RESUMO
AIM: Currently there are some large-scale studies of elevated total vitamin B12 in relation to diseases and their prognosis. Aim of this retrospective study was to determine association of increased B12 as an additional diagnostic marker of oncohematological diseases by a statistical analysis of clinical data of 79,524 patients. MATERIALS AND METHODS: Overall Latvian population representative data on B12 testing in 79,524 patients were obtained from laboratory database. The following exclusion criteria were applied: fluctuating B12 results within a three-month period, elevated (> 100 U/L) alanine transaminase or aspartate transaminase, hepatitis (HAV, HBV, and HCV) infection, reduced glomerular filtration rate (< 45 mL/min/1.73 m2). As a control group, individuals with normal B12 level and any oncologic diagnosis (solid cancer or hematological malignancies) were selected. RESULTS: After application of step-by-step exclusion filters, 1,373 patients were left with significantly increased level of plasma B12 (> 1,700 pg/mL). Odds ratios for oncohematological diseases in total and myeloid leukemia (including acute, chronic and unspecified) in patient group with elevated B12 were found to be 6.0 (95% CI 4.7-7.6; p < 0.0001) and 19.2 (95% CI 13.1-28.0; p <0.0001), respectively, as compared to the control group. CONCLUSION: Elevated total B12 could be considered as a potential marker for oncohematological disorders.