Radiological findings do not support lateral residual turnour as a major cause of local recurrence of rectal cancer

Background: The aim of this study was to determine the sites of local recurrence following radical (R0) total mesorectal excision (TME) for rectal cancer in an effort to elucidate the reasons for recurrence. Methods: Thirty-seven patients with recurrence following curative resection for rectal cancer were identified from a population of 880 patients operated on by surgeons trained in the TME procedure. Two radiologists independently examined 33 available computed tomograms and magnetic resonance images taken when the recurrence was detected. Results: Twenty-nine of the 33 recurrences were found in the lower two-thirds of the pelvis. Two recurrent tumours appeared to originate from lateral pelvic lymph nodes. Evidence of residual mesorectal fat was identified in 15 patients. Fourteen of the recurrent tumours originated from primary tumours in the upper rectum; all of these tumours recurred at the anastomosis and 12 of the 14 patients had evidence of residual mesorectal fat. Conclusion: Lateral pelvic lymph node metastases are not a major cause of local recurrence after TME. Partial mesorectal excision may be associated with an increased risk of local recurrence from tumours in the upper rectum.