Anaemia
A shortage of red blood cells or haemoglobin, causing tiredness and breathlessness. In cancer it comes from the disease itself (marrow infiltration, bleeding, inflammation), from chemotherapy suppressing the marrow, and from some targeted drugs.
Overview
Present in 30-90% of patients depending on cancer and treatment; a defining feature of myeloma, MDS and leukaemia, and the dose-limiting toxicity of PARP inhibitors (olaparib, talazoparib) and of some ADCs and radioligands. Managed by treating the cause, iron replacement, red cell transfusion (with restrictive thresholds) and, cautiously, erythropoiesis-stimulating agents, which raise thrombosis risk and were linked to worse outcomes when used to high targets. Transfusion independence is an endpoint in MDS trials (luspatercept, imetelstat). Fatigue from anaemia is one of the most common and under-treated symptoms in oncology.