Beyond the estrogen receptor: In search of predictive biomarkers for low‐grade serous ovarian cancer

Estrogen receptor immunohistochemistry should not be used in the clinic as an indicator of response to antihormonal therapy; progesterone receptor immunohistochemistry may be prognostic, but further study is needed. Multigene assays to assess for estrogen receptor pathway activation hold potential as a viable diagnostic tool to help determine those patients least likely to respond to single‐agent endocrine therapy and potentially identify patients most appropriate for combination strategies.