ESR1 and neoplasm: The study revealed that elacestrant significantly improved progression-free survival (PFS) in patients with ESR1 mutations detected in circulating tumor DNA (ctDNA) compared to standard endocrine therapy - fulvestrant or aromatase inhibitor (AI), reducing the risk of progression by 45 % (HR 0.55, p = 0.0005) [[12], [13], [14]].