Tight junction disruption via claudin-6 overexpression promotes invasion and recurrence in high-grade endometrial tumors

Table 1 Distribution of clinicopathological characteristics according to claudin-6 expression in 80 patients, n (%)

Parameter	Total (n = 80)	CLDN6 low (n = 56)	CLDN6 high (n = 24)	P value
Age group				0.19
≤ 50	39 (49)	30 (54)	9 (38)
> 50	41 (51)	26 (46)	15 (62)
Family history of cancer				1
Absent	68 (85)	47 (84)	21 (88)
Present	12 (15)	9 (16)	3 (12)
Diagnosis type				< 0.001
High grade Endometrioid	53 (66)	53 (95)	0 (0)
Serous	9 (11)	0 (0)	9 (38)
Carcinosarcoma	15 (19)	3 (5.4)	12 (50)
Clear	2 (2.5)	0 (0)	2 (8.3)
Poorly differentiated	1 (1.2)	0 (0)	1 (4.2)
Tumor size				0.2
< 5 cm	42 (52)	32 (57)	10 (42)
≥ 5 cm	38 (48)	24 (43)	14 (58)
Cervical invasion				0.35
Absent	62 (78)	45 (80)	17 (71)
Present	18 (22)	11 (20)	7 (29)
Myometrial invasion				< 0.010
< 50%	42 (52)	35 (62)	7 (29)
≥ 50%	38 (48)	21 (38)	17 (71)
Lymphovascular invasion				0.024
Absent	28 (35)	24 (43)	4 (17)
Present	52 (65)	32 (57)	20 (83)
Lymph node metastasis				< 0.001
Absent	62 (78)	52 (93)	10 (42)
Present	18 (22)	4 (7.1)	14 (58)
Distant metastasis				1
Absent	76 (95)	53 (95)	23 (96)
Present	4 (5)	3 (5.4)	1 (4.2)
Surgical margin status				0.51
Negative	78 (98)	55 (98)	23 (96)
Positive	2 (2.5)	1 (1.8)	1 (4.2)
FIGO stage				0.32
Stage I	58 (72)	43 (77)	15 (62)
Stage II	9 (11)	6 (11)	3 (12)
Stage III	9 (11)	4 (7.1)	5 (21)
Stage IV	4 (5)	3 (5.4)	1 (4.2)
Tumor recurrence				0.26
Absent	63 (79)	46 (82)	17 (71)
Present	17 (21)	10 (18)	7 (29)
Death events				0.41
Alive	52 (65)	38 (68)	14 (58)
Deceased	28 (35)	18 (32)	10 (42)

This table presents the comparative distribution of clinical, demographic, and pathological characteristics on the basis of claudin-6 (CLDN6) immunohistochemical expression in 80 patients diagnosed with high-grade endometrial carcinoma. Patients were stratified into two groups: Low CLDN6 expression (n = 56) and high CLDN6 expression (n = 24). The parameters evaluated included age; family history of malignancy; tumor histology; size; depth of myometrial invasion; cervical involvement; lymphovascular invasion (LVI); lymph node and distant metastasis; surgical margin status; the International Federation of Gynecology and Obstetrics (FIGO) stage; recurrence; and overall survival outcome. High CLDN6 expression was significantly correlated with unfavourable histological subtypes (including serous carcinoma, carcinosarcoma, and poorly differentiated tumors), increased depth of myometrial invasion, increased frequency of LVI, and increased likelihood of lymph node metastasis (P < 0.05 for all). Other factors—such as patient age, tumor size, cervical invasion, distant metastasis, margin status, FIGO stage, recurrence, and mortality—did not differ significantly between the two groups. Statistically significant P values are highlighted in bold (P < 0.05). FIGO: International Federation of Gynecology and Obstetrics; CLDN6: Claudin-6.