Current practice frequently avoids chemotherapy for most ER-positive breast cancers, including node-positive cases, based on genomic testing, contrary to 1999 NCI recommendations.

“there's been a huge shift in how we use chemotherapy in ER positive breast cancers over the past 25 years from the time in 1999 when the NCI said every woman who had a 1 cm cancer needed chemotherapy to a Time nowadays when we frequently can avoid chemotherapy for most ER positive breast cancers but certainly those that are knowed negative and many of the ones that are knowed positive as well because we understand that based on this genomic test the chemotherapy is just not going to help them do better in the long run”