TGFβ1 overexpression is associated with improved survival and low tumor cell proliferation in patients with early-stage pancreatic ductal adenocarcinoma

The role of transforming growth factor beta-type-1 (TGFβ1) in pancreatic ductal adenocarcinoma (PDAC) progression is stage-dependent. We hypothesized that TGFβ1 expression is associated with survival and proliferation markers in patients with early-stage PDAC. We acquired clinicopathologic, treatment, and mRNA expression data from The Cancer Genome Atlas data set for 106 patients identified with stage I/II PDAC who underwent pancreaticoduodenectomy. Patients were categorized as high expression when mRNA expression was ≥75th percentile for each gene. Average log(2) mRNA expression of TGFβ1 in patients with high expression was 11.6 ± 0.2 and 10.5 ± 0.6 in patients with low expression (P<0.001). Low TGFβ1 expression is associated with shorter median survival compared with high TGFβ1 expression (17 versus at least 60 months; P=0.005). Patients with tumors demonstrating high MKI67 (the gene encoding Ki-67) expression have shorter median survival versus those with lowerMKI67 expression (16 versus 20 months; P=0.026). TGFβ1 and MKI67 are inversely associated (P=0.009). On multivariate analysis, improved survival is associated with TGFβ1 overexpression (P=0.017), adjuvant chemotherapy (P=0.001), and adjuvant radiotherapy (P=0.017), whereas positive surgical margins are associated with worse survival (P=0.002). In patients who undergo pancreaticoduodenectomy for PDAC, high TGFβ1 expression may counteract the worse survival associated with high proliferation.