Background: Esophageal cancer is a lethal disease and the optimal therapy remains unclear. Neoadjuvant chemotherapy provides an increased chance of survival; therefore, we attempted to identify potential molecular markers that might improve evaluations of individual responses to therapy.
Methods: We recruited 109 patients with resectable esophageal squamous cell carcinoma. The patients underwent radical esophagectomy and did not receive any other perioperative treatment. Expression of E2F-1 and molecules involved in its targeted pathways, pERK, Bim, pRb, epidermal growth factor receptor, EZH2 and pAKT, was investigated immunohistochemically.
Results: Correlations were observed between E2F-1 and pRb expression; EZH2 expression was significantly correlated with the degree of carcinoma differentiation (P = 0.01). Stage III patients were found to have longer survival if they did not express pERK than if they did (23 months vs. 11 months, P = 0.01). Patients with E2F-1 not expressing pRb were found to have longer survival times than those with E2F-1 who expressed pRb (18.8 months vs. 8.6 months, P = 0.021). Similarly, stage III patients with E2F-1 but not expressing pERK also survived longer than those expressing pERK (23.5 months vs. 3.9 months, P < 0.001).
Conclusions: A high expression of pERK was significantly associated with poor survival in patients with locally advanced esophageal cancer. Expression of a combination of molecules, rather than of individual molecules, was more predictive of disease prognosis. E2F-1 and molecules of its targeted pathways may be candidate proteins as markers of chemosensitivity in esophageal cancer patients.
Keywords: E2F-1; esophageal squamous cell carcinoma; survival.