Assessment of the predictive role of oestrogen and progesterone receptor status in breast cancer patients treated with neoadjuvant chemotherapy: A retrospective analysis for 689 patients

Background : To explore the predictive indicators in hormone receptor (HR)-positive breast cancer (BC) patients receiving neoadjuvant chemotherapy (NACT) and to evaluate the value of quantitative oestrogen receptor (ER) and progesterone receptor (PR) in predicting tumour response. Methods : Six hundred eighty-nine BC patients with HR-positive status who were treated with anthracycline, epirubicin and taxane NACT treatment were retrospectively analysed. Clinical and pathological features of the patients were used to evaluate the response to NACT. Results : Patients with larger tumour sizes ( OR 1.657 CI 1.186-2.313 p=0.003 ), those who were in a premenopausal status ( OR 1.458 CI 1.039-2.045 p=0.029 ) and those with higher Ki67 levels ( OR 1.735 CI 1.231-2.444 p=0.002 ) exhibited a better therapy response. Among the patients in the postmenopausal subgroup, a lower pretreatment ER or PR expression were associated with a reduction in tumour size, and the cut-off values for ER and PR were 87.5% and 65%, respectively ( p=0.006 and p=0.05 ). Decreased expression of ER and PR was also observed after NACT treatment ( p=0.028 and p<0.001, respectively ) but played only a predictive role in the Her-2-negative subgroup; the cut-off values for decreased ER and PR were 17.5% and 26.5%, respectively ( p=0.044 and p<0.001 ). Conclusions : Semiquantified pretreatment HR expression can be used to predict the response of NACT in postmenopausal BC patients. Decreased ER and PR expression is also associated with a reduction in tumour size in Her-2-negative subtypes treated with NACT.