Cancer Treatment-Related Thrombocytopenia

Introduction

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  A multitude of cancer treatments are known to cause thrombocytopenia (TCP), termed treatment-related thrombocytopenia. Chemotherapy-induced thrombocytopenia (CIT) is a term that refers specifically to thrombocytopenia caused by chemotherapy drugs. Notably, many nonchemotherapy cancer treatments may also cause thrombocytopenia.

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  The normal platelet range is 150,000 to 450,000/µL. The National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) defines TCP according to grade. Grade 1 is 75,000 to 150,000/µL, Grade 2 is 50,000 to 75,000/µL, Grade 3 is 25,000 to 50,000/µL, and Grade 4 is less than 25,000/µL. Although the risk of bleeding with TCP is difficult to ascertain fully, general practice is to avoid surgical procedures for platelets less than 50,000/µL (100,000–75,000/µL for central nervous system [CNS] procedures). Furthermore, spontaneous bleeding is possible at platelet counts less than 20,000/µL, but more consistently at levels of less than 5000 to 10,000/µL. ^,