Prominent oncologist Dr Aju Mathew, consultant oncologist, Malankara Orthodox Syrian Church Medical College, Kolenchery, breaks down the implications of a new inflammation-focused lung cancer blood test and explains its clinical challenges, limitations and future outlook to Unnikrishnan S Edited excerpts:
Since this new blood test detects an ‘invisible’ warning sign of inflammation rather than an actual physical tumour, how will doctors handle a patient who tests positive but has a completely clear, normal lung scan?
The hypothesis of the study is that a drug that can reduce interleukin-1 beta can be used in such patients to prevent lung cancer. The idea is that instead of using the drug for everyone, we can focus it specifically on patients who exhibit these warning signs of inflammation.
Can this blood test tell the difference between lung inflammation caused by smoking versus inflammation caused by severe city air pollution or breathing in kitchen smoke?
It cannot differentiate.
The study suggests that treating high-risk patients with strong anti-inflammatory drugs might stop lung cancer before it starts. What are the long-term side effects or health risks of putting an otherwise healthy, symptom-free person on these powerful drugs for five years?
What is understood from the original study is that there are no major side effects. The problem has been that we do not know whom to give the medicine to. However, this study provides a hypothesis that you can use it specifically for those patients who test positive on this 14-marker test.
How do you see this test actually being used in hospitals in the future—will it be a cheap, yearly health check for everyone over 40, or will it only be given to specific high-risk groups?
I do not see it being used at all in the foreseeable future for various reasons. One is that it has to be validated in a prospective study. Additionally, the drug has to be widely available, affordable, and free of significant side effects for it to be used in a preventive setting.
In the past, blood tests like PSA for prostate cancer caused widespread panic because they frequently gave ‘false alarms,’ leading to unnecessary surgeries and biopsies. What steps are being taken to ensure this new lung cancer test doesn’t cause the same panic?
These tests can cause false alarms.
If a patient’s blood test comes back completely clear, but they are actually harbouring a very early, hidden lung cancer that simply isn’t showing up in the blood yet, how do doctors catch it?
They could still be harbouring cancer cells, so the test could create a false sense of reassurance.
If a patient takes a broad blood test that says they have a high risk for cancer, but regular hospital scans cannot find any tumour, what is the next step for that patient? Should they just live in a state of waiting and watching?
Yes. That is why I still do not recommend this for clinical use now or in the near future.