cT3N0 rectal cancer: potential overtreatment with preoperative chemoradiotherapy is warranted.
OBJECTIVE
Although combined-modality therapy (CMT) is the preferred treatment for T3 and/or lymph node (LN)-positive rectal cancer, the German rectal cancer study published in 2004 demonstrated that 18% of patients deemed suitable for preoperative CMT by endorectal ultrasound (ERUS) may be overstaged. Because data also suggest that LN-negative rectal cancer after total mesorectal excision may not require radiotherapy, it is reasonable to consider omitting radiotherapy for the cT3N0 subset. We therefore determined the accuracy of pre-CMT ERUS or magnetic resonance imaging (MRI) staging, to explore the validity of a nonpreoperative CMT approach for cT3N0 disease.


METHODS
One hundred eighty-eight ERUS-/MRI-staged T3N0 rectal cancer patients received preoperative CMT (fluorouracil based and 45-50.4 Gy) followed by radical resection. Rates of pathologic complete response (pCR) and mesorectal LN involvement were determined.


RESULTS
Tumors were located a median of 5 cm from the anal verge. Sphincter-preserving surgery was performed in 143 patients (76%). Overall pCR was 20%, and 41 patients (22%) had pathologically positive mesorectal LNs. The incidence of positive LNs significantly increased with T stage: ypT0, 3%; ypT1, 7%; ypT2, 20%; ypT3-4, 36% (P = .001).


CONCLUSIONS
The accuracy of preoperative ERUS/MRI for staging mid to distal cT3N0 rectal cancer is limited because 22% of patients have undetected mesorectal LN involvement despite CMT. Therefore, ERUS-/MRI-staged T3N0 rectal cancer patients should continue to receive preoperative CMT. Although 18% may be overstaged and therefore overtreated, our data suggest that an even larger number would be understaged and require postoperative CMT, which is associated with significantly inferior local control, higher toxicity, and worse functional outcome.
Guillem
José G
JG
Department of Surgery, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA. guillemj@mskcc.org
Díaz-González
Juan A
JA
Minsky
Bruce D
BD
Valentini
Vincenzo
V
Jeong
Seung-Yong
SY
Rodriguez-Bigas
Miguel A
MA
Coco
Claudio
C
Leon
Rebecca
R
Hernandez-Lizoain
José L
JL
Aristu
José J
JJ
Riedel
Elyn R
ER
Nitti
Donato
D
Wong
W Douglas
WD
Pucciarelli
Salvatore
S
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D016190:Carboplatin / Q000008:administration & dosage; D002945:Cisplatin / Q000008:administration & dosage; D003131:Combined Modality Therapy; D019160:Endosonography; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D005720:Gamma Rays; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D008198:Lymph Nodes / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011300:Preoperative Care; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*
D016190:Carboplatin; D002945:Cisplatin; D002955:Leucovorin; D005472:Fluorouracil