Are You In This Situation?
I’m having chemotherapy for my lung cancer in Australia and my doctor hasn’t said whether I have any mutations that might lead to a targeted therapy. Is targeted therapy available for me?
At present, the answer to this question depends on which type of lung cancer you’ve been diagnosed with.
Squamous Cell Lung Cancer
- If you have a Squamous Cell Lung Cancer, there are currently no “actionable” or “druggable” targets that allow a new targeted therapy agent to be used. Current best practice is chemotherapy and/or immunotherapy.
Adenocarcinoma (glandular) type of lung cancer – EGFR mutation
- If you have an adenocarcinoma (glandular) type of lung cancer, there is a chance that you have a mutation that does have a drug associated with it. The most common form of mutation is an EGFR mutation. This is more common in people of Asian background as well as women and people who have never smoked. Amongst Caucasians the incidence is approximately 15% (or 1 in 7 people).
- A test is performed to determine whether your cancer has the mutation. If the test is positive (you have the mutation), you may be offered treatment with oral tablets called Tyrosine Kinase Inhibitors or TKIs. TKIs are available on the Pharmaceutical Benefits Scheme (PBS).
- The test for EGFR can take up to 10 working days to get a result. Depending on the stage of your cancer, your Oncologist may commence chemotherapy while waiting for the result so that you have active treatment as early as possible.
Adenocarcinoma (glandular) type of lung cancer – ALK mutation
- A smaller number (around 4%) of adenocarcinomas have an ALK mutation. Testing for an ALK mutation usually involves two tests.
- The first test gives a quick indication of whether or not there is an ALK mutation while the second test is more sensitive and is required before targeted therapy can be prescribed. The first test can be done in a local histopathology lab (such as the one you usually go to for blood tests). This test is an IHC (immunohistochemistry) test and can be done quite quickly, however there is a cost involved.
- If this first test is positive, the sample must be sent away for a more sensitive test before a targeted drug can be prescribed on the PBS.
Adenocarcinoma (glandular) type of lung cancer – ROS1 mutation
- A smaller number (around 1%) of people with adenocarcinoma may have the ROS1 mutation. If you have already had a test which has shown your cancer to be ALK positive, there is no need to test for ROS1 as treatment will be the same. Currently, there is no drug therapy available on the PBS in Australia that is specifically for the ROS1 mutation. There is some evidence that TKIs used for the ALK mutation may work for the ROS1 mutation.
- You would need to discuss with your Oncologist whether these are available and at what cost. Because TKIs are not approved on the PBS for ROS1, patients are required to cover the full cost. SEE UPDATE – NOW APPROVED FROM 1 JAN 2019!
Please note that the information contained in this article is for educational purposes only. It is important that you seek medical advice from a medical practitioner or specialist (e.g., Oncologist) on the most appropriate treatment for your lung cancer.
If you are unsure of the possible mutations for your lung cancer or what the treatment options are, I can help clarify the issues for you.
Contact Dr Hawson for an appointment