Clinical significance of EMA in detection of lymph node micrometastasis of colorectal cancer

Abstract

Objective To evaluate the prognostic impact of a wide spectrum of pathologic parameters in a consecutive series of homogenously treated and well-characterized patients with stage Ⅰ and Ⅱ coloreetal cancer,and the prognostic value of lymph node occult disease(micrometastasis)in disease-free survival rate detected by immunohistechemistry with epithelial membrane antigen.Methods The study included 126 patients operated on by a single surgeon for stage Ⅰ and Ⅱ colorectal tumors.The average postoperative follow-up period was 64.11(range,64-106)months.At least 10 more lymph nodes were harvested and examined in all the specimens.The prognostic value of 10 pathologic parameters,including lymph node occult disease(micrometastasis)detected by immunohistochemistry,was investigated.Results Multivariate analysis identified lymphatic vessel invasion(absent or present;P ＜ 0.05)and depth of tumor invasion(T1,T2,T3 or T4;P ＜ 0.05)in positive and negative lymph nodes by immunohistochemistry with epithelial membrane antigen.The five-year disease-free survival rate was 74.6,68.0 and 46.2 percent for the negative lymph node negative,isolated tumor cells and micrometsstasis groups,respectively.There was significant difference between the lymph node negative and micrometastasis groups(P ＜ 0.05),however;the lymph node negative and isolated tumor cells groups were no significant dfferrence(P ＞ 0.05).Conclusion We propose that patients found micrometastasis in lmphy node with high-risk Stage Ⅰ and Ⅱ colorectal cancer for whom adjuvant therapies may be justified and effective. Key words: Carcinoma of rectum; Prognosis; Lymph node metastasis