Germline DNA repair gene mutations in Taiwan prostate cancer patients.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13640-e13640
Author(s):  
Wilson Huang ◽  
Shauh-Der Yeh

e13640 Background: Genetic testing for inherited mutations in DNA-repair genes such as BRCA1, BRCA2, ATM, PALP2, FANCA has been proposed for high-risk and metastatic prostate cancer patients for personalized therapy and management. Although the prevalence of germline DNA-repair gene mutations among Caucasian populations are known, the frequency of such mutations in Taiwan prostate cancer patients has not been established. In this study, we performed next-generation sequencing (NGS) analysis of BRCA1, BRCA2, ATM, PALP2, and FANCA in 49 prostate cancer patients stratified according to the NCCN risk criteria using blood sample collected from a single hospital center. Methods: 4ml whole blood samples are collected in EDTA tube from prostate cancer patients of low-intermediate, high to very high, regional, and metastatic risks. The samples are subjected to buffy coat fractionation, genomic DNA extraction, library preparation, full-exon NGS, and comparative analysis with all known germline variants. We identified and correlated the frequency of germline DNA-repair gene mutations with patient’s age at diagnosis, Gleason grades, initial PSA, family history of prostate cancer, and NCCN risk. Results: A total of 49 blood samples were tested and analyzed for BRCA1, BRCA2, ATM, PALP2, and FANCA mutations. Among all cases, 6.1% (3/49, 95% confidence interval [CI]: - 0.6%-12.8%) carried pathogenic mutations: 2.0% (1/49) in BRCA1, 2.0% (1/49) in BRCA2, and 2.0% (1/49) in ATM. They were compatible with previously reported mutations and no new germline variants were detected. These mutations were associated with initial PSA and NCCN risk; all identified mutations belonged to Gleason grade 5 and high to very high risk subgroups. No clinical association was observed with patient’s age of diagnosis and family history. Conclusions: In this single hospital center study, we observed a modest incidence of DNA-repair gene mutations in the Taiwan prostate cancer cohort. Germline DNA-repair gene mutations were observed in high risk prostate cancer patients with the highest Gleason grade. Frequencies of the mutations did not differ significantly according to age at diagnosis or family history of prostate cancer. These results were similar to the reported findings in the Caucasian populations. Our findings confirmed the necessity of genetic testing in Taiwan prostate cancer patients. [Table: see text]

JAMA Oncology ◽  
2021 ◽  
Author(s):  
Michael T. Schweizer ◽  
Smruthy Sivakumar ◽  
Hanna Tukachinsky ◽  
Ilsa Coleman ◽  
Navonil De Sarkar ◽  
...  

2018 ◽  
Vol 44 ◽  
pp. S23
Author(s):  
Rosalind Eeles ◽  
Daniel Leongamornlert ◽  
Edward Saunders ◽  
Sarah Wakerell ◽  
Ian Whitmore ◽  
...  

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 5035-5035 ◽  
Author(s):  
Karim Boudadi ◽  
Daniel L. Suzman ◽  
Brandon Luber ◽  
Hao Wang ◽  
John Silberstein ◽  
...  

5035 Background: ARV7+ mCRPC is an aggressive phenotype with a median PFS of 3-4 mo and OS of 7-9 mo. We hypothesized that ARV7+ tumors would be enriched for DNA repair mutations, rendering them more responsive to combined immune checkpoint blockade. Methods: We enrolled 15 mCRPC pts with ARV7+ CTCs (using a CLIA-certified assay) into a single arm phase 2 study. Pts received Nivo 3 mg/kg plus Ipi 1 mg/kg every 3 wk x 4 doses, then maintenance Nivo 3 mg/kg every 2 wk. Targeted sequencing for DNA repair defects was performed on pretreatment tumor biopsies (n=11) or cell-free DNA (n=4). Primary endpoint: PSA50response rate. Secondary endpoints: objective response rate (ORR) in pts with measurable disease, durable PFS (lack of progression ≥24 wk), PSA‐PFS, radiographic (r)PFS, overall survival (OS), and frequency/intensity of AEs. Results: 15 ARV7+ men were enrolled, with median f/u 8.4 (range 1.9–10.5) mo. Median age was 65, 47% had ECOG ≥1, median PSA was 115 ng/mL, 67% had visceral/nodal mets, all had bone mets, and 60% had ≥4 prior regimens for mCRPC. Mean ARV7/AR ratio was 23% (range 3–75%). 6/15 men (40%) had pathogenic DNA repair gene mutations ( BRCA2, ATM, MSH6, FANCM, FANCA, POLH). Overall, the PSA50rate was 1/15 (7%), ORR was 2/8 (25%), durable PFS rate was 3/15 (20%), PSA-PFS was 3.0 (95%CI 2.1–4.9) mo, rPFS was 3.9 (95%CI 2.8–5.5) mo, and OS was 9.5 (95%CI 7.2–NA) mo. Outcomes appeared better in DNA repair deficient (DRD+) tumors vs. DNA repair proficient (DRD–) tumors (TABLE). 15 grade 3-4 treatment-related AEs occurred in 7/15 (46%) men (including 2 hepatitis, 2 colitis, 1 pneumonitis); there were no treatment-related deaths. Conclusions: In this first study targeting ARV7+ mCRPC, treatment with Ipi/Nivo had acceptable safety and encouraging efficacy, particularly in men with DRD+ tumors. DNA repair mutations may be enriched in ARV7+ prostate cancer. Clinical trial information: NCT02601014. [Table: see text]


2018 ◽  
Vol 36 (6_suppl) ◽  
pp. TPS389-TPS389 ◽  
Author(s):  
Charles J. Ryan ◽  
Wassim Abida ◽  
Alan Haruo Bryce ◽  
Arjun Vasant Balar ◽  
Igor Dumbadze ◽  
...  

TPS389 Background: Recent data have shown that up to 25% of patients with advanced prostate cancer, including mCRPC, have a deleterious germline or somatic mutation in BRCA1, BRCA2, ATM, or another homologous recombination DNA repair gene. Such mutations can be used as a molecular marker to select patients for targeted treatment with poly(ADP-ribose) polymerase inhibitors (PARPis), which are lethal to cells with HRD. Treatment with PARPis has shown preliminary evidence of antitumor activity in patients with mCRPC and a mutation in a homologous recombination DNA repair gene (Mateo et al. N Engl J Med. 2015;373:1697-708). These data provide a compelling rationale for evaluating rucaparib, a potent inhibitor of PARP1, PARP2, and PARP3, in patients with mCRPC associated with HRD. Methods: TRITON3 (NCT02975934) is a randomized, phase 3 study evaluating rucaparib 600 mg BID vs physician’s choice of abiraterone, enzalutamide, or docetaxel in patients with mCRPC and a deleterious germline or somatic BRCA1, BRCA2, or ATM mutation (identified by prior local testing or central testing during screening). Patients must have progressed on androgen receptor signaling–directed therapy in the mCRPC setting; prior PARPi treatment or chemotherapy for mCRPC are exclusion criteria. Patients will be randomly assigned in a 2:1 ratio to either rucaparib or physician’s choice, with the possibility for cross over from the comparator treatment to rucaparib upon radiographic progression confirmed by independent radiology review. The primary endpoint is radiographic progression-free survival (modified RECIST v1.1/PCWG3 criteria) assessed by independent radiology review. Secondary endpoints include objective response rate, duration of response, patient-reported outcomes, overall survival, and safety. Pretreatment blood samples collected from all patients will enable development of a noninvasive plasma-based companion diagnostic to select patients who may benefit from rucaparib treatment. Patients (≈400) will be enrolled at > 100 sites worldwide. Clinical trial information: NCT02975934.


2017 ◽  
Vol 35 (6_suppl) ◽  
pp. 10-10 ◽  
Author(s):  
Marc Dall'Era ◽  
Allison Glass ◽  
Primo Lara ◽  
Ryan Hartmaier ◽  
Ralph deVere White ◽  
...  

10 Background: DNA repair gene mutations are important molecular alterations in prostate cancer pathogenesis. Germline mutations in DNA repair genes, particularly BRCA2, were recently recognized as associated with metastatic prostate cancer and may also be particularly sensitive to platinum based chemotherapy and PARP inhibitor therapy. We sought to characterize alterations in DNA repair pathway genes in both primary and metastatic prostate tumors. Methods: We studied the distribution of DNA repair gene mutations in 936 prostate cancers harvested from localized and metastatic tumors. Tumor DNA underwent hybrid capture for all coding exons of 395 cancer-related genes plus select introns from 19 or 31 genes frequently rearranged in cancer and sequenced to a median exon coverage depth of >500x using Illumina sequencing and were analyzed for base substitutions/insertions, copy number alterations and rearrangements. We utilized two described lists of genes involved in DNA repair : our own in-house list of 74 (UCD) and a list of 20 DNA repair genes associated with cancer predisposition syndromes utilized in a recent publication by Pritchard et al. We further stratified the frequency of mutations by tissue site (prostate versus metastases). Results: We identified 228/936 unique samples with at least one likely functional mutation in a DNA repair gene (24.4%). Mutations were identified in 20.1% of prostate tumors (13% UCD, 18.4% Pritchard et al.) and in 18.8% of bone metastases. The highest rates of DNA repair mutations were found in visceral metastases including brain, pelvis and liver, higher than either prostate tissue or bone sites (p=<0.01). The most commonly (≥1% of samples) mutated genes in the DNA repair pathways are: BRCA2 (11.43%), ATM (5.77%), MSH6 (2.46%), MSH2 (2.14%), ATR (1.60%), MLH1 (1.28%), and BRCA1(1.18%). Conclusions: DNA repair gene mutations are more common in metastatic than localized prostate tumors. Visceral metastases appear enriched for these mutations compared with localized tumors or bone metastases. Genomic profiling may identify prostate cancers potentially sensitive to platinum-based chemotherapy or PARP inhibition.


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