Decoding cancer cells and changing the future for treating patients

When you hear the letters GPS, you might automatically think about the navigation system that most of us use to find our way in unfamiliar territory. However, most people don’t know there is another GPS working to make personalized medicine and tumor profiling a reality for cancer patients. This GPS is Genomics and Pathology Services at Washington University in St. Louis, a clinical molecular diagnostic laboratory in the Department of Pathology & Immunology that uses advanced DNA sequencing technology commonly known as ‘next generation sequencing (NGS).’

Whether inherited or not, cancer is a genetic disease and decoding its DNA can help better diagnose, treat and manage it.

When cancer occurs, something in our cells’ DNA has gone wrong – a genetic change. It takes more than just one genetic change to result in cancer, and these changes can be inherited, or more commonly acquired after we are born.

In fact, roughly 85% of all cancers happen as a result of changes that occur over the course of our lives. By exposure to things like cigarette smoke, certain toxic chemicals or UV light from the sun. As we age, our cells’ DNA accumulates more of these changes — which explains why it may take many years for a cancer to develop. These changes cause cells to lose their normal function, as a result, they grow and divide uncontrollably — and form what is called a tumor.

Next generation sequencing makes it possible for doctors to look at and analyze dozens or hundreds or even thousands of cancer-related genes all at the same time. This tumor profiling provides the unique genetic information for a specific cancer.

That information can help doctors to provide a precise and personalized management plan for patients with cancer.

“We can see the actual code of the tumor’s DNA,” says Jonathan Heusel, MD, PhD, chief medical officer at GPS. “In many cases we can identify specific changes that have played a role in the development of that tumor. Armed with that kind of information, we are literally changing the future for our cancer patients. They can be treated individually with drugs that specifically target their tumor cells, based on its genetic code. Not just based on where the tumor is in their body or where it may have arisen. This is a game-changer for oncology.

We no longer think of cancer as a single disease. We don’t even think about treating patients with a given tumor type using the same therapy. Rather we are individualizing sequencing and reading the tumor DNA to reveal not only what type of cancer it might be, but how it is likely to behave and how it is best treated. We look toward a future where even the most aggressive cancer becomes a well-managed chronic disease. And the good news is that future is already underway.”

Talk to your oncologist to find out if tumor sequencing is the correct approach for you. Your physician can order GPS testing by visiting