Abstract 3411
Background
Gastrointestinal stromal tumours (GISTs) account for 1% of all primary gastrointestinal cancers. In cancer, suppressive immune checkpoints, including butyrophilin sub-family 3A/CD277 receptors (BTN3A), programmed death protein (PD-1) and its ligand PD-L1, are often hyper-activated to ensure an effective evasion of tumor cells from immune surveillance. Since recent studies showed that PD-1 and PD-L1 expression in cancer may be an important prognostic factor, the aim of our study was to investigate if soluble forms of inhibitory immune checkpoints can help predict survival in metastatic GIST patients.
Methods
Using specific homemade ELISA assays not yet commercially available, the plasma PD-1, PD-L1, BTN3A1 and pan-BTN3As levels were analyzed in 20 metastatic GIST patients harbouring c-KIT exon 11 mutations, before starting treatment with 400 mg Imatinib. Survival curves were estimated by using the Kaplan-Meier method and log-rank test to evaluate significant differences among them. Data was generated using the MedCalc software for Windows, version 18.2.1.
Results
Kaplan-Meier survival analysis was used to characterize prognostic relevance of soluble PD-1, PD-L1, BTN3A1 and pan-BTN3As in metastatic GIST patients, suggesting that their plasma levels could serve as survival predictor. For each analyzed biomarker, statistically significant differences in progression free-survival (PFS) between patients with plasma concentrations above and under median values were detected. Plasma level thresholds correlated with shorter survival and poor prognosis were established for PD-1 (>6.89 ng/ml), PD-L1 (>0.74 ng/ml), BTN3A1 (>7.19 ng/ml) and pan-BTN3As (>4.38 ng/ml). Conversely, patients with plasma levels under thresholds showed a median PFS that was approximately 58 months longer than to the previous.
Conclusions
Our study, for the first time, reveals that monitoring the concentration of soluble forms of inhibitory immune checkpoints in plasma can help predict survival in metastatic GIST patients and therefore improve their treatments. We showed that high plasma levels of these immune checkpoints correlate with poor outcome and could be used in future as prognostic factors.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Department of Surgical, Oncological and Oral Sciences, Section of Medical Oncology, University of Palermo.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
6079 - Invasive fungal diseases in patients with Hodgkin’s lymphoma before and after allogeneic hematopoietic stem cell transplantation
Presenter: Marina Popova
Session: Poster Display session 1
Resources:
Abstract
5995 - Invasive fungal diseases caused by rare pathogens in patients after hematopoietic stem cell transplantation (HSCT) & chemotherapy
Presenter: Yuliya Rogacheva
Session: Poster Display session 1
Resources:
Abstract
2961 - Safety and pharmacokinetics of novel CXCR4 antagonist YF-H-2015005 in the mobilization of hematopoietic stem cells in patients with non-Hodgkin's lymphoma
Presenter: Weiping Liu
Session: Poster Display session 1
Resources:
Abstract
5771 - Chemotherapy associated Hyponatremia in Hematological Malignancies: A retrospective study of 189 patients treated in a single medical center
Presenter: Vadim Lesan
Session: Poster Display session 1
Resources:
Abstract
1165 - Risk factors for Bacteremia-Associated Mortality of Aeromona sobria in Hematologic Malignancies
Presenter: Gabriel De la Cruz-Kú
Session: Poster Display session 1
Resources:
Abstract
5287 - Use of droplet digital polymerase chain reaction for detecting minimal residual disease: a prospective, multi-institutional study
Presenter: Hyunkyung Park
Session: Poster Display session 1
Resources:
Abstract
1886 - RUBIH2 — Use of NGS in haematological malignancies: from real world data to national recommendations, an innovative program to evaluate the impact of healthcare technology on patient care
Presenter: Severine Coquerelle
Session: Poster Display session 1
Resources:
Abstract
1940 - Outcomes of chronic myeloid leukemia with T315I mutation in the absence of targeted therapy or hematopoietic stem cell transplantation
Presenter: Nageswara Palukuri
Session: Poster Display session 1
Resources:
Abstract
1946 - Is bone marrow examination indispensible in chronic myeloid Leukemia at diagnosis ?
Presenter: Nageswara Palukuri
Session: Poster Display session 1
Resources:
Abstract
1904 - Incidence of Imatinib Resistance in Chronic Myeloid Leukemia (CML) Patients: Experience from Resource Poor Centre of Eastern India
Presenter: Debmalya Bhattacharyya
Session: Poster Display session 1
Resources:
Abstract