ABSTRACT
Objective: To quantitatively detect the serum circulating DNA in patients with breast cancer and evaluate its potential applications. Methods: The copy number of GAPDH gene in serum circulating DNA was measured by real-time quantitative PCR from 100 healthy female volunteers, 100 patients with benign breast lesions, and 200 patients with breast cancer. The copy number of GAPDH gene was used as an indicator for circulating DNA content. Results: With a cut-off value of ≥1×103 copies, the results of serum circulating DNA detection in 93% of healthy females and 95% of patients with benign breast lesions were negative, and 84.5% of patients with breast cancer were positive. The positive rate of serum circulating DNA in patients with I-II stage breast cancer was 84%. The DNA content was significantly different among healthy females, patients with benign breast lesions and the patients with breast cancer (P<0.005). Conclusion: There is a certain amount of tumor-derived circulating DNA in patients with early stage breast cancer. These genetic materials may serve as a type of specific biomarkers. Copyright© 2011 by TUMOR.