Change in the hormone receptor status following administration of neoadjuvant chemotherapy and its impact on the long-term outcome in patients with primary breast cancer

BACKGROUND: To evaluate the impact of change in the hormone receptor (HR) status ( HR status conversion) on the long-term outcomes of breast cancer patients treated with neoadjuvant chemotherapy (NAC). METHODS: We investigated 368 patients for the HR status of their lesions before and after NAC. On the basis of the HR status and the use/non-use of endocrine therapy ( ET), the patients were categorised into four groups: Group A, 184 ET-administered patients with HR-positive both before and after NAC; Group B, 47 ET-administered patients with HR status conversion; Group C, 12 ET-naive patients with HR status conversion; Group D, 125 patients with HR-negative both before and after NAC. RESULTS: Disease-free survival in Group B was similar to that in Group A ( hazard ratio, 1.16; P = 0.652), but that in Group C was significantly lesser than that in Group A ( hazard ratio, 6.88; P<0.001). A similar pattern of results was obtained for overall survival. CONCLUSION: Our results indicate that the HR status of tumours is a predictive factor for disease-free and overall survival and that ET appears to be suitable for patients with HR status conversion. Therefore, both the CNB and surgical specimens should be monitored for HR status. British Journal of Cancer ( 2009) 101, 1529-1536. doi: 10.1038/sj.bjc.6605360 www.bjcancer.com Published online 6 October 2009 (C) 2009 Cancer Research UK