What is the prevalence of anemia in cancer patients undergoing chemotherapy?

Prevalence of Anemia in Cancer Patients Undergoing Chemotherapy

The overall prevalence of anemia during chemotherapy in cancer patients is 54%, with 39% experiencing mild anemia, 14% moderate anemia, and 1% severe anemia. 1

Definition and Classification of Anemia in Cancer Patients

• Anemia in cancer is defined as a decrease in hemoglobin (Hb) level below the normal lower limit, either disease or therapy related 1
• Mild anemia is defined as Hb ≥10 g/dl and ≤11.9 g/dl, moderate anemia as Hb ≥8.0 and ≤9.9 g/dl, and severe anemia as Hb ≤8.0 g/dl 1
• For cancer patients, the National Comprehensive Cancer Network (NCCN) considers Hb level of 11 g/dl or below as a prompt for anemia evaluation 1

Prevalence by Cancer Type

• Anemia prevalence varies significantly by cancer type at diagnosis 1:
  • 32% of patients with non-Hodgkin's lymphoma have anemia at diagnosis 1
  • 49% of patients with gynecologic cancer have anemia at diagnosis 1
  • The highest incidence of chemotherapy-induced anemia is seen in lung cancer (71%) and gynecological cancers (65%) 1

Factors Affecting Anemia Prevalence

• The prevalence of anemia increases with the number of chemotherapy cycles 1
  • The European Cancer Anemia Survey (ECAS) found anemia rates increase from 19.5% in cycle 1 to 46.7% by cycle 5 1
• Platinum-based regimens, commonly used in lung, ovarian, and head and neck cancers, are well-known to induce anemia through combined bone marrow and kidney toxicity 1, 2
• The myelosuppressive effects of cytotoxic agents accumulate over repeated cycles of therapy 1, 2
• Administration of high-risk regimens (with ≥20% risk of anemia in pivotal trials) is an independent predictive factor for severe anemia 3

Mechanisms of Chemotherapy-Induced Anemia

• Chemotherapeutic agents directly impair hematopoiesis in the bone marrow, including synthesis of RBC precursors 1, 2
• Nephrotoxic effects of certain agents (e.g., platinum-containing agents) can lead to decreased renal production of erythropoietin 1, 2
• Cancer itself contributes to anemia through inflammatory cytokines that lead to iron sequestration and decreased red blood cell production 2

Risk Factors for Severe Chemotherapy-Induced Anemia

• Low baseline hemoglobin levels significantly increase the risk of developing moderate to severe anemia during chemotherapy 3, 4
  • 61.9% of patients with mild anemia before chemotherapy develop moderate to severe anemia during treatment 4
• Other risk factors include 3:
  • Body mass index (BMI) less than 23 kg/m²
  • Low hematocrit
  • High haptoglobin
  • High ferritin

Clinical Implications

• Anemia has a negative impact on quality of life and is a major cause of cancer-related fatigue 1
• Anemia is a negative prognostic factor for overall survival in most types of cancer 1
• Patients with anemia have poorer survival and local tumor control than their non-anemic counterparts 5

Monitoring Considerations

• Consider the nadir Hb level (roughly estimated at 2 weeks after chemotherapy, but can vary) when evaluating risk 1
• For patients with a high baseline level, a decrease of 2 g/dl or more should prompt evaluation for anemia 1
• Regular monitoring of hemoglobin levels throughout chemotherapy cycles is essential for early detection and management 2

Understanding the high prevalence of anemia in cancer patients undergoing chemotherapy highlights the importance of proactive monitoring and management strategies to improve patient outcomes and quality of life.