<b><br>Introduction:</b> 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.</br> <b><br>Aim:</b> The study aims to evaluate ApoA-I and ApoB as candidate pre-treatment biomarkers of pR to NAC in patients with GA and EGJA.</br> <b><br>Materials and methods:</b> 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.</br> <b><br>Results:</b> 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).</br> <b><br>Conclusions:</b> 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.</br>Our work fits into the dynamically developing trend of personalized treatment. It describes a potentially important rationale for further evaluation of apolipoprotein A-I and apolipoprotein B as predictors of cancer response to neoadjuvant therapy.
Keywords: apolipoprotein A-I; apolipoprotein B; biomarkers; esophagogastric junction adenocarcinoma; gastric adenocarcinoma; neoadjuvant therapy; pathomorphological response.