Abstract
Wnt7a is a known tumor suppressor gene in non-small cell lung cancer that regulates normal cellular proliferation and differentiation. The purpose of this study was to investigate the clinicopathologic significance of Wnt7a expression in colorectal adenocarcinoma. Wnt7a expression was immunohistochemically examined in 46 normal colorectal tissues, 47 tubular adenomas, 393 adenocarcinomas, and 93 lymph node metastases. Wnt7a was expressed in the cytoplasm. Loss of Wnt7a expression was more frequent in adenocarcinoma and lymph node metastasis compared to that in normal and tubular adenoma (P < 0.001). Wnt7a expression was inversely correlated with tumor size (P = 0.026), gross type (P = 0.008), differentiation (P = 0.009), vascular invasion (P = 0.038), tumor deposit (P = 0.007), tumor invasion (T category) (P = 0.003), lymph node metastasis (N category) (P < 0.001), and AJCC stage (P < 0.001). There was a significant correlation between loss of Wnt7a expression and overall survival and disease-free survival (P < 0.001 and P = 0.001, respectively) on univariable analysis. On multivariable analysis, loss of Wnt7a expression was an independent prognostic factor for both overall and disease-free survival (P = 0.002 and P = 0.047, respectively). Loss of Wnt7a expression may contribute to the carcinogenesis and tumor progression of colorectal adenocarcinoma and may be a new prognostic marker of colorectal adenocarcinoma.