Barb Kunz, senior genetic counselor, the US Oncology Network, spoke with the Journal of Clinical Pathways at the 2023 ASCO Annual Meeting about her study on the impact of social determinants of health on use of germline genetic testing for triple-negative breast cancer in the community oncology setting.

Transcript: 

Barb Kunz: My name is Barb Kunz and I'm a senior genetic counselor with the US Oncology Network.

Can you give some background about your study and what prompted you to undertake it?

Barb Kunz: I support the genetics network of providers in the US Oncology Network, and we have a research subcommittee. And we proposed to look at the germline testing rates of patients who had triple-negative breast cancer because we wanted to find out how well we were doing and then understand that population better. So we proposed that study to Ontada, who supported the study. And we were chosen to do this study.

Can you briefly describe how the study was conducted?

Barb Kunz: The study was conducted through our EHR and Ontada. They collected the patient information for patients for a four and a half year period who had triple-negative breast cancer in our network. And then with our six participating practices in our genetics network, we looked at what were the germline testing rates in that population? And it actually took a lot of work to do that because there's structured data on genetic testing, but then it's in other places as well. It's not always well-documented. And so we had to look at our genetic databases for our genetics programs, and also audit the charts to really learn that information. And then Ontada took that information and evaluated and did the statistical analysis on the population so we could understand more about the tested versus not tested population.

What were the key findings of your study?

Barb Kunz: The key findings of our study is that the germline testing rates were better than I actually thought they were going to be. They were overall 74%. But when we really break it down into different groups, Black patients had a much lower testing rate. And that was disappointing because we would hope that it was not, you didn't see that discrepancy. It was 75% for White patients and 67% for Black patients, so there's certainly work to be done in understanding that difference. There were some other factors that were different in those two populations that tested versus not. Not surprisingly, insurance type with people who had private insurance having the highest rates of testing and self-pay the lowest. And it was between 75% for people who had private insurance and 60% for self-pay with Medicare and Medicaid in between there.

So that's one area that it'd be nice to understand a little bit more why people, and that discrimination a little bit more because sometimes people have insurance, but do they have high deductibles that keep them from doing testing? And then we did see a difference in age, which isn't surprising. There was about a two-year difference in the people who were tested were a little bit younger. But for years we've been telling people to test people who are younger, so I think that's not surprising. Hispanic population did not have lower rates, and Asian population did not either. And so learning that, I think we've got a lot to sift through and learn a little bit more about. What are those differences and how do we address it?

One of the key findings was the mean ADI score was about five points different between those who were not tested at higher scores. So we do know that those pieces tied to zip code and socioeconomic status did play a role in this study.

Looking ahead, what potential impact do you hope your findings will have on improving genetic testing rates among minority patients and those with lower socioeconomic status?

Barb Kunz: My hope is that we work on some systems that will help our providers, will trigger them to offer genetic testing and refer patients to get that testing. And also, that we can work and really understand more granularity in that population and why that testing didn't take place. And is it lower socioeconomic factors, or is it other pieces of people distrust for genetics, which has a long history, right? But you don't want families to lose out on the benefits, especially for cancer treatment and for understanding hereditary cancer in families just because of those factors.

Is there anything else you'd like to add?

Barb Kunz: I think that there was a lot that we learned from this study. One is just trying to understand those rates and then the richness of this data. And I think we've got some other work to do, which I'm excited about.