Pashtoon M. Kasi, MD, MBBS, MS
Researchers are aiming for a more individualized approach to the treatment of patients with metastatic colorectal cancer (mCRC), but progress on this front remains a challenge, said Pashtoon M. Kasi, MD, MBBS, MS.
, Kasi, an assistant professor of Oncology and senior associate consultant in the Division of Hematology/Oncology, Mayo Clinic, discussed advances and unmet needs in mCRC.
OncLive: What is the current treatment approach for patients with advanced CRC?
: CRC is a very heterogeneous disease; in my opinion, it is the poster child for individualized medicine because even though we think of CRC as 1 entity, even the left side of the colon behaves differently than the right side. Mutations also factor into play, as well as age and other characteristics that make the patient's tumor unique. [When it comes to the treatment of patients with] advanced CRC, we have to differentiate between those with widespread metastatic disease or oligometastatic disease. For example, if a patient only has a few metastases in the liver, we start off with chemotherapy first, and if they indeed have these few spots, we can then use a multidisciplinary approach.
By default, we now check every patient for MSI-H/dMMR. One thing that is important to know, and is what causes these tumors to be responsive to immunotherapy, is that dMMR [is linked with a high] number of mutations.
What have been the biggest data that have come out recently?
Many of the advancements made recently have been under the umbrella of individualized medicine. One key aspect from a tumor-based genetic testing perspective is recognizing the different subsets of CRC. The other intriguing thing is that [the tumors] also change over time. Practically speaking, doing repeated biopsies is not very rational; it is an invasive procedure. Liquid biopsies, which employ circulating tumor DNA testing, is a less invasive procedure. There is a chance for these biopsies to be more precise as well. Liquid biopsies are not yet ready for primetime, but they are getting there. Multi-gene testing is making a huge difference.
Is there anything you would like to add?
From an individualized medicine approach, although a lot of people would not consider this standard of care, there were data presented at the 2018 ESMO Congress and other meetings regarding pharmacogenomics, which is determining what drugs are a good idea and which ones aren't. We are increasingly using combination regimens in practice, but cost is an issue.
Bristol-Myers Squibb’s Opdivo (nivolumab) + Low-Dose Yervoy (ipilimumab) is the First Immuno-Oncology Combination Approved for MSI-H/dMMR mCRC Patients Who Progressed Following Treatment with a Fluoropyrimidine, Oxaliplatin and Irinotecan. Published July 11, 2018. Accessed July 11, 2018. https://bit.ly/2uaofBD?rel=0" .
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