Abstract 5213
Background
Anti-PD-1 monoclonal antibody monotherapy achieves poor outcomes in mucosal melanoma, but our previous study has demonstrated that primary malignant melanoma of esophagus (PMME) has a dramatically high response rate (ORR 75%). The genomic landscape of PMME and reasons for this finding have not been extensively investigated.
Methods
Whole exome sequencing were performed in seven treatment-naive PMME tumor samples and matched normal tissues, and genomic data of eight mucosal melanomas was obtained from the International Cancer Genome Consortium. Comprehensive profiling was performed to analyze the of genetic differences of PMME with mucosal melanoma.
Results
The mean depth of coverage was 268X (ranged from 100X to 400X), 1203 SNV/InDels were detected in seven PMME samples, with a mean value of 172 mutations. The median tumor mutation burden (TMB) was 3.58 mutations/Mb (range 0.19-9.58 mutations/Mb), which was significantly than mucosal melanoma (P = 0.021). The mutation spectrum of SNVs displayed more frequency of T>A transition while less frequency of C>T transversion compared to mucosal melanoma. There were 36 genes found to be mutated in more than two PMME tumor samples, and the most significantly mutated genes were CFH (42.9%, 3/7) and MUC16 (42.9%, 3/7). Both BRAF and NRAS were only found in one sample, and no NF1, KIT and SF3B1 mutation were detected. In total, 671 CNVs were detected, and the most frequently amplification chromosomal regions were 10q and 1p, while most frequently deletion in 1q and 8q. Genetic aberrations were mainly enriched in RTK/RAS and WNT pathways.
Conclusions
The TMB is higher in PMME compared to mucosal melanoma, with the highest mutation frequency in CFH and MUC16. CFH has a critical role in the regulation of complement activation, and MUC16 has been reported to be associated with higher tumor mutation load and outcomes in gastric cancer. In summary, our study reveals that the genomic landscape of PMME is different from mucosal melanoma originates from other mucosal membrane sites, and indicates that CFH and MUC16 mutation might be associated with better response to anti-PD-1 monoclonal antibody in PMME patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Peking University Cancer Hospital-Beijing Cancer Hospital.
Funding
Beijing Talents Foundation (2016000021223ZK18), National Natural Science Foundation of China (81672696, 81402264).
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3973 - A randomized phase II study on the OPTimization of IMmunotherapy in squamous carcinoma of the head and neck (SCCHN) – OPTIM (AIO-KHT-0117)
Presenter: Viktor Grünwald
Session: Poster Display session 3
Resources:
Abstract
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