Study on Clinical Factors Involved in Helicobacter pylori-Uninfected, Undifferentiated-Type Early Gastric Cancer.

BACKGROUND: The factors associated with the pathogenesis of Helicobacter pylori-uninfected undifferentiated-type early gastric cancer (HPUGC) remain unclear. This study compared patient characteristics, including medical history and alcohol/tobacco use, of HPUGC patients with characteristics of patients with H. pylori-positive undifferentiated-type early gastric cancer (HPPGC) to clarify and gain understanding on those differences that could play a role in the pathogenesis.

METHODS: This retrospective study included 282 patients who were treated endoscopically from March 2005 to March 2014. This cohort consisted of 232 patients with HPPGC (82.3%) and 50 patients with HPUGC (17.7%). Patient characteristics were analyzed by subgroups of HPUGC vs. HPPGC, with comparisons for age, gender, cancer history, comorbidity of lifestyle diseases requiring medication (hypertension, type 2 diabetes, and dyslipidemia), cumulative amount of alcohol consumption, and smoking history (Brinkman index [BI]).

RESULTS: HPUGC patients were typically younger, had less frequent hypertension, and had higher BI values (p < 0.05 for all parameters). In a younger non-hypertensive subgroup, the OR for high BI (BI ≥340) in the HPUGC group vs. HPPGC group was 5.049 (95% CI 2.458-10.373, p < 0.0001).

CONCLUSIONS: The investigation of clinical factors identified smoking history as being possibly contributing to the pathogenesis of HPUGC. Future research is necessary at the cellular and genetic levels.