Immunophenotyping of ampullary carcinomata allows for stratification of treatment specific subgroups

• Published in: Journal of clinical pathology Vol. 69; no. 5; pp. 431 - 439
• Main Authors: Leo, Joyce M, Kalloger, Steve E, Peixoto, Renata D, Gale, Nadia S, Webber, Douglas L, Owen, David A, Renouf, Daniel, Schaeffer, David F
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.05.2016
• Subjects: Aged; Ampulla of Vater - metabolism; Ampulla of Vater - pathology; Carcinoma, Pancreatic Ductal - metabolism; Carcinoma, Pancreatic Ductal - mortality; Carcinoma, Pancreatic Ductal - pathology; CDX2 Transcription Factor; Common Bile Duct Neoplasms - metabolism; Common Bile Duct Neoplasms - mortality; Common Bile Duct Neoplasms - pathology; Disease-Free Survival; Female; Homeodomain Proteins - metabolism; Humans; Immunophenotyping; Keratin-20 - metabolism; Male; Middle Aged; Mucin-1 - metabolism; Mucin-2 - metabolism; Pancreatic Neoplasms - metabolism; Pancreatic Neoplasms - mortality; Pancreatic Neoplasms - pathology; Prognosis; Survival Rate; PANCREAS; CANCER; HISTOPATHOLOGY; CHEMOTHERAPY
• ISSN: 0021-9746; 1472-4146
• DOI: 10.1136/jclinpath-2015-203337

BackgroundAmpullary carcinomata (AC) can be separated into intestinal (IT) or pancreatobiliary (PB) subtypes. Although morphological, immunohistochemical and molecular differentiation of IT and PB have been well documented; the prognostic significance of histological subtype and whether patients with either subtype benefit from differential chemotherapeutic regimens remains unclear.MethodsAs part of a larger cohort study, patients who underwent resection for AC or pancreatic ductal adenocarcinoma (PDAC) were retrospectively identified. Clinicopathological covariates and outcome were obtained and MUC1, MUC2, CDX2 and CK20 were assessed with immunohistochemistry.ResultsOf 99 ACs, the resultant immunophenotypes indicated 48% and 22% were IT and PB, respectively. Thirty (30%) cases were quadruple negative (QN). Within the PDAC cohort (N=257), the most prevalent immunophenotype was QN (53%). Subsequently, all QN ACs were classified as PB immunohistochemically yielding 47.5% and 52.5% classified as IT and PB, respectively. Involved regional lymph nodes and elevated T-stage were significantly associated with PB compared with IT AC (p=0.0032 and 0.0396, respectively). Progression-free survival revealed inferior survival for PB versus IT AC (p=0.0156).ConclusionsAC can be classified into prognostic groups with unique clinicopathological characteristics using immunohistochemistry. Immunophenotypical similarity of PB and PDAC suggests that treatment regimens similar to those used in PDAC should be explored.