Overexpression of cyclin E isoforms correlates with poor prognosis in rectal cancer

Aims

To investigate the expression of cyclin E isoforms in rectal cancer and its relations to clinicopathological factors and survival.

Materials and methods

Cyclin E expression was assessed by Western blot in 360 resected rectal cancer patients of stage I to III. Multivariate analysis was applied to indicate the independent prognostic markers in this cohort.

Results

Nineteen percent, 24% or 29% patients exhibited elevated levels of full-length (FL) cyclin E, low-molecular-weight (LMW) cyclin E or total cyclin E in their tumors respectively. Significant correlation was observed between cyclin E expression with blood vessel invasion, deeply invasive tumors, histology grade and lymph node metastasis. Moreover, patients with high levels of LMW-cyclin E or total cyclin E had a poorer 5-year overall survival than did patients with low levels of LMW-cyclin E or total cyclin E. In multivariate analysis, both the LMW-cyclin E and total cyclin E, but not FL-cyclin E, remained independent prognostic indicators in both patients with stage I to III and in those with early stage. Patients with elevated LMW- or total cyclin E levels had a hazard ratio for death from rectal cancer of 6.302 (95% CI, 1.903-17.81, p = 0.001) or 4.332 (95% CI, 1.298-16.362, p = 0.001).

Conclusion

Overexpression of the LMW-cyclin E or total cyclin E is a strong predictor for poorer survival in patients with rectal cancer. Therefore, evaluating cyclin E expression may provide useful prognostic information for resectable rectal cancer patients.