OBJECTIVETo study the impact of neoadjuvant therapy on lymph nodes retrieval in locally advanced mid-low rectal carcinoma.

METHODSData collected from 120 patients with locally advanced mid-low rectal cancer (T2-4 and/or N1-2M0) treated from January 2005 to June 2008 was investigated. The patients were divided into two groups: the study group (n=54) was treated with neoadjuvant therapy (preoperative radiation with a total dosage of 50 Gy and synchronous 5-Fu-based chemotherapy) followed by radical tumor resection 4-6 weeks after;the control group (n=66) underwent primary surgery without neoadjuvant therapy. The clinical stage was evaluated before and after neoadjuvant therapy. The total lymph nodes yields, as well as the tumor-positive lymph nodes of each resected specimen was compared between the two groups statistically.

RESULTSClinical downstage was achieved in 30 cases (56%) in study group after neoadjuvant therapy. The number of total lymph nodes and positive lymph nodes harvested from each resected specimen in the control group were 14+/-7 and 2.2+/-3.7, meanwhile those were 9+/-6 and 0.7+/-2.4 in study group, which were all significantly lower than those in control group (P<0.01).

CONCLUSIONSPreoperative radiotherapy combined with chemotherapy can downstage the tumor and reduce the retrieval rate of total lymph nodes and positive lymph nodes in locally advanced rectal cancer. It is necessary to retrieve as many lymph nodes as possible for it has some prognostic significance for the patients.