Annl Oncol: CtDNA state's ability to predict breast cancer treatment remission and recurrence

Access to pathological complete remission (pCR) after new assisted chemotherapy (NAC) is closely related to a good prognosis.
study aims to assess the usefulness of continuous circulatory tumor DNA (ctDNA) monitoring for predicting pCR and metastasis recurrence risk.
291 plasma samples from 84 patients with high-risk early breast cancer who were treated with standard NAC or combined MK-2206 (1KT inhibitors) in the new auxiliary I-SPY 2 trial were isolated to free DNA (cfDNA).
blood samples were taken from pre-treatment (T0), 3 weeks of treatment with yew alcohol (T1), between yew alcohol and cyclocytic therapy (T2), and before surgery (T3).
has designed a personalized ctDNA test that detects mutations specific to up to 16 patients in cfDNA (from pre-treatment all-exon sequencing results) with ultra-deep sequencing.
follow-up time for survival analysis was 4.8 years.
when the ctDNA positive rate at different times affected the recurrence survival rate of no patients at different times T0, 61 of the 84 patients (73%) were ctDNA positive, and the proportion decreased with the treatment (T1: 35%; T2: 14%; T3: 9%).
patients who were still positive for ctDNA at T1 were significantly more likely to have residual lesions after NAC (non-pCR: 83% vs. 52%; advantage ratio 4.33, p-0.012) than individuals who were negative at T1.
the effect of post-NAC pCR and ctDNA status on patients' recurrence-free survival, all patients who received pCR had negative ctDNA (n-17,100%).
significantly increased the risk of metastasis recurrence in patients who did not receive pCR (n-43), ctDNA-positive patients (14 percent) (risk ratio. 95% CI 2.3-46.6); Interestingly, patients who did not receive pCR but were negative with ctDNA (86%) had a good prognosis, comparable to those who received pCR (HR 1.4, 95% CI 0.15-13.5).
ctDNA removal cannot be an important predictive indicator of poor prognosis and metastasis recurrence, and ctDNA removal is even associated with prognostic improvement in patients who do not receive complete pathological remission.
during NAC, personalized ctDNA monitoring for patients with high-risk early-stage breast cancer may help to assess treatment relief in real time and help fine-tune pCR as an alternative endpoint for survival prognostication.