Dr Oberstein on Clinical Applications for Oncodetect in MRD Detection in Solid Tumors

“The goal [of Oncodetect] is to more accurately select patients who might have a higher risk of cancer recurrence and tell us who has a lower risk. That's where it's the most important.”

Paul E. Oberstein, MD, an associate professor in the Department of Medicine at New York University (NYU) Grossman School of Medicine; service chief of the Gastrointestinal Medical Oncology Program; and assistant director of the Pancreatic Cancer Center at NYU Langone Health’s Perlmutter Cancer Center, discussed the use of the Oncodetect test for molecular residual disease (MRD) detection in patients with solid tumors.

Notably, Oncodetect became available for this indication on April 22, 2025.

Identifying circulating tumor DNA (ctDNA) in peripheral blood is technically demanding because the vast majority of cell‑free DNA originates from normal somatic turnover, Oberstein began, adding that neoplastic fragments constitute only a minute fraction of the total. Consequently, an assay must achieve extremely high analytical sensitivity and specificity todetect small amounts of ctDNA and to distinguish pathogenic alterations from background germline or clonal hematopoiesis variants, he said. The Oncodetect platform addresses this challenge by interrogating a broad panel of tumor‑associated mutations, he stated. The larger the catalogue of targetable variants, the greater the probability that at least 1 malignant signal will be captured and the lower the likelihood that benign sequences will be misclassified as tumor derived, he explained.

Oncodetect is an MRD assay, Oberstein continued. In this setting, blood is sampled after definitive therapy, which is most commonly surgical resection, according to Oberstein. Some patients will ultimately relapse, whereas others will remain disease free; ctDNA measurements may help stratify those risks, he said. A post‑operative MRD‑positive result implies a heightened probability of recurrence, whereas sustained MRD negativity suggests a lower risk, Oberstein stated. Such information could influence several aspects of disease management, including the frequency of surveillance imaging, intensity or omission of adjuvant chemotherapy, or enrollment into clinical trials, he noted. More refined risk discrimination would allow for the escalation of systemic therapy in patients with molecular persistence but spare low‑risk patients unnecessary cytotoxic exposure and attendant morbidity, he added. Reliable MRD monitoring might also become a substitute for routine CT scans or other cancer imaging modalities, provided that prospective studies confirm the clinical outcomes seen so far, he said.

Currently, most cancer centers use MRD assays as adjunctive tools: results are incorporated into risk discussions but rarely dictate definitive treatment alterations, Oberstein continued. However, enthusiasm for these assays remains high, as they may offer early warnings that can guide heightened vigilance or timely intervention. Overall, oncologists must counsel patients carefully, outlining both the prognostic utility of MRD positivity and the current evidentiary gaps that preclude routine treatment modification solely on the basis of ctDNA findings, he concluded.