Analysis of extrahepatic bile duct carcinomas according to the New American Joint Committee on Cancer staging system focused on tumor classification problems in 222 patients

Abstract

BACKGROUNDAlthough the sixth edition of the American Joint Committee on Cancer (AJCC) staging system for extrahepatic bile duct carcinoma was updated, the system has a problem on T classification due to its ambiguous definition of T1 as “tumor confined to bile duct histologically” and T2 as “tumor invading beyond the bile duct.”METHODSThe authors considered the outermost part of the muscle layer or fibrous tissue as within the extrahepatic bile duct and considered the area starting from large clusters of adipose tissue as beyond the extrahepatic bile duct. After designing a precise definition of the extrahepatic bile duct wall, they analyzed the new AJCC staging system in 222 patients with of extrahepatic bile duct carcinomas. Then, other clinicopathologic variables for prognosis were evaluated using univariate and multivariate analyses.RESULTSThe 5‐year survival rates for patients with tumors that were classified as T1, T2, T3, and T4 were 53.1%, 29.7%, 24.9%, and 0%, respectively. There was a significant difference in survival between patients with T1 tumors and T2 tumors (P < 0.05), but not between patients with T2 tumors and T3 tumors. Significant prognostic factors included depth of invasion (P < 0.005), lymph node metastasis (P < 0.005), and patient age (P < 0.05).CONCLUSIONSBased on a proposed histologic definition, depth of invasion was practical for evaluating the prognosis of patients with middle and upper extrahepatic bile duct carcinomas. Therefore, the authors recommended changing the current pT1 and pT2 classifications to more precise pathologic terminology. Cancer 2005. © 2005 American Cancer Society.

Clinical and prognostic significances of nuclear and cytoplasmic KIT expressions in extrahepatic bile duct carcinomas

“…1 Surgical resection is currently the most effective therapy only for a limited number of patients. Although chemotherapy and radiation therapy have been administered in an attempt to reduce the recurrence after resection, their effectiveness has not been proven completely.…”

Early bile duct cancer

“…edition were merged into T1 (tumors confined to the bile duct histologically) in the AJCC 6 th edition. It may be difficult to discriminate extrahepatic early bile duct cancer from T1 extrahepatic bile duct cancer exactly in this new staging system, as the current T1 classification is defined using vague terms as "confined to the bile duct" without the mention about a precise histological layer such as a fibromuscular layer [23] . Although the AJCC 6 th edition describes T1 classification as "tumor confined to the bile duct", there is debate on how the bile duct is limited between pathologists also [17] .…”

“…Table 7 summarizes the microscopic findings and locoregional extensions in patients with early bile duct cancer. For histological classification, adenocarcinoma has been found to comprise greater than 90% of advanced bile duct cancers [2,23,37] , while it comprises only 10%-67% of early bile duct cancers [6,7,9,10,34] . On the other hand, papillary carcinoma was more common in early bile duct cancers, comprising up to 31%-90% [6,7,9,19,36] .…”

Neue Aspekte der TNM-Klassifikation von intra- und extrahepatischen Cholangiokarzinomen

“…Da die operativen Möglichkeiten sich ebenso verbessert haben wie die konservativen Therapieansätze [1][2][3][4][5], wurden, um die anatomische Ausbreitung möglichst genau ermitteln zu können, in der 7. Auflage der TNM-Klassifikation differenzierte Klassifikationen für Karzinome der verschiedenen Abschnitte des Gallengangsystems eingeführt [6,7].…”