Clinical significance of lymph node micrometastasis of colorectal cancer detected by immunohistochemistry / 复旦学报（医学版）

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 colorectal cancer, and to investigate the prognostic value of lymph node occult disease (micrometastasis) in disease-free survival rate detected by immunohistochemistry with epithelial membrane antigen and carcinoembryonic antigen. Methods The study included 126 patients operated on by a single surgeon for stage Ⅰ and Ⅱ colorectal tumors. The postoperative follow-up was performed for 64 to 106 months. At least 10 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=0.009) in lymph node positive and negative by immunohistochemistry. The five-year disease-free survival rates were 78.7%, 65.5% and 43.8% for the lymph node negative, isolated tumor cells and micrometastasis groups, respectively. There was significant difference between the lymph node negative and micrometastasis groups (P=0.005). However, the difference between the lymph node negative and isolated tumor cells groups was not statistically significant (P=0.144). Conclusions We propose that for patients found micrometastasis in lymph node with high-risk stage Ⅰ and Ⅱ colorectal cancer, adjuvant therapies are justified and effective.