Heinzelmann-Schwarz V, et al. - In this work, a rationale for using endocrine therapy as maintenance in high-grade serous ovarian cancers (HGSOC) was examined. Researchers observe that primary HGSOC have a slightly higher ESR1 than and a similar ER expression breast cancer where aromatase inhibitor maintenance is routine for decades. Findings reveal the utility of Letrozole in HGSOC. This was particularly observed in patients with chemotherapy resistance or residual disease.