ApoA-I and ApoB levels, and ApoB-to-ApoA-I ratio as candidate pre-treatment biomarkers of pathomorphological response to neoadjuvant therapy in gastric and esophago-gastric junction adenocarcinoma

Introduction: Neoadjuvant chemotherapy (NAC) is a part of the current standard of care in a locally advanced gastric adenocarcinoma (GA) and esophagogastric junction adenocarcinoma (EGJA), but only patients with good pathomorphological response (pR) to NAC benefit from prolonged overall survival. Aim: The study aims to evaluate ApoA-I and ApoB as candidate pre-treatment biomarkers of pR to NAC in patients with GA and EGJA. Materials and methods: Serum samples were collected from 18 patients with GA and 9 with EGJA before the initiation of NAC to determine the ApoA-I and ApoB levels. After NAC tumor regression grade (TRG) was evaluated in resected specimens according to the Mandard's tumor regression grading system and correlated with pre-treatment ApoA-I and ApoB serum concentration, and ApoB-to-ApoA-I serum concentration ratio. Results: We found a positive correlation of ApoA-I level and pR (95% CI: -0.863 to -0.467; P < 0.0001), a negative correlation of ApoB level and pR (95% CI: 0.445 to 0.857; P < 0.0001), a negative correlation of ApoB-to-ApoA-I ratio and pR (95% CI: 0.835 to 0.964; P < 0.0001). Conclusions: ApoA-I and ApoB levels, and ApoB-to-ApoA-I ratio are candidate pre-treatment predictors of pR to NAC in GA and may help to guide personalized therapy.