Abstract 4918
Background
Oncogenic MET signaling is often deployed by tumors for malignant transformation through genomic events like tyrosine kinase domain mutations, juxtamembrane splicing mutation and amplified copy numbers, which can be inhibited by c-MET small molecule inhibitors. We present biochemical and clinical findings on a polymorphism of MET, which is common in the East Asian population.
Methods
Germline DNA (gDNA) of lung, nasopharyngeal, liver, breast, gastric and colon cancer cohorts among East Asians (n = 1,076) were genotyped for MET (p.N375S) polymorphism using digital droplet PCR (ddPCR). Relapse free survival (RFS) with curative intent was compared using log-rank test. Screening for protein-protein interaction was performed with SILAC. Clinical study is now enrolling MET-N375S+ squamous cell (SCC) head and neck patients to be given 30mg afatinib daily. Treatment outcome was determined with F-FDG PET/CT scan. Baseline (BL) and post-treatment biopsies were analyzed with immunohistochemistry for response biomarkers and in situ hybridization-proximity ligation assay (ISH-PLA) for receptor interaction.
Results
Fraction of the MET-N375S+ cases is comparable across cancer patients and cancer-free controls (9-18%). METN375S was associated with significantly shorter relapse-free survival (RFS) in SCC of the head and neck (HNSCC; P = 0.005) and lung (LUSC; P = 0.029). SILAC revealed interaction of MET-N375S with HER2 (P < 0.05). Two patients with refractory HNSCC who completed 1 cycle of afatinib, a pan-HER inhibitor, showed radiological tumour shrinkage and reduction in metabolic activity, with partial response by RECIST 1.1 measurement observed in one patient. Evaluable BL biopsy showed strong MET-HER2 interaction (ISH-PLA) with strong staining of phosphorylated MET and HER2 (IHC), which were significantly reduced post-treatment, indicative of successive intervention of MET-N375S/HER2 signaling.
Conclusions
We established MET-N375S as a biologically-distinct molecular subset of SCC that drives malignancy through HER2 signaling, and could serve as a predictive biomarker to select refractory patients with dismal prognosis for afatinib treatment.
Clinical trial identification
NCT03938012. Actual study start date: October 3, 2017; Estimated primary completion date: October 2021; Estimated study completion date: October 2022.
Editorial acknowledgement
Legal entity responsible for the study
National University Cancer Institute, Singapore.
Funding
National Medical Research Council, Singapore.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3489 - Overall Survival (OS) and Metastasis-Free Survival (MFS) in men with Biochemically Relapsed (BCR) Prostate Cancer after radical prostatectomy (RP) managed with deferred Androgen Deprivation Treatment (ADT): A combined Johns Hopkins and CPDR study
Presenter: Catherine Marshall
Session: Poster Display session 3
Resources:
Abstract
4606 - ARCHES – the role of androgen deprivation therapy (ADT) with enzalutamide (ENZA) or placebo (PBO) in metastatic hormone-sensitive prostate cancer (mHSPC): Post hoc analyses of high and low disease volume and risk groups
Presenter: Arnulf Stenzl
Session: Poster Display session 3
Resources:
Abstract
2975 - Updated survival analyses of a multicentric phase II randomized trial of docetaxel (D) plus enzalutamide (E) versus docetaxel (D) as first line chemotherapy for patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) (CHEIRON study).
Presenter: Orazio Caffo
Session: Poster Display session 3
Resources:
Abstract
2708 - Real-world analysis of patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) receiving vs not receiving chemotherapy in the treatment sequence
Presenter: Alicia Morgans
Session: Poster Display session 3
Resources:
Abstract
2134 - Baseline fracture risk in men with prostate cancer starting the STAMPEDE trial
Presenter: Janet Brown
Session: Poster Display session 3
Resources:
Abstract
3504 - Risk of falls and fractures in patients with castration resistant prostate cancer (CRPC) treated with new hormonal agents – a meta-analysis of randomized controlled trials.
Presenter: Rodrigo Coutinho Mariano
Session: Poster Display session 3
Resources:
Abstract
2342 - Pain progression at initiation of chemotherapy in metastatic Castration-Resistant Prostate Cancer (mCRPC) is associated with a poor prognosis: a post-hoc analysis of FIRSTANA
Presenter: Nicolas Delanoy
Session: Poster Display session 3
Resources:
Abstract
5331 - Pain evaluation in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) treated with radium-223 (Ra-223) in the PARABO observation study
Presenter: Holger Palmedo
Session: Poster Display session 3
Resources:
Abstract
2823 - Time to castration resistant prostate cancer (CRPC) and the risk of developing immune disorders
Presenter: Vincenza Conteduca
Session: Poster Display session 3
Resources:
Abstract
1500 - Retrospective evaluation of neutropenic admission events in metastatic or high-risk hormone-sensitive prostate cancer (HSPC) patients having docetaxel chemotherapy upfront or for castrate-resistant prostate cancer (CRPC) in STAMPEDE
Presenter: Harriet Mintz
Session: Poster Display session 3
Resources:
Abstract