Comparative outcome between chemoradiotherapy and lateral pelvic lymph node dissection following total mesorectal excision in rectal cancer

OBJECTIVE: To evaluate comparative outcome between adjuvant postoperative chemoradiotherapy (postoperative CRT) and lateral pelvic lymph node dissection (LPLD) following total mesorectal excision (TME) in rectal cancer patients. BACKGROUND: Although TME results in lower rate of locoregional recurrence compared with conventional surgery, these 2 treatment modalities following TME have not adequately been appraised until the present trend of preoperative chemoradiotherapy. PATIENTS AND METHODS: Between 1995 and 2000, patients with stage II and III rectal cancer underwent TME plus postoperative CRT (n = 309) or LPLD (n = 176). Patients in the postoperative CRT group received 8 cycles of 5-fluorouracil plus leucovorin and 45 Gy pelvic radiotherapy. Patients in the LPLD group underwent lateral lymph node dissection outside the pelvic plexus. RESULTS: The 5-year overall and disease-free survival rates were 78.3% and 67.3% in the postoperative CRT group, respectively, and 73.9% and 68.6% in the LPLD group, respectively, without significant differences between these groups. Patients in the LPLD group with stage III lower rectal cancer had a locoregional recurrence rate 2.2-fold greater than those in the postoperative CRT group (16.7% vs. 7.5%, P = 0.044). Multivariate analysis showed that APR and advanced T-category (T4) were significantly associated with locoregional recurrence, whereas lymph node metastases, high preoperative serum carcinoembryonic antigen, and APR were significantly associated with shortening of disease-free survival. CONCLUSIONS: Postoperative-CRT and LPLD following TME resulted in comparable survival rates, but the locoregional recurrence rate was higher in the LPLD group. These findings suggest that initial surgery is appropriate for rectal cancer patients who are candidates for low anterior resection without extensive local disease (T1-T3), regardless of lymph node status.