Predictive factors of positive circumferential resection margin after radiochemotherapy for rectal cancer: the French randomised trial ACCORD12/0405 PRODIGE 2.
Circumferential resection margin (CRM) appears as a new powerful prognostic factor of survival after surgery for rectal cancer. We aimed to evaluate predictive factors of positive CRM following preoperative radiochemotherapy in a French trial. Patients with rectal cancer were randomised in long course preoperative radiotherapy 45 Gy plus capecitabine versus 50 Gy plus capecitabine and oxaliplatin. Mesorectal excision was performed 6 weeks after treatment. Impact of clinical, pathological and surgical variables on positive CRM (≤1 mm) were analysed by multivariate analysis. Of 565 randomised patients, CRM was recorded in 390 cases and was positive in 8% (30/390). Patients with 50 Gy plus capecitabine and oxaliplatin had a 6% rate of positive CRM while those treated by 45 Gy plus capecitabine had a 10% rate (p=0.128). Three independent predictive factors of positive CRM were identified: abdominoperineal resection (APR) (odds ratio OR=3.24; p=0.004), vascular tumour invasion (OR=2.78; p=0.026) and poor histological response (modified Dworak 0-2) (OR=9.01; p=0.003). Significant predictive factors of positive CRM are related to type of surgery, especially APR, and poor histological prognostic factors. Intensification of neoadjuvant radiochemotherapy does not seem to have a major role in this study.
CHU Bordeaux, Université Victor Segalen Bordeaux 2, Bordeaux, France. anne.rullier@chu-bordeaux.fr
Anne
A
Rullier
Sophie
S
Gourgou-Bourgade
Marta
M
Jarlier
Frédéric
F
Bibeau
Catherine
C
Chassagne-Clément
Christophe
C
Hennequin
Laurent
L
Tisseau
Agnès
A
Leroux
Francette
F
Ettore
Michel
M
Peoc'h
Marie-Agnès
MA
Diebold
Yves-Marie
YM
Robin
Isabelle
I
Kleinclaus
Laurent
L
Mineur
Christophe
C
Petitjean
Jean-François
JF
Mosnier
Isabelle
I
Soubeyran
Norbert
N
Padilla
Anne-Isabelle
AI
Lemaistre
Jocelyne
J
Bérille
Bernard
B
Denis
Thierry
T
Conroy
Jean-Pierre
JP
Gérard
D059248:Chemoradiotherapy; D013505:Digestive System Surgical Procedures; D005260:Female; D005602:France; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*