Clinical study on regional lymph nodes of colorectal carcinoma

Objective To explore the metastases in regional lymph nodes of colorectal carcinoma and its clinical significance. Methods Fat clearance method was used to detect regional lymph nodes in colorectal cancer and reverse transcriptase- polymerase chain reaction (RT- PCR) to detect the expression of keratin 19(K19) mRNA in regional lymph nodes of 25 cases with colorectal carcinoma. 242 lymph nodes in all were reanalyzed. Results The detecting numbers of lymph nodes increased from 124 by routine method to 147 by fat clearance method in 13 cases of colorectal cancer. Among 84 negative lymph nodes in 12 cases of colorectal carcinoma, 8 lymph nodes were positive for expression of K19 mRNA by RT- PCR which meant micrometastases. Conclusions More regional lymph nodes can be found by fat clearance method and the K19 mRNA RT- PCR method can detect micrometastases of regional lymph nodes sensitively. These two methods are useful to provide accurate stage for colorectal carcinoma patients and information for prognosis and adjuvant therapy.