Perioperative chemotherapy improves survival of patients with locally advanced diffuse gastric cancer

Table 2 Baseline clinicopathologic characteristics of patients with diffuse gastric adenocarcinoma receiving neoadjuvant chemotherapy or adjuvant chemotherapy before and after inverse probability of treatment weighting, n (%)

Characteristic	Before IPTW			After IPTW
	Adjuvant chemotherapy (n = 576)	Neoadjuvant chemotherapy (n = 872)	P value	Adjuvant chemotherapy (n = 1458.4)	Neoadjuvant chemotherapy (n = 1445.0)	P value
Age			0.026			0.916
≤ 45	87 (15.1)	154 (17.7)		232.9 (16.0)	243.1 (16.8)
45-70	328 (56.9)	527 (60.4)		882.9 (60.5)	861.9 (59.7)
≥ 70	161 (28.0)	191 (21.9)		342.6 (23.5)	339.9 (23.5)
Sex			0.347			0.823
Male	268 (46.5)	429 (49.2)		694.4 (47.6)	697.4 (48.3)
Female	308 (53.5)	443 (50.8)		764.0 (52.4)	747.6 (51.7)
Race			0.170			0.314
White	347 (60.2)	568 (65.1)		897.2 (61.5)	938.7 (65.0)
Black	66 (11.5)	86 (9.9)		144.3 (9.9)	140.4 (9.7)
Asian	154 (26.7)	199 (22.8)		394.7 (27.1)	332.9 (23.0)
Other	9 (1.6)	19 (2.2)		22.2 (1.5)	32.9 (2.3)
Diagnosis period			< 0.001			0.942
2004-2010	151 (26.2)	124 (14.2)		270.0 (18.5)	269.8 (18.7)
2010-2020	425 (73.8)	748 (85.8)		1188.4 (81.5)	1175.1 (81.3)
Tumor location			< 0.001			0.988
Upper one-third	45 (7.8)	143 (16.4)		202.5 (13.9)	189.4 (13.1)
Middle one-third	198 (34.4)	283 (32.5)		500.2 (34.3)	488.8 (33.8)
Lower one-third	198 (34.4)	230 (26.4)		417.2 (28.6)	418.5 (29.0)
Overlapping	72 (12.5)	124 (14.2)		181.0 (12.4)	191.2 (13.2)
Unknown	63 (10.9)	92 (10.6)		157.5 (10.8)	157.0 (10.9)
Histology type			0.753			0.999
Diffuse	159 (27.6)	251 (28.8)		400.3 (27.4)	397.9 (27.5)
Signet-ring cell carcinoma	406 (70.5)	608 (69.7)		1034.4 (70.9)	1023.9 (70.9)
Linitis plastica	11 (1.9)	13 (1.5)		23.7 (1.6)	23.2 (1.6)
Grade			0.179			0.056
Well/moderately differentiated	16 (2.8)	14 (1.6)		48.1 (3.3)	22.2 (1.5)
Poorly/undifferentiated	560 (97.2)	858 (98.4)		1410.3 (96.7))	1422.8 (98.5)
T stage			< 0.001			0.996
1	40 (6.9)	46 (5.3)		91.7 (6.3)	87.8 (6.1)
2	60 (10.4)	100 (11.5)		155.9 (10.7))	158.6 (11.0)
3	223 (38.7)	455 (52.2)		683.8 (46.9)	671.7 (46.5)
4	253 (43.9)	271 (31.1)		527.1 (36.1)	526.8 (36.5)
N stage			< 0.001			0.963
0	126 (21.9)	262 (30.0)		418.2 (28.7)	395.0 (27.3)
1	121 (21.0)	241 (27.6)		351.0 (24.1)	356.3 (24.7)
2	132 (22.9)	160 (18.3)		283.7 (19.5)	282.6 (19.6)
3	197 (34.2)	209 (24.0)		405.6 (27.8)	411.1 (28.4)
D2 surgery			< 0.001			0.996
No	310 (53.8)	357 (40.9)		672.7 (46.1)	666.7 (46.1)
Yes	266 (46.2)	515 (59.1)		785.7 (53.9)	778.3 (53.9)
OS (95%CI)
1-year	79.4 (76.1, 82.9)	88.0 (85.8, 90.3)		83.5 (80.5, 86.6)	86.2 (83.6, 88.9)
3-year	48.7 (44.5, 53.4)	54.6 (51.0, 58.5)		53.0 (48.3, 58.1)	51.6 (47.8, 55.6)
5-year	37.9 (33.7. 42.6)	41.2 (37.4, 45.4)		42.7 (37.9, 48.1)	37.8 (34.0, 42.2)
Median OS (95%CI), month	34.0 (31.0, 42.0)	42.0 (38.0, 48.0)		42.0 (35.0, 53.0)	38.0 (35.0, 44.0)
CSS (95%CI)
1-year	81.2 (78.0, 84.6)	89.6 (87.5, 91.8)		85.0 (82.1, 88.0)	87.8 (85.3, 90.4)
3-year	52.4 (48.1, 57.1)	59.0 (55.3, 62.9)		56.5 (51.8, 61.7)	56.0 (52.1, 60.1)
5-year	43.3 (38.8, 48.2)	46.4 (42.4, 50.9)		47.8 (42.8, 53.3)	43.1 (39.0, 47.4)
Median CSS (95%CI), month	42.0 (33.0, 53.0)	52.0 (43.0, 64.0)		53.0 (42.0, 80.0)	45.0 (39.0, 54.0)

OS: Overall survival; CSS: Cancer-specific survival; IPTW: Inverse probability of treatment weighting; CI: Confidence interval.