High Albumin Expression Promotes Tumor Progression in Gastric Adenocarcinoma

Albumin is abundant in human plasma and has been widely studied in cancer mainly in the context of systemic nutrition or the tumor microenvironment; however, the clinicopathologic significance and intracellular role of tumor-cell albumin in gastric adenocarcinoma remain unclear.

We analyzed 187 patients who underwent gastrectomy for gastric adenocarcinoma between 2000 and 2010. Albumin expression was evaluated by immunohistochemistry on tissue microarrays and classified as high versus low based on intensity relative to intra-tumoral stromal cells. Associations with clinicopathologic variables were examined, and disease-free survival (DFS) and disease-specific survival (DSS) were assessed using Kaplan-Meier and Cox regression. Albumin mRNA/protein expression was examined in three metastatic gastric cancer cell lines, and functional assays (wound healing and proliferation) were performed after siRNA-mediated albumin knockdown in Hs746T cells.

High albumin expression was significantly associated with larger tumor size and advanced T and N stages. Albumin expression was not significantly associated with DFS or DSS in univariate or multivariate analyses, whereas T stage and N stage remained independent prognostic factors. In vitro, albumin knockdown significantly impaired migration and reduced proliferative capacity, despite limited detectable reduction in protein levels.

Tumor-cell albumin correlates with gastric cancer progression and functionally contributes to motility and growth at the intracellular level, supporting its role as a marker of aggressive tumor biology rather than an independent prognostic biomarker.