The positive ubiquitin D expression predicts poor survival in postoperative stage II colon cancer patients treated with postoperative adjuvant chemotherapy

Abstract

Objective To investigate the expression of human ubiquitin D (UBD) and its role in tumor relapse and non-relapse group patients who received 5-fluoruracil-based adjuvant chemotherapy after surgery.Methods In this study 106 stage Ⅱ patients treated with postoperative 5-fluoruracil (5-fu)-based adjuvant chemotherapy were enrolled,and divided into two groups:recurrence group (35 cases) and nonrecurrence group (71 cases).The expression of UBD mRNA was detected by real-time quantitative polymerase chain reaction (real-time PCR) in respective 20 matched cancer and normal colonic membrane tissues of stage Ⅱ colon cancer patients in the two groups.Immunohistochemistry was used to study UBD expression in 35 patients with recurrence and 71 non-relapse patient's cancer and normal tissues.Chi-square test or Fisher's exact test were used and evaluated the hazard ratio (HR) of disease-free survival(DFS) and overall survival(OS) by using Cox proportional hazard model.Results The average expression level of UBD mRNA in 20 relapse and non-relapse group patients were 7.64 and 2.07 (x2 =10.7,P ＜ 0.01),respectively ; UBD positive staining in relapse and non-relapse group patients were 86％ (30/35),and 59％ (42/71) (x2 =7.59,P ＜ 0.01).The 5-years DFS (P ＜ 0.05) and OS (P ＜ 0.05) decreased significantly in UBD positive cases.Conclusions UBD is an independent prognostic factor for DFS and OS in postoperative Stage Ⅱ colonic cancer patients treated by post oprative chemotherapy. Key words: Ubiquitins; Colon neoplasms; Antineoplastic combined chemotherapy protocols