Predictive risk factors and prevalence of malignancy in patients with iron deficiency anemia in Taiwan.

Gastrointestinal (GI) tract malignancy is one of the important causes of chronic iron deficiency anemia (IDA). The present study was designed to find out the prevalence and the predictive risk factors of malignancy in the IDA patients. We performed a prospective study in 148 patients with chronic IDA. A series of examinations to explore the GI tract were performed either by radiology and/or endoscopy. A Tc-RBC GI bleeding study was also performed, and prevalence and risk factors of malignancy were calculated. Totally 148 patients were enrolled, with mean age 66.2 years; 88 were male. Eighteen patients (12.2%) were found to have malignant tumors. Ten (6.8%) had benign tumors, and 96 (64.9%) had other benign conditions. No lesions could be detected in 24 patients (16.2%). Clinical symptoms and presence of fecal occult blood could not predict malignancy or any GI lesions. Multivariate logistic regression analysis showed serum ferritin < or =10 microg/L, LDH >250 U/L, and aging as the risk factors of malignancy in the IDA patients (P = 0.003, 0.002, and 0.027; and OR = 7.614, 8.955, and 1.062, respectively). An IDA patient with both serum ferritin < or =10 microg/L and LDH >250 U/L ran a 74.33-times higher risk of malignancy than the patient without (95% CI: 7.115-776.479). Malignancy was an important cause of IDA. High LDH, low serum ferritin, and aging were the risk factors of malignancy in the IDA patients.