256 (49.3)90 (44.1)
 Unknown642
ER status
 Negative245188 (36.1)57 (27.8)0.034
 Positive481333 (63.9)148 (72.2)
 Unknown321
PR status
 Negative323248 (48.2)75 (36.9)0.007
 Positive395267 (51.8)128 (63.1)
 Unknown1183
HER2 status
 Negative505361 (69.2)144 (70.2)0.76
 Positive222161 (30.8)61 (29.8)
 Unknown211
Subgroup
 Luminal376261 (50.1)115 (56.1)0.22
 HER2+222161 (30.9)61 (29.8)
 TN12899 (19.0)29 (14.1)
 Unknown321
Regimens
 Anthracycline with or without taxane582424 (81.1)158 (76.7)0.42
 Taxane13591 (17.4)44 (21.4)
 Others128 (1.5)4 (1.9)
Trastuzumab use
 No688498 (95.2)190 (92.2)0.12
 Yes4125 (4.8)16 (7.8)
Surgery type
 BCS299214 (40.9)85 (41.3)0.93
 Mastectomy430309 (59.1)121 (58.7)

NOTE. Luminal subgroup: ER+ and/or PR+, HER2; TN subgroup: ER/PR/HER2.

Abbreviation: BCS, breast-conserving surgery.

  • aPIK3CA mutant compared with wild-type.