Research of relationship between the change of molecular marker of breast cancer after neoadjuvant chemotherapy and therapeutic effect

Objective To research whether the changes of estrogen receptor (ER) , progesterone receptor (PR), HER2 associate with the efficacy, during the course of neoadjuvant chemotherapy(NAC)(anthracycline and docetaxel), and to research whether these changes will affect the molecular subtypes. Methods One hundred and thirty seven cases of patients given NAC (anthracycline and docetaxel) were retrospectively analyzed from November 2011 to June 2015 in the Affiliated Hospital of Academy of Military Medical Sciences. ER, PR, HER2 and Ki67 expression were tested by immunohistochemistry.According to immunohistochemistry results, the cases were divided into 4 molecular subtypes: Luminal A, Luminal B, triple negative and HER2 positive. Changes of ER, PR, HER2 and Ki67 expression and molecular subtypes after neoadjuvant chemotherapy were tested by Chi-square test and Fisher′s exact test, and Kappa test was used to test the consistency of molecular markers and molecular subtypes before and after NAC. Results Concordance rate of ER, PR, HER2 and Ki67 were 88.32%, 83.21%, 94.16% and 75.91 respectively.There was no significant difference in ER, PR and HER2 before and after NAC(P values were all more than 0.05). Ki67 average value had fallen from 35.75% to 19.12% after NAC(P<0.05). Molecular subtypes would haven not been changed after NAC, except for cases with Hormone receptors(HR)positive and HER2 negative (P=0.488). Concordance rate of molecular subtypes between pre-NAC biopsies and post-NAC specimens was 57.66% (Kappa=0.4020). Conclusion NAC leads to a decrease of Ki67 value in invasive breast cancer cases, and makes an effect on tumors with molecular subtype of HR+ , HER2-. Key words: Breast neoplasms; Neoadjuvant therapy; Receptors, Estrogen; Receptors, Progesterone; Genes, erbB-2