Lung Cancer: What’s a Biomarker?

Doctors used to consider lung cancer as one single disease. Now we know that there are 2 major types of lung cancer: small cell lung cancer and non-small cell lung cancer. And within these 2 types, there are several more subtypes. It was discovered that certain tumor cells had genetic mutations, which led to the knowledge that these changes or damage in the genes might play a role in causing cancer cells to grow. There is now a better understanding of what drives the growth of certain cancers.

This is important because knowing the particular type or subtype of lung cancer, along with information about what might be driving the cancer’s growth, can help you and your doctor develop a treatment plan.

Biomarkers in Non-Small Cell Lung Cancer
We know today that more than half of lung adenocarcinoma cases (the most common subtype of non-small cell lung cancer) have an identifiable molecular driver. These molecular drivers are also called ‘biomarkers’.

Biomarkers can tell you what is inside the lung cancer cells that might be driving the tumor’s growth. Currently, there are at least 10 known biomarkers in non-small cell lung cancer for which patients may be tested. Although the majority of these biomarkers are still under investigation, there are two biomarkers that are associated with approved drug therapies. These biomarkers are called epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK).

As we learn more about biomarkers, the diagnosis and treatment of lung cancer will become even more specific. 

What’s Molecular Profiling?
After obtaining a sample of a tumor from the patient, usually from surgery or a biopsy, doctors (called pathologists) will look and see what the lung cancer cells look like under a microscope. The different types of lung cancer cells may look different under the microscope.

The pathologist may also do further tests to see what’s inside those lung cancer cells and to look for biomarkers that may be driving the cancer growth. Identifying whether there are any biomarkers inside the lung cancer cells is called ‘molecular profiling’.

Is It For Everyone?
There are a few important things to keep in mind when it comes to molecular testing.

Even though there is no sure way to know whether you would test positive for a biomarker, not all patients with lung cancer may be candidates for molecular testing—there are other factors that also need to be considered, so it’s important to discuss with your doctor whether this testing is right for you and if it will be performed on your tumor cells.
If there is enough tissue from a previous biopsy, your doctor can send this to be tested. Otherwise, another biopsy may be required. In general, results from molecular tests will come back within 2 weeks.
If your tumor tests indicate a biomarker for which there is no approved drug therapy, there may be available clinical trials for medicines being tested for that type of tumor. Talk to your doctor if you are interested in participating in a clinical trial. Your healthcare team will be able to answer your questions, help you find more information and suggest if a clinical trial might be right for you.

Your Cancer Treatment Team: It Takes a Village
Your cancer care team may include primary care physicians, oncologists, radiation oncologists, surgeons, and pulmonologists, along with oncology nurses, pharmacists, social workers, nutritionists, and other healthcare professionals. Keeping an open dialogue with your healthcare team is important. If your doctor doesn’t recommend molecular testing or other testing you may think you need, it is okay for you to ask why not.

You and your team of healthcare providers can be full partners in your care—knowing who they are and what they do can help you be ready to ask them the questions that you feel are important to you.

Marc Chioda is an Associate Medical Director on the Lung Cancer team at Pfizer Oncology.

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