Mary F. Mulcahy discusses the potential implications of the EPOCH trial in clinical practice.
Mary F. Mulcahy, MD: The EPOCH study demonstrated that there’s an improvement in progression-free survival with the addition of Yttrium-90 [Y-90] TheraSphere to systemic chemotherapy. This demonstrates a number of important features that we can take advantage of going forward. One is that colorectal cancer metastases respond to intra-arterial therapy. There was previously some concern that these would not respond very well, but this study, in addition to others, demonstrates that there’s a role for intra-arterial therapy in colorectal cancer metastases. No. 2, by looking at some of these subgroup analyses, we can better define the population of patients who may get true benefit by the addition of a liver-directed therapy to their systemic chemotherapy.
The challenge is always in managing the extrahepatic metastases. We found that patients who had any extrahepatic lesion detected at the time of enrollment—a lesion that we felt was not metastatic disease—had the identical benefit from Y-90 as patients who didn’t have any extrahepatic lesion identified at baseline. This allows us to apply this therapy to the real world, where we always find some type of an extrahepatic lesion on the imaging aside from the disease in the liver. By knowing that, with careful patient selection, we can identify patients who don’t have significant extrahepatic burden of disease, and we can identify patients who could potentially benefit from the addition of Yttrium-90 to their systemic chemotherapy.
Further studies are needed to identify the right way to deliver Yttrium-90 for these patients. There may be a role for splitting the dose and doing lobar therapy instead of whole liver, as we did. There may be a role for re-treating areas at the time of progression. Understanding how to best use this treatment to achieve the greatest benefit is a reasonable research pursuit. This therapy can be very beneficial for a select number of patients who have good liver function, have liver-only metastatic disease, don’t have a surgical or ablative local option, and have a good performance status and preserved liver function to tolerate the therapy. While it might not be a large percentage of patients with colon cancer, it represents a significant number of patients with metastatic disease to the liver who can benefit from this therapy.
In addition to the advancement in colorectal cancer treatment, there’s a lot to be learned from this study. This was a major undertaking, an international study of a procedure that we were able to take to completion and demonstrate a benefit. This sets the stage for doing other international studies with device-related procedures so that we can accrue to them and complete them in a timely fashion and learn more how to advance this field. There’s a lot to be learned about how to assess and measure the response to the therapy. That’s always a challenge after radioembolization or any other liver-directed therapy. What’s a pertinent response that will give us a hint into a survival benefit? Understanding how to best evaluate these patients in an ongoing fashion so that we can get answers relatively quickly, we can get these studies accrued to so that we can get this therapy out to people who could benefit and not pursue therapy that’s not beneficial.
Transcript edited for clarity.