Will linking diagnostic tests for lung cancer to treatment deliver the promise of personalised medicine?

November was lung cancer awareness month, a time to assess where we are in cancer treatment and to consider future strategies to help prolong life and avoid the most challenging side effects.

Not long ago, if you were diagnosed with lung cancer, only standard treatment options – whether surgery, chemotherapy and/or radiation – were available. Today, medications tailored to your individual genetic makeup can attack and block mutant cancer cells without harming healthy cells nearby, with companion diagnostic tests to match mutation to medicine.

Targeted therapies are designed to help the patients who will most benefit, but for such treatments to be possible there must be a corresponding diagnostic test to identify the mutations causing the cancer to replicate on a molecular level, and to inform the treatment plan.

For patients to benefit, their tumours must be analysed, yet a recent study1 found that more than 25 percent of patients with non-small cell lung cancer were not being tested for the specific mutations that play a role in tumour growth and proliferation in up to 60 percent of patients. This was not due to a lack of tumour tissue available or to the risks associated with undergoing biopsy.

Those patients now have an alternative, as we have recently launched a test that can use plasma – taken from a simple blood test – or tumour tissue to detect 42 mutations in the epidermal growth factor receptor (EGFR) gene. Now test results are available in about eight hours, a significant improvement over past tests that could take days to deliver results, and, unlike biopsies that show the presence of EGFR mutations in a single tumour, the blood plasma test can detect mutations anywhere in the body. Meaning, if the original tumour has metastasised, the test will still pick up the EGFR mutation. Once identified, eligible patients can benefit from existing, targeted companion treatments.

Roche has been investing in ‘liquid biopsy’ research in order to remove the barriers that prevent patients from accessing innovative molecular testing. Obtaining tumour tissue often requires invasive, risky biopsies and it has its limitations because tumour tissue only presents a single snapshot in time and is subject to sampling bias resulting from tumour heterogeneity. Therefore, using a simple blood draw increases access to and ease of testing. Our cobas EGFR Mutation Test v2 is one of only 10-15 examples of molecular tests paired to treatment, of which the most widely known is the test and treatment for the HER2 gene in breast cancer.

Pairing test and treatment is at the forefront of personalised medicine, especially in oncology, because it helps patients – through targeted treatment based on their individual molecular profiles, better side effect profiles and better outcomes – and it offers physicians an additional way to test for gene mutations, even in patients with advanced disease. It also benefits payers, who want more value in cost-effective treatments.

We are currently working to apply the cobas test to monitor treatment response and progression of the cancer. Clinical trials will be needed to prove the validity of such applications, and they will need approval from regulatory agencies, but it is our hope that patients will have their plasma tested at periodic check-ups to learn if their tumour has progressed, developed additional drug-resistance mutations or whether the treatment continues to prevent the tumour from growing.

This is the future for advanced cancer care; the promise of personalised medicine – fitting the right treatment to the right patient at the right dose and the right time – is being fulfilled and the hope for the future couldn’t be more promising.

1. The study was reported at the reported at the European Lung Cancer Conference

The author:

Walter Koch is head of global research at Roche Molecular Diagnostics