Location of pelvic recurrence after «curative» low anterior resection for rectal cancer

Aims: It has been emphasized that the mesorectum is the key to local recurrence after resection for rectal cancer. In view of this we studied the location of recurrences, relative to the bed of the primary tumour, the neorectum and the level of anastomoses, in patients referred for recurrences after low anterior resection (LAR) in the «pre-total mesorectal excision (TME) era». Methods The relative level above the anal verge of the primary cancer, the anastomosis and the recurrence was registered by proctoscopy in 46 patients operated on for recurrent cancer after low anterior resection. The origin of the recurrence was determined from the operative specimen. Results: The median level of the primary cancers was 10 cm above the anal verge, with the anastomoses 2 cm lower, the majority being within 2 cm. Most recurrences were within 1 cm of the anastomosis. No rectal cancer occurred more than 3 cm distal to the anastomosis. Seventy to 80% of recurrences started peri-rectally, most invading the anastomosis. Conclusions: The tumour bed is most often the origin of the recurrence. Recurrences were mostly due to inadequate radial, and in a few cases longitudinal, dissection of the mesorectum. Virtually all recurrences were within reach of the examining finger. At follow-up of rectal cancers most local recurrences can therefore be identified earlier by digital examination than by proctoscopy.