Improving HER2 Biomarker Testing in mCRC - Episode 8

Identifying Appropriate Candidates for NGS Testing

Kanwal Raghav, MD, MBBS, discusses appropriate candidates for HER2 testing and current utilization strategies for biomarker testing in mCRC.

Kanwal Raghav, MD, MBBS: For HER2 testing, as far as metastatic colorectal cancer is concerned, we identify patients based on whether we’re looking for clinical care or research trials. As far as clinical care is concerned, in most cases we look for RAS and BRAF wild-type patients who are diagnosed with metastatic disease. In the research setting, we have expanded this testing to RAS-mutated cases. Not only do we assess amplifications, which is commonly the criteria for actionable target, such as HER2, as far as the NCCN [National Comprehensive Cancer Network] Guidelines are concerned, we also look for HER2 expression levels and sometimes HER2 mutations.

We’re routinely using next-generation sequencing [NGS] in all patients with metastatic colorectal cancer. We still don’t use it in the early-stage setting, but we use it in every patient with metastatic colorectal cancer at diagnosis. Subsequently, we also use next-generation sequencing at critical points when they have progressed on therapy.

To completely optimize the use of NGS and to increase its uptake, it should be a part of quality metrics when it comes to performance. We’ve already done that. There’s precedence of this in breast cancer, in which reporting of ER [estrogen receptor], PR [progesterone receptor], and HER2 for all newly diagnosed breast cancer is a part of standard of care. NGS should become the standard of care at diagnosis for patients with metastatic colorectal cancer.

There are a lot of upcoming biomarkers in not just colorectal cancer but also other tumor types. The first step to being able to develop a targetable subset or population that you can explore in a clinical trial is identifying those biomarkers. If NGS is used as a standard of care in these patients at diagnosis, knowing very well that patients with metastatic colorectal cancer don’t have many therapy options, it will help us develop population subsets of colorectal cancer that we can successfully explore in clinical trials. If we keep identifying subsets based on what has already proven to be successful—for example, KRAS 12C and HER2 amplification are small subsets of colorectal cancer but applying NGS has allowed us to explore these in clinical trials—that’s how you can not only provide appropriate and good clinical care for them but also prepare for when those clinical care options run out.

It helps us not only identify targets that we can use drugs against in a clinical setting but also [find] patients for other biomarker-driven clinical trials in the future.

Transcript edited for clarity.