Claudin 18.2 is a potential therapeutic target for zolbetuximab in pancreatic ductal adenocarcinoma

Table 1 Classification of sample types investigated by claudin 18.2 staining

Sample type	Samples, n	CLDN18.2 expression
		Positive fraction ≥ 1%, n (%)	Staining intensity = 3+, n (%)
PDAC	93	88 (94.6)	50 (56.8)
Para-cancerous	86	81 (94.2)	32 (39.5)
Normal	13	0 (0.0)	0 (0.0)

CLDN18.2: Claudin 18.2; PDAC: Pancreatic ductal adenocarcinoma.

Table 2 Claudin 18.2 expression and correlation with clinicopathological characteristics of pancreatic ductal adenocarcinoma

Clinicopathological parameter	Variable	Total valid, n (%)	CLDN18.2 expression		P value
			Positive, n (%)	Negative, n (%)
Age	< 63	49 (52.7)	23 (46.9)	26 (53.1)	0.680
	≥ 63	44 (47.3)	23 (52.3)	21 (47.7)
Sex	Female	44 (47.3)	24 (54.5)	20 (45.5)	0.409
	Male	49 (52.7)	22 (44.9)	27 (55.1)
Localization	Head and neck	52 (65.0)	23 (44.2)	29 (55.8)	0.350
	Body and tail	28 (35.0)	16 (57.1)	12 (42.9)
CA199	High1	65 (81.3)	33 (50.8)	32 (49.2)	0.570
	Normal2	15 (18.7)	6 (40.0)	9 (60.0)
T category	T1	14 (15.1)	6 (42.9)	8 (57.1)	0.773
	T2	47 (50.5)	24 (51.1)	23 (48.9)
	T3	26 (28.0)	14 (53.8)	12 (46.2)
	T4	6 (6.4)	2 (33.3)	4 (66.7)
	T1 + T2	61 (65.6)	30 (49.2)	31 (50.8)	1.000
	T3 + T4	32 (34.4)	16 (50.0)	16 (50.0)
	T1	14 (15.1)	6 (42.9)	8 (57.2)	0.773
	T2 + T3 + T4	79 (84.9)	40 (50.6)	39 (49.4)
N category	N0	57 (61.3)	23 (40.4)	34 (59.6)	0.019a
	N1	27 (29.0)	15 (55.6)	12 (44.4)
	N2	9 (9.7)	8 (88.9)	1 (11.1)
	N0	57 (61.3)	23 (40.4)	34 (59.6)	0.034a
	N1 + N2	36 (38.7)	23 (63.9)	13 (36.1)
M category	M0	79 (84.9)	35 (44.3)	44 (55.7)	0.022a
	M1	14 (15.1)	11 (78.6)	3 (21.4)
AJCC stage	I	38 (40.9)	16 (42.1)	22 (57.9)	0.058
	II	28 (30.1)	11 (39.3)	17 (60.7)
	III	13 (14.0)	8 (61.5)	5 (38.5)
	IV	14 (15.0)	11 (78.6)	3 (21.4)
	I	38 (40.9)	16 (42.1)	22 (57.9)	0.293
	II + III + IV	55 (59.1)	30 (54.5)	25 (45.5)
	I + II	66 (71)	27 (40.9)	39 (59.1)	0.012a
	III + IV	27 (29)	19 (70.4)	8 (29.6)
	I + II + III	79 (84.9)	35 (44.3)	44 (55.7)	0.022a
	IV	14 (15.1)	11 (78.6)	3 (21.4)
Local infiltration	Yes	57 (71.3)	29 (50.9)	28 (49.1)	0.625
	No	23 (28.7)	10 (43.5)	13 (56.5)
Vascular invasion	Yes	12 (15.0)	7 (58.3)	5 (41.7)	0.542
	No	68 (85.0)	32 (47.1)	36 (52.9)
Nerve invasion	Yes	23 (28.7)	17 (73.9)	6 (26.1)	0.006b
	No	57 (71.3)	22 (38.6)	35 (61.4)
Vessel carcinoma embolus	Yes	27 (33.8)	13 (48.1)	14 (51.9)	1.000
	No	53 (66.2)	26 (49.1)	27 (50.9)
Grading	G1/G2	45 (48.4)	20 (44.4)	25 (55.6)	0.409
	G3	48 (51.6)	26 (54.2)	22 (45.8)

^aP < 0.05.

^bP < 0.01.

¹High indicates CA199 > 39 U/mL.

²Normal indicates CA199 ≤ 39 U/mL.

AJCC: American Joint Committee on Cancer; CLDN18.2: Claudin 18.2.