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
3695 - A Phase 1b/2 Study of Onvansertib (PCM-075) in Combination with FOLFIRI and Bevacizumab for Second Line Treatment of Metastatic Colorectal Cancer in Patients with a KRAS Mutation
Presenter: Heinz Josef Lenz
Session: Poster Display session 2
Resources:
Abstract
4250 - Phase II study of avelumab in combination with cetuximab as a rechallenge strategy in pre-treated RAS wild type metastatic colorectal cancer patients: CAVE (cetuximab-avelumab) Colon.
Presenter: Erika Martinelli
Session: Poster Display session 2
Resources:
Abstract
5234 - The ORCHESTRA trial; A phase III trial of adding tumor debulking to systemic therapy versus systemic therapy alone in multi-organ metastatic colorectal cancer (mCRC).
Presenter: Lotte Bakkerus
Session: Poster Display session 2
Resources:
Abstract
5294 - EMERGE: Epigenetic Modulation of the Immune Response in Gastrointestinal cancers
Presenter: Elizabeth Cartwright
Session: Poster Display session 2
Resources:
Abstract
913 - Phase III, international, multicenter, randomized, open-label trial of adjuvant nab-paclitaxel plus gemcitabine (nab-P/G) vs gemcitabine (G) alone for surgically resected pancreatic adenocarcinoma (APACT): subgroup analyses
Presenter: Margaret Tempero
Session: Poster Display session 2
Resources:
Abstract
1668 - FOLFIRINOX in locally advanced (LA) and borderline resectable (BR) pancreatic adenocarcinoma : update of the AGEO cohort.
Presenter: Edouard Auclin
Session: Poster Display session 2
Resources:
Abstract
2559 - Impact of adjuvant treatment with nab-paclitaxel and gemcitabine (nab-P+GEM) vs gemcitabine alone (GEM) on health-related quality of life (QoL) in patients (pts) with surgically resected pancreatic adenocarcinoma (PA) in the Adjuvant Pancreatic Adenocarcinoma Clinical Trial (APACT)
Presenter: Hanno Riess
Session: Poster Display session 2
Resources:
Abstract
4897 - Early detection of pancreatic ductal adenocarcinoma using methylation signatures in circulating tumor DNA
Presenter: Xiao-ding Liu
Session: Poster Display session 2
Resources:
Abstract
1755 - Evaluation of minimal important difference (MID) for the European Organisation for Research and Treatment of Cancer (EORTC) Pancreatic Cancer Module (PAN26) in patients with surgically resected pancreatic adenocarcinoma
Presenter: Michele Reni
Session: Poster Display session 2
Resources:
Abstract
2876 - Multispectral analysis of lymphocyte complexity in periampullary adenocarcinoma
Presenter: Sebastian Lundgren
Session: Poster Display session 2
Resources:
Abstract