Published by CAP Today
July 2026
An excerpt of the original article is posted below:
In select patients, taking aim at metastatic CRC
Author: Valerie Neff Newitt
July 2026—Being able to distinguish the subset of patients with stage IV colorectal cancer who have a chance at cure with ablation or resection from those who do not has been the aim of two University of Chicago physicians who developed a biomarker for colorectal liver metastases called PersonaCRC.
There are two elements to the test, says Sean Pitroda, MD, professor of radiation and cellular oncology at UChicago Medicine and developer with Ralph Weichselbaum, MD, Daniel K. Ludwig distinguished service professor, chair of radiation and cellular oncology, and co-director of the UC Ludwig Center for Cancer Research. Dr. Pitroda is chief medical officer of PersonaDx, the company behind PersonaCRC; Dr. Weichselbaum is chief scientific officer.
One element of the test is the molecular subtype of the colorectal liver metastasis: canonical, immune, and stromal. The second element is the integrated risk category that combines the molecular information and five clinical factors known as the clinical risk score, taken from the patient chart, to classify the patient’s metastases as low, intermediate, or high risk. “These have the strongest implications for survival, patterns of failure, and treatment planning,” Dr. Pitroda says.
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The sequencing data (available in about 10 days) is transmitted from Caris to Protean BioDiagnostics of Orlando, Fla. “Once Protean has the data, they make it accessible to PersonaDx to run the PersonaCRC classifier,” Dr. Pitroda says. PersonaDx (whose CEO is Kevin Donnelly, also a PersonaDx co-founder) performs the analysis and integrates the AI, molecular data, and clinical input and generates the final report within 48 hours, which is then made available to the oncologist.
Dr. Pitroda foresees the test having applications that go beyond which patients should get a local therapy for liver metastasis. But for now, the data support ordering the test in patients with newly diagnosed liver metastases who are being evaluated for local therapy or patients who have already undergone a liver resection and later present with recurrent disease for which clinicians must decide whether additional local therapy or a systemic approach is the best path. Another appropriate use, Dr. Pitroda says, would be for a patient with a metastasis that is “borderline resectable, with a risk-benefit calculation that’s a little uncertain, or where standard studies give mixed or ambiguous signals about the potential prognosis.”
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Dr. Weichselbaum calls it “the single most determinative test for cure, noncure that’s available medically.
“It defines risk prognostic groups with great differences in survival.”
“What we’re doing,” Dr. Pitroda says, “is adding a molecular dimension to the characterization that the pathologist is providing at the histologic level. It’s building on it but offering a level of detail that unfortunately is invisible to the naked eye or under the microscope.”