407P - K-TrackTM: A streamlined personalized assay to detect molecular residual disease in solid tumors

Background

Circulating tumor DNA (ctDNA) has emerged as a promising biomarker to monitor molecular residual disease (MRD) in solid tumors after curative-intent treatment. Since imaging and plasma-derived protein biomarkers both have limited sensitivity and specificity, ctDNA could complement conventional methods to guide post-operative monitoring and treatment plans for patients. This study evaluated the clinical utility of our tumor-informed, personalized ctDNA assay to identify patients at high risk of recurrence.

Methods

This prospective multi-center study enrolled 510 patients with liver, colorectal, breast, lung, gastric and ovarian cancers who were eligible for curative-intent surgery. Genomic DNA extracted from tumor tissue and paired white blood cells was subjected to massively parallel sequencing of 150 cancer-related genes. A proprietary algorithm ranked the top somatic mutations unique to each patient, which were then used to detect ctDNA in serial plasma samples.

Results

The pre-operative detection rate of ctDNA was 91%, 97%, 62%, 65%, 57%, and 46% for colorectal, liver, lung, ovarian, high-risk breast cancer, and gastric cancer respectively; the specificity was >99% as ctDNA was not detected in the plasma from healthy donors. Our interim analysis after a 20-month follow-up demonstrated that 88% of patients with recurrence and/or metastasis (35/40) had ctDNA detected in their post-operative plasma samples. On average, such ctDNA detection was 5 months (up to 13 months) earlier than clinical diagnosis. Post-operative ctDNA was also found as an independent prognostic factor for disease-free survival in multiple types of cancer (p<0.001).

Conclusions

K-Track™ assay provides longitudinal ctDNA monitoring that showed clinical utility in predicting disease-free survival and early relapse detection in cancer patients. This simplified and cost-effective approach enables MRD monitoring to be more accessible in routine clinical practice in developing countries.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Medical Genetics Institute, Ho Chi Minh City, Vietna.

Funding

Gene Solutions JSC, Ho Chi Minh city, Vietnam.

Disclosure

All authors have declared no conflicts of interest.