Helicobacter pylori-seronegative gastric carcinoma: a subset of gastric carcinoma with distinct clinicopathologic features.

BACKGROUND/AIMS: The frequent association of gastric atrophy and intestinal metaplasia in gastric cancer (GC) might preclude serologic detection of Helicobacter pylori (H. pylori) infection in GC. By using polymerase chain reaction (PCR) for detection, we would like to determine whether there exists a subset of genuinely H. pylori-negative GC patients, and whether they have distinct clinicopathologic features or not.

METHODOLOGY

IgG antibodies against H. pylori were determined by ELISA in sera, and H. pylori DNA was detected by PCR in resected gastric specimens from 160 GC patients. Clinicopathologic characteristics were then compared among group A: seropositive, group B: seronegative but PCR-positive, and group C: seronegative and PCR-negative.

RESULTS

Among 160 patients, 105 (65.6%) were classified as group A, 25 (15.6%) as group B, and 30 (18.8%) as group C. Group B patients were older and had more infiltrative tumor growth than group A. Group C had a significantly higher frequency of female predominance, and their cancers were of a more cardiac location and of the diffuse histologic subtype than those of groups A and B.

CONCLUSIONS

A significant portion (15.6%) was negative to ELISA but positive to PCR, suggesting that older ages and infiltrative tumor growth might preclude serologic detection of H. pylori infection by impairing humoral responses. Although the majority (81.2%) has a strong association with H. pylori infection, an H. pylori-negative subset indeed exists and has distinct clinicopathologic features, supporting that causes other than H. pylori infection are involved in GC carcinogenesis.