Expression And Its Significance Of Retinoic Acid Receptor-alpha In Colon Cancer

Background:With the increased life level, changed life-style of people and population of the aged increasing in our country, the morbidity of colon cancer tends to increase every year in China. Because colon cancer often hides its manifestations at the beginning, patients don’t feel any uncomfortable and can’t find out their disease. When patients notice their symptoms or signs and go to hospital for diagnosis, the stage of neoplasm is so late that patients don’t have a good therapeutic effect. According to The national cancer prevention and control outline (2004-2010), colorectal cancer was one of the eight major cancers which needed to be prevented and treated emphatically. Although the comprehensive treatments of colon cancer have developed rapidly and gained marvelous achievements,5-year survival rate of the patients has not elevated obviously. Retinoid nuclear receptor was always thought to be a possible breach for the prevention and treatment of colon cancer. The majority of materials used in RNR research were cancer cells in vitro, and few researchers took specimens of human cancers as materials.Objective:We could study the different expression of RARα between normal colon mucosa and colon cancer tissue by immunohistochemistry method. Then we studied the relationship between the expression of RAR a in colon cancer and clinicopathological data of patients. The level of serum CEA is an important indicator for estimating prognosis of patients with colon cancer. We could study the relationship between the expression of RAR α and CEA level.Methods:We collected the intact clinicopathological data of60patients who had received surgical therapy for colon cancer in Gastrointestinal Surgery of Shandong Provincial Hospital from January2011to June2011. We could study the different expression of RAR a between normal colon mucosa and colon cancer tissue of60patients by immunohistochemistry method. We could detect the level of serum CEA before surgery by chemiluminescence. The positive result was the coloration on the nucleus of normal epithelial cell or cancer cell. SPSS18.0was used for analyzing the correlation between the expression of RARα in colon cancer and clinicopathological data of patients.Results:The expression rate of RARα in colon cancer (46.7%) was significantly lower than those in normal tissue (80.0%)(P=0.000)。The expression rate of RAR α in advanced stage(TNM stage Ⅲand Ⅳ)(31.0%) was significantly lower than those in early stage(TNM stage I and II)(61.3%)(P=0.019)。And its expression rate in patients with lymph nodes metastasis (32.1%) was also significantly lower than those in patients without lymph nodes metastasis (59.4%)(P=0.035)。 However, there were no significant differences of RAR a expression in ages, genders and pathological tissue differentiations. The level of serum CEA in advanced stage (TNM stage Ⅲ and Ⅳ)(48.3%) was significantly higher than those in early stage(TNM stage Ⅰ and Ⅱ)(12.9%)(P=0.003)。And its level in patients with lymph nodes metastasis (46.4%) was also significantly higher than those in patients without lymph nodes metastasis (15.6%)(P=0.009).There was no correlation between the expression rate of RAR a in colon cancer and the level of serum CEA (P=0.438)Conclusions:1. The expression rate of RAR a in colon cancer was significantly lower than those in normal tissue. RAR a expression in the tumor tissues was decreased with colon cancer TNM stage, suggesting that it may participate in the occurrence of colon cancer.2. The level of serum CEA before surgery was increased with colon cancer TNM stage. There was no correlation between the expression rate of RAR a in colon cancer and the level of serum CEA.