Abstract:
Objective To explore the correlation between the expression of guanine nucleotide binding protein alpha subunit (Gsα) and the main clinicopathological characteristics and prognosis of pseudomyxoma peritonei (PMP).
Methods Sixty-five postoperative specimens from PMP patients following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were collected. Routine histopathological examination was performed and quantitative immunohistochemical analysis was conducted to evaluate Gsα protein expression. Univariate and multivariate analyses were performed to explore the correlations between the Gsα protein expression levels and the major clinicopathological characteristics—including survival status—of patients.
Results Among the 65 PMP patients, 35 (53.8%) showed a high expression whereas 30 (46.2%) showed a low expression of the Gsα protein. Clinicopathological factors positively correlated with a high expression of Gsα in univariate analysis included increased preoperative tumor marker levels (χ2=3.68, P=0.087), intraoperative ascite volume (χ2=3.69, P=0.055), peritoneal cancer index (PCI) score (χ2=3.12, P=0.077), completeness of cytoreduction (CC) score (χ2=2.72, P=0.099), and histopathological grade (χ2=5.85, P=0.016). Multivariate analysis confirmed a high-grade disease with/ without signet ring cells as the only independent pathological factor positively correlated with a high expression of Gsα odds ratio (OR)=3.47, P=0.029. Cox regression analysis identified four independent prognostic factors: age hazard ratio (HR)=8.08, 95% confidence interval (CI): 2.42-26.97, P=0.001, presence of past surgery (HR=0.24, 95%CI: 0.07- 0.81, P=0.022), histopathological grade (HR=3.92, 95%CI: 1.12-13.70, P=0.032), and Gsα protein expression (HR=3.25, 95%CI: 1.01-10.5, P=0.048).
Conclusions High expression of the Gsα protein is positively correlated with high-grade PMP with/ without signet ring cells, and is indicative of poor prognosis.