A prospective study of receptor profiles in breast cancer and the ipsilateral axillary lymph node metastases measured simultaneously in treatment naïve cases.

Background: The heterogeneity of receptor profiles in breast cancer is well known. The differing receptor profiles of primary breast cancer and nodal metastases have been investigated and found to range between 10-50% depending on the hormone receptor tested. A study comparing the hormone status of primary breast cancers and the synchronous ipsilateral involved sentinel lymph node has not been performed in a South African population.

Method: This is a prospective study where two specialist radiologists performed the simultaneous core needle biopsies of the primary breast cancer and the clinically positive axillary nodes. All receptor status analysis was conducted by one specialist histopathologist.

Results: Of 141 patients who gave written informed consent for this study, 29 were excluded; 112 patients met the inclusion criteria. Anonymised demographics of age, clinical stage, HIV status and metastatic screening were recorded. The simultaneous biopsies and receptor measurements identified 10 patients with discordant receptor status in the positive axillary lymph nodes. In each case, the receptor profile of the axillary lymphatic metastases was more aggressive than that of the primary tumour. The luminal A subtype had a significantly greater risk of discordance than other subtypes ( = 0.02).

Conclusion: Core needle biopsy and receptor analysis should be considered on the positive axillary nodes in breast cancer patients. Adjuvant treatment should be targeted to the receptor profile of the lymph node metastases.