Characteristics and prognosis of primary gastric adenosquamous carcinoma: A multicenter retrospective study based on propensity score matching

Table 1 Characteristics of the primary gastric adenosquamous carcinoma and gastric adenocarcinoma groups

Characteristic	GAC (n = 468)	PGASC1 (n = 108)	P value
Age in years (≤ 60/> 60)	163/305	38/70	0.940
Sex (female/male)	152/316	23/85	0.020
Surgical resection (incomplete resection/complete resection)	275/193	64/44	0.920
Primary site (non-cardia/cardia)	361/107	60/48	< 0.001
pT stage2 (pT1/pT2/pT3/pT4)	79/51/31/307	2/5/35/66	< 0.001
pN stage2 (pN0/pN1/pN2/pN3)	163/76/99/130	21/27/26/34	0.010
pM stage2 (pM0/pM1)	434/34	92/16	0.010
Lymphovascular invasion (VI-/VI+)	302/166	48/60	< 0.001
Perineural invasion (PI-/PI+)	315/153	54/54	0.001
Chemotherapy (no/yes)	155/313	53/55	< 0.01

¹This cohort of patients with primary gastric adenosquamous carcinoma included the patients lost to follow-up.

²Based on the American Joint Committee on Cancer (8^th edition) staging system.

GAC: Gastric adenocarcinoma; PGASC: Primary gastric adenosquamous carcinoma; pM: Pathological metastasis; pN: Pathological node; pT: Pathological tumor; VI: Lymphovascular invasion; PI: Perineural invasion.

Table 2 Immunohistochemical analysis of primary gastric adenosquamous carcinoma and gastric adenocarcinoma

Characteristics	GAC (n = 468)	PGASC1 (n = 108)	P value
P53 (-/+)	171/297	18/34	0.780
PD-L1 (< 10%/≥ 10%)	455/13	66/10	< 0.001
HER2 (-, +, ++/+++)	436/32	74/1	0.070
Ki-67 (≤ 50%/> 50%)	159/309	37/44	0.040

¹This cohort of patients with primary gastric adenosquamous carcinoma included the patients lost to follow-up.

GAC: Gastric adenocarcinoma; PGASC: Primary gastric adenosquamous carcinoma; PD-L1: Programmed cell death-ligand 1; HER2: Human epidermal growth factor receptor 2.

Table 3 Characteristics of patients with primary gastric adenosquamous carcinoma and gastric adenocarcinoma before and after propensity score matching

Characteristics	Before PSM			After PSM
	GAC (n = 468)	PGASC1 (n = 89)	P value	GAC (n = 77)	PGASC (n = 77)	P value
Age, years (≤ 60/> 60)	163/305	31/58	> 0.990	26/51	27/50	0.870
Sex (female/male)	152/316	17/72	0.010	19/58	17/60	0.700
Surgical resection (incomplete resection/complete resection)	275/193	58/31	0.260	44/33	46/31	0.740
Primary site (non-cardia/cardia)	361/107	52/37	< 0.001	49/28	43/34	0.320
pT stage2 (pT1/pT2/pT3/pT4)	79/51/31/307	2/5/21/61	< 0.001	2/3/7/65	2/5/19/51	0.050
pN stage2 (pN0/pN1/pN2/pN3)	163/76/99/130	16/20/22/31	0.020	19/12/12/34	16/20/16/25	0.240
pM stage2 (pM0/pM1)	434/34	76/13	0.020	64/13	65/12	0.830
Chemotherapy (no/yes)	155/313	39/50	0.050	29/48	28/49	0.870

¹This cohort of patients with primary gastric adenosquamous carcinoma included the patients with available overall survival data.

²Based on the American Joint Committee on Cancer (8^th edition) staging system.

GAC: Gastric adenocarcinoma; PGASC: Primary gastric adenosquamous carcinoma; pM: Pathological metastasis; pN: Pathological node; pT: Pathological tumor; PSM: Propensity score matching.