ßV-tubulin expression is associated with outcome following taxane-based chemotherapy in non-small cell lung cancer.

BACKGROUND: Tubulin-binding agents (TBAs) are effective in non-small cell lung cancer (NSCLC) treatment. Both ßIII- and ßV-tubulins are expressed by cancer cells and may lead to resistance against TBAs. METHODS: Pre-treatment samples from 65 locally advanced or oligometastatic NSCLC patients, who underwent uniform induction chemotherapy with paclitaxel and platinum followed by radiochemotherapy with vinorelbine and platinum were retrospectively analysed by immunohistochemistry. Protein expression of ßIII- and ßV-tubulin was morphometrically quantified. RESULTS: Median pre-treatment H-score for ßIII-tubulin was 110 (range: 0-290), and 160 for ßV-tubulin (range: 0-290). Low ßIII-tubulin expression was associated with improved overall survival (OS) (P=0.0127, hazard ratio (HR): 0.328). An association between high ßV-tubulin expression and prolonged progression-free survival (PFS, median 19.2 vs 9.4 months in high vs low expressors; P=0.0315, HR: 1.899) was found. Further, high ßV-tubulin expression was associated with objective response (median H-score 172.5 for CR+PR vs 120 for SD+PD patients, P=0.0104) or disease control following induction chemotherapy (170 for CR+PR+SD vs 100 for PD patients, P=0.0081), but not radiochemotherapy. CONCLUSION: Expression of ßV-tubulin was associated with treatment response and PFS following paclitaxel-based chemotherapy of locally advanced and oligometastatic NSCLC patients. Prolonged OS was associated with low levels of ßIII-tubulin. Prospective evaluation of ßIII/ßV-tubulin expression in NSCLC is warranted.