Recently a cancer patient asked me, “How can diagnostic tests help decide the best treatments for me?”
It’s a great question, and for cancer, diagnostic tests have a special meaning, with life-saving potential.
Cancer diagnostic tests are lab tests that tell us something about the cancer. Usually, they help first to understand and confirm the cancer type. Secondly, diagnostic tests tell us more about how the cancer grows and spreads. This may help to figure out which medicines will specifically target the tumor cells without impacting healthy normal cells as much. Doctors call the second case ‘targeted’ or ‘precision’ medicine.
There are hundreds, if not thousands, of diagnostic tests that we can use to learn more about the cancer.
“So,” continues the patient, “How does my oncologist (and I) decide which one(s) are right for me?”
This is another excellent question. Sometimes, there are standard tests for a cancer type. For example, every patient will have three traditional diagnostic tests for breast cancer that tell us how to attack that cancer: Estrogen Receptor, Progesterone Receptor, and HER-2. Each of these tests is performed individually, and the results correspond to using one type of medicine.
But what about the majority of cancer types that have no standard diagnostic tests, are in an advanced or metastatic stage, or have a high risk of returning?
For these patients (and indeed for most cancer patients), another test can be performed that looks at hundreds of potential ways to attack the cancer, all at the same time with one tumor sample from a prior biopsy or prior surgery.
This critical test, called Next-Gen Sequencing, has been recognized and approved by the FDA and is frequently covered by insurance. Companies like Foundation Medicine, Caris, and Guardant offer a Next-Gen Sequencing test, and additional companies and hospitals are competing to bring the best tests to patients.
Next-Gen Sequencing works by looking at the building blocks of a tumor, the DNA of the cancer, and its genes, that get changed when a normal cell becomes a cancer cell. These genes are different than those in the patient’s healthy cells since they belong specifically to the cancer. Next-Gen Sequencing technology looks at hundreds of these genes with one cancer test, particularly genes that are often changed in the cancer and those with known (or investigational) drugs that can attack the cancer.
Some doctors prefer to wait for a cancer recurrence before performing Next-Gen Sequencing. Cancer and its genes can indeed change over time, so getting a fresh biopsy on a recent tumor for testing is never wrong if it can be done safely. However, because these tests will take a few weeks, results won’t usually be back in time to decide on the next steps. For this reason, doctors like Dr. Reardon at the Dana Farber Cancer Institute say, “I recommend next-generation sequencing be done as soon as possible when a patient is diagnosed with cancer. It’s important to get access to that tumor tissue and take advantage of the state-of-the-art technology that’s routinely available now…” TRK Inhibitors: Evolution of a Tumor-Agnostic Treatment Approach). We, at Sagely Health, wholeheartedly agree!
As unbiased cancer experts, our goal is to identify therapies that can successfully be used to attack the cancer. In about half of all patients, Next-Gen Sequencing reveals at least one and sometimes more than one medicine that should be tried. When patients do not hear any answers about what comes next, if the cancer returns or grows, the combination of Next-Gen Sequencing and our expert analysis can provide science-based ideas that work. It is not our only approach, but it is certainly a helpful one.
Yet we understand that it can be difficult, especially for cancer patients, to know what to do to get this testing, or even how to approach the topic with their oncologist. This is why we don’t stop only at a recommendation but produce personalized guidance reports that identify these options, together with an unbiased and personalized rationale. When requested by the patient, we are happy to speak directly to their doctor to advocate and answer questions, and we even help to prepare the paperwork so as not to cause additional burden to the doctor. However, most of the time, we find that our influential reports are enough to trigger testing like Next-Gen Sequencing.
And we don’t just stop at Next-Gen Sequencing. As mentioned, there are hundreds, if not thousands of potentially useful diagnostics tests. Deciding which to use is part of our personalized guidance. For example, there is another test, called whole exon sequencing (abbreviated as WES) that looks at 20,000 genes with one test. One might assume that testing more genes is better than Next-Gen Sequencing, and indeed, if the test quality was as high, one day it might be. However, there are still some innovative approaches that make this technology useful, and for specific cancer patients, it is a consideration to combine with Next-Gen Sequencing.
Therefore, if you are or know a cancer patient whose cancer may return or grow, we would encourage you to ask your doctor about Next-Gen Sequencing and seek our guidance to turn these (and other) insights into hopeful options.