The Effect Of Lateral Lymph Node Dissection On The Postoperative Recurrence Rate Of Mid-low Rectal Cancer

Rectal cancer is one of the malignant tumors which possess high morbidities and mortalities worldwide. In China, the morbidity of rectal cancer is at the third place, and mortality,10.25/0.1million, at the fifth place among malignant tumors. Compared to western countries, the domestic characteristics of rectal cancer as followed:the proportion of mid-low rectal cancer, approximately 70%, is higher than that in the western. And in most cases, doctors could find the tumor by careful digital rectal examination. Another one is that the morbidity of youthful patients is as high as 15%. Most cases, which come to see doctors as the typical changing of defecating habit occurs, are of advanced rectal cancer when they get clinical diagnosis. According to the test, the proportion of the cases which tumors invade the mesorectal layer or surpass it, is 84.5%(231/287). It is not difficult to diagnose rectal cancer through careful physical examination and fitting assistant examinations, and evaluate the case with histopathological classification and intramural invasion so as to determine the individual therapeutic schedule. Surgery as the main method combined with chemoradiotheropy is the typical treatment. Surgical operation based on TME has greatly developed that could combine lateral lymph node dissection and pelvic automatic nerve preservation. Recently the concept of Multidisciplinary Synthetic Therapy appeals to draw increasingly more attention. As the regularity of perirectal lymphatic drainage is known, lateral lymph node takes a important role in perirectal lymph node metastasis, especially in mid-low rectal cancer in which lateral lymphatic metastasis is the main direction as confirmed by plenty of researches. However, there exists universal controversy that whether it is necessary of lateral lymph node dissection for mid-low rectal cancer, and whether the extended resection can reduce the recurrence rate and improve the survival rate. Japanese researchers have reached a widespread agreement of the value of lateral lymph node dissection. By contrasted, the western researchers reckon that lateral lymph node metastasis demonstrates the occurrence of distant metastasis, and it could not improve patient prognosis.Purpose:To research the effect of lateral lymph node dissection on the postoperative recurrence rate of mid-low rectal cancer.Methods:Retrospective research about 287 mid-low rectal cancer cases during 2006 to 2009, divided into two groups:one is test group in which patients have received extended operation of TME-based lateral lymph node dissection, the other control one including patients got operation of TME-only. By analysis of the lymph node metastasis and the postoperative recurrence rate between the two groups, draw a conclusion that whether the extended operation in mid-low rectal cancer could reduce the recurrence rate.Results:There is no significant difference in recurrence rate according to different Dukes Classifications between two groups. Test group with the general recurrence rate of 4.2% has significant difference compared to control group of 15.3%. According to Dukes and histopathological classification, lymph node/lateral lymph node metastasis rate turns out to be higher with more invasive Dukes classification and more malignant histopathological type.ConclusionsThe author reckons that the extended operation of TME-based lateral lymph node dissection could reduce the postoperative recurrence rate in mid-low rectal cancer. And according to Dukes and histopathological classification, lymph node/lateral lymph node metastasis rate turns out to be higher with more invasive Dukes classification and more malignant histopathological type.