CITCCA study data demonstrate strong association between ctDNA status and recurrence risk in stage I-III colorectal cancer

SAGA Diagnostics, a pioneer in blood-based cancer detection and precision medicine redefining the standard for ultrasensitive and early molecular residual disease (MRD) detection, joins collaborators from the Karolinska Institutet to present new clinical data showcasing the ultrasensitive detection of ctDNA in colorectal cancer (CRC) using Pathlight at the 2026 American Society for Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium, January 8-10 in San Francisco, CA.

The CIrculating Tumour DNA (ctDNA) as a Prognostic and Predictive Marker in Colorectal CAncer (CITCCA) study is one of the largest CRC ctDNA studies conducted to date, particularly in rectal cancer. Within the larger multicenter, prospective study, Pathlight retrospectively analyzed ctDNA from 377 patients with stage I–III colorectal cancer (25% of patients were stage 1), including 232 (~60%) patients with colon cancer and 145 (~40%) patients with rectal cancer, who received standard-of-care treatment and follow-up across seven centers in Sweden between October 2020 and January 2024. The primary objective was to evaluate the association between ctDNA status and recurrence-free interval (RFI), defined as the time from surgery to first radiological confirmation of recurrence.

Analysis of the data demonstrated:

• Patients who were ctDNA-positive following treatment experienced significantly higher rates of recurrence compared to ctDNA-negative patients. Overall, the hazard ratio was 38.5; 33.8 for colon cancer patients and 93.5 for rectal cancer patients.
• Three-year RFI was ~30% for ctDNA-positive patients versus ~90% for ctDNA-negative patients, highlighting the strong prognostic value of ultrasensitive ctDNA detection using Pathlight.
• 42.5% of ctDNA-positive patients at the clinical landmark (4-6 weeks post-surgery) had ctDNA levels in the ultrasensitive range (<100 ppm), indicating that a substantial proportion of high-risk patients would only be identified using an ultrasensitive assay.
• Recurrence risk was markedly higher in ctDNA-positive patients who did not receive adjuvant chemotherapy (ACT), demonstrating that ctDNA may help guide ACT treatment decisions.

“The CITCCA study provides compelling prospective evidence that ctDNA is a powerful predictor of recurrence in patients with stage I–III colorectal cancer,” said Professor Anna Martling, MD, Karolinska Institutet, Stockholm, Sweden and principal investigator of the study. “The striking difference in three-year recurrence-free interval between ctDNA-positive and ctDNA-negative patients highlights the clinical value of structural-variant-based ultrasensitive MRD detection. Tools like Pathlight have the potential to meaningfully improve how we risk-stratify patients and tailor treatment and follow-up strategies.”

Poster details:

Abstract #208/Poster #H20: Ultrasensitive Structural Variant-based ctDNA detection of MRD in Colorectal Cancer – the CITCCA study

Date: January 10, 2026; Times: 7:00-7:55 AM PST and 12:00 PM-1:30 PM PST

Presenter: Cecilia Merk, MD, Karolinska Institutet, Stockholm, Sweden

“Data from the CITCCA study reinforce the critical role of ctDNA as a prognostic biomarker in early-stage colorectal cancer,” said Wendy Levin, MD, MS, Chief Clinical Officer, SAGA Diagnostics. “Importantly, more than 40% of ctDNA-positive patients had residual disease at levels only detectable with ultrasensitive methods, as enabled by Pathlight’s structural-variant-based approach. This finding underscores that test sensitivity matters – not just for identifying patients at highest risk of recurrence, but for informing more personalized decisions around adjuvant therapy and follow-up. We are proud to collaborate with the Karolinska Institutet on a study of this scale and quality, which advances the clinical evidence base for MRD-guided decision making for patients with colorectal cancer.”

The poster presented at ASCO GI will be available on SAGA’s website after the presentation.

About SAGA Diagnostics

SAGA Diagnostics^® is redefining the early detection of molecular residual disease (MRD), empowering treatment decisions with greater insight and confidence. Pathlight™, the company’s flagship product, is an ultra-sensitive, blood-based, multi-cancer MRD test that is now available for commercial use in the U.S. for patients with early-stage breast cancer. SAGA is partnering with pharmaceutical and biotechnology companies, as well as commercial entities, to support early through late-stage cancer development programs across a range of cancer types. SAGA’s headquarters and CLIA-certified laboratory are located in the heart of the life science ecosystem in Research Triangle Park, North Carolina. SAGA Diagnostics combines world-class genomic expertise with a leadership team deeply experienced in MRD, all aligned in the mission to intercept cancer at its earliest stages when it is most treatable.

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"The striking difference in three-year recurrence-free interval between ctDNA-positive and ctDNA-negative patients highlights the clinical value of structural-variant-based ultrasensitive MRD detection."