A study on the number of lymph node harvested after radical resection of invasive rectal carcinoma

Abstract

Objective To evaluate the number of lymph node harvested during radical resection of invasive rectal carcinoma(stage Ⅰ toⅢ).Methods From January 2000 to June 2008,the pathological data of colorectal carcinoma patients who were operated on were retrospectively reviewed.Exclusion criteria included recurrent colorectal tumor,Tis tumor,R1 or R2 resection,tumor resection transanally or endoscopically,synchronous diseases affecting the surgical procedure for the reetal cancer(familial adenomatous polyposis.synchronous coloreetal carcinoma)and rectal cancer receiving perioperative neoadiuvant chemoradiation.Statistical analysis was performed using Mann-Whitney Test and Chi-Square Test (SPSS 15.0).Results were expressed as mean±SEM.Results A total of 2282 patients were identified.including 1216 cases in the rectal carcinoma group and 1066 cases in the colon carcinoma group.There were no significant difference in gender(719/1216 vs.593/1066,P=0.092)and overall TNM stage (P=0.067)between the two groups.But patients of rectal cancer were younger(58.6±0.4 vs.62.0±0.4.P=0.000).The lymph node retrieval in the rectal carcinoma group was significantly less than that of colon carcinoma group(9.4±0.1 vs.10.5±0.1,P=0.000).There were significantly less rectal cancer patients with a 1ymph node harvest equal to or more than 12 nodes(P=0.000).Patients in the low rectal cancer group(≤7 cm from the anal verge.n=834)had less lymph nodes harvested than the mid-high rectal cancer group(＞7 am and≤15 cm from the anal verge.n=382)(9.2±0.1 vs.9.9±0.2,P=0.009).Conclusion The lymph node harvest in the rectal carcinoma group was significantly less than that in the colon carcinoma group.A new standard may be necessary to define the adequate number of lymph nodes for rectal cancer. Key words: Colorectal neoplasms; Surgery; Pathology; Lymph node