Abstract 851P
Background
Homologous recombination deficiency (HRD) refers to the state of tumor cells which received defects in DNA-damage repair mechanisms. The HRD phenotype encodes important proteins for DNA homologous recombination repair (HRR) which can serve as a biomarker of therapeutic efficacy. Here, we explored the frequency and clinical significance of HRD gene mutations in non-cutaneous melanoma to provide experience for clinical options.
Methods
The data of 978 Chinese non-cutaneous melanoma patients using next-generation sequencing techniques with 81 or 425 cancer-related genes were collected. Among them, 881 patients were detected with 81 genes and 97 with 425 genes. The survival analysis was used to find the correlations between HRR gene mutations and clinical outcomes.
Results
In non-cutaneous patients, 10.8% (106/978) patients were found the genomic alterations in HRR genes. The frequently mutated genes were ATM (3.9%), ARID1A (3.8%), BRCA2 (2.8%), BRCA1 (1.5%), BRIP1 (0.4%), ATR (0.1%), PALB2 (0.1%), ARID2 (0.1%), FANCA (0.1%) and RAD50 (0.1%). Among 106 patients with HRR gene mutation, 54.7% were males and 65.4% were under 65 years old. 8.0% (27/335) patients were acral melanoma, 9.6% (40/418) patients with mucosal melanoma, 15.2% (5/33) patients with uveal melanoma and 21.5% (34/158) patients with unknown melanoma. In addition, 28.3% had ulcer in primary sites. 21.7% were in stage IV and 4 patients were with M1a, 1 with M1b, 14 with M1c, 4 with M1d. From January 2008 to January 2022, 29 patients among 106 patients with HRR gene mutation died. The median follow-up time was 32.00 months (95% CI: 27.14-36.86 months) and the median overall survival was not reached. The 1-year, 3-year and 5-year survival rates were 92.8%, 63.8%, 55.6%, respectively.
Conclusions
ATM and ARID1A are the most common genomic alterations with HRR genes and patients with HRR gene mutations maybe get survival benefits from treatment.
Editorial acknowledgement
Legal entity responsible for the study
Peking University Cancer Hospital and Institute.
Funding
National Natural Science Foundation of China, Beijing Municipal Administration of Hospitals Incubating Program, Beijing Municipal Administration of Hospitals’ Youth Programme.
Disclosure
All authors have declared no conflicts of interest.