Multivariable logistic regression analysis revealed that low baseline RBC count (<3.3 × 106 cells/μL), low baseline hematocrit level (<35%), low baseline hemoglobin level (<11.6 g/dL), and BRCA1/2 mutation were significantly associated with the onset of grade ≥3 anemia (adjusted OR, 3.39; 95% CI, 1.28–9.62; P = 0.017, adjusted OR, 3.63; 95% CI, 1.28–11.64; P = 0.021, adjusted OR, 3.89; 95% CI, 1.39–12.21; P = 0.014, and adjusted OR, 4.09; 95% CI, 1.55–11.67; P = 0.006, respectively). The gene discussed is BRCA1; the disease is anemia.