STM: Personalized biomarkers from tumor DNA can help in cancer management
A new technique called personalized analysis of rearranged ends (PARE) provides an accurate and specific way to monitor tumors by identifying personalized biomarkers from tumor DNA, according to a study published in the Feb. 24 issue of Science Translational Medicine.

Victor E. Velculescu, MD, PhD, associate professor of oncology at the Sidney Kimmel comprehensive Cancer Center at Johns Hopkins University in Baltimore, and colleagues demonstrated that PARE is sensitive and can be used to develop personalized biomarkers to enhance the clinical management of cancer patients.

"PARE uses genetic characteristics unique to the tumor to monitor disease progression. By exploiting rearrangements specific to the patient's tumor, we have developed a personalized approach for detection of residual disease," said co-author Rebecca J. Leary, a graduate student at Johns Hopkins.

“Analysis of four colorectal and two breast cancers with massively parallel sequencing revealed an average of nine rearranged sequences (range, four to 15) per tumor,” according to Velculescu and colleagues.

Moreover, the researchers demonstrated that the identified breakpoints can be used to detect tumor DNA in the presence of large quantities of normal DNA and in patient plasma.

The numerous potential applications of PARE include accurate identification of surgical margins free of tumor and the analysis of regional lymph nodes as well as the measurement of circulating tumor DNA after surgery, radiation or chemotherapy and short-term monitoring of circulating tumor DNA may be also useful in the testing of new drugs, said Velculescu and colleagues.

"As PARE becomes affordable, it will be a helpful addition for physicians to tailor patient care and may become a useful supplement to traditional monitoring by imaging or other approaches," said Leary.