Role of Genetic Testing Expands for Both Patients and Providers in Oncology

Whitney Ducaine, MGC, CGC, CN-BM

Whitney Ducaine, MGC, CGC, CN-BM

Prior to recent advancements, genetic testing was primarily used to define the tumor, where cancer developed, and familial patterns of the disease. However, genetic testing plays an important role now in selecting the appropriate therapy for each patient.

Genetic testing is now prevalent in a number of cancer types, including lung, colorectal, prostate, and breast cancers. With the availability of FDA-approved immunotherapeutic agents, such as immune checkpoint inhibitors or PARP inhibitors, genetic testing plays an important role in detecting which patients are most appropriate to receive these new therapies.

In addition to informing treatment decisions, physicians can still rely on genetic testing to provide the patient with more information on whether their cancer developed from an inherited mutation that may put their family members at greater risk. Overall, the use of genetic testing continues to evolve and play bigger roles in oncology as the field continues to grow.

“Genetics is here to stay, and it is going to get even more involved as we learn more,” said Whitney Ducaine, MGC, CGC, CN-BM. “I think that is a really exciting part of how we can help patients.”

In an interview withTargeted Oncology, Ducaine, director, Cancer Genetics Services, InformedDNA, discussed the evolution of genetic testing in oncology. She highlighted the importance of having conversations with genetic counselors to help inform the patient on their familial risks as well to help inform treatment decisions.

TARGETED ONCOLOGY: Can you provide a brief overview of how role of genetic testing has evolved

Ducaine:There has been a huge evolution in how genetics have been integrated into cancer care and oncology. It’s always been a part of it but just in terms of how we understand how cancer happens, like how tumors grow and develop. It has shifted to learning not just about how cancers develop and that there are some families with a higher incidence due to inherited markers, like theBRCAgenes or Lynch syndrome. More recently, things have shifted to the treatment of cancer, not just by the tumor site and where did the cancer start but by the genetics of the tumor.

This shift has become a big change in how cancer treatment occurs. Genetics can determine if there an inherited mutation this person has versus an acquired mutation in their tumor, and how pharmacogenetics can be front and center in their treatment. That is 1 of the biggest differences. More people are having their tumors profiled and their chemotherapies determined based on the genetic makeup of the tumor.

TARGETED ONCOLOGY: How can genetics be used to identify a patient’s reaction to a specific drug?

Ducaine:From how patients used to go and get the diagnosis and treatment, it shifted to become focused; I think of it as an upside-down triangle. Everything keeps narrowing down to how patients can get more personalized treatment. Every tumor appears to be different, so how can treatment be specific to that person?

From a patient’s reaction, it can be either quite daunting that there is this huge influx of information. It was a lot of information before and a topic that is honestly scary with new words that can be terrifying, but I think the field has shifted so that it is empowering to have a lot of options and a lot of hope for patients. It is exciting even though it is daunting information.

A lot of patients think the information is exciting and how treatments that they never would have considered being available for patients years ago may have just come out of clinical trials and are available for patients now. For example, olaparib (Lynparza) is utilized now for many different types of tumors, as well as pembrolizumab (Keytruda), so that is exciting and gives patients a lot of hope. How genetic counselors can incorporate genetics into that is they help people understand how this impacts them and their family members. For example, is it something that just impacts themselves and their treatment or could there be an inherited marker that is picked up in the tumor testing that could then help their family members. That could give them hope as well that there is information for their family members who may be worrying about their relative but then they think about themselves and their risk. It’s a natural flow of thought for people.

TARGETED ONCOLOGY: In what cancer types in particular is this more prevalent right now?

Ducaine:It is becoming more prevalent in most cancers, I would say. Lung cancers, though, is a big one, as well as colon cancer. They’ve been doing this for a while now in breast cancer. Prostate cancer is another one. The list is exhaustive. I think there are solid tumors that are eligible for pembrolizumab because they have a marker on them that immunotherapy can use. It’s a lot more than we ever imagined that this can impact.

TARGETED ONCOLOGY: What more needs to be done to further advance genetic testing in oncology?

Ducaine:There are a couple different ways that patients can benefit from genetic testing and increase their access to it. One is that oncologists and those directly involved in the treatment, they will always be on top of the newest and greatest treatments, and genetic testing comes with that to figure out who is the best treatment.

Also, it can help them with knowing if the tumor testing helps with just treatment or is it something that they need to dive deeper into figuring out why did this tumor happen. A lot of people with cancer ask that question, why did I get cancer? Why did this happen? Genetic counseling can help answer that question if we are trying to figure out was something inherited. A lot of people might wonder if this is running in their family. If the patient has their treatment plan figured out, maybe that test will open the door to say they found something in the tumor and now they don’t know if it’s a part of my tumor or potentially just a part of the whole body. That part of the discussion is where we can help as genetic counselors and how InformedDNA is working with a lot of different oncology care teams and clinical trials to make sure that patients do not fall through the cracks. This testing can open the door to a lot of other genetic testing that can help answer that question.

I think it is key for making sure people know we have looked under every rock, nook, and cranny to make sure we are not just treating the patient now but treating them in the future to make sure something else doesn’t come up or for their family members. I think some people don’t know if they should have genetic testing done and what kind of testing is out there; that’s where genetic experts are advocates to help patients figure all that out.

TARGETED ONCOLOGY: Would you like to share advice with community oncologists in terms of genetic testing?

Ducaine:Genetic testing is daunting, and it is getting more complicated every year. However, there is a community of experts and providers that are all here together in this field. It is exciting where the field is going. That is 1 of the reasons I got into oncology and genetics, because there is never a dull moment. The field is always rapidly changing, and that is both exciting and overwhelming for patents. Similarly, it is quite overwhelming for all of the healthcare providers as well, but in a good way because we are always having to stay on top of things in the field to see why we do what we do to help our patients get the best care. Genetics is here to stay, and it is going to get even more involved as we learn more. I think that is an exciting part of how we can help patients.

TARGETED ONCOLOGY: What makes your job at InformedDNA unique?

Ducaine: