Negative surgical margins are important for local control of rectal cancer treated with sphincter-preserving surgery. However, the association of rectal cancer recurrence
with close distal margin
is not well established.
Data were extracted from a prospective database of patients collected between 1991 and 2003. Included were 627 patients who underwent curative low anterior resection with total mesorectal excision for rectal cancer 2 to 12 cm from the anal verge. Three hundred ninety-nine patients received neoadjuvant therapy, 65 received postoperative adjuvant therapy alone, and 163 were treated with surgery alone. Median follow-up was 5.8 years.
On multivariable analysis, overall recurrence
was associated with pathologic stage, lymphovascular invasion, and distal margin
. Mucosal recurrence
was uncommon; only 16 events were recorded, and of those only 8 were at the initial site of isolated tumor recurrence
; 7 of the 8 were surgically salvaged. On univariable analysis, mucosal recurrence
was associated with close distal margin
(5 vs 2% at 5 y) and lymphovascular invasion (7 vs 2%). Pelvic recurrence
, other than isolated mucosal recurrence
, was associated with distal location (6 vs 4% at 5 y) and lymphovascular invasion (11 vs 4%). Distal margin
as a continuous variable was associated with overall recurrence
(excluding isolated mucosal recurrence
Close distal resection margin identifies patients with increased risk of mucosal and overall cancer recurrence
. Although neither causality nor a minimally acceptable margin length can be defined, the data support the importance of achieving a clear distal resection margin in the surgical management of rectal cancer.