Is ctDNA the Road Map to the Landscape of the Clonal Mutational Evolution in Drug Resistance? Lessons from the PALOMA-3 Study and Implications for Precision Medicine

The correlative circulating tumor DNA (ctDNA) studies of the PALOMA-3 clinical trial showed that acquired resistance to fulvestrant and palbociclib is associated with clonal evolution and acquired mutations in RB1, PIK3CA, and ESR1, with the latter two related to fulvestrant resistance. These results highlight the potential of ctDNA as a tool to detect mechanisms of resistance and infer the next line of treatment. (C) 2018 AACR.