Significance of preoperative radiotherapy and lateral lymph node dissection for locally advanced rectal cancer - a comparative study involving different hospitals]

The aim of this study was to compare the results between lateral lymph node dissection (LLND) alone, and preoperative radiotherapy (preRT) followed by LLND, for the treatment of locally advanced rectal cancer. This study assessed 44 consecutive patients with lower rectal cancer (clinical Stages II and III) without lateral lymph node metastasis by preoperative imaging at two hospitals. Twenty-five patients at one hospital received preoperative short-course radiation therapy (total 25 Gy) followed by a curative LLND operation (preRT group), and 19 patients at another hospital underwent a curative operation by LLND alone (non-preRT group). The 5-year locoregional relapse-free survival, disease-free survival, and overall survival rates were not different between the preRT and non-preRT groups. Although three patients in each group had lateral lymph node metastases, none developed pelvic sidewall recurrence. This study suggests that preRT followed by curative surgery with LLND for lower rectal cancers without lateral lymph node metastasis before surgery would not improve survival and local control rates.