Radical treatments for gynaecological cancers: HOPE or HYPE?

Dr Stephen Wong

Peter MacCallum Cancer Centre

Clinical implementation of circulating tumour

DNA analysis for personalised oncology:

From blocks to blood

@stephenqwong

ctDNAfragment size ~160bp

Characteristics of ctDNA

Adapted from D. Leja, NHGRI

ctDNA as a “Liquid Biopsy”Tumour (blocks) sampling

Plasma (blood) sampling

Tumour (blocks) sampling

Plasma (blood) sampling

Methods of ctDNA detection

Increasing sensitivity

Increasing genomic coverage

Single Locus Assays

(eg Digital PCR)

Targeted sequencing approaches

(eg hybrid capture,

amplicon)

Whole genome

sequencing

Quantitative Analysis

• Tumour burden• Disease

monitoring

Genomic Analysis

• Molecular profiling

• Clonal evolution

ctDNA testing workflowBlood taken Blood Spin

Issue report

EDTA tube (within 1 hour)Streck tube (within 14 days)

NGS technology

Plasma storage

Plasma DNA extraction

10-50 mls of blood

Adapted from Wan et al, Nature Reviews Clinical Oncology, 2017

Cancer detection:Screening or early diagnosis

Risk stratification and prognostication

Molecular profiling and treatment selection

Surveillance: Detection of minimal residual disease

Monitoring response to therapy and clonal evolution

Clinical Applications

ctDNA and minimal residual disease

Minimal Residual Disease in Stage III melanoma

Tan et. al., Annals of Oncology, 2019

Distant metastatic free survival: Baseline

Distant metastatic free survival: Postoperative

Minimal Residual Disease detection and Monitoring

during Adjuvant Therapy in Stage III Melanoma

HR 4.9, 95% CI 2.4-10,

p=0.22x10-4

HR 14, 95% CI 5.7-

36, p=0.16x10-7

Postoperative ctDNA detected (n=15)

Postoperative ctDNA not detected (n=48)

Tan et. al., Annals of Oncology, 2019

Adapted from Wan et al, Nature Reviews Clinical Oncology, 2017

Cancer detection:Screening or early diagnosis

Risk stratification and prognostication

Molecular profiling and treatment selection

Surveillance: Detection of minimal residual disease

Monitoring response to therapy and clonal evolution

Clinical Applications

Biopsy available

Molecular profiling

(long waiting time)

Molecular profiling

of advanced cancer

Tumour tissue Plasma

Biopsy not available

Standard treatment

Blood always available

1-2 day results

Targeted Therapy ctDNA

SEGMENT and M-BCB (Metastatic Breast Circulating Biomarker Study)

Molecular Profiling in Breast Cancer

Digital PCR NGS

Molecular profiling using ctDNA analysis in Breast Cancer

• Cost• Turn around time• Performance• Reproducibility

Research Diagnostics

Screening for PIK3CA mutations enables enrolment on PI3K inhibitor clinical trial

Andjelija ZivanovicChen-Fang WengMiriam YeungUnpublished

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Number of patients enrolled

Identification of targetable mutations

Cancer detection:Screening or early diagnosis

Risk stratification and prognostication

Molecular profiling and treatment selection

Surveillance: Detection of minimal residual disease

Monitoring response to therapy and clonal evolution

Clinical Applications

Adapted from Wan et al, Nature Reviews Clinical Oncology, 2017

Disease monitoring using ctDNAMelanoma molecular subtypes

BRAF mut

NRAS mut

BRAF/NRAS WT TERT promoter mutations

Mar V, Wong SQ et al, Clin Can Res 2013

BRAF mutant pt. NRAS mutant pt.

BRAF/NRAS WT pt. TERT mutant pt.

Disease monitoring using ctDNA

Wong et. al., Journal of Clinical Oncology - Precision Oncology, 2017

Identifying treatment resistance using ctDNA

Reversion of BRCA1/2 Germline Mutations Detected in Circulating Tumor DNA From Patients With High-Grade Serous Ovarian Cancer

Christie et al, JCO 2017

Is ctDNA ready for prime timePre analytical variability

Standardisation of sample processing

Analytical validity

Different assay performance characteristics

Assay validation: quality control, robustness

Lower limit of detection ranging from 1%

What is the minimal analytical sensitivity and specificity to maximise clinical utility

Cross platform comparisons

Clinical Validity

Concordance b/w tissue and plasma; ? discordance due to biological or analytical factors

How consistently and accurately the test detects or predicts the intermediate or final outcome of interest; PPV and NPV

Clinical utility

How likely is the test to significantly improve patient outcomes?

Endometrial cancer ctDNA study

CODEC Study – Circulating tumOur Dna in endometrial cancer

A prospective, pilot, “proof-of-concept” ctDNA study

45 patients from all stages

Aim: Determine if ctDNA analysis:

-can prognosticate for RFS/OS

-can be used as a MRD tool

-can reflect tumour responses in comparison to other biomarkers, e.g. CA125, HE4, PET scans

Rachel Delahunty, Petermac, Epworth, RWH

Acknowledgements

Sarah-Jane Dawson

(and lab)

Mark Dawson

(and lab)

Grant McArthur

Con Tam

Andrew Roberts

John Seymour

Michael Dickinson

Shahneen Sandhu

Jeanette Raleigh

Athena Hatzimihalis

Rod Hicks

Jason Callahan

Tony Papenfuss

Jason Li

Ismael Vergara

Petermac Molecular

Genomics core

Sherene Loi

Geoff Lindeman

Stephen Fox

Molecular Pathology

Ben Solomon

Richard Marias

CASCADE investigators

MRV investigators

Collaborators

Faculty Disclosure

Honoraria/

Expenses

Consulting/

Advisory

Board

Funded

Research

Royalties/

Patent

Stock

Options

Ownership

/ Equity

Position

EmployeeOther

(please specify)

March 30 - April 2, 2014Sheraton Sonoma CountyPetaluma, California

Off-Label Product Use

Will you be presenting or referencing off-label or investigational use of a therapeutic product?

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X No, nothing to disclose

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