<35 years

N = 741, No. (%)

≥35 years

N = 741, No. (%)

χ2

P-value

T stage

4.521

0.340

T1

243 (32.8)

213 (28.7)

T2

339 (45.7)

358 (48.3)

T3

91 (12.3)

107 (14.4)

T4

55 (7.4)

54 (7.3)

Unknown

13 (1.8)

9 (1.2)

Lymph node status

3.134

0.371

N0

294 (39.7)

268 (36.2)

N1

210 (28.3)

236 (31.8)

N2

124 (16.7)

131 (17.7)

N3

113 (15.2)

106 (14.3)

Tumor stage

2.555

0.465

1

160 (21.6)

137 (18.5)

2

314 (42.4)

335 (45.2)

3

260 (35.1)

263 (35.5)

Unknown

7 (0.9)

6 (0.8)

Histologic grade

3.976

0.264

G1

68 (9.2)

70 (9.4)

G2

256 (34.5)

279 (37.7)

G3

383 (51.7)

348 (47)

Unknown

34 (4.6)

44 (5.9)

ER

0.396

0.529

Negative

221 (22.8)

210 (28.3)

Positive

520 (70.2)

531 (71.7)

Tumor subtype

5.281

0.260

Luminal A

89 (12.0)

115 (15.5)

Luminal B

369 (49.8)

348 (47)

HER2

58 (7.8)

47 (6.3)

Triple-negative

103 (13.9)

102 (13.8)

Unknown

122 (16.5)

129 (17.4)