Primary endocrine therapy can be effective in decreasing lymph node burden in hormone receptor positive breast cancers.

Abstract

Background: Breast cancer is a significant global health concern. Primary endocrine therapy (PET) and primary chemotherapy (PCT) are employed to manage hormone receptor positive breast cancers in the neoadjuvant setting. We hypothesise that PET is as effective as chemotherapy to treat axillary metastases.

Methods: All patients treated for breast cancer at Tygerberg Hospital Breast Unit during the period of 2016-2019 were included. Patients who did not receive PCT or PET were excluded, as were patients who did not undergo axillary lymph node dissection (ALND).

Results: The sample consisted of 176 patients. The median age was 49.2 years (IQR = 42.4-57.9 years; range = 25.1-84.6 years), and 174/176 (98.9%) were female. Of the 176 patients, 35/176 (19.9%) had luminal A cancers, while 141/176 (80.1%) had luminal B cancers. Among these patients, 150/176 (85.2%) underwent PCT while 26/176 (14.8%) received PET. The lymph node burdens found via ALND were similar for patients who underwent PCT (median = 25.0%; IQR = 0.0-50.0%) and PET (median = 16.8%; IQR = 0.0-89.0%; p = 0.66). The rates of patients with no nodal involvement were also similar for patients who underwent PCT (47/150 = 31.3%) and PET (9/26 = 34.6%; p = 0.74). Multivariate analysis showed that there were no significant confounding effects due to age, sex, HIV status, molecular subtype or AJCC stage.

Conclusion: Our study showed no statistically significant difference in the lymph node burden regardless of whether PET or PCT was given to patients with a hormone receptor positive breast cancer.