Prognostic significance of cyclin E overexpression in laryngeal squamous cell carcinomas

Cyclin E plays a pivotal role in the regulation of G1-S transition and relates to malignant transformation of cells. However, the clinical significance of cyclin E in patients with laryngeal squamous cell carcinoma (LSCC) remains unknown. We examined the expression of cyclin E in 102 patients with LSCC and analyzed its relation to clinicopathological parameters, cell proliferation, and clinical outcome. Cyclin E overexpression was observed in 54 cases (52.94%) of LSCC and was significantly correlated with the tumor site (P = 0.012), tumor size (P = 0.006), poor differentiation (P = 0.026), lymph node metastasis (P = 0.012), and advanced stage (P = 0.002). A positive correlation between the cyclin E expression and proliferative activity of tumor cells was found (r = 0.896; P < 0.0001). Kaplan-Meier analysis showed that shorter disease-free and overall survival was significantly associated with proliferating cell nuclear antigen (PCNA) overexpression and cyclin E overexpression. When PCNA and cyclin E are combined, the patients with both PCNA overexpression and cyclin E overexpression had the poorest prognoses when compared with the other cases. Additionally, in early stage (I-II) cases, cyclin E was also revealed to possess a significant prognostic role. By multivariate analysis, lymph node metastasis and cyclin E overexpression were independent prognostic factors for disease-free survival, and tumor size, lymph node metastasis, advanced stage, as well as cyclin E overexpression were independent prognostic factors for overall survival. These findings indicate that cyclin E overexpression is associated with unfavorable clinicopathological parameters and represents an independent marker for cell proliferation and prognosis of LSCC.