AJCC 7th edition staging classification is more applicable than AJCC 8th edition staging classification for invasive IPMN

Zhiyao Fan,Jin Xu,Guopei Luo,He Cheng,Quanxing Ni,Yitao Gong,Chen Liu,Kaizhou Jin,Xianjun Yu,Qiuyi Huang

doi:10.1186/s12957-019-1682-9

Abstract

BackgroundBoth the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) staging systems have been introduced for pancreatic adenocarcinoma. However, the applicability of these classifications for invasive intraductal papillary mucinous neoplasms (IPMN) has not been systematically examined.MethodsPatients with invasive IPMN were retrieved from a cohort of 18 geographical sites (1973–2014 varying) in the Surveillance, Epidemiology, and End Results (SEER) cancer registry. The 7th and 8th editions of the AJCC staging were compared. Survival rates and multivariate analyses were computed.ResultsIn total, 1216 patients with resected invasive IPMN were included. A major difference between the 7th and 8th systems is the definition of stage IIA (7th, beyond the pancreas without involvement of major arteries; 8th, maximum tumor diameter > 4 cm). The hazard ratio (HR) of stage IIA disease (versus stage IA, HR = 2.33, P < 0.001) was higher than that of stage IB disease (HR = 1.48, P = 0.087) by the 7th edition classification, whereas the HR of stage IIA disease (HR = 1.26, P = 0.232) was even lower than that of stage IB disease (HR = 1.48, P = 0.040) by the 8th edition classification. In addition, for the 8th edition staging system, tumor size was not a predictor of survival in patients with resectable tumor > 2 cm (size > 4 cm versus > 2 ≤ 4 cm, HR = 0.91, P = 0.420).ConclusionsThe AJCC 7th edition staging classification is more applicable than the 8th edition classification for invasive IPMN.

Highlights

Intraductal papillary mucinous neoplasm (IPMN) is a rare neoplasm of the pancreas, its incidence keeps rising in recent years because of the growing use of diagnostic scrutiny [1, 2]
For stage classification by the American Joint Committee on Cancer (AJCC) 7th edition, the hazard ratio (HR) of stage IIA disease was higher than that of stage IB disease in multivariate analyses
These findings suggest that the staging classifications in the AJCC 7th edition were more applicable for invasive intraductal papillary mucinous neoplasms (IPMN) than the AJCC 8th edition’s

Summary

Introduction

Intraductal papillary mucinous neoplasm (IPMN) is a rare neoplasm of the pancreas, its incidence keeps rising in recent years because of the growing use of diagnostic scrutiny [1, 2]. Given the variable risks of malignancy, great importance has been attached to the management of IPMN [3,4,5,6,7]. The risk of malignancy for patients with main-duct IPMN may be as great as 57–92%, whereas the risk for patients with branch-duct IPMN is variable (6–46%) [8]. Few studies have focused on the management of invasive IPMN [11,12,13,14]. Both the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) staging systems have been introduced for pancreatic adenocarcinoma. The applicability of these classifications for invasive intraductal papillary mucinous neoplasms (IPMN) has not been systematically examined

Methods

Results

Conclusion