Pancreatic and duodenal invasion in distal bile duct cancer: paradox in the tumor classification of the American Joint Committee on Cancer.
BACKGROUND
Distal bile duct cancer often invades the pancreas and/or duodenum. Invasion of the pancreas is defined as a T3 and that of the duodenum as a T4 tumor in the T classification of the American Joint Committee on Cancer (AJCC). The aim of this study was to assess whether this T classification is rational from the viewpoint of prognostic power.


METHODS
Ninety-five patients with distal bile duct cancer were retrospectively analyzed according to the current T classification of the AJCC.


RESULTS
The main determinant of pT3 (n = 32) and pT4 (n = 30) was pancreatic and duodenal invasion, respectively, and the survival rates for patients with pT3 and pT4 are similar (p = 0.595). Duodenal invasion was present in 39% of the patients with pancreatic invasion, whereas pancreatic invasion was observed in 86% of those with duodenal invasion. The survival for patients with pancreatic invasion was not significantly different (p = 0.283) whether or not there was concomitant duodenal invasion (n = 19 and n = 37, respectively). Multivariate analysis identified venous invasion, distant metastasis, histologic grade, and pancreatic invasion as independent prognostic factors.


CONCLUSIONS
Although duodenal invasion usually occurs after pancreatic invasion, it is not a significant prognostic factor while pancreatic invasion is. The current T classification should be revised since it expresses tumor extension but does not reflect a survival in distal bile duct cancer.
Ebata
Tomoki
T
Division of Surgical Oncology, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan. tomoki@med.nagoya-u.ac.jp
Nagino
Masato
M
Nishio
Hideki
H
Igami
Tsuyoshi
T
Yokoyama
Yukihiro
Y
Nimura
Yuji
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000145:classification* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D001653:Bile Ducts, Intrahepatic; D018281:Cholangiocarcinoma / Q000145:classification* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D003549:Cystic Duct / Q000473:pathology; D004386:Duodenum / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D010179:Pancreas / Q000473:pathology*; D016577:Pancreaticoduodenectomy; D016019:Survival Analysis