Can a liquid biopsy detect mutations in lung cancer at 40?

Question

Hello doctor,

I am a 40-year-old female, undergoing treatment for lung cancer for the last year. My doctor now suggested a liquid biopsy to check for new mutations because the disease response is changing. I do not fully understand this test. Can a liquid biopsy detect new mutations in lung cancer at age 40? And is it as accurate as a tissue biopsy?

Please guide.

Answer 1

Hi,

Welcome to icliniq.com.

I am deeply concerned about your worries.

I will explain simply and clearly. A liquid biopsy is a blood test that looks for small pieces of tumor DNA (deoxyribonucleic acid) in your blood. Cancer cells release this DNA, and analyzing it allows us to detect new mutations or changes in the tumor without another invasive biopsy.

Yes, a liquid biopsy can detect new mutations in lung cancer, especially when disease behavior is changing, or treatment is no longer working. It is very useful for identifying targets, such as EGFR (epidermal growth factor receptor) resistance mutations, and for helping doctors choose the next treatment.

However, it is not as accurate as a tissue biopsy in all cases. If the amount of tumor DNA in the blood is low, the test may miss mutations (false negative). But if it detects a mutation, it is usually reliable.

In practice, doctors often use liquid biopsy first because it is simple, safe, and quick, and if the results are unclear or negative. Still, suspicion remains, so a tissue biopsy may be advised.

Overall, it is a very helpful modern test to guide treatment decisions, especially in cases like yours where the disease pattern is changing.

Hope I have addressed all of your queries and concerns. Do follow up whenever needed.

Thank you.

Can a liquid biopsy detect mutations in lung cancer at 40?

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