Evaluation of Two Different Analytical Methods for Circulating Tumor Cell Detection in Peripheral Blood of Patients with Primary Breast Cancer

Table 1

Baseline characteristics of patients for whom CTC detection before adjuvant chemotherapy was performed using the Cell Search System (CSS) or using manual immunocytochemistry (MICC).

Variable	CSS; 𝑁=1972	MICC; 𝑁=1198	𝑃-value^1
Age (years)			0.929^2
Median	53.0	53.0
Range	21–78	22–85
Tumor stage			0.707^3
pT1	818 (41.5%)	473 (39.5%)
pT2	1021 (51.8%)	640 (53.4%)
pT3	100 (5.1%)	66 (5.5%)
pT4	27 (1.4%)	16 (1.3%)
unknown	6 (0.3%)	3 (0.3%)
Nodal stage			0.895^3
pN0	664 (33.7%)	418 (34.9%)
pN1	908 (46.0%)	545 (45.5%)
pN2	277 (14.0%)	165 (13.8%)
pN3	123 (6.2%)	70 (5.8%)
Histological grading			0.457^3
G1	97 (4.9%)	59 (4.9%)
G2	931 (47.2%)	592 (49.4%)
G3	940 (47.7%)	544 (45.4%)
unknown	4 (0.2%)	3 (0.3%)
Histological type			0.170^3
ductal	1590 (80.6%)	997 (83.2%)
lobular	238 (12.1%)	121 (10.1%)
other	140 (7.1%)	78 (6.5%)
unknown	4 (0.2%)	2 (0.2%)
Estrogen receptor status			0.697^3
negative	589 (29.9%)	365 (30.5%)
positive	1380 (70.0%)	829 (69.2%)
unknown	3 (0.2%)	4 (0.3%)
Progesterone receptor status			0.174^3
negative	678 (34.4%)	440 (36.7%)
positive	1289 (65.4%)	754 (62.9%)
unknown	5 (0.3%)	4 (0.3%)
HER2 status			0.819^3
negative	1452 (73.6%)	886 (74.0%)
positive	483 (24.5%)	289 (24.1%)
unknown	37 (1.9%)	23 (1.9%)
Menopausal status			0.560^3
premenopausal	822 (41.7%)	512 (42.7%)
postmenopausal	1150 (58.3%)	686 (57.3%)
Type of surgery			0.407^3
breast conserving	1382 (70.1%)	856 (71.5%)
mastectomy	587 (29.8%)	340 (28.4%)
unknown	3 (0.2%)	2 (0.2%)
Adjuvant chemotherapy			0.930^3
FEC-DG	968 (49.1%)	590 (49.2%)
FEC-DOC	1004 (50.9%)	608 (50.8%)

1All tests without unknowns.
²Mann-Whitney 𝑈 test.
³Chi-square test.
FEC-DG: 3 cycles of fluorouracil-epirubicin-cyclophosphamide followed by 3 cycles of docetaxel and gemcitabine; FEC-DOC: 3 cycles of fluorouracil-epirubicin-cyclophosphamide followed by 3 cycles of docetaxel.