Clinicopathological characteristics predict lymph node metastases in ypT0-2 rectal cancer after chemoradiotherapy.
OBJECTIVE
Changes in rectal cancer treatment include increasing emphasis on organ preservation. Local excision after chemoradiotherapy (CRT) for rectal cancer with excellent clinical response reduces morbidity and mortality compared to total mesorectal excision, although residual lymph node metastases (LNM) may cause local recurrence. Our aim is to identify clinicopathological factors predicting the presence of residual LNM in rectal cancer patients with ypT0-2 tumours after neoadjuvant CRT. These risk factors may help to select patients who can be spared radical surgery without compromising oncological outcomes.


RESULTS
Rectal cancer patients with ypT0-2 tumours after CRT and radical resection from five centres treated between June 1999 and February 2012 were included. Histopathology was reviewed extensively. Clinicopathological characteristics and their association with residual LNM were investigated. Of 657 consecutive CRT-treated rectal cancer patients 210 with ypT0-2 disease were included. Residual nodal disease was found in 44 cases (21.0%). Independent predictors of LNM were clinical nodal involvement (cN+) [odds ratio (OR): 2.79, 95% confidence interval (CI): 1.04-7.48, P = 0.042], high-grade histopathology assessed in the post-CRT resection specimen (OR: 6.46, 95% CI: 1.23-34.02, P = 0.028) and residual tumour diameter (RTD) ≥10 mm (OR: 2.54, 95% CI: 1.06-6.09, P = 0.036). An algorithm combining these factors stratified patients adequately according to LNM risk, independently of ypT category.


CONCLUSIONS
Clinical nodal involvement, high-grade histopathology and RTD ≥10 mm are strong and independent predictors of residual nodal disease in rectal cancer patients with ypT0-2 tumours after CRT. Risk stratification based on these factors may help to identify patients suitable for organ preserving therapy and should be validated in appropriately selected populations.
Department of Pathology, Radboud University Medical Centre, Nijmegen, the Netherlands. steven.bosch@radboudumc.nl.
Steven L
SL
Bosch
Department of Surgery, Catharina Hospital Eindhoven, Eindhoven, the Netherlands.
Thomas A
TA
Vermeer
Pathology and Tumour Biology, Leeds Institute of Cancer and Pathology, St James's University Hospital, University of Leeds, Leeds, UK.
Nicholas P
NP
West
Department of Gastroenterology and Hepatology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
Hendrik A M
HA
Swellengrebel
Department of Radiotherapy, Leids University Medical Centre, Leiden, the Netherlands.
Corrie A M
CA
Marijnen
Department of Gastroenterology and Hepatology, Netherlands Cancer Institute, Amsterdam, the Netherlands.
Annemieke
A
Cats
Department of Surgery, Erasmus MC Cancer Institute, Rotterdam, the Netherlands.
Cornelis
C
Verhoef
Pathology and Medical Microbiology, Eindhoven, the Netherlands.
Ineke
I
van Lijnschoten
Department of Surgery, Radboud University Medical Centre, Nijmegen, the Netherlands.
Johannes H W
JH
de Wilt
Department of Surgery, Catharina Hospital Eindhoven, Eindhoven, the Netherlands.|Department of Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands.
Harm J
HJ
Rutten
Department of Pathology, Radboud University Medical Centre, Nijmegen, the Netherlands.
Iris D
ID
Nagtegaal
D000368:Aged; D059248:Chemoradiotherapy; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging / Q000379:methods*; D012004:Rectal Neoplasms / Q000473:pathology* / Q000628:therapy
chemoradiotherapy; local excision; lymph node metastasis; rectal cancer; ypT