Prevalence and Factors Associated With Achlorhydria Among Patients With Gastric Cancer: A Two-Year Cross-Sectional Study.

BACKGROUND: Achlorhydria, characterized by absent or markedly impaired gastric acid secretion, has been associated with nutritional deficiencies, bacterial overgrowth, and chronic gastric mucosal injury. Altered gastric acid secretion may influence the clinical presentation and biological behavior of gastric cancer; however, evidence regarding its prevalence and associated factors among patients with gastric cancer in South Asia remains limited. OBJECTIVE: This study aimed to determine the prevalence of achlorhydria and evaluate its associations with demographic, laboratory, and clinicopathological characteristics among patients with histologically confirmed gastric cancer. METHODS: A hospital-based cross-sectional study was conducted at Dhaka Medical College Hospital, Bangladesh, from January 2022 to December 2023. One hundred consecutive adult patients with histologically confirmed gastric adenocarcinoma were enrolled. Achlorhydria was defined as a fasting intragastric pH >6.0 measured from gastric aspirate using a calibrated digital pH meter. Demographic, clinical, laboratory, and tumor-related data were collected. Categorical variables were compared using Pearson's chi-square or Fisher's exact test, as appropriate. Variables selected based on univariate analysis and clinical relevance were entered into a multivariable logistic regression model to identify factors independently associated with achlorhydria. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated. RESULTS: The mean age of participants was 60.8 ± 9.4 years, and 68.0% were male. Achlorhydria was identified in 38 patients, corresponding to a prevalence of 38.0% (95% CI: 28.5-48.3). Female sex (aOR: 5.10; 95% CI: 2.00-13.00; p = 0.001), hemoglobin ≤10 g/dL (aOR: 2.95; 95% CI: 1.17-7.48; p = 0.022), and proximal/body-predominant tumor location (aOR: 3.63; 95% CI: 1.41-9.34; p = 0.007) were independently associated with achlorhydria. Long-term proton pump inhibitor use was associated with achlorhydria in univariate analysis but was not independently associated after multivariable adjustment (aOR: 2.12; 95% CI: 0.76-5.91; p = 0.15). CONCLUSIONS: Achlorhydria was common, affecting more than one-third of patients with gastric cancer. Female sex, anemia, and proximal/body-predominant tumor location were independently associated with achlorhydria. Given the cross-sectional design, these findings should be interpreted as associations rather than causal relationships. Larger prospective multicenter studies incorporating comprehensive assessment of gastric mucosal pathology and gastric acid secretory function are warranted to clarify the temporal relationship and clinical significance of achlorhydria in gastric cancer.