Timing of surgery after neoadjuvant chemotherapy for gastric cancer: Impact on outcomes

Table 1 Demographic and tumor characteristics according to the neoadjuvant chemotherapy-surgery interval time and pathological complete response status n (%)

	< 4 wk (n = 111)	4-6 wk (n = 48)	> 6 wk (n = 17)	P value	pCR (n = 40)	No pCR (n = 136)	P value
Age, yr, mean ± SD	55.5585 ± 10.8079	59.7916 ± 9.7891	61.5882 ± 9.5985	0.014	57.375 ± 9.862354	57.27206 ± 10.88013	0.908
Sex				0.974			0.174
Male	87 (78.38)	37 (77.08)	13 (76.47)		28 (70.00)	109 (80.15)
Female	24 (21.62)	11 (22.92)	4 (23.53)		12 (3.00)	27 (19.85)
Chemotherapy cycles				0.692			1.000
< 4	39 (35.14)	17 (35.42)	4 (23.53)		14 (35.00)	46 (33.82)
≥ 4	72 (64.86)	31 (64.58)	13 (76.47)		26 (65.00)	90 (66.18)
ASA, yr, mean ± SD				0.083			0.467
1	8 (7.21)	1 (2.8)	2 (11.76)		4 (10.00)	7 (5.15)
2	97 (87.39)	39 (81.25)	15 (88.24)		32 (80.00)	119 (87.50)
3	6 (5.40)	8 (16.67)	0		4 (10.00)	10 (7.35)
Histology (before NACT)				0.398			0.658
Tubular adenocarcinoma	90 (81.08)	40 (83.33)	15 (88.24)		34 (85.00)	111 (81.62)
Mucinous	10 (9.01)	1 (2.08)	0 (0.00)		1 (2.50)	10 (7.35)
Signet ring cell	9 (9.11)	4 (8.33)	1 (5.88)		3 (7.50)	11 (8.09)
mixed type1	2 (1.80)	3 (6.25)	1 (5.88)		2 (5.00)	4 (2.94)
Differentiation (before NACT)				0.000			0.032
Well	2 (1.80)	0 (0.00)	15 (88.24)		2 (5.00)	0 (0.00)
Moderate	28 (25.23)	10 (20.83)	1 (5.88)		10 (25.00)	35 (25.74)
Poor	81 (72.97)	38 (79.17)	1 (5.88)		28 (79.00)	101 (74.26)
Clinical T stage				0.006			0.027
2	31 (27.93)	17 (35.42)	6 (35.29)		15 (37.50)	39 (28.68)
3	24 (21.62)	19 (39.58)	8 (47.06)		16 (40.00)	35 (19.85)
4	56 (50.45)	12 (25.00)	3 (17.65)		9 (22.50)	62 (51.47)
Clinical N stage				0.170			0.012
Positive	89 (80.18)	33 (68.75)	11 (64.71)		24 (60.00)	109 (88.97)
Negative	22 (19.82)	15 (31.25)	6 (35.29)		16 (40.00)	27 (11.03)
Tumor location				0.650			0.044
Upper	45 (40.54)	23 (47.92)	6 (35.29)		10 (25.00)	64 (47.06)
Middle	16 (14.41)	7 (14.58)	2 (11.76)		6 (15.00)	19 (13.97)
Lower	45 (40.54)	14 (29.17)	7 (41.18)		22 (55.00)	44 (32.35)
Diffuse type2	5 (4.51)	4 (8.33)	2 (11.76)		2 (5.00)	9 (6.62)
Tumor diameter (before NACT)				0.134			0.069
≤ 2 cm	15 (13.51)	8 (16.67)	2 (11.76)		7 (17.50)	18 (2.21)
2-5 cm	50 (45.05)	21 (43.75)	13 (76.47)		24 (60.00)	60 (69.85)
≥ 5 cm	46 (41.44)	19 (39.58)	2 (11.76)		9 (12.50)	58 (27.94)
Surgical procedure				0.363			0.002
Proximal gastrectomy	21 (18.92)	10 (20.83)	2 (11.76)		9 (22.50)	24 (17.65)
Distal gastrectomy	32 (28.83)	10 (20.83)	8 (47.06)		19 (47.50)	31 (22.79)
Total gastrectomy	58 (52.25)	28 (58.33)	7 (41.18)		12 (30.00)	81 (59.56)
NACT-surgery interval time							0.043
< 4 wk					27 (67.50)	84 (61.76)
4-6 wk					6 (15.00)	42 (30.88)
> 6 wk					7 (17.50)	10 (7.35)
ypT stage				0.045
0	27 (24.32)	6 (12.50)	7 (41.18)
1	7 (6.31)	9 (18.75)	3 (17.65)
2	25 (22.52)	6 (12.50)	2 (11.76)
3	38 (34.23)	15 (31.25)	4 (23.53)
4	14 (12.61)	12 (25.00)	1 (5.88)
ypN stage				0.187
0	67 (60.30)	23 (47.92)	14 (82.35)
1	7 (6.31)	7 (14.58)	2 (11.76)
2	16 (14.41)	5 (10.42)	1 (5.88)
3a	14 (12.61)	8 (16.67)	0
3b	7 (6.31)	5 (10.42)	0

¹Mixed type: the tumor contains at least two kinds of cancer cell with different pathological classification, and the proportion of cancer cells in each type is similar;

²Diffuse type: the region of tumor is beyond one part of the stomach (three parts of the stomach: cardiac and gastric fundus, gastric body, and pylorus and gastric antrum). pCR: Pathological complete response; NACT: Neoadjuvant chemotherapy.