Table 1.

Patient and tumor characteristics by PIK3CA mutation status

CharacteristicOverall cohort (n = 590)Mutation typeP*
WT (n = 398)Any PIK3CA (n = 192)
n (%)n (%)n (%)
Age (y)
    Median (range)58 (27-89)57 (27-89)61 (33-89)0.002
    <50160 (27%)123 (31%)37 (19%)0.01
    50-69304 (52%)195 (49%)109 (57%)
    ≥70126 (21%)80 (20%)46 (24%)
Menopausal status
    Pre158 (27%)118 (30%)40 (21%)0.02
    Post426 (72%)274 (69%)152 (79%)
    N/A6 (1%)6 (2%)
Race
    Caucasian467 (79%)315 (79%)152 (79%)0.42
    Black54 (9%)37 (9%)17 (9%)
    Asian17 (3%)9 (2%)8 (4%)
    Hispanic21 (4%)17 (4%)4 (2%)
    Other20 (3%)12 (3%)8 (4%)
    Unknown11 (2%)8 (2%)3 (2%)
Tumor size (mm)
    Median (range)20 (0-150)20 (1-150)18 (0-140)0.08
T stage
    T01 (0%)1 (0%)0.02
    T1332 (56%)207 (52%)125 (65%)
    T2225 (38%)166 (42%)59 (31%)
    T323 (4%)16 (4%)7 (4%)
    T49 (2%)8 (2%)1 (1%)
Nodal status
    Negative300 (51%)190 (48%)110 (57%)0.03
    Positive246 (42%)177 (44%)69 (36%)
    Unknown44 (7%)31 (8%)13 (7%)
N stage
    N0300 (51%)190 (48%)110 (57%)0.16
    N1129 (22%)92 (23%)37 (19%)
    N254 (9%)37 (9%)17 (9%)
    N362 (11%)47 (12%)15 (8%)
    Unknown45 (8%)32 (8%)13 (7%)
Stage
    I211 (36%)128 (32%)83 (43%)0.07
    II204 (35%)144 (36%)60 (31%)
    III117 (20%)83 (21%)34 (18%)
    IV23 (4%)18 (5%)5 (3%)
    Unknown34 (6%)24 (6%)10 (5%)
Grade
    127 (5%)11 (3%)16 (8%)<0.0001
    2204 (35%)116 (29%)88 (46%)
    3288 (49%)225 (57%)63 (33%)
    N/A/Unknown71 (12%)46 (12%)25 (13%)
Histology
    Ductal474 (80%)318 (80%)156 (81%)0.04
    Lobular60 (10%)38 (10%)22 (11%)
    Ductal, lobular30 (5%)18 (5%)12 (6%)
    Special type25 (4%)23 (6%)2 (1%)
Lymphovascular invasion
    Negative312 (53%)205 (52%)107 (56%)0.27
    Positive199 (34%)140 (35%)59 (31%)
    Unknown79 (13%)53 (13%)26 (14%)
ER
    Negative186 (32%)142 (36%)44 (23%)0.0005
    Positive366 (62%)225 (57%)141 (73%)
    Unknown38 (6%)31 (8%)7 (4%)
PR
    Negative229 (39%)173 (43%)56 (29%)0.0002
    Positive314 (53%)189 (47%)125 (65%)
    Unknown47 (8%)36 (9%)11 (6%)
HR
    Negative143 (24%)116 (29%)27 (14%)<0.0001
    Positive408 (69%)251 (63%)157 (82%)
    Unknown39 (7%)31 (8%)8 (4%)
HER2
    Negative440 (75%)281 (71%)159 (83%)<0.0001
    Positive60 (10%)54 (14%)6 (3%)
    Unknown90 (15%)63 (16%)27 (14%)

NOTE: Statistical tests are based on available data; duct carcinoma in situ, unknown, and N/A not included in P value calculation.

  • 2 test used for binary/categorical variables; t test used for continuous variables.

  • Pathology review identified one ductal carcinoma in situ (T0) without invasive cancer.

  • Lobular carcinomas and tumors with special type histology were not analyzed for grade and are designated N/A.