Comparison between preoperative chemoradiotherapy and lateral pelvic lymph node dissection in clinical T3 low rectal cancer without enlarged lateral lymph nodes

Aim: The standard strategy for clinical T3 rectal cancer without enlarged lateral lymph nodes is preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) in Western countries and TME with bilateral lateral pelvic lymph node dissection (LPLND) in Japan. This study compared surgical, pathological and oncological results of these two strategies.Method: Patients who underwent preoperative CRT followed by TME in France (CRT + TME group) and those who underwent TME with LPLND in Japan (TME + LPLND group) for clinical T3 rectal adenocarcinoma without enlarged lateral lymph nodes from 2010 to 2016 were retrospectively analysed.Results: In total, 439 patients were included in this study. The estimated local recurrence rate (LRR), disease- free survival and overall survival at 5 years post-surgery was 4.9%, 71% and 82% in the CRT + TME group, and 8.6%, 75% and 90% in the TME+ LPLND group, respectively. Lateral LRR versus non-lateral LRR was 0.5% versus 4.2% in the CRT + TME group and 1.8% versus 6.2% in the TME+ LPLND group. Obturator nerve injury and iso- lated pelvic abscess were shown only in the TME+ LPLND group. Urinary complications were more frequent in the TME + LPLND group than in the CRT + TME group.Conclusion: Disease- free survival was not significantly different after TME with LPLND and after CRT followed by TME. LRR was not significantly different after both strategies; however, there was a trend for higher LRR after TME with LPLND than after CRT fol- lowed by TME. Obturator nerve injury, isolated lateral pelvic abscess and urinary compli- cations should be noted when TME with LPLND is applied.

Automated summary

This study compared the outcomes of two different strategies for clinical T3 rectal cancer without enlarged lateral lymph nodes: preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) and TME with bilateral lateral pelvic lymph node dissection (LPLND). The results showed that disease-free survival and overall survival were similar between the two groups, but the TME + LPLND group had a slightly higher rate of local recurrence. The TME + LPLND group also had more complications, including obturator nerve injury, isolated pelvic abscess, and urinary complications.