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
2840 - Effects of Aerobic and Resistance Exercise on Android:Gynoid Fat Ratio in Breast Cancer Survivors
Presenter: Christina Dieli-Conwright
Session: Poster Display session 2
Resources:
Abstract
869 - Impact of Education for Breast self examination in Rural Indian Women on Early Detection - results of POC study
Presenter: Sneha Parchuri
Session: Poster Display session 2
Resources:
Abstract
1951 - Breast cancer incidence and survival in renal transplant patients: 35-year experience
Presenter: Michalis Kontos
Session: Poster Display session 2
Resources:
Abstract
2017 - The changing landscape of breast cancer incidence after treatment for Hodgkin’s disease
Presenter: Amelia Benjamin
Session: Poster Display session 2
Resources:
Abstract
1780 - Number of deliveries as a prognostic factor in different breast cancer subtypes
Presenter: Anniina Jääskeläinen
Session: Poster Display session 2
Resources:
Abstract
4650 - Effects of supervised and adapted exercise program in the quality of life and strength of breast cancer survivors: MAMA MOVE Gaia trial
Presenter: Ana Joaquim
Session: Poster Display session 2
Resources:
Abstract
4962 - Study On the Socioeconomic and Clinical Factors Affecting the Proportion of Breast Conserving Surgery in Chinese Women Breast Cancer
Presenter: Jin Zhang
Session: Poster Display session 2
Resources:
Abstract
5451 - Clinical decision making and multidisciplinary team meetings (MDMs) in early breast cancer. Is the agreement between planned and applied therapeutic program?
Presenter: Marco Giavarra
Session: Poster Display session 2
Resources:
Abstract
888 - The value of genetic counselling in breast cancer genetic testing and clinical management
Presenter: Vicki Kiesel
Session: Poster Display session 2
Resources:
Abstract
4005 - Elderly patients in the Japanese Breast Cancer Registry
Presenter: Masataka Sawaki
Session: Poster Display session 2
Resources:
Abstract