- Detectable levels of circulating tumor DNA (ctDNA) following surgery and adjuvant chemotherapy are associated with worse recurrence-free survival in stage III colon cancer.
Why this matters
- ctDNA may predict patient response to treatment after surgery and adjuvant chemotherapy.
- ctDNA levels after adjuvant chemotherapy may be the most relevant predictor, according to an accompanying editorial.
- Multicenter cohort study (n=96).
- Tumor DNA was detected by sequencing 15 genes for mutations commonly associated with cancer.
- Funding: Victorian Cancer Agency; NIH; Virginia and D. K. Ludwig Fund for Cancer Research; John Templeton Foundation.
- Median follow-up, 28.9 months.
- All 96 patients had at least 1 somatic mutation in the primary tumor among the 15 genes tested.
- Following surgery, 21% of patients had detectable ctDNA, and this was associated with worse recurrence-free survival (HR, 3.8; P<.001 this remained significant after adjustment for clinicopathologic risk factors p>
- Following adjuvant chemotherapy, 17% had detectable ctDNA, and this was associated with a worse 3-year recurrence-free interval (30% vs 77%; HR, 6.8; P<.001>
- No validation cohort.
- Modest sample size.