Abstract 2145
Background
The pathological classification of pancreatic neuroendocrine neoplasms (PanNENs) has been revised based on the World Health Organization (WHO) 2017 classification. Well-differentiated PanNENs were previously classified as G1, G2, or G3 according to the Ki-67 labeling index (LI), which shows the cell proliferation ability. Although the Ki67 LI cut-off for G1 and G2 was changed from ≤2% to < 3% from WHO 2010 to 2017, there are few reports on the impact of G2 tumor malignancy associated with this change.
Methods
Patients with PanNENs G1/G2 classified by WHO 2017 Ki-67 LI cut-off who underwent pancreatic resection at our institution between July 1987 and March 2019 were retrospectively analyzed. We excluded patients with synchronous distant metastasis at the time of diagnosis. Their clinicopathological variables were analyzed.
Results
Sixty-two patients (median age: 58 years; range: 18–84 years) were examined. The G1/G2 groups comprised 40/22 and 48/14 patients based on WHO 2010 and 2017 classifications, respectively. Eight patients were reclassified from G2 to G1, two of which were T2 or more based on TNM classification; one patient had lymph node metastasis positivity, and all patients survived without recurrence. Disease recurrence occurred in 4/4 G1/G2 patients according to both WHO 2010 and 2017. G2 patients had shorter 5- and 10-year disease-free survivals (DFSs) than those of G1 patients based on WHO 2010 (90.9% and 90.9% vs. 84.5% and 70.4%, p = 0.179) and significantly shorter DFS based on WHO 2017 (91.9% and 91.9% vs. 78.6% and 58.9%, p = 0.036). The Ki-67 LI cut-off by ROC analysis was 3%, supporting the WHO 2017 classification. In multivariate analysis for DFS, tumor size >25 mm and vascular invasion positivity, but not G2, were risk factors for recurrence. The high-risk group with these factors had significantly worse 5- and 10-year disease-specific survivals (DSSs) compared to the low-risk group (100% and 100% vs. 90.9% and 68.2%, p = 0.045).
Conclusions
Revision of the Ki-67 LI cut-off for PanNENs G1/G2 based on WHO 2017 may be appropriate but G2 is not a risk factor for DFS. Tumor size >25 mm and vascular invasion positivity are potential risk factors. High-risk patients should be closely monitored during follow-up.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3773 - Impact of centralisation of national cancer services on patient outcomes for hepatobiliary cancers in Ireland 2000 – 2016
Presenter: David O Reilly
Session: Poster Display session 2
Resources:
Abstract
3180 - Genomic analysis of hepatobiliary lithiasis associated cholangiocarcinoma revealed a distinct subtype feature.
Presenter: Lunda Gu
Session: Poster Display session 2
Resources:
Abstract
4891 - Comparison of the impact of stereotactic body radiation therapy vs. radiofrequency ablation on liver function in patients with single hepatocellular carcinoma: A propensity score matching analysis
Presenter: Masayuki Ueno
Session: Poster Display session 2
Resources:
Abstract
3203 - Exploratory analysis based on tumor location and early metabolic tumor response of REACHIN, a randomized double-blinded placebo-controlled phase II trial of regorafenib after failure of gemcitabine/platinum-based chemotherapy for advanced and metastatic biliary tract tumors.
Presenter: Anne Demols
Session: Poster Display session 2
Resources:
Abstract
1602 - Predictive Value of Neutrophil-Lymphocyte Ratio (NLR) And Platelet-Lymphocyte Ratio (PLR) In Hepatocellular Carcinoma (HCC) Patients Treated with Nivolumab (N)
Presenter: Sirish Dharmapuri
Session: Poster Display session 2
Resources:
Abstract
2848 - Preliminary Safety and Pharmacokinetics of a New Lysosomotropic Oral Agent, GNS561, in a First-in-Human Study in Advanced Primary Liver Cancer Patients
Presenter: Ahmad Awada
Session: Poster Display session 2
Resources:
Abstract
1396 - A phase 1b trial of lenvatinib (LEN) plus pembrolizumab (PEMBRO) in unresectable hepatocellular carcinoma (uHCC): updated results
Presenter: Josep Llovet
Session: Poster Display session 2
Resources:
Abstract
1139 - Multicentric prospective study of validation of angiogenesis-related gene polymorphisms in HCC patients treated with sorafenib: Final results of INNOVATE study
Presenter: Andrea Casadei-gardini
Session: Poster Display session 2
Resources:
Abstract
4688 - Prognostic and predictive factors from the phase 3 CELESTIAL trial of cabozantinib (C) versus placebo (P) in previously treated advanced hepatocellular carcinoma (aHCC)
Presenter: Tim Meyer
Session: Poster Display session 2
Resources:
Abstract
1492 - A phase Ib study of pembrolizumab following trans-arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC): PETAL.
Presenter: David Pinato
Session: Poster Display session 2
Resources:
Abstract