Vitamin B12 Deficiency After Gastrectomy for Gastric Cancer An Analysis of Clinical Patterns and Risk Factors

Objective: To identify risk factors for postgastrectomy vitamin B-12 deficiency and the time course of its development. Background: Postgastrectomy vitamin B-12 deficiency worsens the quality of life of gastric cancer survivors, and vitamin B-12-related neuropathy is irreversible if recognized late. However, the clinical pattern of vitamin B-12 deficiency development after gastrectomy remains unclear. Methods: We reviewed 645 patients with gastric cancer who underwent distal subtotal gastrectomy (DG; n = 469) or total gastrectomy (TG, n = 176) between 2003 and 2010. Univariate and multivariate analyses were performed to identify risk factors for vitamin B-12 deficiency and time to deficiency. Results: Cumulative vitamin B-12 deficiency rates were 100% for TG and 15.7% for DG 4 years after surgery (P < 0.001). The median time to vitamin B-12 deficiency was 15 months after TG, whereas the median time was not reached after DG. Preoperative vitamin B-12 level was the only risk factor for vitamin B-12 deficiency after TG, whereas both preoperative vitamin B-12 level and age were risk factors after DG. There was positive linear correlation between preoperative vitamin B-12 levels and the time to vitamin B-12 deficiency after either TG (P < 0.001) or DG (P = 0.017). Conclusions: Vitamin B-12 deficiency is an inevitable and rather early metabolic sequela after TG. Elderly patients with low preoperative vitamin B-12 levels are more likely to experience vitamin B-12 deficiency after DG. Thus, preoperative measurement and regular postoperative monitoring of vitamin B-12 levels are necessary for early detection and treatment of postgastrectomy vitamin B-12 deficiency.