The anemia symptoms that appeared in the first two cycles of FAC chemotherapy (early anemia) were associated with the presence of three genetic factors: ABCC1 rs129081 common homozygote GG (OR 3.52; 1.018–10.51; p = 0.023), AKR1C3 rs3209896 variant AG (OR 5.85; 1.56–21.83; p = 0.008), and RALBP1 rs12680 allele C (OR 4.41; 1.42–13.74; p = 0.009) (Table 1). Here, ABCC1 is linked to anemia (phenotype).