Discordance in receptor status between primary and recurrent breast cancer and its clinical signif cance

Objective Toinvestigate the discordance expression of estrogen receptor (ER), progesterone receptor (PR), and Her-2 between primary and recurrent tumors in patients with recurrent breast cancer and its effect on disease-free survival (DFS). Methods One hundredand seventy-five women with recurrent breast cancer whounderwent biopsy in Chinese PLA General Hospital fromApril 1, 1999 toAugust 31, 2013 were enrolledin this study, the expression of ER and PR were testedin 175 patients while the Her-2 status was ascertainedin 128 patients. Results Discordance in ER, PR, and Her-2 between the primary and the recurrent was 35.4% (McNemar's test P=0.003), 39.4% (P=0.030), and 14.8% (P=0.001), respectively. The positive conversion rate of ER and PR were 10.9% and 14.3%, and the negative conversion rate were 24.6% and 25.1% which were higher than the positive conversion rate (P_ER=0.003, P_PR=0.030). The positive and negative conversion rate of Her-2 were 13.3% and 1.6%, the former was higher than the later (P=0.001). The discordance in ER and Her-2 between the primary and the recurrent was relevant totumor size (P_ER=0.010, P_Her-2=0.042). A statistically tendency in DFS tointra individual HR status and Her-2 status in primary tumor and relapse was noted. Conclusion Breast cancer is a highly heterogeneous disease. Some patients with breast cancer experience alteredHR and Her-2 status throughout tumor progression. The molecular classification of breast cancer is associatedwith DFS possibly. The discordance in HR and Her-2 between the primary and the recurrent is relevant totumor size. Once breast cancer relapses, it may showhigher degree of malignant.