Published online May 28, 2020. doi: 10.3748/wjg.v26.i20.2618
Peer-review started: January 28, 2020
First decision: February 27, 2020
Revised: March 25, 2020
Accepted: May 14, 2020
Article in press: May 14, 2020
Published online: May 28, 2020
In recent years, awareness of eradication therapy has increased in Japan. As Helicobacter pylori(H. pylori) infections decrease, the proportion of gastric cancers arising from H. pylori uninfected gastric mucosa will increase. The emergence of gastric cancer arising in H. pylori uninfected patients though rarely reported, is a concern to be addressed and needs elucidation of its clinicopathological features.
Previously, H. pylori-uninfected gastric cancer including case report such as undifferentiated gastric cancer or fundic gland-type gastric cancer was reported. However, due to the rare frequency, there was very few reports. In the future, H.pylori-uninfected gastric cancer may increase relatively; therefore, importance of clarifying the clinicopathological features of those is desired. In this study, we experienced 30 cases of H. pylori-uninfected early gastric cancer and could classify histopathological features of these.
To clarify clinicopathological feature of H. pylori-uninfected gastric cancer (HpUNGC) treated by endoscopic submucosal dissection (ESD).
This study is retrospective study. A total of 2462 patients with 3375 instances of early gastric cancers that were treated by ESD were enrolled in our study between May 2000 and September 2019. We defined a patient as H. pylori-uninfected using the following three criteria; i) the patient did not receive treatment for H. pylori, which was determined by investigating medical records and conducting patient interviews, ii) lack of endoscopic atrophy, and iii) the patient was negative for H. pylori after being tested at least twice using various diagnostic methods, including serum anti-H. pylori-IgG antibody, urease breath test, rapid urease test, and microscopic examination.
Of these, 30 lesions in 30 patients were diagnosed as HpUIGC. Histologically 30 HpUIGC lesions were classified into 4 types (fundic gland type adenocarcinoma, foveolar type well-differentiated adenocarcinoma, intestinal phenotype adenocarcinoma, and pure signet-ring cell carcinoma). Unlike previous reports, most of the lesions (22/30 lesions) were the differentiated type.
In this study, we classified 30 HpUIGCs into 4 types histologically. Unlike previous reports, there were more differentiated cancers than undifferentiated cancers. Although the most of HpUIGC showed gastric phenotype, it is essential to recognize that there are not a few intestinal phenotype adenocarcinomas among HpUIGCs. HpUIGC is very rare, among which, histologically high incidence of undifferentiated adenocarcinoma. Besides undifferentiated adenocarcinoma and gastric fundic gland type adenocarcinoma, there is another HpUIGC having different histopathological features. HpUIGC may show various type of his-topathological features. Histologically, HpUIGC is classified into at least 4 types (fundic gland type adenocarcinoma, foveolar type well-differentiated adenocarcinoma, intestinal phenotype adenocarcinoma, and pure signet-ring cell carcinoma). To the best of our knowledge, the present study reports the largest number of HpUIGC cases that had been evaluated for both endoscopic and pathological findings. To recognize clinicopathological feature of HpUIGC will be helpful for early detection of HpUIGC in the future clinical practice.
To recognize the various clinicopathological features of HpUIGC is useful for clinical diagnosis in the future. Because HpUIGC is rare frequency, we consider multicenter clinical trial for case collection to elucidate more detail of the clinicopathological characteristics of HpUIGC. Multicenter observational trial is the best method for the future research.