Long-term outcomes after pancreatoduodenectomy for ampullary cancer: The influence of the histological subtypes and comparison with the other periampullary neoplasms

Background: Ampullary carcinoma (AC) is histologically classified as intestinal (In-AC), pancreaticobiliary (Pb-AC) or mixed-AC. The prognostic role of AC subtypes has been debated and remains unclear. The aims of this study were to evaluate outcomes after pancreatoduodenectomy (PD) for each subtype of AC and to compare these with pancreatic ductal adenocarcinoma [PDAC] and distal cholangiocarcinoma [DCC]. Methods: PDs performed for AC between 2010 and 2018 were retrospectively evaluated. Histological subtype was obtained for all patients. One-year, 3-year and 5-year disease-free-survival (DFS) and overall survival (OS) rates were calculated. Kaplan-Meier survival analysis was performed to compare Pb-AC, In-AC and mixed-AC. Comparison with PDs performed for PDAC and DCC during the same period was also performed. Results: A total of 97 patients undergoing PD for AC were evaluated: 34 (35.1%) In-AC, 54 (55.7%) Pb-AC and 9 mixed-AC (9.3%). DFS and OS rates for Pb-AC were significantly lower compared to In-AC (p < 0.05 and p < 0.01), but similar to mixed-AC (p = 0.3 and p = 0.4). Adjuvant therapy was not associated with increased survival, regardless of the histological subtype (p > 0.05). During the same period, 337 and 53 PDs for PDAC and DCC, respectively, were performed. In-AC was associated with significantly better outcomes compared to PDAC and DCC (p < 0.001); DFS and OS rates for Pb-AC and mixed AC were significantly higher compared to PDAC (p < 0.001), but similar to DCC (p > 0.05). Conclusions: Pb-AC has significantly worse survival compared to In-AC. Moreover, mixed-AC should be considered as Pb-AC. Pb-AC and mixed-AC seem to have better prognosis compared to PDAC, but similar to DCC.