Resultados del estudio Concordance: Relevancia clínica de la determinación del ADNtc mediante la tecnología BEAMing
Ana Vivancos Circulating tumor DNA extended RAS mutational analysis as a surrogate of mutational status of tumor samples in metastatic colorectal cancer and its impact on patient selection for anti-EGFR therapy.
Julieta Grasselli1,3, Elena Elez1,2, Ginevra Caratù4, Judit Matito4, Cristina Santos3, Teresa Macarulla1,2, Joana Vidal5, Margarita Garcia3 José María Viéitez6, David Paéz7, Esther Falcó8, Carlos Lopez Lopez9, Enrique Aranda10,Frederick Jones11, Vishal Sikri11, Paolo Nuciforo12, Rodrigo Dienstmann1,13, Clara Montagut4, Josep Tabernero1,2, Daniel Azuara14, Ramon Salazar3 , Ana Vivancos10.
1-Department of Medical Oncology, Vall d’Hebron Institute of Oncology, Barcelona, Spain; 2-Department of Medical Oncology, Vall d’Hebron University Hospital, Barcelona, Spain; 3-Department of Medical Oncology, Catalan Institute of Oncology, L´Hospitalet, Barcelona, Spain; 4- Cancer Genomics Group,Vall d’Hebron Institute of Oncology, Barcelona, Spain; 5-Department of Medical Oncology, Del Mar University Hospital, Barcelona, Spain; 6-Department of Medical Oncology, Asturias University Hospital, Oviedo, Spain; 7-Department of Medical Oncology, Santa Creu i Sant Pau University Hospital, Barcelona, Spain; 8- Department of Medical Oncology, Son Llatzer University Hospital, Palma de Mallorca Spain; 9- Department of Medical Oncology, Marques de Valdecilla University Hospital, Santander, Spain; 10- Department of Medical Oncology, Reina Sofía University Hospital, Córdoba , Spain; 11-Sysmex Inostics, Illinois, United States; 12-Molecular Oncology Group, Vall d’Hebron Institute of Oncology, Barcelona, Spain; 13- Oncology Data Science Group, Vall d’Hebron Institute of Oncology, Barcelona, Spain; 14-Traslational Research Laboratory, Catalan Institute of Oncology, L´Hospitalet, Barcelona, Spain.
Accepted for publication, Annals of Oncology Liquid biopsy and ctDNA
● Circulating-free DNA (cfDNA) is a naturally occuring DNA that is present in the bloodstream. We can isolate it from the plasmatic fraction of blood.
● Circulating-free tumor DNA (ctDNA) is a part of cfDNA, cell-free DNA released from a solid tumor and, therefore, carries mutations or other genomic alterations.
● Liquid biopsy refers to the ability to detect mutations / alterations present in a patient’s tumor from a blood sample. ctDNA: circulating tumor DNA Derives from tumour cells
Crowley, E. et al. (2013) Liquid biopsy: monitoring cancer-genetics in the blood Nat. Rev. Clin. Oncol. doi:10.1038/nrclinonc.2013.110 Critical aspects in primary vs plasma concordance rates
Intratumor ctDNA Targeted heterogeneity mCRC shedding therapies
Clonality Tumor load Selection mCRC: APC, KRAS vs Met locations mCRC: anti-EGFR, RAS BRAF, PIK3CA Necrosis, other clones Lung: EGFR indel 19 vs biological processes Lung: EGFR T790M T790M vs C797S Liquid biopsy analysis in mCRC
BEAMing
RAS PANEL (BEAMing) Gene Exon Mutation KRAS 2 G12S/R/C/D/A/V 2 G13D 3 A59T 3 Q61L/H/R 4 K117N 4 A146T/V NRAS 2 G12S/R/C/D/A/V 2 G13D/R/V 3 A59T 3 Q61K/L/R/H 4 K117N 4 A146T BEAMing has an analytically validated CE kit for plasma, OncoBEAM Design and Objectives
DESIGN OBJECTIVES Retrospective and multicentric (n=150) Primary RAS testing Concordance analysis defined as SoC* tumor BEAMing tumor BEAMing plasma plasma and tissue based RAS (Sens 1-5%) (Sens 1%) (Sens 0.02-0.04%) mutation testing to establish the eligibility for anti-EGFR therapy.
Secondary
PFS description by tumor and BEAMin g plasma plasma determination in patients who received anti-EGFR therapies M SoCU tumor OS description by tumor and BEAMing tumor T plasma determination
*The real-time conventional assay (qPCR) was performed using the real-time PCR machine Light Cycler® 480 (Roche Life Science) using a custom panel of TaqMan® probes to detect point mutations in exons 2/3/4 of KRAS and NRAS. Main inclusion criteria
Patient demographics
n (%) Gender Male 107 (73) Female 40 (27) Age median (range) 65y (30- 86) Stage at diagnosis Early 46 (31) Advanced 101 (69) Primary site Right 36 (25) Left 33 (22) Colon unspecified 31 (21) Rectum 47 (32) Tumor tissue for RAS testing Primary 122 (85) Metastatic 22 (15) Number of metastatic sites at ctDNA collection 1 66 (45) 2 54 (37) 3+ 27 (18) Metastatic site at ctDNA collection Liver 101 (69) Lung 60 (41) Node 46 (31) Peritoneal 31 (21) Other 27 (18) Treatment Description
Number Percentage 0 61 41% Number therapies metastatic setting 1 45 31% prior to ctDNA collection 2 35 24% 3+ 6 4% Received anti-EGFR therapy after to Yes 68 46% ctDNA collection No 79 54%
7.3 m (4.5-not reached) 7.7 m (5.8-11.3)
17.7 m (13.8-not reached) n= 13 n=20 n=35 Median (CI95%) Median overall survival in All patients 35.9 m (29.7-42.9) metastatic setting Median (range) Median time from tumor to Not exposed to therapy 1.2 m (0-34) ctDNA collection Exposed to therapy 20.4 m (0.4-282) Concordance analysis SoC tumor/BEAMing plasma
Overall concordance
67 51 9 3 90.9%
64 51 6 9 88.5%
83 48 9 6 89.7%
BEAMing plasma
SoC tumor M BEAMing tumor U T Concordance analysis SoC tumor/BEAMing plasma
40.1 % RAS mut BEAMing plasma 36.7 % RAS mut SoC tumor SoC BEAMing tumor plasma
WT wild-type/ mut mutated Discordant: mutations detected only in plasma
Discordant: mutations detected only in tumor
Clinical relevance: PFS in RAS wild-type population
PFS 2nd and 3rd line RAS WT by SoC tumor PFS 2nd and 3rd line RAS WT by BEAMing plasma
Median 8.7m (6.43 – 10.23) Median 8.7m (6.77 – 11.27)
SoC (n=51) PFS 8.7 m (6.4-10.2) n=51 n=47
Irinotecan backbone regimen
WT wild-type Clinical relevance: Overall survival
OS in metastatic setting by SoC tumor OS in metastatic setting by BEAMing plasma
39.1 m (32.1-not reached) 42.9 m (36.5-not reached)
28.7 m (24.9-41.3) 27.8 m (24.6-35.6)
n= 147 n= 147
HR=1.65 (95%CI: 1.04 – 2.64) HR=1.92 (95%CI: 1.21 – 3.06)
WT wild-type mut mutated MAF analysis plasma vs tumor
MAF analysis: distribution of alleles in plasma
RAS mutant samples= 61 High sensitivity is required for reliable cfDNA profiling
MAFs
29% 0.01-0.1% 39% 0.1-1% >1% >5% 21% 11%
50% of patients show ctDNA at <1% fraction MAF analysis Conclusions
A concordance rate of 89.7% was achieved between ctDNA RAS testing and standard techniques for patients eligible to anti-EGFR-based therapy performed “in house” in a real world population
In this retrospective study, plasma RAS determination by BEAMing captures a population responding to anti-EGFR therapy at the same level as SoC RAS testing in tumor
Discordant samples could be explained due technical sensitivity, temporal or spatial heterogeneity and low tumor burden that could affect ctDNA release
Sensitivity is the crucial technical aspect in ctDNA analysis
The feasibility and practicability of ctDNA analysis may translate into significant impact in clinical practice for anti-EGFR treatment selection
Thanks!!! Vivancos Lab (VHIO) Ginevra Caratù Julieta Grasselli (Institut Català d’Oncologia) Judit Matito Frederick Jones (Sysmex) Vishal Sikri (Sysmex) Enrique Aranda Vall D’Hebron Hospital (Hospital Universitario Reina Sofía, Córdoba) Elena Elez Clara Montagut (Hospital Mar) Paolo Nuciforo Daniel Azuara (Institut Català d’Oncologia) Rodrigo Dienstmann Ramon Salazar (Institut Català d’Oncologia) Nuria Pardo Enriqueta Felip Josep Tabernero
Pregunta 1
La Concordancia entre plasma y tejido depende de:
1- la liberación de ctDNA o shedding
2- la clonalidad de la mutación objeto de estudio
3- los tratamientos previos dirigidos que haya recibido el paciente
4- todos los anteriores
Pregunta 2
El uso de tecnologías ultrasensibles para la biopsia líquida es debido a:
1- estas técnicas permiten secuenciar muchos genes
2- el ctDNA puede estar presente en fracciones alélicas muy pequeñas en plasma
3- las mutaciones en RAS en colon son subclonales
4- todas las anteriores