Thiamine Deficiency and Neurological Symptoms in Patients with Hematological Cancer Receiving Chemotherapy: A Retrospective Analysis.

 Patients with hematological cancer receiving chemotherapy have a high risk of thiamine deficiency due to accelerated thiamine usage by tumor cells. Mild or severe thiamine deficiency can lead to varying degrees of neurological symptoms. We evaluated the relationship between thiamine deficiency and neurological symptoms, including mild or nonspecific symptoms, and the influence of chemotherapy on thiamine serum levels in patients with hematological cancer receiving chemotherapy.  We retrospectively identified 42 patients diagnosed with hematological cancer at our hospital, using electronic medical records collected from March 2019 to March 2020. We evaluated the risk factors associated with neurological symptoms (mild-to-severe cognitive impairment, attention impairment, and mood or emotional disorder), the relationship between the presence of neurological symptoms and thiamine serum levels, and changes in thiamine serum levels after chemotherapy.  Thiamine deficiency was significantly associated with neurological symptoms. The thiamine serum levels in the group with neurological symptoms were significantly lower than those in the group without neurological symptoms. The Wilcoxon rank-sum test showed that thiamine serum levels after chemotherapy were significantly lower than those before administration of chemotherapy.  Thiamine serum levels in patients with hematological cancer may be used as a reference to maintain neurological status during chemotherapy.