Clinical analysis of serum vitamin B12 levels in patients with gastric cancer before and after surgery

Abstract

Objective To investigate the factors which have effects on serum vitamin B12 levels in patients with gastric cancer before surgery, as well as the short-term effect of radical operation on serum vitamin B12 levels. Methods The clinical data of 177 patients with gastric cancer who underwent radical gastrectomy in Peking Union Medical College Hospital from 2009 to 2014 was analyzed retrospectively. The relationship between preoperative serum vitamin B12 levels and clinicopathological features was analyzed and the short-term effects of different radical operations on serum vitamin B12 levels were compared. Results The serum vitamin B12 levels in 18.6% gastric cancer patients were lower than normal values. The NRS 2002 (Nutrition Risk Screening 2002) score in lower vitamin B12 group was higher than that in normal group (69.7% vs. 47.9%, χ2=5.102, P=0.024). The anemia proportion in lower vitamin B12 group was higher than that in normal group (57.6% vs. 35.4%, χ2=5.514, P=0.019). The infection proportion of Helicobacter pylori in lower vitamin B12 group was higher than that in normal group (66.7% vs. 47.2%, χ2=4.061, P=0.044). The serum vitamin B12 level in gastric cancer patients one month after operation was lower than before operation [(390±226) pg/ml vs. (462±240) pg/ml, t=5.669, P=0.000]. The serum vitamin B12 level in patients receiving total gastrectomy one month after operation was lower than that in patients receiving subtotal gastrectomy [(347±216) pg/ml vs. (417±229 )pg/ml, t=2.025, P=0.044]. Conclusions Preoperative gastric cancer patients may suffer from vitamin B12 deficiency, which is related with NRS2002 score, anemia and Helicobacter pylori infection. Gastrectomy increases the risk of vitamin B12 deficiency. Key words: Stomach neoplasms; Vitamin B12 deficiency; Gastrectomy