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DNA test may be effective biomarker in breast cancer treatment
Circulating tumor DNA was identified in nearly 100% of a cohort of women with metastatic breast cancer, according to study results.
The researchers noted that circulating cell-free DNA carrying tumor-specific alterations have not been investigated as thoroughly as other circulating biomarkers in breast cancer.
The current study was a comparison of radiographic images of tumors with the assay of circulating tumor DNA, cancer antigen 15-3 (CA 15-3) and circulating tumor cells.
Thirty eligible participants had metastatic disease and were receiving systemic therapy.
Twenty-nine of the 30 women (97%) with somatic genomic alterations had circulating tumor DNA. CA 15-3 was detected in 21 of 27 women (78%), whereas circulating tumor cells were detected in 26 of 30 (87%).
Circulating tumor DNA levels were associated with a greater dynamic range than the comparators. These levels also were linked to a greater correlation with changes in tumor burden than CA 15-3 or circulating tumor cells.
The earliest measure of treatment response was circulating tumor DNA, and that was observed in 10 of 19 women (53%).
“This proof-of-concept analysis showed that circulating tumor DNA is an informative, inherently specific and highly sensitive biomarker of metastatic breast cancer,” the researchers wrote.