A retrospective review of 325 patients was undertaken to analyse wheth
er involvement of the radial resection margin (RRM) could predict loca
lly recurrent disease or distant metastases in patients who had curati
ve surgery for rectal or rectosigmoid cancer. Information on the RRM w
as available in 253 patients. The RRM was involved in 31 (12 per cent)
. Nine of these 31 patients developed local recurrence (29 per cent),
while only 17 local recurrences were diagnosed in 217 patients (8 per
cent) without involvement of the RRM (P<0.01). At 2 years the overall
local recurrence rate was 10 per cent. Distant metastases were diagnos
ed in 46 patients (18 per cent) and RRM involvement was identified as
a prognostic factor depending on lymph node involvement (N stage) (P=0
.02). Local recurrence and some distant metastases result from microsc
opically incomplete resection. Assessment of the radial depth of tumou
r invasion by careful histological examination of the specimen may be
used for selection of patients for adjuvant radiotherapy and/or chemot
herapy.