Molecular residual disease and efficacy of adjuvant chemotherapy in patients with colorectal cancer
- Study type
- Observational study
- Study name
- GALAXY (CIRCULATE-Japan)
- Design
- Prospective observational cohort study (GALAXY observational arm of the CIRCULATE-Japan platform); interim analysis; registration: UMIN000039205
- Sample size
- 1039 patients analysed (of 1563 enrolled at 92 centres)
- Source
- Nat Med · 2023
In plain words
In this large Japanese study, a trace of tumour DNA in the blood was checked one month after surgery for bowel cancer. Patients who had this trace were about 10 times more likely to have the cancer come back, and these were the patients who benefited most from chemotherapy. In contrast, patients with a negative test did well whether or not they had chemotherapy.
Key results
Treatment arms and regimens
18% of patients (187 of 1039). Adjuvant chemotherapy (mainly capecitabine with or without oxaliplatin) at the physician's discretion and non-randomised. Drug doses are not reported in the paper.
852 patients; adjuvant chemotherapy or observation at the physician's discretion (among high-risk stage 2 or stage 3 patients, 41.2% received chemotherapy). Drug doses are not reported in the paper.
Source of the regimen details: Full text of the paper (PMC9873552): capecitabine alone or with oxaliplatin; doses not reported
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 in Japan with resectable stage 2 to 4 colorectal cancer (and resectable recurrence) whose ctDNA was assessed before and after surgery with a personalised tumour-informed assay (Signatera; 16 patient-specific mutations).
Endpoints
Disease-free survival (DFS) by postoperative ctDNA status; association of ctDNA with benefit from adjuvant chemotherapy; ctDNA dynamics and clearance.
Safety and side effects
This is an observational diagnostic study and reports no treatment safety data.
Clinical significance and place in guidelines
GALAXY was the largest prospective postoperative ctDNA cohort at the time of publication and showed that ctDNA is the strongest prognostic factor for recurrence. These findings are observational and non-randomised, and they formed the basis for the sister randomised trials (VEGA for ctDNA-negative patients and ALTAIR for ctDNA-positive patients) on the CIRCULATE-Japan platform.
Limitations
Observational, non-randomised study; the chemotherapy decision was at the physician's discretion and there may be selection bias; short follow-up (median 16.74 months) at the interim analysis; Japanese population.
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.