Expression And Clinical Pathological Significance Of ALDH1 In Colorectal Adenoma And Colorectal Carcinoma

Objective:with the improvement of living stangdards and the change of eating habits, the incidence of colorectal carcinoma is increased gradually, At the same time the rate of colonoscopy in patients with digestive tract disease is far lower than developed European and American countries,So when a lot of patients with colorectal cancer got definitive diagnosis and treatment,they have been in the middle-late stage of disease. Even if they are treated with surgery combined with radiation and chemotherapy, the long-term curative effect is still poor. Often we see a lot of patients received surgical radical surgery happen recurrence or distant metastasis of tumor,the 5-year survival rate of patients is still low.So how can we enable patients to get early diagnosis and early treatment, in order to improve the 5-year survival rate, in addition to develop colonoscopy in the symptomatic elderly patients of domestic.The study found that the cause of the colorectal cancer occurrence and development is also very important.For nearly 20 years the propose and research results of the theory of Cancer stem cells reveal the main reason of the malignant tumor’s occurrence, development and metastasis is the cancer stem cells exist in the tumor tissues. Medical researchers at home and abroad have isolated Cancer stem cells from breast cancer, glioma, prostate, lung, melanoma, liver cancer, ovarian cancer, pancreatic cancer and Colorectal cancer etc. Identification of Cancer stem cells in dependence on the specific cancer stem cell markers. The separartion and identification of cancer stem cell rely on specific cancer stem cell markers in the surface of tumor. Nearly ten years the researchers have found surface biomarkers of colorectal cancer stem cells are CD133, CD44, CD166, rich in leucine repeated unit D protein coupled receptor 5(Lgr5) and ALDH1 etc. ALDH1 was discovered in recent years as the colorectal tumor stem cell marker, domestic and foreign related research is not too much, many scholars think ALDH1 is a very promising cancer stem cell surface markers.Our research is to investigate the expression of aldehyde dehydrogenase 1(ALDH1) in primary colorectal carcinoma, in colorectal adenoma with atypical hyperplasia and in normal tissue adjacent to carcinoma, explore the relationship between expression of ALDH1 and Clinical pathological features of the colorectal cancer.Methods: The research objects were selected from feb 2011 to may 2014, from general surgery and Digestive internal medicine,mianyang people’s hospital, sichuan province. Among the objectst there are 60 cases of colorectal cancer(CRC), 15 cases of colorectal adenomas(CRA), With the approval of science and education department of hospital and the director of pathological department agreed, extract all the pathological specimens of 85 cases in the department of pathology,and Fromthose patients with colorectal cancer cases we selected 10 cases of normal tissue adjacent to carcinoma(adjacent cancer tissues, ACT) specimens as controls.All specimens were confirmed by pathological diagnosis, and 15 cases of colorectal adenomas were moderate to severe atypical hyperplasia. After completing pathological slice of 95 cases of pathological specimen, detect of ALDH1 protein expression in the organization of CRC, CRA and ACT using immunohistochemical enzyme method of the polymer(Labelled dextran polymer, LDP).Analysis of ALDH1 protein expression in each organization’s,and the relationship between ALDH1 expression and clinical pathological factors of CRC.Results: The positive expression of ALDH1 in colorectal cancer tissues are 51 cases in 60 cases, positive expression rate is 85%. 6 cases of colorectal adenomas ALDH1 positive expression in 15 cases, the expression of the negative are 9 cases, Positive expression rate is 40%.ALDH1 expression of 2 ACT cases is positive expression in 10 cases, Negative expression is 8 cases, positive expression rate is 20%.The Fisher’s Exact Test ’(Exact probability method) inspection conclusion. The expression of ALDH1 in tissue adjacent to carcinoma, colorectal adenomas and colorectal cancer are statistically different(P < 0.001). The three ALDH1 positive expression rate is not completely consistent.Further to compare colorectal carcinoma to colorectal adenomas、the tissue adjacent to colorectal carcinoma、the tissue adjacent to colorectal adenomas respectively, the results found that colorectal carcinoma and colorectal adenomas, tissue adjacent and colorectal carcinoma on the ALDH1 positive expression rate was statistically different. Experiment found that there were no difference(P > 0.05) of ALDH1 expression in colorectal cancer patients with age, gender, tumor site, tumor differentiation degree and lymph node metastases. And there is statistically significant difference(P < 0.05) in the clinical TNM stages of cancer. By statistical analysis,the expression of ADHL1 in colorectal carcinoma was not correlated with the age, gender,cancer site, cancer differentiation degree and lymph node metastases of colorectal cancer(P>0.05), however, the expression of ALDH1 was significantly correlated with TNM stages of cancer(P<0.05).Conclusion: ALDH1 expression in colorectal cancer tissue was significantly higher than that of colorectal adenoma and normal colorectal tissues,,the difference was statistically significant.In patients between different age groups, gender there were no statistial significant defferences in the distribution of ALDH1 expression,,so patient’s age, gender and ALDH1 express are not correlated. ALDH1 positive express no statistically significant differences in the aspects of different pathological changes, with or without lymphatic metastasis, with different degree of differentiation,The difference between different clinical TNM staging of colorectal carcinoma and ALDH1 positive expression difference was statistically significant(P < 0.05).ALDH1 expression have significant correlation with clinical TNM staging of colorectal carcinoma., prompt ALDH1 may become an auxiliary examination clinical index relevant TNM staging of colorectal carcinoma in the future. The experiment proved that ALDH1 has certain specific expression in colorectal carcinoma. ALDH1 as a new cancer stem cell markers can be used in the diagnosis of colorectal cancer. This study statistical methods using SPSS16.0 statistical software package for analysis,the inspection level is set to 0.05,when P < 0.05, supose that the difference is statistically significant,. Statistical methods are : Use 2?inspection for difference, when there is a theoretical frequency is too small, shall not apply to the 2? inspection,choose the Fisher’ Exact Test.