The Role Of NgBR In Neoadjuvant Chemotherapy For Estrogen Receptor Positive Breast Cancer

Objectives: Breast cancer has become the most common cancer in the world.70% of breast cancer is ER positive breast cancer.Compared with Her-2 positive breast cancer and triple-negative breast cancer,ER positive breast cancer is less likely to achieve pathological complete response（p CR）after neoadjuvant chemotherapy.Resistance to chemotherapeutic drugs is an important factor preventing ER positive breast cancer from reaching p CR.This study included patients with ER positive breast cancer who received neoadjuvant chemotherapy,and explored the drug resistance of NgBR in ER positive breast cancer by comparing the relationship between NgBR expression and p CR.Methods: 1.A total of 60 patients with ER positive breast cancer（all patients received complete neoadjuvant chemotherapy）admitted to the Breast Surgery Department of Bethune First Hospital of Jilin University from 2014 to 2019 were included.Clinical data and pathological data of the enrolled patients were collected.According to whether p CR was achieved after neoadjuvant chemotherapy,60 patients were divided into the p CR group and the non-p CR group.Immunohistochemistry（IHC）technique was used to stain the puncture tissue of breast tumor from 60 patients before neoadjuvant for NgBR,phos-Akt（pAkt）,Bax,and Bcl-2 antibodies.The relationship between NgBR expression and patients’ pathological remission status after receiving neoadjuvant chemotherapy was analyzed.And the correlation between NgBR and Akt phosphorylation level,Bax,and Bcl-2 expression was analyzed.2.The chi-square test was used to analyze the correlation between clinicopathological parameters and NgBR expression in the included 60 breast cancer patients.3.The effect of NgBR expression on disease-free survival（DFS）and overall survival（OS）was analyzed using Kaplan-Meier survival analysis.Results:（1）In this study,we found a significant difference in the expression of NgBR between the p CR and non-p CR groups（P<0.05）.In the nonp CR group,the positive rate of NgBR expression was 70.8%（34/48）,while the positive rate of NgBR expression in the p CR group was 8.3%（1/12）.（2）We analyzed the relationship between NgBR and various clinical parameters.The results showed that the positive rate of NgBR expression in the Ki-67≤20% group was 78.9%（15/19）,and the positive rate of NgBR expression in the Ki-67>20% group was 48.8%（20/41）,in which the difference was statistically significant（P<0.05）.There was no significant difference in NgBR expression with age,menopause,tumor size,tumor stage,and progesterone expression status.（3）The immunohistochemical staining of NgBR,pAkt,Bcl-2 and Bax was performed on the biopsy tissue sections of 60 breast cancer patients to observe the correlation between NgBR and pAkt,Bcl-2,and Bax protein expressions.We used Kendall’s tau-b correlation coefficient to evaluate the correlation between NgBR expression and the expression of each protein.The results did not show any correlation between NgBR and each protein.（4）The patients were divided into 2 groups according to the expression of NgBR in the punctured tissue of breast tumor,to analyze the effect of NgBR expression on DFS and OS.Kaplan-Meier analysis showed that there was no significant difference in DFS（P=0.158）and OS（P=0.072）between the two groups.The 3-year DFS of the NgBR-positive group and the NgBR-negative group were 88.14% vs 100%,and the 5-year DFS was 84.75% vs 94.40%,respectively;the 3-year OS was 91.08% vs 100%,and the 5-year OS was 87.12% vs 100%,respectively.Conclusions: 1.Neoadjuvant chemotherapy is less effective in NgBR-expressing ER positive breast cancer.2.The 5-year disease-free survival and overall survival of NgBRnegative patients are better than NgBR-positive patients.