Immunophenotyping of ampullary carcinomata allows for stratification of treatment specific subgroups.
BACKGROUND
Ampullary 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.


METHODS
As 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.


RESULTS
Of 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).


CONCLUSIONS
AC 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.
Division of Anatomic Pathology, Vancouver General Hospital, Vancouver, British Columbia, Canada The University of British Columbia, Vancouver, British Columbia, Canada.
Joyce M
JM
Leo
The University of British Columbia, Vancouver, British Columbia, Canada Pancreas Centre BC, Vancouver, British Columbia, Canada.
Steve E
SE
Kalloger
Division of Medical Oncology, BC Cancer Agency, Vancouver, British Columbia, Canada.
Renata D
RD
Peixoto
Anatomical Pathology, BC Cancer Agency, Vancouver, British Columbia, Canada.
Nadia S
NS
Gale
Division of Anatomic Pathology, Vancouver General Hospital, Vancouver, British Columbia, Canada The University of British Columbia, Vancouver, British Columbia, Canada Pancreas Centre BC, Vancouver, British Columbia, Canada.
Douglas L
DL
Webber
Division of Anatomic Pathology, Vancouver General Hospital, Vancouver, British Columbia, Canada The University of British Columbia, Vancouver, British Columbia, Canada Pancreas Centre BC, Vancouver, British Columbia, Canada.
David A
DA
Owen
The University of British Columbia, Vancouver, British Columbia, Canada Pancreas Centre BC, Vancouver, British Columbia, Canada Division of Medical Oncology, BC Cancer Agency, Vancouver, British Columbia, Canada.
Daniel
D
Renouf
Division of Anatomic Pathology, Vancouver General Hospital, Vancouver, British Columbia, Canada The University of British Columbia, Vancouver, British Columbia, Canada Pancreas Centre BC, Vancouver, British Columbia, Canada.
David F
DF
Schaeffer
D000368:Aged; D014670:Ampulla of Vater / Q000378:metabolism / Q000473:pathology*; D000071616:CDX2 Transcription Factor; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D003138:Common Bile Duct Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D053554:Keratin-20 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism; D055262:Mucin-2 / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D011379:Prognosis; D015996:Survival Rate
D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; C507499:KRT20 protein, human; D053554:Keratin-20; C524625:MUC2 protein, human; D018396:Mucin-1; D055262:Mucin-2
CANCER; CHEMOTHERAPY; HISTOPATHOLOGY; PANCREAS