Expression and clinical significance of B cell ectopic gene 2 in pancreatic cancer tissue / 中华胰腺病杂志

ABSTRACT

Objective:To investigate the expression of the B cell ectopic gene 2 (BTG2) in the pancreatic cancer tissue and analyze its relationship with the clinicopathological features and prognosis.Methods:46 pairs of pancreatic cancer tissues and corresponding adjacent tissues kept in paraffin in the pathology department, and 9 fresh pancreatic cancer tissues and corresponding adjacent tissues resected by surgery in Department of Pancreatic Surgery of Sinopharm Dongfeng General Hospital from June 2015 to December 2020 were collected. BTG2 gene expression in 46 pairs of pancreatic cancer tissues and corresponding adjacent tissues were detected by immunohistochemical staining, and high and low BTG2 expression groups were divided. BTG2 gene expression in 9 fresh pancreatic cancer tissues and corresponding adjacent tissues were detected by RT-PCR. The correlation between BTG2 protein expression level and clinicopathological features was analyzed. Furthermore, the survival curve and death risk curve were drawn using the Kaplan-Meier method, and the Cox regression hazards model was applied for the univariate and multivariate analysis of the factors affecting the prognosis of pancreatic cancer.Results:29 of 46 (63.04%) pancreatic cancer tissues had high BTG2 expression, and 38(82.61%) of corresponding adjacent tissues had high BTG2 expression; and BTG2 high expression rate of adjacent tissues was significantly higher than that of cancer tissues. Three out of 9 pancreatic cancer tissues were highly differentiated, and six cases had medium-and low differentiation. The BTG2 expression of highly differentiated pancreatic carcinoma was significantly higher than that of moderately and poorly differentiated carcinoma tissues [(0.66±0.07 vs 0.24±0.18); the expression level of adjacent tissues was significantly higher than that of cancer tissues (1.00±0.00 vs 0.38±0.30), and all differences were statistically significant (all P values <0.001). Low BTG2 expression in pancreatic cancer was associated with low tumor differentiation and vascular invasion (all P values <0.05), but was not correlated with tumor location, volume, lymph node metastasis, CA19-9 level and postoperative liver metastasis. The median survival of high BTG2 expression group was significantly longer than that of low BTG2 expression group (525 d vs 266 d, P<0.001). Among patients with survival time ≥300 d, the survival time was significantly higher in the high BTG2 expression group than in the BTG2 low expression group (616±135d vs 426±113 d), and the difference was statistically significant ( P<0.001). Among patients with survival time <300 d, there was no significant difference between BTG2 high and low expression group. The results of the univariate analysis showed that tumor differentiation degree, vascular invasion, BTG2 expression, CA19-9 levels, and postoperative liver metastasis were all associated with the prognosis of pancreatic cancer. The results of the multivariate analysis showed that BTG2 expression level ( HR=2.572, 95% CI1.140-5.802, P=0.023), vascular invasion ( HR=0.023, 95% CI0.072-0.572, P=0.003) and postoperative liver metastasis ( HR=0.240, 95% CI0.102-0.564, P<0.001) were independent risk factors affecting the prognosis of patients with pancreatic cancer. Conclusions:BTG2 expression in pancreatic cancer tissues was significantly lower than that in adjacent tissues, and its low expression was associated with strong aggressiveness, low differentiation degree and poor prognosis of pancreatic cancer. The effect of BTG2 on the prognosis in pancreatic cancer patients was mainly in the long term.