Objectives: Small-cell lung cancer (SCLC) accounts for about 20% of total lung cancer, and systemic chemotherapy is the major therapy for all stages of SCLC. Although most SCLC patients are characterized by initial chemosensitivity to the standard first-line platinum-based regimens, a significant fraction of patients are intrinsic nonresponders.
Methods: Genome-wide scan of 440 093 single-nucleotide polymorphisms (SNPs) was conducted using peripheral blood DNA to identify variants associated with response to first-line carboplatin or cisplatin plus etoposide chemotherapy in 245 patients with SCLC and the results were replicated in another set of 183 patients.
Results: By set association analysis, 20 SNPs were identified to be associated with treatment response, with odds ratios (95% confidence interval) ranging from 2.36 (1.56-3.57) to 4.38 (2.12-9.29) and these results were confirmed in the replication phase. Most of these SNPs (14/20) were clustered on chromosomes 22p11.23, 6q24.3, and 20p12.2 containing BTBD3, STXBP5, and BCR genes.
Conclusion: Germline genetic variations influence the effectiveness of platinum-based chemotherapy of SCLC and further studies are needed to test the value of these findings for personalized chemotherapy.