ER+ and ER- tumors exhibit different histopathological and clinical properties. Receptor determination exists as a marker with predictive value rather than prognostic importance. Patients with invasive breast cancer (n=2849) were investigated retrospectively between 1981 and 2013. Patients were separated to four subgroups, as follows: ER+; non-luminal HER2+; ER-/PR-/HER2-; ER-PR+. We investigated the effects of ER positivity on long-term survival in breast cancers, by considering their pathological properties, surgical method applications, chemotherapy preferences, and combined hormonal treatments with regard to ER, PR and HER2 status. ER+ cases were premenopausal, and they existed with low-grade, small-sized and early stage tumors (P<0.05). One thousand three hundred and eighty five cases (68.6%) were administered chemotherapy, which was followed by hormone therapy. Non-luminal HER2+ tumors were found to exhibit longer survival, when compared to triple negative and ER- tumors (P=0.010). Triple negative cases had the shortest survival rates; survival values determined in the HER2+ and ER-/PR+ cases were found to be between the survivals of ER+ and TN tumors. ER, PR and HER2 positivity was not concomitant with a risk of recurrence (P>0.05). Furthermore, recurrence risk rose significantly when age, tumor stage and tumor grade increased (P<0.05). ER+ tumors are observed in women of advanced age, but have a good clinical response. Currently, receptor determination is still generally preferred as a practical application. ER analysis in the early stage breast cancers for women of advanced ages must be considered as an indicator of anti-estrogenic therapy administration, rather than prognostic importance.
Keywords: Breast cancer subtype; estrogen receptor; survival.