Tumor Stroma Area and Other Prognostic Factors for Survival and Disease-Free Survival in Pancreatic Ductal Adenocarcinoma Patients Submitted to Operation

Abstract

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) patients have a poor overall survival. Clinicopathologic factors have different impacts on survival; however, their magnitude is not fully clarified. The aim of this study was to identify prognostic factors for PDAC patients submitted to operation at our institution. METHODS: Retrospective study: 148 PDAC patients submitted to operation. Tumor stroma area calculated using QuPath-0.2.3 software. Statistical analysis performed on SPSS. Study approved by the ethics committee. RESULTS: Median overall survival (OS) was 18 months and median disease-free survival (DFS) was 10 months. Three- and 5-year OS was 26.9% and 16.4%, and DFS was 2.4% and 1.2%, respectively. Of these patients, 58.8% had a recurrence, mainly hepatic (34.6%). In univariable regression, AHT, diabetes mellitus (DM), abdominal pain, T>2, lymphovascular invasion (LVI), stage>II, R≥1, and recurrence were significantly associated with worse OS. Adjuvant treatment was associated with 38.2% reduction in the risk of death. Calcium (CA) 19.9 >500 U/L and aspartate aminotransferase (AST) ≥100 U/L correlated with DFS on univariable and multivariable regression. Regarding stroma area (SA), using >1.9E+11 µm2 as cutoff value for all stages, no significant relation was found between SA and OS (31 vs 21 months, p = 0.495). For stage II, patients with a SA >1.9 µm2 (p = 0.072) seem to have longer OS, and a SA >2 µm2 was associated with an R0 resection (p = 0.037). For stage III patients, SA >1.9 µm2 was associated with a lower histologic grade (p = 0.031), and a SA >2 µm2 was associated with a preoperative AP ≥120 U/L (p = 0.009) and a lower preoperative AST (≤35 U/L; p = 0.004). CONCLUSION: PDAC patients submitted to operation with unfavorable prognosis may be identified. Patients with pretreatment CA19.9>500 U/L and AST≥100 U/L have a higher risk of recurrence. Tumor stroma seems to have a protective effect, and preoperative AP could help predict the amount of tumor stroma.