Endoscopy 2014; 46(01): 32-38
DOI: 10.1055/s-0033-1344958
Original article
© Georg Thieme Verlag KG Stuttgart · New York

Evaluation of Ki-67 index in EUS–FNA specimens for the assessment of malignancy risk in pancreatic neuroendocrine tumors

Toshiyuki Hasegawa
1  Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan
,
Kenji Yamao
1  Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan
,
Susumu Hijioka
1  Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan
,
Vikram Bhatia
2  Department of Medical Hepatology, Institute of Liver and Biliary Sciences, Delhi, India
,
Nobumasa Mizuno
1  Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan
,
Kazuo Hara
1  Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan
,
Hiroshi Imaoka
1  Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan
,
Yasumasa Niwa
3  Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan
,
Masahiro Tajika
3  Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan
,
Shinya Kondo
3  Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan
,
Tutomu Tanaka
3  Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan
,
Yasuhiro Shimizu
4  Department of Gastrointestinal Surgery, Aichi Cancer Center Hospital, Nagoya, Japan
,
Taira Kinoshita
4  Department of Gastrointestinal Surgery, Aichi Cancer Center Hospital, Nagoya, Japan
,
Takuhiro Kohsaki
5  Department of Gastroenterology and Hepatology, Kochi Medical School, Kochi, Japan
,
Isao Nishimori
5  Department of Gastroenterology and Hepatology, Kochi Medical School, Kochi, Japan
,
Shinji Iwasaki
5  Department of Gastroenterology and Hepatology, Kochi Medical School, Kochi, Japan
,
Toshiji Saibara
5  Department of Gastroenterology and Hepatology, Kochi Medical School, Kochi, Japan
,
Waki Hosoda
6  Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Nagoya, Japan
,
Yasushi Yatabe
6  Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Nagoya, Japan
› Author Affiliations
Further Information

Publication History

submitted 18 January 2013

accepted after revision 08 August 2013

Publication Date:
11 November 2013 (eFirst)

Background and study aim: Malignancy in pancreatic neuroendocrine tumors (PNETs) is graded by assessing the resected specimens according to the World Health Organization (WHO) 2010 criteria. The feasibility of such grading using endoscopic ultrasound-guided fine-needle aspiration (EUS–FNA) specimens remains unclear. The aim of this study was to ascertain the optimal method of measuring the Ki-67 index in EUS–FNA specimens, using resected specimens as the criterion standard.

Patients and methods: A total of 58 consecutive patients diagnosed with PNETs between March 1998 and May 2011 were included. The study measured intratumoral Ki-67 index heterogeneity, concordance rates of PNET grading by EUS–FNA with grade of the resected tumor, optimal method of measuring the Ki-67 index in EUS–FNA specimens, and survival analysis based on EUS–FNA specimen grading.

Results: Intratumoral dispersion of Ki-67 index in resected specimens was 0.033 for Grade 1 and 0.782 for Grade 2 tumors (P < 0.001). Concordance rates for WHO classification between EUS–FNA and resected specimens were 74.0 % using the mean Ki-67 index in EUS–FNA specimens and 77.8 % using the highest Ki-67 index. The concordance rate rose to 90 % when EUS–FNA samples with less than 2000 tumor cells were excluded (26 % of EUS–FNA cases). The Kaplan–Meier survival curves were significantly stratified by the EUS–FNA grading of PNETs with 5-year survival rates of 100 %, 58.3 %, and 0 %, for Grade 1, Grade 2, and neuroendocrine carcinoma (NEC) tumors, respectively.

Conclusions: Grading of PNETs by the highest Ki-67 index in EUS–FNA specimens with adequate cellularity has a high concordance with grading of resected specimens, and can predict long term patient survival with high accuracy.