I spent more than 10 years in clinic, counseling women and men regarding hereditary cancer syndromes. Somatic tumor tests were newly emerging when I departed from clinical practice to industry in 2015. I distinctly remember having patients ask me for the results from their genetic testing during pre-test genetic counseling. At that time, my response was something along the lines of, “Oh, that’s a different type of genetic test. We are going to examine the genetics you were born with, not the genetics of your tumor.” You can imagine the confused looks on the faces of the patients. Many of you may even have seen them for yourselves.

Flash forward to 2019, and I find myself completely immersed professionally in the world of cancer biology and tumor genetics. We now have such things as molecular tumor boards, comprehensive genomic profiling, and liquid biopsy tests. Circulating tumor DNA, circulating tumor cells, and molecular residual disease are now common vocabulary in the field of oncology. Microsatellite instability is no longer just a marker for Lynch syndrome; it can also inform prognosis and possible treatment with immunotherapy, amongst other tumor markers. Tumors themselves are now analyzed for aberrations to their DNA, messenger RNA, and protein expression. 

And just like hereditary cancer multi-gene panels, not all molecular oncology tests are created equally. Each test has a unique purpose, methodology, and clinical application. There are tests to aid in therapy and clinical trial selection, as well as tests to detect persistent molecular residual disease, treatment response monitoring, and recurrence monitoring. Tests for early detection of cancer in otherwise asymptomatic patients are under intense research and development. Some of these tests incorporate whole exome sequencing, and some do not. Likewise, some tests may incorporate the germline sequence in some manner, either filtering for somatic mutations only or providing a full analysis with reporting of germline findings.

To state it simply, molecular tumor testing has exploded. It is one of the quintessential examples of how personalized medicine has been adopted into clinical practice.

As cancer genetic counselors, it is vital we stay abreast of newly emerging molecular tests for cancer and not just in the hereditary space. Aside from potentially identifying candidates for germline testing through somatic tumor analysis, we also need to help educate patients and physicians alike on the vast differences between one cancer genetic test and another. Who is better equipped for this task than genetic counselors?

There are also opportunities for genetic counselor employment within the oncology diagnostic space, filling leadership roles in medical affairs, clinical operations, and medical education, to name a few. Learning new specialties, or even subspecialties, can be exhilarating and challenging at the same time. I encourage genetic counselors to lean in to this advancing field, break through discomforts, and grow professionally through their ventures.

When I think back to my years in clinic, I laugh at the thought of being so blasé about those newly emerging somatic tumor tests. Little did I know how revolutionary such molecular tumor tests could be to the field of oncology, not to mention the influence they would have on my professional career.

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