This podcast was published with an earlier version of this review, but it is still valid for the version published in December 2020.

Alongside the thousands of Cochrane Reviews of the effects of treatments, there are some which investigate interventions intended to reduce the side effects of these treatments. One such review, updated in December 2015, looks at the levonorgestrel intrauterine system for endometrial protection in women with breast cancer who are taking tamoxifen. Irene Su, from the University of California in San Diego, USA, tells us more.