Our previous studies demonstrated an association between MRD status and the recurrence risk or benefit from adjuvant chemotherapy in patients with colon cancer and bladder cancers. However, limited data are available in low-shedding tumours like renal cell carcinoma. So we started the multicentre prospective MONSTAR-SCREEN-3 trials.

Can you describe the MONSTAR-SCREEN-3 study design and patient population?

Our MONSTAR-SCREEN-3 study consisted of various types of cancers including renal cell carcinomas. This study was specifically applied an ultra-sensitive whole genome sequence-based MRD assay for various types of cancers. Basically whole exome sequencing sometimes lacks sufficient sensitivity for some types of cancers. We believe that a whole genome sequence-based approach can increase the detection of MRD.

What were the findings regarding MRD detection and its correlation with relapse risk?

We found 100% positivity at baseline and 11.1% at one month post-surgery with 50% ultrasensitive levels. We also found that ctDNA level is associated with clinical stage or tumour size or lymph node metastasis status. Importantly, our patients with recurrence had persistently ctDNA positive after surgery, so indicating that a whole-genome sequencing approach is very feasible and may predict recurrence earlier than currant practice.

What are the next steps for validating this approach and integrating it into clinical practice?

We have enrolled 29 patients and this is a preliminary result. Now we are expanding this cohort to 150 patients and hopefully we can stratify the patients with adjuvant therapy for ctDNA-positive patients so we don’t need to do unnecessary adjuvant therapy for ctDNA-negative patients. Now our ctDNA-guided therapy is upcoming, the next step, upcoming therapy for solid tumours. So we can apply this whole genome sequencing approach even to renal cell carcinoma.