Retrospective Study of the Correlation Between Pathological Tumor Size and Survival After Curative Resection of T3 Pancreatic Adenocarcinoma: Proposal for Reclassification of the Tumor Extending Beyond the Pancreas Based on Tumor Size

Masanao Kurata,Minako Nagai,Takumi Fukumoto,For The Multicenter Study Group Of Pancreatobiliary Surgery (Msg‐Pbs) ,Masahiko Gosho,Fuyuhiko Motoi,Michiaki Unno,Hiroki Yamaue,Yoshiaki Murakami,Ippei Matsumoto,Hiroaki Yanagimoto,Manabu Kawai,Kenichiro Uemura,Masayuki Sho,Sohei Satoi,Goro Honda

doi:10.1007/s00268-017-4077-5

Abstract

BackgroundEven though most patients who undergo resection of pancreatic adenocarcinoma have T3 disease with extra-pancreatic tumor extension, T3 disease is not currently classified by tumor size. The aim of this study was to modify the current TNM classification of pancreatic adenocarcinoma to reflect the influence of tumor size.MethodsA total of 847 consecutive pancreatectomy patients were recruited from multiple centers. Optimum tumor size cutoff values were calculated by receiver operating characteristics analysis for tumors limited to the pancreas (T1/2) and for T3 tumors. In our modified TNM classification, stage II was divided into stages IIA (T3aN0M0), IIB (T3bN0M0), and IIC (T1-3bN1M0) using tumor size cutoff values. The usefulness of the new classification was compared with that of the current classification using Akaike’s information criterion (AIC).ResultsThe optimum tumor size cutoff value distinguishing T1 and T2 was 2 cm, while T3 was divided into T3a and T3b at a tumor size of 3 cm. The median survival time of the stages IIA, IIB, and IIC were 44.7, 27.6, and 20.3 months, respectively. There were significant differences of survival between stages IIA and IIB (P = 0.02) and between stages IIB and IIC (P = 0.03). The new classification showed better performance compared with the current classification based on the AIC value.ConclusionsThis proposed new TNM classification reflects the influence of tumor size in patients with extra-pancreatic tumor extension (T3 disease), and the classification is useful for predicting mortality.

Highlights

Pancreatic adenocarcinoma is the most lethal common cancer and the eighth leading cause of cancer-related death in men and the ninth leading cause of death in women throughout the world [1]
This proposed new TNM classification reflects the influence of tumor size in patients with extrapancreatic tumor extension (T3 disease), and the classification is useful for predicting mortality
We reviewed all data from patients with pancreatic adenocarcinoma who had undergone pancreatectomy with curative intent to calculate tumor size cutoff values (Tco values) for tumors extending beyond the pancreas

Summary

Introduction

Pancreatic adenocarcinoma is the most lethal common cancer and the eighth leading cause of cancer-related death in men and the ninth leading cause of death in women throughout the world [1]. It has a very poor prognosis, with a 1-year survival rate of 25% and 5-year survival rate of 5%. The aim of this study was to modify the current TNM classification of pancreatic adenocarcinoma to reflect the influence of tumor size. In our modified TNM classification, stage II was divided into stages IIA (T3aN0M0), IIB (T3bN0M0), and IIC (T1-3bN1M0) using tumor size cutoff values. The new classification showed better performance compared with the current classification based on the AIC value

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