Association Of AP-4 Expression In Regional Lymph Nodes With Recurrence In Colorectal Cancer

Background:Colorectal carcinoma(CRC)is one of the tumors that have rising morbidity and mortality both internal and abroad during these years, with the incidence rate is only pulmonary carcinoma, gastric carcinoma, hepatocarcinoma. With the development of the society and living environment, the incidence rate of colorectal carcinoma increased from 10/100000 in 60' to 36.1/100000 in these days because of the changes of diet and living customer. The current treatment of colorectal cancer surgery is still the key tool. The past 20 years, Method of radical resection of colorectal cancer continue to improve, but the prognosis has not improved significantly in patients with radical surgery about 30% to 40% at 5 years showed metastasis and recurrence. These patients also underwent routine examination before, found no overt metastases, metastatic small objective, therefore, not only for the timely detection of micrometastases in colorectal cancer recurrence and prognosis is important, but also have special valueable for clinical treatment. The molecular biology of the specific detection of colorectal cancer markers is an effective indicator of micrometastasis.ObjectiveInvestigate the expression of transcription factor AP-4 in colorectal cancer local lymph nodes,determine whether assessment of occult lymph node metastasis or not an effective indicator;To read the relationship of AP-4 expression and colorectal cancer recurrence; Provide the basis for clinical molecular biology of colorectal cancer staging, prognosis and clinical treatment .Methods1. Immunohistochemical detection of 594 lymph nodes of colorectal cancer by 73 patients (1-33 pieces / cases with a median of 10/cases) .Pathologically HE staining confirmed metastasis is 258, no significant transfer of normal lymph nodes is 336, Detection of AP-4 expression and clinical pathologic parameters. Criterion: In paraffin sections,AP-4 protein expression was mainly localized in the nucleus, showing brownish yellow granules. According to the proportion of all cells and staining intensity of positive cells, the expression of the AP-4 to do semi-quantitative determination.The results by two experienced pathologist assessed, get the mean. Determine the results: A: Points by the number of color cells, no positive staining in tumor cells as compared with 0 points, positive cell rate of≤10% to 1 score, 11% to 50% for 2 score, 51% to 75% for the 3 score,> 75% 4 score. B: points by cell color depth, no positive cells were 0 score, light yellow to 1 score, brown for 2 minutes, dark brown for 3 minutes. Number of points = A×B. 0 score as -, 1 to 4 score as + , 5 to 8 as + +, 9 to 12 as + + +.2. Get 280 of fresh lymph node diameter≥5mm (1-41 pieces / cases with a median of 6.5 / cases) from 28 patients with resected colorectal cancer patients, by RT-PCR method to detect AP-4 in fresh colorectal cancer lymph node tissues.3. SPSS13.0 statistical analysis software used to analyze the expression of the AP-4 and clinical pathological factors using chi-square test, P <0.05 as statistically significant.Results1,Immunohistochemistry:(1) in 73 patients with colorectal cancer in 594 lymph node detection in 314 AP-4 expression positive in lymph node (positive rate was 52.86%), 258 of lymph node metastasis in 242 lymph node expression of AP-4 positive (positive rate of 93.80%), 72 examine AP-4 expression positive in 336 HE staining of normal lymph node tissue (positive rate was 21.43%); (2) 47 cases ofⅢ-Ⅳpatients with only three cases of lymph node-negative, 44 patients more than one or more lymph nodes were detected in AP-4 expression positive; 26 cases in the 0 ~Ⅱpatients, 11 cases (42.31%) patients with lymph node-negative AP-4 expression (P <0.01), the remaining 15 cases (57.69%) patients one or more lymph nodes were detected in AP-4 expression; (3) AP-4 expression was no significant correlation to sex, age, tumor location, gross type (P> 0.05), but significant correlation with tumor differentiation, invasion depth and Duke `s phases (P < 0.05).2,RT-PCR: Of 28 patients, 23 were detected to one or more lymph nodes for AP-4 expression. And histological examination of 15 cases with tumor metastasis in 59 lymph nodes were positive by PCR testing, histological examination negative in 13 cases of 221 lymph nodes, there are 8 patients with Dukes A, B in 51 positive lymph nodes detected by PCR;Conclusion1,AP-4 may serve as the existence of lymph node occult metastasis is an effective indicator;2,AP-4 is highly expressed in the local lymph nodes of colorectal cancer indicate high risk of relapse;3,AP-4 provide the valuable reference for the clinical molecular biology of colorectal cancer staging, prognosis and clinical。...