Correlation Between Expression Of Hormone Receptors, PS2, C-erbB-2 And Ki-67 And Response To Neoadjuvant Chemotherapy In Breast Cancer

OBJECTIVE: The first aim of this analysis was to evaluate the changes in biological molecular markers (ER, PR, pS2, C-erbB-2 and Ki-67) before and after primary chemotherapy in patients with operable breast cancer and investigate the influence of preoperative chemotherapy on molecular markers. The second objective of this analysis was to assess the possible relationship between biological factors and curative effect of chemotherapy. Knowledge of factors predicting tumor response can avoid administration of treatment to patients who are not likely to respond.METHODS: This study included 45 patients with stageⅡ_a toⅣbreast infiltrative ductal carcinoma who received neoadjuvant chemotherapy from April 2005 to January 2007. Biological molecular markers (ER, PR, pS2, C-erbB-2 and Ki-67) determinations were performed by immunohistochemistry in pre-neoadjuvant core biopsies tissues and final surgical specimens. Curative effect and changes of markers expression were evaluated after 3-4 cycles of neoadjuvant chemotherapy. The reason of changes induced by neoadjuvant chemotherapy and their correlations with tumor response were analyzed.RESULTS: After neoadjuvant chemotherapy, there were 5 cases of pathological complete remission (pCR), and other 40 cases were enrolled in the neoadjuvant chemotherapy group. The quantitative changes of ER, PR, pS2, C-erbB-2 and Ki-67 expression were 17.5％, 15％, 7.5％, 22.5％and 32.5％, respectively. The changes of their status were 22.5％, 42.5％,45％, 12.5％and 50％, respectively. The difference of Ki-67 before and after primary chemotherapy was significant (t=3.218, P=0.003). Statistical analysis was performed using Spearman's rank correlation. No statistical association between clinical response and expression of PR, pS2, C-erbB-2. However, there were significant Spearman's correlations between changes of ER, Ki-67 expression and clinical response (P＜0.05).CONCLUSION: Neoadjuvant chemotherapy induced variations of markers (ER,PR,pS2,C-erbB-2,Ki-67) expression in patients with breast cancer. The investigating results have shown that the changes of ER, Ki-67 expression may be related to tumour response, and could be used to predict the sensitivity of treatment. These relationships should be assessed in a larger cohort of patients. The mechanisms and clinic significance of changes should be further investigated, too.