Xét nghiệm brca và hrd trong ung thư

HỘI NGHỊ Y HỌC LIÊN NGÀNH LẦN THỨ XÉT NGHIỆM BRCA VÀ HRD TRONG UNG THƯ BS Hoàng Anh Vũ Trung tâm Y Sinh học Phân tử - Đại học Y Dược TPHCM ĐẠI HỌC Y DƯỢC TPHCM, ngày 16 tháng 09 năm 2023 NỘI DUNG Đột biến gen BRCA1/2 khiếm khuyết tái tổ hợp tương đồng (HRD: Homologous recombination deficiency) ung thư; Khai thác đặc tính đột biến gen BRCA1/2 HRD điều trị ung thư; Xét nghiệm đột biến gen BRCA1/2 HRD Vài nét gen BRCA Sửa chữa xác đứt gãy mạch đơi (DSB) tái tổ hợp tương đồng (homologous recombination repair) p53 Detection of DSB Cell cycle checkpoints CHEK2 ATM 5’ to 3’ resection PPP2R2A RAD50 MDC1 MRE11 HRR is: RAD51 loading RAD52 • Slow • Specific RPA CHEK1 PALB2 BARD1 Strand invasion ATR BRCA1 RAD51 BRCA2 BRIP1 FANCL CDK12 • Accurate RAD54L Branch migration RAD51B RAD51C Polymerases RAD51D Holliday junction resolution Resolvases HRR gene Other genes No crossing over Crossover Nối đầu tận không tương đồng (NHEJ) chế sửa sai thay thế, tiềm ẩn nhiều sai sót Core mechanism Stress Double-strand break Ku NHEJ is: • Error-prone DNA-PKcs End binding • Fast P P End processing Artemis NHEJ results in genomic instability Ligation and fill-in More rounds of end processing and ligation Pol µ DNA ligase IV XRCC4:XLF Repaired DSB (NHEJ=non-homologous end joining) Frequent microhomology Variable extent of deletion Junctional nucleotides added CÁC CƠ CHẾ GÂY RA HRD Genetic Mutation BRCA1/2 Mutation Epigenetic HRD Other causes • Gene mutation: PTEN, Fanconi anemia genes (FANCA, FANCB, FANCC, FANCD2…), core HR RAD genes (RAD50, RAD51, RAD51C, RAD51L1, RAD51L3, RAD52…), HR‐related DNA damage response genes (ATM, ATR, CHEK1,CHEK2) • Epigenetic: Promoter methylation of BRCA1/2 • Others: Amplification EMSY or undetermined??? Khơng có khả sửa sai DNA → Mất ổn định gen HRD xảy nhiều loại ung thư Data from CHORD: Frequency of homologous recombination deficiency by cancer typea Frequency of HRD (%) 60 Primary 52.3 • 50 40 Biallelic inactivation of BRCA1, BRCA2, RAD51C and PALB2 identified as the most common genetic cause of HRD 29.6 30 23.7 20 10 6.4 7.3 5.9 13.1 13.3 11.8 5.6 Pan-cancer Ovarian Breast Pancreatic Cancer type aHRD identified based on genome-wide mutational scar-based pan-cancer Classifier of Homologous Recombination Deficiency HRD, homologous recombination deficiency Nguyen L, et al Nat Comm 2020;11:5584 This scientific exchange meeting is organised and funded by AstraZeneca CONFIDENTIAL - FOR PERSONAL USE ONLY, NOT FOR ONWARD DISTRIBUTION Prostate Trong ung thư buồng trứng dịch độ mô học cao, HRD chiếm tỷ lệ khoảng 50%1,2 10 HR=homologous recombination; HRR=homologous recombination repair Konstantinopoulos PA, et al Cancer Discov 2015;5(11):1137–54; da Cunha Colombo Bonadio RR et al Clinics (Sao Paulo) 2018;73(suppl 1) :e450s Published 2018 Aug 20 doi:10.6061/clinics/2018/e450s Giải trình tự gen: NGS (next generation sequencing) Sanger TƯ VẤN Ý NGHĨA CỦA KẾT QUẢ XÉT NGHIỆM BRCA Presence of pathogenic/likelypathogenic BRCA 1/2 mutations Test Result • Interpretation • • Index case has a higher predisposition to develop cancer (primary and second malignancies) including breast, ovary, pancreas, and melanoma Therapeutic implications like sensitivity to platinum and PARPi First-degree relatives/family members are at 50% of risk at carrying the alteration Presence of benign/likelybenign BRCA 1/2 mutations • • • Absence of BRCA 1/2 mutations The variant has been confirmed as not clinically relevant • Implies an average risk of developing cancer, similar to the general population Implies an average risk of developing cancer, similar to the general population • These patients should undergo further investigation of family history evaluation and multigene testing to identify affected genes other than BRCA These patients should undergo further investigation of family history evaluation and multigene testing to identify affected genes other than BRCA Verma A, et al Indian J Cancer 2019;56:S38-47; EMQN Guidelines 2007 Available at: http://www.emqn.org/emqn/digitalAssets/0/232_EMQNBRCAguidelines0908.pdf Last accessed 7th November 2015 VUS • Unknown functional implications based on current published literature or in silico analysis • Lab and physician keep track of VUS reclassifications • Risk can not be accurately quantified by test alone but may be increased by testing other affected family members Chỉ xét nghiệm BRCA đơn gây bỏ lỡ bệnh nhân có HRD(+) Proportion of people with ovarian cancer identified as HRD* via: gBRCAm: 19%†‡1 tBRCAm: 29%2 tBRCAm + genomic instability test: 48%2 *Data taken from the PAOLA-1 clinical trial1,2 HRD-positive determined by tBRCAm and/or genomic instability score ≥42 in the Myriad myChoice® CDx2 †A minority (0–36%) of gBRCAm are LGRs Routine PCR-based genetic testing methods are not capable of detecting LGRs3 ‡Data taken from the PAOLA-1 French Cohort CDx=companion diagnostic; gBRCAm=germline BRCA mutation; LGR=large genomic rearrangements; HRD=homologous recombination deficiency; PCR=polymerase chain reaction; tBRCAm=tumour BRCA mutation Callens C, et al J Natl Cancer Inst 2020 Epub ahead of print doi: 10.1093/jnci/djaa193; Ray-Coquard I, et al Presentation LBA2_PR presented at ESMO Annual Conference 2019, 27 September - October, Barcelona, Spain; Ewald I, et al Genet Mol Biol 2009;32(3):437–446 “Nguyên nhân” “hậu quả” HRD 1,2 HR=homologous recombination *Alternative potential molecular mechanisms not measured by HRR gene panel Hoppe MM, et al J Natl Cancer Inst 2018;110(7):704-713; Konstantinopoulos PA, et al Cancer Discov 2015;5(11):1137-1154 Đo lường HRD thường thông qua đặc điểm bất ổn định gen, kết hợp với tình trạng đột biến BRCA HRD test Tumour BRCA mutation1 Presence of BRCA mutation Genomic instability1 Example: Myriad myChoice® genomic instability Loss of heterozygosity (LOH)1 Presence of a single allele3 Yes No Telomeric allelic imbalance (TAI)1 A discrepancy in the 1:1 allele ratio at the end of the chromosome (telomere) Large-scale state transitions (LST)1 Transition points between regions of abnormal and normal DNA or between two different regions of abnormality4 Score out of 1003 BRCAm, BRCA mutation; CDx, companion diagnostic; FFPE, formalin fixed paraffin embedded; HRD, homologous recombination deficiency; tBRCA, tumour BRCA1 and/or BRCA2 Myriad myChoice HRD Technical Specifications Available at: https://myriad-web.s3.amazonaws.com/myChoice/downloads/myChoiceHRDTechSpecs.pdf (Accessed September 2020); Ray-Coquard I, et al N Engl J Med 2019;381:2416–2428; Ryland GL, et al BMC Med Genom 2015;8:45; Jenner ZB, et al Fut Oncol 2016;12:1439–1456 This scientific exchange meeting is organised and funded by AstraZeneca CONFIDENTIAL - FOR PERSONAL USE ONLY, NOT FOR ONWARD DISTRIBUTION Định nghĩa HRD dương tính HRD=homologous recombination deficiency Myriad myChoice HRD Technical Specifications Available at: https://myriad-web.s3.amazonaws.com/myChoice/downloads/myChoiceHRDTechSpecs.pdf (Accessed December 2021); Ray-Coquard I, et al N Engl J Med 2019;381:2416–2428; Jenner ZB, et al Fut Oncol 2016;12(12):1439–1456 33 MỘT SỐ BỘ KIT XÉT NGHIỆM HRD Ví dụ HRD Dương tính: Myriad myChoice® CDx test Myriad myChoice® CDx test Tumour BRCAnalysis® HRD-positive: HRD-negative: Genomic instability (LOH, LST, TAI) BRCAm and/or Score ≥422 Non-BRCAm and Score