Primary Endocrine Therapy for Hormone Receptor Positive Breast Cancer: a Viable Treatment Alternative

Endocrine therapy in hormone receptor positive breast cancer has been demonstrated to prolong disease free-survival. This study evaluates our experience with primary endocrine therapy in patients with oestrogen receptor positive (ER+) breast cancer. Patients treated with primary endocrine agents were evaluated over 4-years period. The ER and progesterone receptor status was performed using the Allred score. ER+ patients were offered primary endocrine therapy if unfit for surgery/chemotherapy, with metastases, locally advanced cancer or declined surgery. Tamoxifen was the initial first-line agent but replaced by letrozole later in the study. Clinical response was assessed using UICC criteria. 91 patients were treated with median age of 80 years (50-96). The median duration of the treatment was 20 months (2-60). The histology was ductal in 79, lobular in 8 and tubular variety in 4. The reasons for primary endocrine therapy included advanced age (25), patients unfit for surgery (29), locally advanced disease (14), metastatic disease (7) and patient declining surgery (16). 80% of the patients derived clinical benefit from the therapy, 15 patients had progressive disease (PD) and response data were not available in 3 patients. Two patients died of metastatic disease and 4 non-cancer causes. Patients with PD had poorer survival compared with those that derived CB (P-value = 0.0001). Overall 5-year survival was 93.4% and cancer specific survival was 97.7%. Primary endocrine therapy for ER+ breast cancer does produce an excellent benefit with disease control and can prolong survival. This method should be considered as a viable option in patients who do not or cannot undergo surgery/chemotherapy.