Presence of postoperative cDNA may predict risk of recurrence in colorectal cancer
Based on the prognostic value observed in the study, the researchers suggest that assessing the status of circulating tumor DNA (ctDNA) as early as the week after surgery could help in patients’ risk stratification and taking decision-making for postoperative management.
As data accumulates on the potential of circulating tumor DNA (ctDNA) as a biomarker in several cancers, a large multicenter study indicates that the presence of postoperative ctDNA is highly predictive of relapse in patients with ctDNA. stage II-III colorectal cancer.
The results of the study showed that being positive for cDNA 3 to 7 days after the operation resulted in patients being almost 11 times more likely to have disease recurrence. This increased risk remained even after adjuvant chemotherapy (ACT), with cDNA-positive patients being 12 times more likely to have a recurrence.
Based on the prognostic value observed in the study, the researchers suggest that assessing the status of the cDNA as early as the week after surgery could help in patient risk stratification and decision making for management. postoperative.
“It is revolutionary that, unlike any other conventional factor that stratifies the risk of recurrence (high vs. low), the detection of ActDNA is a reflection of the MRD itself (yes vs. no),” commented the researchers . “As ActDNA measurement technology continues to evolve and demonstrate its importance, real-time detection of MRM using ActDNA can help guide the precise administration of ACT,” evaluating the effectiveness of ACT and monitoring disease recurrence. “
Unlike the 20 patients who tested positive for cDNA and had a 2-year recurrence-free survival (SSR) rate of just under 40.0%, the 220 (91.7%) patients who were negative for l CDNAs had a low risk of recurrence, with a 2-year RFS rate of 89.4%.
The study also found that serial detection of cDNA identified recurrent disease before X-ray imaging. Serial cDNA analyzes identified recurrent disease about 5 months before X-ray imaging, the researchers said, and accurately identified recurrent disease 92% of the time.
“The results of 240 patients strongly support the idea that the positive status of cDNA may reflect the existence of [minimal residual disease] and therefore the extremely high risk of recurrence of the disease, ”explained the researchers. “Over the entire clinical course, cDNA status remained the most significant and independent predictor of SSR among all clinicopathological risk factors, although multivariate analysis may not be powerful. given the small size of the cDNA positive patient subgroup, and the dynamic change in cDNA status was in good agreement with course and clinical results.
A subgroup analysis comparing patients who received ACT with patients who did not receive ACT showed that cDNA was significantly associated with RFS in both groups, indicating that the combination of ActDNA to RFS is independent of ACT use.
Chen G, Peng J, Xiao Q et al. Circulating postoperative tumor DNA as risk markers for recurrence in stage II to III colorectal cancer. J Hematol Oncol. Published online May 17, 2021. doi: 10.1186 / s13045-021-01089-z