Can pathological complete response in the primary tumour following pre-operative pelvic chemoradiotherapy for T3-T4 rectal cancer predict for sterilisation of pelvic lymph nodes, a low risk of local recurrence and the appropriateness of local excision?
BACKGROUND
Local excision is considered inappropriate treatment for T3-T4 rectal adenocarcinomas, as it cannot provide prognostic information regarding lymph node involvement and has a high risk of pelvic recurrence. Preoperative chemoradiation (CRT) studies in rectal cancer suggest that a pathological complete response (pCR) in the primary tumour provides an excellent long-term outcome. If downstaging to stage pT0 predicts a tumour response within the perirectal and pelvic lymph nodes, this may allow local excision to be performed without increased risk of pelvic recurrence. This retrospective study aimed to determine the incidence of involved lymph nodes following pCR (ypT0) after preoperative CRT and total mesorectal excision.


METHODS
The outcome and treatment details of 211 patients undergoing preoperative CRT for clinically staged T3-T4 unresectable rectal adenocarcinomas between 1993 and 2003 at Mount Vernon Hospital were reviewed.


RESULTS
Data were recorded from the 143 patients who completed treatment with a median follow-up of 25 months. Twenty-three patients (18%) were found to have had a pCR. Four out of 23 patients (17%) had involved lymph nodes. No pelvic recurrences developed after a ypCR. Overall survival was similar for patients with ypT0 or residual tumour.


CONCLUSIONS
Pathological complete response in the primary tumour failed to predict a response in the perirectal lymph nodes (p=0.08). The degree of response predicted a lymph node response (p=0.02). The detection of ypCR identified patients with a low rate of pelvic recurrence. This may in the future allow selection of patients for whom local excision can be performed without a higher risk of local relapse.
Hughes
R
R
Mount Vernon Cancer Centre, Northwood, Middlesex, UK, HA6 2RN.
Glynne-Jones
R
R
Grainger
J
J
Richman
P
P
Makris
A
A
Harrison
M
M
Ashford
R
R
Harrison
R A
RA
Livingstone
J I
JI
McDonald
P J
PJ
Meyrick Thomas
J
J
Mitchell
I C
IC
Northover
J M A
JM
Phillips
R
R
Wallace
M
M
Windsor
A
A
Novell
J R
JR
D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant; D003082:Colectomy / Q000379:methods; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging; D010388:Pelvis; D011237:Predictive Value of Tests; D011336:Probability; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016896:Treatment Outcome