Abstract 1743
Background
Antigen recognition by MHC class I molecules is a key step for the initiation of the immune response. We hypothesized that expression of these molecules could be a marker of immune activated breast cancers.
Methods
We used data from KM Plotter to develop an exploratory cohort and then utilized information from Cancer Genome Atlas (TCGA) and METABRIC to create two validation cohorts. Raw data were re-processed and analyzed using plyr R and Bioconductor. Definition of molecular subtypes as well as identification of mutations was performed using RNAseq from TCGA. We used NetMHC 4.0 epitope-HLA to predict binding to MHC I molecules. Cox proportional hazards regression was computed to correlate gene expression and survival outcome. Multiple genes were combined into a signature by using their mean expression.
Results
There was a weak but positive correlation between mutational burden and the expression of most MHC class I molecules. In the exploratory cohort, expression of HLA-A and HLA-B was associated with favorable relapse free survival (RFS) and overall survival (OS) in the basal-like subgroup. This was confirmed in the METABRIC dataset (OS HLA-A, HR: 0.59, CI 0.42-0.82; p = 0.002; HLA-B, HR: 0.60, CI 0.44-0.82; p = 0.001); and in the TCGA dataset (OS HLA-A, HR: 0.34, CI 0.16-0.75; p = 0.005; HLA-B, HR: 0.21, CI 0.01-0.71; p = 0.005). Expression of HLA-A and HLA-B was associated with biomarkers of T cell activation (GZMA, GZMB and PRF1) and improved the predictive capacity of known immunologic signatures (IFN gamma signature, expanded immune gene signature and Cytotoxic T lymphocyte). Several neopeptides expressed in breast cancer were also identified including FUK, SNAPC3, GC, ANO8, DOT1L, HIST1H3F, MYBPH, STX2, FRMD6, CPSF1, or SMTN, among others.
Conclusions
Expression of HLA-A and B is associated with T cell activation and identifies immune activated, basal-like breast cancers with favorable prognosis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Instituto de Salud Carlos III (PI16/01121), ACEPAIN; Diputación de Albacete, CIBERONC, CRIS Cancer Foundation, scientific foundation of the AECC, implementation research program of the UCLM Spanish System of Science, Technology and Innovation-Secti (co-funded by the European Commission/FSE funds).
Disclosure
A. Ocaña: Research grant / Funding (institution): Entrechem; Travel / Accommodation / Expenses: Merck. All other authors have declared no conflicts of interest.
Resources from the same session
2664 - Phase (Ph) II study of MBG453 + spartalizumab in patients (pts) with non-small cell lung cancer (NSCLC) and melanoma pretreated with anti–PD-1/L1 therapy
Presenter: Nicholas Mach
Session: Poster Display session 3
Resources:
Abstract
1285 - Preliminary results of STELLAR-001, a dose escalation phase I study of the anti-C5aR, IPH5401, in combination with durvalumab in advanced solid tumors.
Presenter: Christophe Massard
Session: Poster Display session 3
Resources:
Abstract
3808 - GOLFIG chemo-immunotherapy in metastatic colorectal cancer (mCRC) patients: A fifteen year retrospective analysis
Presenter: Pierpaolo Correale
Session: Poster Display session 3
Resources:
Abstract
5677 - Immune correlates in peripheral blood samples in a preoperative window of opportunity randomized trial of nivolumab with or without tadalafil in resectable squamous cell carcinoma of the head and neck (SCCHN)
Presenter: Larry Harshyne
Session: Poster Display session 3
Resources:
Abstract
4854 - Phase 1 evaluation of AB928, a novel dual adenosine receptor antagonist, combined with chemotherapy or AB122 (anti-PD-1) in patients (pts) with advanced malignancies
Presenter: John Powderly
Session: Poster Display session 3
Resources:
Abstract
4344 - Phase 1 Trial of CV301 in Combination with Anti-PD-1 Therapy in Non-squamous NSCLC
Presenter: Arun Rajan
Session: Poster Display session 3
Resources:
Abstract
4555 - Safety and efficacy results of the combination of DPX-Survivac, pembrolizumab and intermittent low dose cyclophosphamide (CPA) in subjects with advanced and metastatic solid tumors: preliminary results from the hepatocellular carcinoma (HCC), NSCLC, bladder cancer, & MSI-H cohorts
Presenter: Henry Conter
Session: Poster Display session 3
Resources:
Abstract
3012 - Excellent CBR and Prolonged PFS in Non-Squamous NSCLC with Oral CA-170, an Inhibitor of VISTA and PD-L1
Presenter: Vivek Radhakrishnan
Session: Poster Display session 3
Resources:
Abstract
2536 - Phase Ib/II trial of TG4001 (Tipapkinogene sovacivec), a therapeutic HPV-vaccine, and Avelumab in patients with recurrent/metastatic (R/M) HPV-16+ cancers
Presenter: Christophe Le Tourneau
Session: Poster Display session 3
Resources:
Abstract
1845 - Induction of tumor-infiltrating functional CD8 positive cells and PD-L1 expression in esophageal cancer by S-588410
Presenter: Takashi Kojima
Session: Poster Display session 3
Resources:
Abstract