Dr Ajay Goel Discusses Future of MicroRNAs in CRC Prognosis, Treatment

Ajay Goel, PhD, AGAF, professor and chair of the Department of Molecular Diagnostics and Experimental Therapeutics at City of Hope, a cancer research and treatment organization, spoke with The American Journal of Managed Care^® about how microRNAs are a useful tool in testing prognosis and diagnosis for colorectal cancer (CRC) based on new studies presented at Digestive Disease Week.

Transcript

What is the significance of your findings for the inclusion of miRNA in the diagnosis and prognosis of CRC?

So, our team has been working on microRNAs and other RNA-based markers for a long time. And we have strategically made that focus because we know that these microRNAs are very, very stable. And we don't just work on microRNAs, we are looking at exosome-based microRNAs, which means these are tumor-released exosomes. So, these are tiny vesicles, or extracellular vesicles or exosomes, which are shed by the cancer cells themselves. And they're released to bloodstream which we can capture.

So, the beauty is that we have developed this exosome-based microRNA signature, which offers a combination of very high sensitivity because these microRNAs could be free floating in the blood, and also the microRNAs which are encapsulated within the exosomes. So, we're looking at a combination of exosome-based microRNAs and total circulating microRNAs by combining the 2 together because that allows us to have maximum possible sensitivity and specificity for finding advanced polyps and cancers.

So, this is clinically very important. I told you there are...commercial tests available for colon cancer screening, but most of them do a very good job of finding advanced cancers. But where they fail is finding high-risk polyps and early-stage cancers. So I just told you the numbers, our exosome-based liquid biopsy can find with 94% accuracy, highest polyps, which is absolutely unheard of, and almost 96% accuracy for finding early-stage cancers. So these are very exciting findings, which there is no other commercial test which comes close to that. So that's about detection.

The prognostic implication of microRNAs is not a liquid biopsy. It is a microRNA base, but it is a tissue base. So, the goal there is that every patient who gets early-onset colon cancer, they undergo surgical operation to take their colon cancer out. So, we always have access to their colonic tissue or their cancer tissue. What we have done is we can take a small part of the cancer which comes out, and we can run these microRNA markers, which can help us tell the prognosis of these patients. Because we can look at the changes in the expression of microRNAs and can say this patient has a high likelihood for cancer recurrence within 2 years within 5 years, within 10 years within 20 years. So this is magical, because this allows the oncologists and surgeons to take care of those patients after surgery more precisely.

So, this is a perfect example of precision oncology. Right now most of these patients only typically receive surgery. And then they're not typically given any additional chemotherapy. But based on these markers, given that we have now the information that some of these patients will recur, we can give them more aggressive chemotherapies and we can follow them a lot more closely compared to what we're doing in the clinical practice now.