Nuclear expression of ERβ was significantly decreased in the G3 subgroup compared to better differentiated cancers (p <  0.01) and correlated with ovarian cancer markers CEA (95% CI 0.1598–0.4465; p <  0.0001) and CA72–4 (95% CI 0.05953–0.3616; p <  0.01). Here, CEACAM5 is linked to cancer.