Differential features of gastric cancer patients, either Helicobacter pylori positive or Helicobacter pylori negative

Background: Helicobacter pylori infection is associated with an increased r isk of gastric cancer In Helicobacter pylori negative patients, factors dif ferent from those in Helicobacter pylon: positive patients may be involved in gastric carcinogenesis. Methods: Thirty-nine recently diagnosed consecutive patients with gastric c ancer were investigated Gastric biopsies were obtained for detection of Hel icobacter pylori (by immunohistochemistry), non-Helicobacter pylori flora ( by modified Giemsa and culture) and histological assessment according to th e Sydney classification by Haematoxylin-Eosin staining. In serum samples, H elicobacter pylori antibodies were determined by IgG enzyme-linked immunoso rbent assay, IgA enzyme-linked immunosorbent assay, and Western blotting. F urthermore, serum gastrin, pepsinogen A and C and plasma chromogranin A wer e determined. Results: Helicobacter pylori was detected by immunohistochemistry in 53.8%, by IgG; in 56.4%, by IgA in 33.3%, and by Western blotting in 74.4% of the 39 patients. Ten patients (25.6%) were negative by both histology and sero logy. Non-Helicobacter pylori flora was detected in 27 of the 39 patients ( 69.2%) with a similar frequency in Helicobacter py lori positive and negati ve patients. Helicobacter pylori positivity was found significantly more of ten in diffuse than intestinal type carcinoma patients (p<0.05). Elevated g astrin levels and antrum-sparing atrophic gastritis were more fre quent in Helicobacter pylori negative than in Helicobacter pylori positive patients (p<0.05). Conclusions: In 10 out of 39 gastric cancer patients, no evidence of previo us or current Helicobacter pylori infection could be demonstrated. Non-Heli cobacter pylori was found in 69.2% of patients regardless of the Helicobact er pylori status. Further studies are needed to establish the contribution of non-Helicobacter pylori flora as well as antrum-sparing atrophic gastrit is with hypergastrinaemia to the development of gastric cancer.