Targeting Lung Cancer: How Precision Medicine is Directing Cancer Therapy Today

The field of precision medicine has been gaining steam over the past two years. During this period, the launch of the Precision Medicine Initiative and the All of Us Research Program have catapulted “precision medicine” into our mainstream dialogue and helped stimulate more research in this rapidly growing field.

The goal of precision medicine is for doctors to tailor prevention and treatment for each patient based on their unique genetic makeup, environment, and lifestyle. It’s all about making our medical care as unique as we are, instead of the traditional “one-size-fits-all” approach to healthcare. For example, people who have certain genetic variants in their tumors may respond exceptionally well to a particular medication, while that treatment may only be minimally effective in people who do not have those genetic variants.

Researchers continue to study precision medicine, and the All of Us Research Program will help scientists and physicians revolutionize the field of medicine. But in some medical fields, precision medicine is already making a difference in patient care. Targeted treatment of lung cancer is among the most remarkable examples to date.

Lung cancer is one of the most common cancers worldwide, and one of the deadliest. In the US, 6.5% of people will develop lung cancer over the course of their lifetime, making up 13.3% of all new cancer diagnoses in the US. Worldwide, lung cancer causes more cancer-related deaths in men than any other form of cancer, and is the second leading cause of cancer death in women.

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Cancer is fundamentally a genetic disease. Glitches in the sequence of DNA or changes in the ways that genes are controlled can hijack a cell’s machinery, prompting uncontrolled cell growth, and eventually, tumor development. Oncologists however, can leverage some of these errors and target them using specific drugs to stop the growth of the tumor.

“Diligent research into the unique genetic and epigenetic properties of lung cancer has made this field a pioneer in precision medicine. Doctors can use large-scale molecular approaches to identify genetic aberrations that can in turn become targets for precise therapy, extending the survival and positive outcomes for their patients,” says Kenneth Ramos, MD, PhD, PharmB, Interim Dean of the College of Medicine - Phoenix, Associate Vice President for Precision Health Sciences, and Director of the Center for Applied Genetics and Genomic Medicine at the University of Arizona Health Sciences.

One gene that is commonly mutated in lung cancer is called EGFR. The EGFR gene normally makes a protein that helps cells process signals from the environment that tell it when to grow – and when to stop growing. In lung cancer, mutations in this gene make cells ignore all signals to halt growth, and keep the cells growing and multiplying constantly. Clinical research studies have found drugs that target these mutations, and stop the growth of tumors with EGFR mutations, increasing the “progression free survival” time – the length of time where a patient has little to no progression of their disease.

EGFR mutations are not present in all lung cancers. Women, people of Asian ancestry, and people who never smoked, or only smoked lightly, are more likely to present with mutations in the EGFR gene compared to other lung cancer patients. To date, there are nine additional genes that researchers have identified to play central roles in lung cancer, and clinical trials are ongoing to focus treatments on these genetic targets. As research in this area continues, the number of genes, targeted therapies, and options available to patients to treat their lung cancer will continue to expand.

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More and more physicians are ordering genetic testing, or molecular profiling, for their patients with lung cancer. The goal is to generate valuable genomic data that can be integrated with other clinical data to better understand the driving forces behind their cancer, and to identify the best way to fight it. Tumor molecular profiling uses a technique called DNA sequencing, which looks at a person’s genetic makeup, and finds the places where the DNA has changed. Based on current clinical trials and approved drugs, if every patient with an advanced form of lung cancer were to undergo molecular profiling of their tumor, up to 69% of them would have a genetic mutation that could be treated with a known drug.

Researchers and clinicians at UAHS are already using precision medicine to treat lung cancer patients, and studying new precision therapies for cancer. Molecular profiling tests that physicians and researchers are using to treat and study lung cancer are just one example of precision medicine working today in Arizona to help patients fight their cancers with precise, targeted therapies.

Precision medicine takes on many forms, even in lung cancer. Current approaches identify genetic mutations driving tumors and focus therapy to combat those mutations. But research is ongoing to understand how doctors can use information about a patient’s biological and exposure history to both treat and identify patients and populations at high risk of lung cancer. Right now, lung cancer is one of the best examples for precision medicine. As research continues, we will find new strategies to prevent and treat not just lung cancer, but other diseases a well.

“Precision health will dominate the future of medicine,” says Dr. Ramos. “The advances that we are making now will benefit future generations by making prevention and more precise, targeted treatments a reality for all.”