Immunohistochemical study of nuclear factor‐κB expression in esophageal squamous cell carcinoma: prognostic significance and sensitivity to treatment with 5‐FU

Nuclear factor‐κB (NF‐κB) is expressed in many types of cancers. It has been suggested that the expression of NF‐κB is associated with poor prognosis and resistance to chemoradiation therapies. This study evaluated the relationship between the expression of NF‐κB and the prognosis and sensitivity of esophageal squamous cell carcinoma (ESCC) to chemotherapy. One hundred and nine ESCC specimens, from patients who had undergone radical esophagectomy, were divided into two groups depending on the expression of NF‐κB. Surgical data and prognosis were compared between the two groups. NF‐κB‐positive tumors were detected in 61.5% of the cases. In 69 patients with stage II and III disease, 41 patients who were NF‐κB‐positive showed poor survival. The sensitivity of esophageal squamous cell carcinoma cell lines to 5‐fluorouracil (5‐FU) was analyzed by their NF‐κB expression, and the effect of 5‐FU was evaluated on the proliferation and activity of two cell lines of cultured ESCCs expressing NF‐κB. ESCCs with activated NF‐κB had poor sensitivity to 5‐FU. These results suggest that the increased expression of NF‐κB is associated with poor prognosis in patients with ESCC. NF‐κB may be a target for ESCC therapy because of its selective expression in this type of cancer.