ctDNA-based molecular residual disease and survival in resectable colorectal cancer
- Study type
- Observational study
- Study name
- GALAXY (CIRCULATE-Japan)
- Design
- Prospective observational cohort study (updated GALAXY analysis, CIRCULATE-Japan); registration: UMIN000039205
- Sample size
- 2240 patients (of 6061 enrolled)
- Source
- Nat Med · 2024
In plain words
This update of the GALAXY study, with more than 2000 patients, showed that a positive ctDNA blood test after surgery for bowel cancer is linked not only to the cancer coming back but also to shorter survival. The good news is that in ctDNA-positive patients, chemotherapy greatly reduced the risk, and patients whose blood stayed clear of ctDNA had very good results.
Key results
Treatment arms and regimens
15.93% of patients (336 of 2109). Adjuvant chemotherapy at the physician's discretion (non-randomised).
1773 patients; adjuvant chemotherapy or observation at the physician's discretion.
Source of the regimen details: Observational study; chemotherapy regimen and dose at the physician's discretion and not specified in the paper
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
Patients with resectable stage 2 to 3 colon cancer or stage 4 colorectal cancer; patients with stage 1 to 3 rectal cancer were not included in the analysis. Personalised tumour-informed ctDNA assay (Signatera).
Endpoints
Disease-free survival (DFS) and overall survival (OS) by ctDNA status; benefit from adjuvant chemotherapy; sustained versus transient ctDNA clearance.
Safety and side effects
This is an observational diagnostic study and reports no treatment safety data.
Clinical significance and place in guidelines
This analysis provided the first large data set on the association of ctDNA-based MRD with overall survival in resectable colorectal cancer and showed the importance of serial ctDNA monitoring (sustained versus transient clearance). The evidence is observational, and changing treatment based on ctDNA should be confirmed in randomised trials.
Limitations
Observational, non-randomised study (selection bias in receipt of chemotherapy is possible); moderate follow-up (median 23 months); mostly Japanese population; funding and collaboration from the assay manufacturer.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.