Variants of FasL and ABCC5 are predictive of outcome after chemotherapy-based treatment in osteosarcoma

Objectives: Previous pharmacogenetics studies showed that genetic variants could be indicative of the response to chemotherapy. We aimed to investigate whether variants of FasL, MSH2, ABCC5, CASP3 and CYP3A4 are associated with the outcome after chemotherapy-based treatment in osteosarcoma. Methods: 132 osteosarcoma patients who had completed the neoadjuvant chemotherapy in our center were included. 5-year progression-free survival (PFS) was assessed from the initial treatment to the earliest sign of disease progression or death from any cause. 5 SNPs were genotyped using TaqMan SNP Genotyping Assay, including rs763110 of FasL, rs4638843 of MSH2, rs939338 of ABCC5, rs2720376 of CASP3 and rs4646437 of CYP3A4. Patients were classified into two groups according to the 5-year PFS (event/no event). The chi-square test was used to analyze difference of genotype frequency. Logistic regression analysis was used to determine the independent predictors of the PFS rate. Results: The overall 5-year PFS was 61.4% (81/132). Genotype TT/CT of rs763110 and genotype GG/AG of rs939338 were significantly associated with the event of 5-year PFS (p = 0.028 for rs763110; p = 0.039 for rs939338). Patients with no risk allele showed a 5-year PFS of 73.7% (42/57), which was significantly higher than a PFS of 54.2% (26/48) for patients with one risk allele and 48.1% (13/27) for patients with two different risk alleles (p = 0.03). Logistic regression analysis showed that allele T of FasL rs763110 and allele G of ABCC5 rs939338 were independent risk factors of the 5-year PFS. The ORs were 2.14 (95%CI = 1.13–3.35, p = 0.01) for rs763110 and 1.73 (95%CI = 1.05–2.52, p = 0.03) for rs939338, respectively. Conclusions: The association of variants of FASL and ABCC5 with survival outcome after chemotherapy was validated in patients with osteosarcoma. Our findings may provide a new insight into a more personalized treatment for patients with osteosarcoma. Keywords: Pharmacogenetics, Osteosarcoma, Variants, FASL, ABCC