Retrospective Study
Copyright ©The Author(s) 2021.
World J Clin Cases. Jul 6, 2021; 9(19): 5046-5053
Published online Jul 6, 2021. doi: 10.12998/wjcc.v9.i19.5046
Table 2 Clinical and pathological features of patients with primary breast cancer in different age groups, n (%)

< 40 yr
40-59 yr
≥ 60 yr
χ2
P value
Left14 (41.2)50 (54.3)9 (39.1)4.2460.374
Right20 (58.8)40 (43.5)13 (56.5)
Bilateral 0 (0.0)2(2.2)1 (4.3)
Carcinoma in situ4 (11.8)16 (17.4)1 (4.3)2.7830.249
Invasive carcinoma30 (88.2)76 (82.6)22 (95.7)
Tis2 (5.9)14 (15.2)0 (0.0)15.4690.051
T116 (47.1)31 (33.7)10 (43.5)
T212 (35.3)38 (41.3)9 (39.1)
T34 (11.8)7 (7.6)1 (4.3)
T40 (0.0)2 (2.2)3 (13.0)
N017 (50.0)57 (62.0)10 (43.5)6.4860.371
N111 (32.4)19 (20.7)8 (34.8)
N25 (14.7)8 (8.7)2 (8.7)
N31 (2.9)8 (8.7)3 (13.0)
M034 (100)9 1(98.9)21 (91.3)6.3040.043
M10 (0.0)1 (1.1)2 (8.7)
Luminal A7 (20.6)16 (17.4)8 (34.8)6.1540.63
Luminal B(HER2 negative)13 (38.2)32 (34.8)9 (39.1)
Luminal B (HER2 positive)8 (23.5)28 (30.4)3 (13.0)
HER2 over expression type3 (8.8)6 (6.5)2 (8.7)
Three negative type3 (8.8)10 (10.9)1 (4.3)