Six diseases reap benefits of biomarkers, genetic tests
Non-small cell lung cancer
Clinicians can use different types of biomarkers to better understand how each patient’s cancer is unique. In non-small cell lung cancer, some biomarkers, such as ALK and EGFR, are mutated forms of genes involved in normal cell growth, while others like PD-L1 allow some cells to avoid being detected by the immune system. “By identifying individuals’ tumor biomarkers, clinicians can determine the treatment that is most appropriate for them, whether it's an approved medication or participating in a clinical trial,” says Suman B. Rao, MD, medical oncologist, MedStar Franklin Square Medical Center, Baltimore.
Biomarkers are like pieces to a puzzle that give doctors a more well-defined picture of a patient’s lung cancer, Rao continues. Biomarker test results can also help doctors make informed decisions about the most appropriate treatment. Several different biomarkers can be used to plan treatment in non-small cell lung cancer, including EGFR, ALK, ROS-1, and the recently discovered PD-L1.
Biomarker testing can also help reduce a patient’s exposure to unnecessary treatments—which may reduce healthcare costs.
Massimo Cristofanilli, MD, associate director for precision medicine and translational research at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University at Northwestern Memorial Hospital, Chicago, says biomarkers are enabling clinicians to better understand breast cancer as a disease for each individual patient.
“We now understand that breast cancer is not only one disease,” he says. “Studies have shown that there are at least four different disease subtypes. Within these subtypes, new genomic abnormalities sometimes arise during treatment, making them ineffective. Therefore, giving the same treatment to every patient is not beneficial. Improving patient selection and more personalized treatment are key.”
In the past, the only two biomarkers used to determine treatment were estrogen receptor and HER2 oncogene expression. “These two biomarkers provide some discrimination between a distinct type of treatment and two targeted therapies with chemotherapy,” Cristofanilli says. “In the last five years, we have learned that an estrogen receptor positive for breast cancer—which is the most common type—is further divided into two different types of disease—luminal A and luminal B. Luminal A is more sensitive to most hormonal therapy agents than those used in the past. Luminal B is more resistant and sometimes requires a combination of therapies, including chemotherapy.