Fig. 6: Multimodal ctDNA detection for post-operative MRD and adjuvant therapy response tracking in colorectal cancer without matched tumour.
From: Multimodal cell-free DNA whole-genome TAPS is sensitive and reveals specific cancer signals
A Tracking post-operative MRD in case GEL193. ctDNA was detectable in the plasma 1 year after surgery and this correlated with inoperable metastatic rectal cancer and a possible lung adenocarcinoma suggested through radiological examination, both of which were recorded ~3 years after the post-operative plasma sample was collected. B Tracking response to adjuvant therapy following surgery. Case GEL282 (Bi) did not have detectable ctDNA immediately after the last cycle of treatment. However, low ctDNA burden was detected 5 months later, which correlated with the presence of tubular adenomas with low grade dysplasia in the sigmoid colon at around the same time. Case GEL432 (Bii) did not have detectable ctDNA shortly after the last cycle of treatment and was still alive ~6 years after the last plasma sample was collected. C Confusion matrix (Ci) and event-free (i.e., no recurrence, metastasis, or precancerous adenomas present) survival (Cii) in 9 patients with colorectal cancer. In 8 out 9 patients, ctDNA burden after the end of surgery and/or adjuvant therapy correlated with the presence/absence of clinical events, such as recurrence or pre-cancerous adenomas (Ci). Absence of ctDNA detection after the end of surgery/adjuvant treatment correlated (hazard ratio: 8.2; 95% CI: 1.3–53.1; two-sided log-rank test p value = 0.02) with longer survival times (Cii). Dx diagnosis, Sx surgery, Tx0 first cycle of adjuvant therapy, Tx1 last cycle of adjuvant therapy, RR recurrence, LGD low-grade dysplasia. Source data is provided as a source data file.
