What's the prognosis for diagnostic testing in lung cancer?
Recent advances in science and clinical research have changed the way cancer patients are diagnosed and treated, a fact that can be often overlooked. By way of illustration, let’s look at the recent history of non-small cell lung cancer (NSCLC) – the most common type of lung cancer, itself the major cause of death worldwide. Only a generation ago, in the 1980s, patients diagnosed with NSCLC had only basic chemotherapy available and only around 10% would survive for a year. Fast forward to the late 2000s and the advent of personalised medicine and combination targeted therapies meant that over 50% of patients could expect to live for over 12 months, if not much longer. With so many promising innovations hopefully becoming available over the next few years, who knows what we might soon be able to achieve?
Today, we understand that every patient with their own specific tumour(s) needs to receive individualised treatment that targets the genetic defects that caused the cancer to arise in the first place. However, unfortunately, significant progress in this area has generated significant new challenges that need to be overcome.
In order to be able to personalise cancer treatments for patients, we have to be able to run diagnostic tests on tumour tissue, which means that either tissue from a surgical procedure or a biopsy has to be available. Unfortunately, with current technology there often isn’t enough tissue of the right quality to run all the analyses necessary – a situation that will only get worse as we now know that tumours can “evolve” over time, meaning that multiple diagnostic tests may need to be performed on tissue from the same patient.
As shown above, recent novel and innovative science and research can help to improve the situation. There are diagnostic tests now in development that can investigate tumour tissue for multiple biomarkers at the same time. It is even possible to see whether there are multiple genetic defects in the same tumour cell.
The image below comes from an investigational 4-plex diagnostic test (i.e. one that can detect up to four different, cancer-promoting, genetic defects in one tissue sample at the same time. As you can see, three of the four biomarkers showed up positive in this particular slice of lung tumour as pink, light blue and green staining (normal tissue is unstained, i.e. dark blue):
This patient would therefore be a candidate for therapies that target one or more of the three genetic markers in question. Below is another example image from another multiplex diagnostic test; once again, each bright colour indicates tissue that contains a specific genetic defect that could be a target for therapy:
Advances in cancer diagnostics haven’t remained focused purely at the tumour itself. Very recently, cancer researchers have discovered that there is genetic material – DNA – from the tumour circulating in the blood that can be analysed. While the amount of tumour DNA in patients’ blood is extremely small, recent major technological advances may make it possible to make treatment decisions based on blood analysis results. Since it is obviously much more convenient for everyone involved to obtain and test a blood sample rather than get a biopsy performed, these blood-based diagnostic tests have the potential to significantly advance cancer care in the near future.
In summary, significant advances in cancer treatment have been made through the development of novel innovative drugs. However, perhaps of equal importance are the ongoing rise of advanced diagnostic technologies to analyse the tumour and blood of patients to allow the best decision of which treatment to choose. All of the researchers in this area in the Roche group are proud to be at the forefront of this emerging revolution in cancer care.