Sequencing of Biomarker Testing for Ovarian Cancer

Chad A. Hamilton, MD: What are you doing these days? I’m curious because I talk to so many people, and there are many little variations.

Robert W. Holloway, MD: It’s an interesting topic. I look at what the NCCN [National Comprehensive Cancer Network] Guidelines say about tissue testing and next-generation sequencing for ovarian cancer. It’s not in the guidelines, but there’s a position paper attachment that covers the territory that you mentioned. With all the members of the NCCN Guidelines committee, there was a wide variation of practice and opinion. They couldn’t come to a consensus statement for exact guidelines, to the best of my understanding, for tissue testing. Some people, like you, do HRD [homologous recombination deficiency] testing along with germline testing. Others do next-generation sequencing and use the loss of heterozygosity scores that are attached to the various companies that do that testing.

Like many people, I’m doing this testing earlier and earlier for a variety of reasons, recognizing that the vast majority of our patients recur and recognizing that we do have frontline maintenance options. It’s more imperative to us to get this testing going earlier and then go to treatment so we can be prepared to discuss at 3-week visits with our patients. This is on an ongoing basis, about what we’re going to do for maintenance therapy. Make that plan early so we don’t get to the end of the process and then have to wait another month to get tissue testing and then have that discussion. That’s part of it, recognizing that majority of our patients eventually recur.

I’ve been more of a fan of a broad-panel next-generation sequencing approach and LOH [loss of heterozygosity] scores. I use Caris [Life Sciences] mostly, so I also get IHC [immunohistochemistry] testing on a variety of factors and look at PD-L standing. I have patients for whom I’ve used immunotherapy and who are perhaps MSI [microsatellite instability] stable but PD-L positive, and I’ve been able to incorporate that. I have clinical trials that require that we test early to stratify patients, whether they’re BRCA mutated or not, so that’s also gotten my whole office system used to getting this diagnosis. We have midlevel providers in our clinic who stay on top of that with me so people don’t fall through the cracks. We get down to an interval debulking, and we still haven’t tested. We’ve morphed to get it earlier, and I have a team approach with midlevels who keep us on track getting everyone tested early. That’s been our approach.

Chad A. Hamilton, MD: It almost becomes like a quality metrics that you can look at as far as the number of patients that you’re testing.

Transcript edited for clarity.