Expression of pyruvate dehydrogenase is an independent prognostic marker in gastric cancer

Table 1 Expression of pyruvate dehydrogenase in non-neoplastic mucosa and cancerous tissues in gastric cancer

Tissue sample	n	PDH							P value1
		-	+-	Total	+	++	Total	PR (%)	χ2test
Adjacent normal mucosa	265	46	20	66	159	40	199	75.09	0.001
Primary cancer tissue	265	50	68	118	102	45	147	55.47

¹Pearson χ² test. PDH: Pyruvate dehydrogenase.

Table 2 Relationship between pyruvate dehydrogenase expression and clinicopathological features of gastric carcinomas

Clinicopathologic variable	n	PDH expression
		-	+	PR (%)	P value1
	265	118	147	55.47
Sex					0.577
Female	71	34	37	52.11
Male	194	84	110	56.7
Age (yr)					0.902
< 60	133	60	73	54.89
≥ 60	132	58	74	56.06
Tumor size (cm)					0.347
< 4	80	32	48	60.00
≥ 4	185	87	98	52.97
Depth of invasion					0.093
Tis-1	25	7	18	72.00
T2-4	240	111	129	53.75
Lauren grade					0.001
Intestinal type	130	38	92	70.77
Diffuse type	135	81	54	40.00
TNM Stage					0.010
0-I	38	8	30	78.95
II-IV	227	110	117	51.54
Lymph node metastases					0.033
Negative	81	28	53	65.43
Positive	184	90	94	51.09
Lymphatic invasion					0.002
Absent	198	76	122	61.62
Present	67	41	26	38.81

¹Pearson χ² or Fisher’s exact test. PR: Positive rate; PDH: Pyruvate dehydrogenase.

Table 3 Association of PDH expression with different subtypes of gastric adenocarcinoma according to WHO classification

Tissue Sample	n	PDH				PR (%)
		-	+-	+	++
Well-differentiated	44	6	9	12	17	65.91
Moderately differentiated	76	9	16	36	15	67.11
Poorly differentiated	100	30	31	31	8	391
Mucinous	30	2	6	17	5	73.33
Signet ring cell	15	3	6	6	0	40
Total	265	50	68	102	45	55.50

¹Compared with well-differentiated P = 0.004, moderately differentiated P < 0.001, or mucinous. P value obtained from Pearson χ² test; PDH: Pyruvate dehydrogenase.

Table 4 Univariate and multivariate analysis for overall survival after surgery using Cox relative risk

Variable	Univariate analysis		Multivariate analysis
	RR (95%CI)	P value	RR (95%CI)	P value
PDH expression in tumor (positive vs negative)	0.552 (0.462-0.658)	< 0.0011	0.608 (0.504-0.734)	< 0.0011
PDH expression in NNM (positive vs negative)	0.830 (0.699-0.987)	0.035	0.869 (0.727-1.039)	0.123
Age (≥ 60 yr vs < 60 yr)	1.446 (1.030-2.032)	0.033	1.447 (1.010-2.073)	0.044
Tumor size (< 4 cm vs≥ 4 cm)	2.297 (1.505-3.504)	< 0.0011	1.492 (0.956-2.329)	0.078
Depth of invasion (Tis-1 vs T2-4)	5.114 (1.889-13.843)	0.0011	1.683 (0.567-4.995)	0.348
Lauren grade (intestinal-type vs diffuse-type)	1.978 (1.396-2.803)	< 0.0011	1.574 (1.081-2.292)	0.0181
TNM Stage (0-I vs II-IV)	1.809 (1.504-2.176)	< 0.0011	1.512 (1.191-1.920)	0.0011
Lymph node metastasis (positive vs negative)	3.146 (1.989-4.977)	< 0.0011	1.733 (1.061-2.830)	0.0281
Lymphatic invasion (positive vs negative)	2.041 (1.424-2.924)	< 0.0011	1.271 (0.875-1.847)	0.208
Histological type (differentiated vs undifferentiated)	1.460 (1.033-2.063)	0.032	1.058 (0.667-1.678)	0.811

¹Significant difference. RR and 95%CI were assessed using univariate and multivariate Cox regression analysis. RR: Relative risk.