The purpose of this study is to investigate “liquid biopsies” as a method of evaluating RAS mutation status in patients with advanced colorectal cancer. This involves determining the accuracy of results of “liquid biopsies”, compared to genetic testing of cancer tissue. Different methods of testing “liquid biopsies” will be studied and compared. The study will also assess whether the ability of “liquid biopsies” to detect cancer gene mutations is different at different time points.
This study is a prospective cohort study that will recruit 100 patients at approximately 10-15 sites in Australia. The study will recruit patients with advanced colorectal cancer who have not received previous chemotherapy. The results of “liquid biopsies” will not direct an individual patient’s treatment in this trial.
A study evaluating liquid biopsies to profile metastatic colorectal cancer
To validate liquid biopsies as an alternative to tissue based
assays to determine ras status
– To compare different modalities of evaluating mutation
status in ctDNA
– To assess the impact of timing of sample collection on
detection of mutation status
Colorectal cancer is the most commonly diagnosed cancer in the Australian population. Surgery, with or without chemotherapy and radiotherapy, can be used to cure colorectal cancer that is diagnosed early. Most cases of advanced colorectal that have spread to other organs cannot be cured. Advanced colorectal cancer is treated with chemotherapy and other drugs, known as targeted therapies.
One type of targeted therapy used to treat advanced colorectal cancer is antibodies targeted against the epithelial growth factor receptor (EGFR). Examples of EGFR-targeted antibodies include cetuximab and panitumumab. EGFR-targeted antibodies are only effective in patients with colorectal cancers that do not have mutations in certain genes, known as KRAS and NRAS. Cetuximab and panitumumab do not work in colorectal cancers with mutations in the KRAS or NRAS genes. Therefore, for each patient with advanced colorectal cancer, it is important to assess whether there are mutations in KRAS and NRAS genes in order to determine if EGFR-targeted antibodies will be effective. This process is known as evaluation of RAS mutation status.
CLINICAL TRIAL DESIGN
This study is a prospective cohort study that will recruit 100 patients at approximately 10-15 sites in Australia. The study will recruit patients with advanced colorectal cancer who have not received previous chemotherapy. The results of “liquid biopsies” will not direct an individual patient’s treatment in this trial. All cancer treatments will be chosen by the doctor treating each patient.
A/Prof Niall Tebbutt