ヒグチ　リヨウタ   Higuchi Riyouta   樋口　亮太    所属   医学部 医学科（附属八千代医療センター）    職種   講師
論文種別	総説
言語種別	英語
査読の有無	査読あり
表題	Is the New T1 Category as Defined in the Eighth Edition of the AJCC Pancreatic Cancer Staging System an Improvement?
掲載誌名	正式名：Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract 略　 称：J Gastrointest Surg ISSNコード：18734626/1091255X
巻・号・頁	24(2),pp.262-269
著者・共著者	Kwon Wooil, Park Taesung, He Jin, Higuchi Ryota, Son Donghee, Lee Seung Yeoun, Kim Jaeri, Byun Yoonhyeong, Kim Hongbeom, Kim Sun-Whe, Wolfgang Christopher L, Yamamoto Masakazu, Jang Jin-Young
発行年月	2020/02
概要	BACKGROUND:The new T1 pancreatic cancer by the eighth edition of the AJCC staging system discards the concept of "extension beyond the pancreas" and focuses on size only. Furthermore, the new T1 is divided into T1a, T1b, and T1c based on size. The evidence pertaining to these changes has not been evaluated. This is to evaluate the feasibility of the new T1 definition in the pancreas head cancer cohort.METHODS:Data from 540 patients with T1 pancreatic ductal adenocarcinoma as defined by the eighth edition were collected from Korea, Japan, and the USA. Invasive IPMNs were excluded. Survival analyses were performed.RESULTS:Of the 540 patients, 181 patients were T1 according to the seventh edition and 359 were down-staged to T1 from the former T3 because the concept of "extension beyond the pancreas" was discarded. The 5-year survival rate and the median survival of T1 patients were 30.6% and 27 months, respectively. Comparing tumors that extend beyond the pancreas (new T1) and those confined within the pancreas (original T1), the latter showed significantly longer median survival (43 vs. 24 months, p < 0.001). In terms of T1a/b/c, there were no significant differences in survival. Using MaxStat, subdividing into two groups using 1.1 cm as the cut-off value, yielded significantly discrete prognostic groups (p < 0.001).CONCLUSION:The new T1 definition may be more practical, but the implications of the concept of "extension beyond the pancreas" should be re-investigated. Further, the subcategorization of T1a/b/c may not be adequate and may require revision or deletion.
DOI	10.1007/s11605-019-04464-x
PMID	31823321