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

Objective 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 Ⅲβ/Ⅳ non-small cell lung cancer(NSCLC) patients. Methods A total of 92 stage Ⅲβ/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. Results 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 1 p-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. Conclusions 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.