Anaemia is defined as a haemoglobin level <14g/dl for men and <12g/dl for women. Anaemia is a frequent finding in cancer patients, occurring >40% of cases, the incidence of anaemia may rise to 90% in patients treated with chemotherapy.
The pathophysiology origins of anaemia in cancer can be grouped into different categories:
- Blood loss
- Increased production of red blood ceels
- Decreased production of functional red blood cells
These three mechanisms are often intricately linked, and the origin of anemia in cancer patients is often multifactorial. It works this way:
CANCER INDUCED ANAEMIA: This results from a fine interplay of pro- and antiapoptotic factors inducing a fine tuned selective differentiation of the trilineage committed haematopoietic stem cell. A slight disruption of this equillibrium will present as one of the many facets of blood count changes. GATA-1 and GATA-2, tumor necrosis factor (TNF), interleukin-6, interleukin-1, interferon-y all play a role in this:
- TNF INDIRECTLY INHIBITS THE THE PROLIFERATION OF ERYTHROID PROGENITOR CELLS BY TRIGGERING NUCLEAR FACTORS-kB AND GATA-2 PATHWAYS THUS SUPPRESSING ERYTHROPOIETIN PRODUCTION.
- INTERLEUKIN-6 INDUCES LIVER PRODUCTION OF HEPCIDIN WHICH DECREASES IRON ABSORPTION FROM THE BOWEL AND ITS UTILIZATION IN THE BONE MARROW.
- OTHER CYTOKINES SUCH AS INTERLEUKIN-1, INTERLEUKIN-6 AND INTERFERON-y, HAVE BEEN SHOWN TO INHIBIT ERYTHROID PRECURSORS IN VITRO.
CHEMOTHERAPY ASSOCIATED ANAEMIA: Some chemotherapeutic agents induce anaemia by impairing haematopoiesis. In addition the nephrotoxic and cytotoxic agents such as platinum salts can also lead to the persistence of anaemia through reduced erythropoietin production by the kidney. This type of anaemia is commonly seen in lung cancers and gynaecological malignancy partly due to the fact that their treatment requires platinum based regimens.
TREATMENT: Iron therapy and blood transfusion. These pose their side effects. This is due to deranging effects of cancer on the body system.
REFERENCE: European Society for Medical Oncology.