Anemia/etiology; Anemia/therapy; Antineoplastic Agents/adverse effects; Blood Component Transfusion; Hematinics/therapeutic use; Iron Compounds; Neoplasms/complications; Neoplasms/therapy; Anemia/chemically induced; Anemia/drug therapy; Anemia/economics; Anemia/prevention & control; Antineoplastic Agents/administration & dosage; Blood Component Transfusion/economics; Drug Costs; Fatigue/chemically induced; Fatigue/drug therapy; Health Care Surveys; Hematinics/economics; Humans; Infusions, Intravenous; Iron Compounds/administration & dosage; Iron Compounds/adverse effects; Iron Compounds/economics; Iron Compounds/metabolism; Medical Oncology/statistics & numerical data; Neoplasms/metabolism; Pharmacists/statistics & numerical data; Physicians/statistics & numerical data; Practice Patterns, Physicians'/statistics & numerical data; Quality of Life; Reimbursement Mechanisms; Severity of Illness Index; United States; Workforce