“The most important part of lung cancer is having it detected and diagnosed early,” says Dr. Andrea Wolf, a lung cancer surgeon at Mount Sinai Health System. “I cannot stress the importance of lung cancer screening enough.”

For patients diagnosed with lung adenocarcinoma, one of the most common forms of non-small cell lung cancer (NSCLC), molecular testing has become an increasingly important part of treatment planning.

WATCH: Questions to Ask Your Doctor About Molecular Testing for Lung Cancer

“Particularly for patients with adenocarcinoma, molecular testing is critical, as there are a lot of pathways and, kind of, the way cancer develops and spreads that are understood better now,” Dr. Wolf explains.

Why Molecular Testing Has Become So Important

Over the last two decades, researchers have discovered that many lung cancers are driven by specific genetic mutations or molecular abnormalities. These findings have fueled the development of targeted therapies designed to attack the unique features of a patient’s cancer.

“There are a lot of medications that target those specific pathways for patients with advanced cancers,” Dr. Wolf says. “So molecular testing is very important.”

Molecular profiling, often performed through next-generation sequencing (NGS), analyzes a tumor’s DNA and other biomarkers to identify genetic alterations that may help guide treatment decisions. The list of actionable biomarkers continues to grow as scientists better understand how lung cancer develops and spreads.

WATCH: What’s It Like to Get Next-Generation Sequencing for Lung Cancer?

Today, comprehensive testing may evaluate dozens or even hundreds of genes and molecular markers.

PD-L1 Testing Helps Guide Immunotherapy

One of the most commonly tested biomarkers is PD-L1 (programmed death-ligand 1), a protein found on the surface of some cancer cells.

PD-L1 helps tumors evade detection by interacting with PD-1 receptors on immune cells, effectively telling the body’s immune system not to attack the cancer.

Testing for PD-L1 expression is now considered a routine part of many lung cancer evaluations because higher levels are linked to a stronger response to immunotherapy drugs such as pembrolizumab (Keytruda), nivolumab (Opdivo), and atezolizumab (Tecentriq).

Even patients with low levels of PD-L1 expression may still benefit from these therapies, which have become a cornerstone of treatment for many forms of advanced lung cancer.

EGFR Mutations Can Open the Door to Targeted Therapies

Another important molecular marker is EGFR, or epidermal growth factor receptor.

The EGFR gene produces a protein involved in cell growth and division. When mutations occur, the signaling pathway can become overactive, leading to uncontrolled cancer growth.

Patients whose tumors harbor EGFR mutations may be candidates for targeted medications known as tyrosine kinase inhibitors (TKIs), including osimertinib (Tagrisso), erlotinib (Tarceva), and gefitinib (Iressa).

These treatments work by blocking the abnormal EGFR signaling pathway that drives cancer growth. Research has demonstrated benefits not only in advanced-stage disease but also in certain early-stage lung cancer patients following surgery.

Other Targetable Mutations Continue Expanding Treatment Options

Modern molecular profiling often evaluates a wide range of additional biomarkers, including:

• ALK rearrangements
• ROS1 fusions
• KRAS mutations
• BRAF mutations
• HER2 mutations
• MET alterations
• RET fusions
• NTRK fusions

Many of these alterations have approved targeted treatments available today.

For patients with advanced disease, identifying one of these molecular drivers can dramatically alter treatment recommendations and may provide access to therapies specifically designed to target the cancer’s biology.

New Testing Platforms Are Making Profiling More Comprehensive

Several commercially available NGS platforms allow physicians to test hundreds of genes simultaneously from a single tumor sample.

Examples include:

• FoundationOne CDx, which analyzes 324 genes and includes microsatellite instability (MSI) and tumor mutational burden (TMB) information.
• OmniSeq Insight, which evaluates more than 500 genes while also providing immune profiling data, including PD-L1 testing.
• Cobas EGFR Mutation Test v2, which focuses specifically on identifying EGFR mutations in tissue and blood samples.

Patients are encouraged to ask their healthcare team whether the molecular testing being performed is comprehensive enough for their specific cancer type and stage.

Early Detection Still Comes First

As exciting as precision medicine has become, Dr. Wolf believes patients should not lose sight of an even more important goal: finding lung cancer before it has a chance to spread.

“Early detection and lung cancer screening are the most important,” she says. “Getting diagnosed, and ideally getting diagnosed at an early stage before testing is even relevant to treatment.”

Current guidelines recommend yearly lung cancer screening with a low-dose CT scan for adults ages 50 to 80 who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years.

For many patients diagnosed with localized lung cancer, surgery remains the primary treatment approach.

“The treatment for early-stage lung cancer is removal,” Dr. Wolf says.

When lung cancer is caught before it spreads, outcomes can be remarkably strong.

After surgery for early-stage lung cancer, survival can be 65%, 85%, even up to 100%, Dr. Wolf notes.

Questions to Ask Your Doctor

• Am I eligible for lung cancer screening?
• Has my tumor had comprehensive molecular testing?
• Do my results qualify me for a targeted therapy or immunotherapy?
• Am I a candidate for surgery?
• Are there clinical trials that might be right for me?

Learn more about SurvivorNet's rigorous medical review process.

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