Background Both 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. Methods Patients 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. Results In 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). Conclusions The AJCC 7th edition staging classification is more applicable than the 8th edition classification for invasive IPMN.
[1]Fudan Univ, Shanghai Canc Ctr, Dept Pancreat Surg, 270 DongAn Rd, Shanghai 200032, Peoples R China;
[2]Fudan Univ, Shanghai Med Coll, Dept Oncol, 270 DongAn Rd, Shanghai 200032, Peoples R China;
[3]Shanghai Pancreat Canc Inst, Shanghai 200032, Peoples R China;
[4]Fudan Univ, Pancreat Canc Inst, Shanghai 200032, Peoples R China
(8.0+极速模式)