We noticed that older cancer patients had a higher prevalence of a history of anemia at admission (p=0.039), were more likely to be in palliative care (p=0.009), had a poorer ECOG performance status (p=0.029), required more blood transfusions (p=0.011), and had more Hb decrease levels (g/dL) during treatment (p=0.020) compared to younger patients (<65 years). The gene discussed is GSTM1; the disease is anemia.