Subclinical thiamine deficiency identified by pretreatment evaluation in an esophageal cancer patient

Despite the fact that both thiamine deficiency (TD) and Wernicke encephalopathy (WE) have been observed to some degree in cancer patients, such cases of TD and/or WE reported to date have all been diagnosed after the initiation of treatment. We here report a case of TD that presented without the commonly accepted triad of WE symptoms based on a total nutritional evaluation prior to the onset of treatment for cancer. The patient was a 71-year-old man with esophageal cancer who was referred to the oncology outpatient clinic for evaluation to determine the treatment plan. Although he did not present with delirium, cerebellar signs, or ocular symptoms, TD was suspected based on a reduction in appetite lasting 2 months as thiamine stores in the body are depleted in as few as 18 days. Blood findings showed a marked decline in serum thiamine level supported, which the diagnosis of TD. This case revealed the existence of a cancer patient with subclinical TD prior to the onset of treatment for cancer. Due to the fact that TD can occur without the characteristic symptoms as in this case, we believe it is important that total nutritional evaluation of cancer patients always be considered.