Who this is for:
If you or someone close to you has been diagnosed with lung cancer and you are unsure why doctors are waiting before starting treatment — or whether a second opinion might change the plan.
When someone is diagnosed with lung cancer, the instinct is often to start treatment immediately. That is completely understandable. But in many cases, the most important decision is not how quickly treatment starts — it is choosing the right treatment from the beginning.
In my practice in Melbourne, Australia, I often see patients locally and internationally — including from the Philippines, Indonesia, Maldives, and Sri Lanka — where early molecular testing has completely changed the treatment approach.
What is molecular testing?
Molecular testing looks at the DNA of the cancer, rather than just how it appears under the microscope. It identifies specific changes (mutations) that are driving the cancer’s growth.
In lung cancer, these commonly include [1]:
• EGFR mutations
• ALK rearrangements
• ROS1 alterations
• HER2 mutations
These are not rare findings. In many patients — particularly those who have never smoked — these results completely determine the treatment pathway.
Why waiting for results matters
Starting treatment before molecular results are available can sometimes lead to the wrong first treatment choice.
For example:
• A patient with an EGFR mutation may initially receive chemotherapy
• However, the most effective treatment is often a targeted tablet [2], not chemotherapy
Once treatment has started, it can make it more difficult to transition cleanly to the most appropriate therapy.
This is why, in carefully selected situations, a short delay to obtain molecular results is not harmful — it is strategically important.
Where second opinions often change the plan
In many cases, patients come for a second opinion after treatment has already been recommended or even started.
One of the most common issues I see is that:
• Molecular testing was delayed
• Or not fully completed before treatment decisions were made
This can significantly alter the initial pathway.
A second review at this stage can help ensure that:
• All relevant mutations have been tested
• The treatment plan is aligned with the biology of the cancer
How treatment decisions change
If a targetable mutation is identified:
• Treatment often shifts to targeted therapy (oral tablets)
• These are usually more effective and better tolerated
• They are also more likely to control disease in areas such as the brain
If no mutation is found:
• Chemotherapy or immunotherapy remains appropriate
So the decision is not delayed — it is refined.
Why the first decision matters so much
The first treatment often shapes everything that follows.
Getting this right can:
• Prolong disease control
• Reduce unnecessary toxicity
• Preserve future treatment options
Getting it wrong early can make later decisions more complex.
When should you consider a second opinion?
• If treatment is being started before molecular results are available
• If you have been told chemotherapy is the only option
• If your cancer has progressed and you are unsure about next steps
Patients from Melbourne and across the Asia-Pacific region, including the Philippines, Indonesia, Maldives, and Sri Lanka, often seek a second opinion at this stage.
Key takeaway
• The biology of the cancer matters as much as the diagnosis
• Waiting for molecular results can lead to a better first treatment choice
• The first decision often determines the course of treatment
Dr Dilanka De Silva is a medical oncologist based in Melbourne, Australia, with a focus on precision oncology and international second-opinion care.
1. Makarem M, Jänne PA. Top advances of the year: Targeted therapy for lung cancer. Cancer. 2024 Oct 1;130(19):3239-3250. doi: 10.1002/cncr.35423. Epub 2024 Jun 21. PMID: 39031586.
2. Soria JC, et al. “Osimertinib in Untreated EGFR-Mutated Advanced Non-Small-Cell Lung Cancer.” New England Journal of Medicine, 2018