[Influence of P-glycoprotein expression on chemotherapeutic response of metastatic breast carcinoma].
OBJECTIVE
The clinical study showed that the P-glycoprotein(P-gp) expression was closely associated with the chemotherapeutic effect, response rate, prognosis, and survival time. Until now, few clinical papers have reported about metastatic sites and its response to chemotherapy with P-gp expression in metastatic breast carcinoma. The current study was designed to investigate the role of P-gp expression and its clinical value of chemotherapy for the patients with different metastatic sites of this carcinoma.


METHODS
P-gp expression in 46 postoperative patients with metastatic breast carcinoma was detected by SABC immunohistochemical method. 43 cases treated with combination regimen: Cyclophosphamide 600 mg/m2 i.v. on day 1, Pirarubicin 60 mg/m2 i.v. on day 1, 5-Fluorouracil 600 mg/m2 i.v. on days 1 and 8. Repeat the cycle every 3 weeks for at least 2 cycles. The correlation between P-gp expression and chemotherapeutic response was analyzed.


RESULTS
1) P-gp expression positive rate was 56.5%, the P-gp expression in the patients with lung or liver viscera metastasis was higher than that in skin or lymph node metastasis (P = 0.049). 2) The overall response rate was 58.1% in 43 patients. The response rate of the P-gp negative group was higher than the P-gp positive group(P < 0.01). 3) The response rate in the patients with skin and lymph node metastasis was higher than the patients with lung and liver metastasis (P < 0.05). 4) The postoperative patients who had received CAF(cyclophosphamide + adriamycin + 5-fluorouracil) or CMF(cyclophosphamide + methotrexate + 5-fluorouracil) regimen adjuvant chemotherapy previously, the response rate of metastatic diseases to chemotherapy had no significant difference (P > 0.05).


CONCLUSIONS
P-gp expression may be considered as an index for evaluating multidrug resistance, guiding drug use, and judging prognosis of the patients with metastatic breast carcinoma.
Li
En-xiao
EX
Department of Medical Oncology, First Hospital of Xi'an Jiaotong University, Xi'an 710061, P. R. China. Lienxiao@pub.xaonline.com.cn
Li
Yi
Y
Yang
Jin
J
He
Jing
J
Chen
Ling
L
Wang
Jian-bo
JB
Zhou
Xiao-juan
XJ
Li
Rong
R
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis* / Q000502:physiology; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018432:Drug Resistance, Multiple / Q000502:physiology*; D004358:Drug Therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011182:Postoperative Care
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1