The Role of Biomarkers in ROS1+ Cancer Treatment

Cancer treatment has evolved significantly with the advent of precision medicine, allowing for therapies tailored to specific genetic alterations. For patients with ROS1+ cancer, biomarkers play a crucial role in diagnosis, treatment selection, and ongoing disease monitoring. Understanding these biomarkers can help patients and healthcare providers make informed decisions about their treatment journey.

What are biomarkers?

Biomarkers are biological indicators found in blood, tissues, or other body fluids that provide insights into a patient’s disease. In ROS1+ cancer, biomarkers help determine the presence of ROS1 gene rearrangements, which are critical for selecting targeted therapies.

How biomarkers guide ROS1 cancer treatment

1. Diagnosis and identification

   • ROS1+ cancer is identified through biomarker testing.  Common methods of testing tumor tissue biopsies from lung biopsies are next-generation sequencing (NGS), fluorescence in situ hybridization (FISH), or immunohistochemistry (IHC). Some liquid biopsy tests (which are done on blood samples) have also been approved for biomarker testing in lung cancer, although testing on tumor tissue is preferred. These tests detect ROS1 gene fusions, which are uncommon but important drivers of certain lung cancers and other rare cancers.

2. Selection of targeted therapies

   • Once ROS1 rearrangement is confirmed, patients may be eligible for ROS1 targeted therapies, also known as tyrosine kinase inhibitors (TKIs). Drugs like crizotinib, entrectinib, lorlatinib, and repotrectinib have been developed to specifically inhibit the ROS1 fusion protein, slowing or stopping tumor growth.

3. Monitoring treatment response and resistance

   • Biomarkers are also used to track a patient’s response to therapy. When progression occurs, biomarker testing can detect emerging resistance mutations and help guide treatment adjustments. For example, resistance mutations like G2032R can impact the effectiveness of first-line TKIs, prompting a switch to other TKIs.

4. Personalizing future treatments

   • Research into additional biomarkers continues to refine treatment approaches. Identifying co-mutations or other molecular changes can help predict response to new therapies and combination treatments, further advancing precision medicine in ROS1+ cancer care.

Why biomarker testing matters

For patients diagnosed with ROS1+ cancer, comprehensive biomarker testing is essential. It ensures they receive the most effective targeted treatment available and allows for proactive management of drug resistance. Advocacy groups, such as The ROS1ders, emphasize the importance of testing and access to cutting-edge therapies, helping patients navigate their treatment options.

Looking ahead

The role of biomarkers in ROS1 cancer treatment will continue to expand as new research emerges. Ongoing clinical trials are exploring different approaches to monitoring treatment, novel inhibitors, and combination therapies to overcome resistance mechanisms. Staying informed about biomarker-driven advances can empower patients and their care teams to make the best possible treatment decisions.

If you or a loved one has ROS1+ cancer, speak with your oncologist about comprehensive biomarker testing. For more resources and community support, visit The ROS1ders.