Prognostic significance of CCND1 amplification/overexpression in smoking patients with esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the main subtype of esophageal cancer, with 5-year survival rate less than 30%. In order to offer an individual therapeutic approach, it is necessary to identify novel prognostic factors to recognize high-risk patients. Given the high frequency of CCND1 abnormalities and the important biological effects of smoking in ESCC, we explored the potential relationship between CCND1 abnormalities and smoking in ESCC patients. CCND1 status was examined by fluorescence in situ hybridization and immunohistochemical staining in ESCC tissue microarrays (n = 519). CCND1 amplification and cyclinD1 overexpression were found in 53.2 and 34.1% ESCC, respectively. CCND1 amplification (P = 0.142 for DFS and P = 0.191 for OS) and cyclinD1 overexpression (P = 0.035 for DFS and P = 0.092 for OS) tended to be poorer prognostic factors in all patients. Among smoking patients, those with CCND1 amplification had significantly poorer prognosis, with a median DFS and OS of 25.0 and 30.0 months compared to not reached and 52.0 months for those without CCND1 amplification (P = 0.020 and 0.018). A similar trend was found in the 68 patients with cyclinD1 overexpression (P = 0.043 and 0.048). Further univariate and multivariate analysis revealed CCND1 amplification was independently poorer prognostic factor in smoking patients, which was not found in non-smoking patients. Smokers with CCND1 amplification or cyclinD1 overexpression have poorer survival, which help us to identify distinct groups of patients with apparently poorer outcome and would enable appropriate follow-up and treatment strategies.