title: MIB-1 labeling index, Ki-67, is an indicator of invasive intraductal papillary mucinous neoplasm.
abstract: Despite strict criteria for the observation of intraductal papillary mucinous neoplasm (IPMN), it remains difficult to distinguish invasive IPMN from non-invasive IPMN. The aim of the present study was to identify an indicator of invasive IPMN. The present study retrospectively evaluated 53 patients (28 with non-invasive and 25 with invasive IPMN) who underwent resection of IPMN, and examined the usefulness of the MIB-1 labeling index as an indicator of invasive IPMN. The MIB-1 labeling indexes in patients with invasive IPMN were significantly higher compared with those with non-invasive IPMN (P<0.001). A receiver operating characteristic curve revealed that the area under the curve was 0.822. These results suggested that a cut-off level for the MIB-1 labeling index should be set to 15.5% to distinguish invasive from non-invasive IPMN. A multivariate analysis using a logistic regression model revealed the MIB-1 labeling index (hazard ratio, 18.692; 95% confidential interval, 4.171-83.760; P<0.001) and the existence of mural nodules (hazard ratio, 6.187, 95% confidential interval, 1.039-36.861; P=0.045) were predictive factors for invasive IPMN. However, no statistically significant differences were observed between patients with a lower MIB-1 labeling index and patients with a higher MIB-1 labeling index (P=0.798). The MIB-1 labeling index must be considered as a candidate for the classification of IPMN.
authors.affiliation: Department of Cancer Biology and Electronics, Fukushima Medical University, Fukushima 960-1295, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Shimura
authors.affiliation: Department of Organ Regulatory Surgery, Fukushima Medical University, Fukushima 960-1295, Japan.
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Kofunato
authors.affiliation: Department of Organ Regulatory Surgery, Fukushima Medical University, Fukushima 960-1295, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Okada
authors.affiliation: Department of Organ Regulatory Surgery, Fukushima Medical University, Fukushima 960-1295, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Yashima
authors.affiliation: Department of General Surgical Science, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Okada
authors.affiliation: Department of General Surgical Science, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Araki
authors.affiliation: Department of Surgery and Laparoscopic Surgery, Gunma Prefecture Saiseikai-Maebashi Hospital, Maebashi, Gunma 371-0821, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hosouchi
authors.affiliation: Department of General Surgical Science, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kuwano
authors.affiliation: Department of Organ Regulatory Surgery, Fukushima Medical University, Fukushima 960-1295, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Takenoshita
keywords: IPMN; Ki-67; MIB-1; invasive IPMN; mural nodule