DNA damage response (DDR) variants and effects on the tumor transcriptome and microenvironment in east Asian (EA) prostate cancers (PCa).

Authors

null

Boon Hao Hong

National Cancer Centre Singapore, Singapore, Singapore

Boon Hao Hong , Alexander K. Hakansson , Enya Ong , Wen Min Chow , Kae-Jack Tay , Jeffrey K.L. Tuan , Michael L.C. Wang , Lui Shiong Lee , Ravindran Kanesvaran , Yang Liu , Elai Davicioni , Li Yan Khor , Melvin Lee Kiang Chua

Organizations

National Cancer Centre Singapore, Singapore, Singapore, Veracyte, Inc., Vancouver, BC, Canada, Singapore, Singapore, Singapore, National Cancer Centre of Singapore, Singapore, Singapore, Singapore General Hospital, Singapore, Singapore, Department of Radiation Oncology, Singapore, Singapore, Sengkang General Hospital, Singapore, Singapore, Veracyte, Inc., San Francisco, CA

Research Funding

Other
National Medical Research Council Singapore Clinician Scientist Award, Duke-NUS Oncology Academic Program Goh Foundation Proton Research Programme, NCCS Cancer Fund, and the Kua Hong Pak Head and Neck Cancer Research Programme

Background: Aberrations of the DDR pathway have been shown to be prognostic of survival and predictive of PARP inhibition in PCa. We have previously reported on the prevalence of germline DDR mutations based on a 32-gene set in localized PCa in EA men, and observed comparable rates with that of White men. Here, we performed additional analyses investigating for associations between DDR variants to the somatic transcriptome of localized PCa. Methods: We utilized a prospectively recruited cohort of 172 EA patients, with centrally assessed Gleason’s score (GS) by an expert pathologist. Germline profiling was performed by whole exome sequencing (100X) using the Illumina Novaseq (CA). Joint genotyping was performed to annotate variants that were deemed to be pathogenic (P)/likely pathogenic (LP)/conflict of interest pathogenic (CIP) based on the CADD and REVEL scores. Tumor transcriptome was profiled using the Decipher Genomic Classifier (GC, Veracyte, CA) based on the Affymetrix ST array (ThermoFisher, CA). Results: Among the subset of 172 EA men, we observed DDR variants in 26 (15%) patients, which was comparable to the larger cohort of 890 men from the same institution. Among the DDR mutations, 2 (7.7%) were classified as P/LP, while 24 (92.3%) were CIP. Decipher GC scores were comparable between patients with and without DDR mutations (median GC score 0.87 vs 0.53, Mann-Whitney U P=0.10). For luminal-basal subtyping by either the PAM50 and Prostate specific subtyping models, we did not observe a difference for the basal (P=0.48) and luminal subtypes (P=0.21). Interestingly, DNA repair gene-set expression were comparable between patients with DDR mutations versus those without (median score -0.2 vs -0.17). However, we observed microenvironment differences for immune-related genes, where patients harboring DDR mutations manifested a less immune-suppressive environment versus those without (PDL2: -0.15 vs 0.2; Treg: 0.09 vs 0.13; MDSC: 0.03 vs 0.07, respectively). Conclusions: Herein, we report an extension of our previous work (Lua, et al. ASCO GU, 2023), where we show potential linkages between the germline DDR variant status and the tumor transcriptome. Our findings suggest the influence of germline DDR variants that extends beyond tumorigenesis.

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Abstract Details

Meeting

2023 ASCO Breakthrough

Session Type

Poster Session

Session Title

Poster Session A

Track

Breast Cancer,Central Nervous System Tumors,Developmental Therapeutics,Genitourinary Cancer,Hematologic Malignancies,Thoracic Cancers,Other Malignancies or Topics

Sub Track

Omics for precision medicine

Citation

JCO Global Oncology 9, 2023 (suppl 1; abstr 75)

DOI

10.1200/GO.2023.9.Supplement_1.75

Abstract #

75

Poster Bd #

E1

Abstract Disclosures

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