Plasma DNA as a potential biomarker for breast cancer detection

Abstract

Breast cancer is a major malignancy among Indonesian women. It is often diagnosed in
the later stages of cancer, which leads to poor prognosis and survival of the patients.
This study investigated plasma DNA concentration as a potential biomarker for breast
cancer. The benefit of using this detection is the cost-effectiveness and the samples can
be collected from patients using non-invasive methods. Plasma samples were obtained
from healthy controls (n=18) and cancer patients (n=22). Each sample was split into
two equal portions for DNA isolation using two different methods for the NaI method
and a commercially available kit (Qiagen/ QA) method. The DNA concentration was
determined by using a GeneQuant spectrophotometer (Pharmacia). The t-test was used
for statistical analysis, which was performed using the SPSS 17.0 software. Compared to
the commercial method, extraction using NaI yielded higher DNA concentration, both from
samples of healthy controls and cancer patients (p=0,008 and p=0.000, respectively).
Furthermore, regardless of the isolation method used, the plasma DNA concentration
was higher in healthy controls than in cancer cases (p=0,032 and p=0.005, for NaI
and QA methods, respectively). In conclusion, isolation methods significantly affect DNA
concentrations. The plasma DNA concentration of healthy controls is significantly higher
than those of the cancer cases, suggesting that plasma DNA concentration might be a
potential biomarker for breast cancer detection with less invasive sampling method than
tissue biopsies.