Expert: Genomic Testing Can Help Oncologists Customize Treatment Based on the Tumor Type

Dr. Ramaswamy Govindan, MD, a medical oncologist at the Washington University School of Medicine in Saint Louis, Missouri, joins Pharmacy Times to discuss the expanding capabilities of genomic testing to identify gene alterations that make it easier to find appropriate treatments for a variety of cancer types at the 2023 ASCO Annual Meeting in Chicago, Illinois from June 2 through 6.

PT Staff: Why is genomic testing literacy important for oncologists? Is this tool widely available?

Ramaswamy Govindan, MD: I think, as you know, targeted therapies play an important role in many cancers, including lung cancer, the cancer that I treat. It is important for us to really understand some of the basics of the key oncogenic, genomic alterations that are driving these cancers. And while the currently available reports on the genomic testing are now made quite easy for individuals to follow [and understand] what these alterations mean, understanding the knowledge of gene sequencing targeted therapies—what do these alterations mean? What are the resources available for you to look up? What does the specific alteration a particular gene mean? You can now go and look at the significance of these alteration— [I think] the publicly available websites will be very useful for practicing clinicians.

PT Staff: What is the availability of this tool, even compared to a decade ago?

Ramaswamy Govindan, MD: Yeah, that's a great question. You know, the next generation sequencing is relatively new compared to many other technologies we use over the past 10 years. We've learned a lot on how to do this more effectively and rapidly, in a high-throughput fashion. Also [it’s evolved] in ways that can help our patients by getting the results turned around very quickly. It is a technology that is evolving continually. So, we can sequence these gene alterations more effectively and for lower cost. It's truly spectacular to see how far this field has moved along over the past 10- and 15- years.

PT Staff: What is testing methodology? How do oncologists read genomic test results?

Ramaswamy Govindan, MD: As I said, today the reports from these third-party vendors really have really enhanced the reporting methodology. So, it is easy for clinicians to read the report make some sense of this genomic alterations, or the alterations in the tumor cells. But still, if you want to have more background information that are the sources, that's the purpose of this course, and really help them utilize the tools that are available online tools and resources they can go to. But so far, I think, I have to say the field has come a long way. And these reports generated by the companies are clearer, easier to read, and they even have potential or possible suggestions for treatment, and then available treatment trials. And it is really, you know, it is very, very useful for practicing as a clinician.

PT Staff: Are there “universal,” or more common gene sequences/protein markers that indicate tumor abnormalities?

Ramaswamy Govindan, MD: So the idea of doing the sequencing is, is truly to find out what specific alterations are present in the tumor cell. So, just to take you back to the workflow, patients have symptoms, or they are diagnosed. You have cancer one way or the other [and] a biopsy is done; [whether it is] diagnosis of cancer diagnosis or where the cancer started. They're all made before we know about the gene alterations within a tumor. The idea of doing this gene sequencing testing is to figure out what specific therapies we can choose.

And that's the whole point of gene sequencing tests that we do in the clinic and the tumor patients. And then—with the patients with tumors in the tumor samples—we figure out if this particular tumor driven by a particular gene for which we have this drug to essentially guide them for specific therapy; guide the physician to specific therapies for these patients, for example, lung cancer. [Lung cancer] is a very common cancer where this is utilized. There are two kinds non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). In the NSCLC, there are 3 different types as a type that I know: carcinoma, and that's driven by specific gene alterations like estimated glomerular filtration rate (EGFR) gene or anaplastic lymphoma kinase (ALK)-rearrangement, or Rat sarcoma virus (RAS) or rearranged during transfection (RET). And finding those specific gene alterations is so important because the therapies for EGFR-driven tumor is very different than the therapy given for patients whose tumors are driven by our RAS or RET gene. And so it is almost like you're deciding which of the therapies will be suitable for a given patient.

So it is almost like it is customizing for a given tumor. And I think, to that extent, our therapies are becoming more precise, customized to a patient's type of tumor. If you look at a microscope, all these have no carcinomas. EGFR-driven, outdriven, RAS, RET, they look more or less the same. So there is not that much different under a microscope, but then the gene testing would tell us which way to go. And there are many patients who don't have any of these alterations that tumor cells and we treat them differently to that that is also useful knowledge that these tumors don't have this gene alteration. So then we use chemotherapy, immunotherapy, and a combination and those things. It is a very important component of a treatment decision-making in patients with NSCLC.