Interleukin-17A polymorphisms predict the response and development of tolerance to FOLFOX chemotherapy in colorectal cancer treatment.

Polymorphic variants in IL-17A gene were differentially associated with colorectal cancer (CRC) susceptibility but their link with response and toxicity to CRC treatment have not yet been evaluated. We investigated association between seven IL-17A variants with the response and toxicity to CRC treatment in 294 patients with CRC. IL-17A genotyping was done by real-time PCR. MAF of rs3748067 was significantly higher in CRC cases resistant to FOLFOX treatment (R+) than non resistant (R-). Significantly higher rs3804513 MAF was noted in R+ versus R- colon cancer (CC). Higher rs2275913 and rs10484879, and reduced rs3804513 MAF were seen in rectal cancer (RC) tolerant to FOLFOX (T+) compared to (T-) patients. Strong association of rs3819025, rs3804513, and rs7747909 was found with tolerance to RC treatment. rs3748067 was associated with FOLFOX tolerance in CC but not RC. Significant higher frequency of AGGCAGG and GAGCAGG haplotypes was seen among R + CC, thus assigning non-favorable nature to these haplotypes. Higher and lower frequencies of GAGTAAG and AGGCTGA haplotypes, respectively, were observed in T + RC, thereby assigning FOLFOX-tolerant and non-tolerant nature to these haplotypes. The obtained results suggest that IL-17A variants and haplotypes may be a target for future management of CRC treatment.