3 ways biomarker testing helps personalize cancer treatment

Biomarker testing represents one of the most significant advances in cancer care in decades, and the growing area of study promises even more improvements and better outcomes ahead.

Endeavor Health oncologist Dhruv Bansal, MD, an expert in immunotherapy and clinical lead in thoracic/lung oncology, breaks down how biomarker or somatic testing is used to help drive optimal care today.

Unlike traditional genetic testing that identifies inherited mutations that may put you at higher risk for developing certain cancers and other conditions, biomarker testing, also known as tumor genetic testing or somatic testing, looks at parts of cancer cells, including genes and sometimes protein expression, to learn more about an individual’s cancer.

Each cancer has unique biomarker profiles that can help reveal how aggressive it may be and which treatments will work best.

There are three major ways physicians are using tumor genetic testing today, explained Dr. Bansal.

1. Detection of minimal residual disease (MRD). Somatic testing after treatment can tell us whether a patient is cancer-free, often with greater confidence than imaging, said Dr. Bansal. “These tests can detect the presence or absence of cancer following treatment earlier than scans,” he added. That information can be critical in determining next steps for treatment and helps detect recurrence before patients develop symptoms.

2. Targeted treatment plans. Tumor samples for somatic testing are now the gold standard to inform treatment decision-making for many cancers, including lung cancer, said Dr. Bansal. In-house testing at Endeavor Health offers an efficient way to identify biomarkers that respond to widely different drugs. “Frequently, we can’t start treatment until we have the results. We don’t want to give chemotherapy to everyone or anyone who doesn’t need it or won’t respond to it,” added Dr. Bansal.

   For example, the most common mutation in lung cancer is EGFR (epidermal growth factor receptor), which shows up in close to 30% of non-small cell lung cancers and responds to specific targeted medications, explained Dr. Bansal. “There are dozens of other mutations with very specific targeted treatments. These treatments are usually more effective and less toxic than traditional chemotherapy, which used to be given to most lung cancer patients.”

   Certain somatic testing is also used prior to the treatment of early-stage lung cancer to determine whether chemotherapy is necessary.

3. Multi-cancer early detection (MCED). The MCED test, a simple blood test, analyzes both DNA and proteins to detect changes suggestive of cancer. Endeavor Health is part of a collaborative study with Exact Sciences that will enroll up to 25,000 participants over a 5-year period, tracking patient data to better understand and improve MCED testing. MCED testing holds great promise for the future and for improving early detection, particularly for cancers where we don’t currently have a good screening tool, said Dr. Bansal.

Biomarker testing is transforming oncology by giving physicians clearer insight into each patient’s cancer and disease progression, helping guide more personalized and effective treatment.

“For one patient, I can use somatic testing at diagnosis, during treatment, and after treatment to determine if they are in remission or if further treatment is necessary,” said Dr. Bansal. “These tests give us critical information and have given way to lifesaving treatments for advanced lung cancer, melanoma, and others.”