In irinotecan-treated patients, T allele of ABCB1C1236T SNP was associated with a lower risk of asthenia(OR = 0.047; 95 % CI = 0.004–0.493; P = 0.011) and Tallele of ABCB1 C3435T SNP was associated with a lower risk of diarrhea (OR = 0.177; 95 % CI = 0.034–0.919;P = 0.039), and individuals with two copies of GSTT1 gene had a lower risk for asthenia (OR = 0.093; 95 %CI = 0.011–0.794; P = 0.030).
The post-menopausal status was related to high levels of asthenia in docetaxel protocol whereas CYP2B6 polymorphism (rs3745274) was related to high levels in FAC protocol.
It could further be shown that volunteers homozygous for the T-allele of SNP rs2416054 showed higher scores in the HA4 subscale 'Fatigability and asthenia' (Pnominal=0.0006), remaining significant after correction for multiple testing (Pwy-corrected=0.045).