Assessment of cell-free DNA (cfDNA) concentrations in the perioperative period can predict risk of recurrence in patients with non-metastatic breast cancer

Background: Circulating cell-free DNA (cfDNA) is a potential non-invasive biomarker of disease status in patients with cancer, and provides important diagnostic and prognostic information in breast cancer. The goal of this study was to quantify cfDNA concentrations during the perioperative period and investigate its potential utility to detect recurrence outcomes in patients with breast cancer. Methods: Sixty-two (n = 62) patients with non-metastatic breast cancer, undergoing curative-intent surgery were screened for inclusion. Blood samples were collected from these patients: pre-operatively (Preop) and post-operatively (PO) at either of the following PO time points; PO week 1-2, PO week 3-4 and PO weeks 5-12 following surgery. cfDNA was extracted and quantified using nanodrop spectrophotometer. Results: In a cohort of 62 patients (age, median (IQR), 51.5(45.0-65.0) years), with a median follow-up of 90 months (interquartile range (IQR),60-120 months), significant association was observed between cfDNA concentrations and risk of recurrence in patients with breast cancer. The group of patients who had disease recurrence during follow-up had significantly higher cfDNA concentrations (cutoff:400 ng/ml) compared to the group of patients who remain disease-free (Preop and PO period: p < 0.0001). The median Recurrence Free Survival (RFS) between the Disease Recurrence (DR) and the Disease Free (DF) groups of patients with breast cancer were 12(20-28.5) months and 72.00 (96-120) months; p < 0.0001). Univariate and multivariate cox regression analysis indicated that postoperative cfDNA concentration (Hazard ratio:5.0, 95% Confidence Interval:1.19-21.28, p = 0.028) was an independent negative prognostic factor for RFS in patients with non-metastatic breast cancer. Conclusion: Our study demonstrated that high postoperative cfDNA is associated with increased risk of future recurrence in patients with non-metastatic breast cancer. Further, prospective studies are warranted to validate its clinical utility in breast cancer.