Validity of serum amyloid A and HMGB1 as biomarkers for early diagnosis of gastric cancer

BACKGROUND AND AIM: Gastric carcinomais a frequent neoplasm with poor outcome, and its early detection would improve prognosis. This study was designed to evaluate the possible use of new biomarkers, namely SAA and HMGB1, for early diagnosis of gastric cancer. METHODS: A total of 100 patients presenting with gastric symptoms were included. All patients underwent upper endoscopic evaluation, histopathological diagnosis and serum CEA, SAA, and HMGB1 measurements. RESULTS: Patients were classed endoscopically with neoplastic, inflammatory, and normal-appearing gastric mucosa: 50, 25, and 25 patients, respectively. Histologically, half the patients had chronic gastritis and the remaining cases gastric carcinoma of diffuse (n=28) or intestinal (n=22) type. SAA at cutoff of 18.5 mg/L had the best validity to differentiate gastritis from gastric carcinoma, with AUC, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of 0.99, 98%, 100%, 100%, and 98%, respectively, followed by HMGB1 at cutoff of 14.5 pg/μL, with AUC, sensitivity, specificity, PPV, and NPV of 0.91, 70%, 96%, 94.6%, and 76.2%, respectively. Sensitivity, specificity, PPV, and NPV of serum CEA at cutoff of 2.9 ng/mL to differentiate gastritis from gastric carcinoma were 42%, 72%, 60%, and 55.4%, respectively, with AUC of 0.53. Nonetheless, higher serum levels of both SAA and HMGB1 reflected higher tumor grade (P=0.027 and P=0.016, respectively) and advanced tumor stage (P-OBrk-0.001 for both). CONCLUSION: Serum levels of both SAA and HMGB1 could be of great value for early diagnosis of gastric carcinoma, comparable to the diagnostic role of serum CEA, which is not valid for early diagnosis of gastric cancer.