Relationship between proliferative activity of cancer cells and clinicopathological factors in patients with esophageal squamous cell carcinoma

Abstract

To assess whether the molecular markers of malignant tumors could improve the understanding of tumor characteristics, and to observe the characteristics of expression of cell cycle markers Ki-67 and cyclin A in esophageal carcinoma and to analyze the relationship between proliferative activity of cancer cells and clinicopathological factors. Seventy of surgically resected esophageal squamous cell carcinoma (SCC) were examined by immunohistochemistry utilizing commercially available antibodies. Nuclear staining was regarded as a positive result. At least 50 fields in each tumor and non-tumor section were evaluated at a medium power (X200) to determine the proportion of tumor cells and the staining intensity of nuclei in the entire sections. Ki-67 and cyclin A were only expressed in base cells of normal esophageal mucosa. The positive immuno-staining of nuclei of SCC was significantly higher than that in normal esophageal mucosa (t=13.32 and t=7.52, respectively, P<0.01). The distribution of positively stained was more diffuse and stronger in poorly differentiated SCC. Both Ki-67 and cyclin A expressions were related to histological grades of tumors (t=3.5675 and t=3.916; t=2.13, respectively, P<0.05) but not to the sex and age of the patients, tumor size, lymphatic invasion, location, or stage grouping. The proliferative activity of cancer cells may be understood by immunohistochemistry of Ki-67 and cyclin A in Chinese patients with esophageal SCC. These cell cycle markers may serve as an indicator of cancer cell proliferation rate. The overexpression of cell cycle markers Ki-67 and cyclin A suggests the poor SCC differentiation in patients with esophageal carcinoma.