Mutations in the gene encoding the oestrogen receptor (ER) have been identified in aggressive breast tumours.

About 70% of breast cancers express the ER, which helps to propel rampant growth. Several drugs target the effects of the sex hormone on its receptor, but tumours often develop resistance to such treatment.

Independent teams led by Sarat Chandarlapaty at the Memorial Sloan-Kettering Cancer Center in New York, Arul Chinnaiyan at the University of Michigan in Ann Arbor and Ido Wolf at the Tel Aviv Sourasky Medical Center in Israel, sequenced tumours from a total of 104 patients with metastatic breast cancer and found ER mutations in 25. Further work indicated that these mutations could keep the receptor active even in the absence of oestrogen.

Drugs that inhibit the receptor in other ways might stall aggressive tumours, the researchers say.

Nature Genet. http://doi.org/pxp; http://doi.org/pxq (2013)

Cancer Res. http://dx.doi.org/10.1158/0008-5472.can-13-1197 (2013)