Abstract / Summary
Downregulation of secretory leukocyte protease inhibitors (SLPI) in human hepatocellular carcinoma (HCC) is associated with poor prognosis. We previously reported the upregulation of SLPI in canine HCC, which showed strong enhancement on arterial-phase computed tomography (CT). However, the relationship between the enhancement pattern of canine HCC on arterial-phase CT and prognosis remains unclear. Canine hepatocellular adenoma (HCA) displays enhancement patterns similar to those of HCC on arterial-phase CT. We hypothesized that SLPI expression is associated with arterial-phase enhancement, presence of multiple hepatic lesions, and prognosis. Dogs with HCC ( n = 9) and HCA ( n = 4) were selected for the study. Resected HCC was classified as either enhancement or non-enhancement, and the number of hepatic lesions in HCC and HCA was classified as solitary or multiple on CT. The prognosis was evaluated over a 15-month postoperative follow-up period. Real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay for SLPI were performed on resected tumors and adjacent normal liver tissues. Dogs were classified as having enhancement HCC ( n = 3), non-enhancement HCC ( n = 6), or enhancement HCA ( n = 4). SLPI mRNA differed significantly among enhancement HCC, non-enhancement HCC, and HCA ( p = 0.02, ε² = 0.58). Tumor/normal SLPI protein ratios showed no significant differences among the three groups ( p = 0.73, ε² = 0). In two non-enhancement HCC and two HCA cases, SLPI showed discrepancies between mRNA and protein expression levels. In HCC, multiple lesions significantly occurred in low SLPI ratio cases ( p = 0.048, Φ = 0.8). SLPI expression showed no significant association with recurrence or metastasis in either tumor type. Decreased SLPI expression may be associated with multifocal hepatic lesions or masses.