The correlation between chemotherapeutic efficacy and breast cancer susceptibility gene 1 and class IIIβ-tubulin protein expression in non-small cell lung cancer patients

Abstract

To investigate the predictive value of breast cancer susceptibility gene 1 (BRCA1) and class IIIβ-tubulin protein expression in tumor tissue for the efficacy of taxol and cisplatin combined chemotherapy (TP) in stage IIIB/IV non-small cell lung cancer (NSCLC) patients. A total of 92 stage IIIB/IV NSCLC patients were recruited with 87 patients evaluated. Bronchoscopy or lung puncture tumor biopsy samples were obtained with BRCA1 and class IIIβ-tubulin protein expression examined immunohistochemically before chemotherapy. The patients were randomly assigned to be received 4 to 6 cycles of TP chemotherapy regiments and followed up until death or lost. Response rate (RR), overall survival (OS) and time to tumor progression (TTP) were assessed. Among the 87 evaluated patients, the positive expression rates of BRCA1 and class IIIβ-tubulin were 57.5% (50/87) and 48.3% (42/87) respectively. There was no significant difference in clinical characteristics among patients with different positive expression rate. According to different expression of BRCA1 and class IIIβ-tubulin, the patients were divided into four groups: group A (low expression of both BRCA1 and class IIIβ-tubulin), group B (high expression of both BRCA1 and class IIIβ-tubulin), group C (high expression of only BRCA1) and group D (high expression of only class IIIβ-tubulin). The RR was higher in group A than other three groups (60.7%, 34.8%, 9/19 and 6/17 respectively). The OS and TTP were longer in group A than other three groups [OS: (539.4 ± 17.6) days, (267.2 ± 20.5) days, (325.6 ± 24.1) days and (283.7 ± 26.2) days respectively; TTP: (256.9 ± 28.4) days, (143.8 ± 17.6) days, (179.3 ± 19.8) days and (152.6 ± 23.5) days respectively]. There were no significant differences among the other three groups. The expression level of BRCA1 and class IIIβ-tubulin in tumor tissue is probably a predictor for the efficacy of TP chemotherapy in NSCLC patients. TP chemotherapy is more suitable for the NSCLC patients with lower expression of both BRCA1 and class IIIβ-tubulin. Our study may provide a new sight for tailored chemotherapy in NSCLC patients.