Purpose: Second-line chemotherapy of advanced non-small cell lung cancer (NSCLC) with docetaxel or pemetrexed allows to achieve objective response rate only in 5-10 % of patients. Recent studies have shown that single nucleotide polymorphisms (SNPs) in genes encoding proteins which regulate dynamics of microtubules may be considered as predictive factors of response to taxane-based chemotherapy. STMN1 gene encodes stathmin 1, which plays role in cell division by regulation of microtubules depolarisation, and this process may be associated with taxanes' effectiveness.
Materials and methods: Using HRM-PCR technique, we evaluated the -2166C>T SNP of STMN1 gene in DNA from peripheral blood leucocytes of 54 advanced NSCLC patients treated in second-line monotherapy with docetaxel or paclitaxel.
Results: Patients with TT genotype of STMN1 gene demonstrated significantly longer progression-free survival (PFS) and the lower risk of early disease progression after second-line treatment compared to patients with other STMN1 genotypes (median PFS: 7 and 2 months; p = 0.0154; HR = 0.371; 95 % CI 0.184-0.743). Early disease progression during second-line chemotherapy was significantly more frequently observed in patients with CC genotype of STMN1 in contrast to patients with presence of T allele (median PFS: 2 and 4 months; p = 0.0385; HR = 1.776; 95 % CI 0.905-3.445).
Conclusion: Only selected NSCLC patients could benefit from second-line chemotherapy. Therefore, investigations of novel predictive molecular factors for proper qualification of patients to second-line taxane-based chemotherapy are justified. Studied SNP of STMN1 gene may have potential predictive role in such therapy.
Keywords: Docetaxel; Non-small cell lung cancer; Paclitaxel; STMN1; Second-line chemotherapy.