Blood DNA Methylation-Based Assay for Early Diagnosis of Breast Cancer

In a study in Nature Communication, researchers at Shandong University in China describe a new multiplex quantitative methylation-specific PCR-based assay to detect breast cancer from within blood samples called BC-mqmsPCR. For this study, the researchers analyzed genome-wide DNA methylation profiles of peripheral blood mononuclear cells from around 800 patients using Illumina's Infinium Human Methylation 850K BeadChip. They noted 289 differentially methylated CpG positions associated with breast cancer and selected four markers for their BC-mqmsPCR assay. In their analysis of 206 BC, 170 normal controls, and 125 other tumor samples, the assay outperformed the traditional tumor markers CA153, CA125, and CEA at diagnosing early-stage breast cancer and breast cancer tumors less than 1.5 centimeters in size. For instance, it could distinguish early-stage breast cancer patients from normal controls with an area under the curve of 0.940, a sensitivity of 93 percent, and a specificity of 90 percent. "BC-mqmsPCR can also identify tumors earlier than existing clinical procedures, showing the potential to improve early diagnosis of [breast cancer] and patient prognosis," the authors write.