Abstract 1234
Background
Gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) is a poorly differentiated grade 3 neuroendocrine neoplasm, of which the overall survival is poor with limited treatment options. Immune checkpoint related therapy such as PD-1 blocking has successfully been used in some solid tumor treatment. In this study, we investigated the infiltration of immune-cells and PD-1/PD-L1 blockade biomarkers to improve understanding of the tumor immune microenvironment in GEP-NEC.
Methods
Stromal and tumor cells expressing CD3, CD8 and CD68 protein were assessed in 32 cases of GEP-NEC by immunohistochemistry. Their tumor mutational burden (TMB) and microsatellite instability (MSI) were measured by gene sequencing. Software mSINGS MSIsensor and MSIseq were used to evaluate MSI and MSI status was set when more than two software showed the MSI. The Mann-Whitney U test and Kruskal-Wallis test were used to analyze the correlation of markers expression with clinicopathological parameters. Kaplan -Meier curves were applied in survival analyses.
Results
In the study, 65.6% of the patients were male and the median age was 65. The predominant primary sites were stomach (66%) and pancreas (19%). High infiltration (more than 25% stromal area infiltration) of CD3, CD8 and CD68 immune cells were found in 84%, 47% and 81% of the patients, respectively. High expression of CD3 correlated with high expression of CD8 and CD68 (p < 0.05). Average of TMB was 5.84 mutations per megabase. 57% of the patients were classified as having intermediate TMB (5-15 mutations/megabase) with the remaining classified as having low TMB (0-5 mutations/megabase). None of the patients was in MSI status under our evaluation. Among the baseline characteristics, patients in stage IV of TNM showed lower CD8 expression (p < 0.05). No significant association was observed between the investigated markers and survival.
Conclusions
The study contributes to the understanding of immune microenvironment of GEP-NEC. The association of clinicopathological features with PD-1/PD-L1 blockade biomarkers and immune cells in GEP-NEC were explored. This understanding should help to improve predictions of the impact of the PD-1/PD-L1 pathway in GEP-NEC patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Chinese Academy of Medical Sciences (CAMS) Initiative for innovative Medicine (CAMS-I2M) 2017-I2M-1-001.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1109 - First Canadian Interim Analysis from the Phase IIIb CompLEEment-1 Ribociclib + Letrozole HR+ HER2- Advanced Breast Cancer Trial
Presenter: Cristiano Ferrario
Session: Poster Display session 2
Resources:
Abstract
4401 - Real-world effectiveness of first-line palbociclib + letrozole for metastatic breast cancer 4 years post approval in the US
Presenter: Jonathan Kish
Session: Poster Display session 2
Resources:
Abstract
5876 - Palbociclib-Fulvestrant (PALBO-FUL) and Everolimus -Exemestane (EVE-EXE) for Second line Hormonal Treatment (HT) of Metastatic Breast Cancer (MBC) with Lobular Histology: a Propensity Score Matched Analysis of a Multicenter ‘Real-World’ Patients (pts) Series.
Presenter: Armando Orlandi
Session: Poster Display session 2
Resources:
Abstract
3587 - Dose-escalation study of G1T48, an oral selective estrogen receptor degrader (SERD), in postmenopausal women with ER+/HER2- locally advanced or metastatic breast cancer (ABC)
Presenter: E Dees
Session: Poster Display session 2
Resources:
Abstract
5696 - Final results of the STEM trial: SFX-01 in the Treatment and Evaluation of ER+ Her2- Metastatic breast cancer (mBC)
Presenter: Sacha Howell
Session: Poster Display session 2
Resources:
Abstract
1475 - Alpelisib (ALP) + Fulvestrant (FUL) in Hormone-Receptor Positive (HR+), Human Epidermal Growth Factor Receptor-2–Negative (HER2–) Advanced Breast Cancer (ABC): Subgroup Analysis by Presence of Visceral Metastasis (VM) in the SOLAR-1 Trial
Presenter: Mario Campone
Session: Poster Display session 2
Resources:
Abstract
2549 - Phase 1 Dose Escalation Study of a Selective Androgen Receptor Modulator RAD140 in Estrogen Receptor Positive (ER+), HER2 Negative (HER2-) Breast Cancer (BC)
Presenter: Erika Hamilton
Session: Poster Display session 2
Resources:
Abstract
3787 - A Phase I study of XZP-3287, a novel oral CDK4/6 Inhibitor, administered on a continuous dosing schedule, in patients with advanced solid tumours
Presenter: Binghe Xu
Session: Poster Display session 2
Resources:
Abstract
4835 - Phase-I dose-escalation and expansion study of the PARP inhibitor, fluzoparib (SHR3162), in patients with advanced solid tumors
Presenter: Huiping Li
Session: Poster Display session 2
Resources:
Abstract
5083 - Phase 2 study of DHP107 (Liporaxel®, oral paclitaxel) in first-line, HER2 negative recurrent/metastatic breast cancer (OPTIMAL study, NCT03315364)
Presenter: Jin-Hee Ahn
Session: Poster Display session 2
Resources:
Abstract