Gender and smoking differences in cell cycle marker expressions and p-TNM stage in non-small cell lung carcinoma

Background and aim: A gender difference has been linked to the incidence and mortality of lung carcinomas. However, a comprehensive investigation including immunohistochemical studies of the gender difference involved in lung carcinoma progression has not been conducted. Methods: A total of 66 adenocarcinoma (AD) and 102 squamous cell carcinoma (SQ) samples were analyzed using immunohistochemistry for cell cycle-specific markers cyclin A, cyclin B1, cyclin D1 and Ki-67. Automated silver-enhanced in situ hybridization was used to evaluate epidermal growth factor receptor (EGFR) copy number. Results: For AD, male sex was significantly associated with the expression of cyclinA, cyclinB1 and high pathological tumor-node-metastasis (p-TNM) staging. For SQ, ever-smokers were associated with the expression of cyclin B1 and cyclin D1. For AD, ever-smokers were associated with the expression of cyclin A, cyclin B1 and Ki-67. There is no statistical significant correlation of smoking history with p-TNM stage and EGFR gene copy number in the AD or SQ, although the number of cases is limited. Conclusions: These results indicate that a gender difference contributes to AD growth and that smoking is associated with SQ and AD growth. The differential effects of gender and smoking differences may contribute through different pathways for AD and SQ subtypes.