Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World Journal of Gastrointestinal Surgery. Sep 27, 2015; 7(9): 196-202
Published online Sep 27, 2015. doi: 10.4240/wjgs.v7.i9.196
Response to chemoradiotherapy and lymph node involvement in locally advanced rectal cancer
Luis J García-Flórez, Guillermo Gómez-Álvarez, Ana M Frunza, Luis Barneo-Serra, Manuel F Fresno-Forcelledo
Luis J García-Flórez, General and Digestive Surgery Service, Hospital San Agustín, 33401 Avilés, Spain
Luis J García-Flórez, Luis Barneo-Serra, Manuel F Fresno-Forcelledo, Department of Surgery, University of Oviedo, 33006 Oviedo, Spain
Guillermo Gómez-Álvarez, Ana M Frunza, Coloproctology Section, General Surgery, Hospital Universitario Central de Asturias, 33011 Oviedo, Spain
Manuel F Fresno-Forcelledo, Pathology, Hospital Universitario Central de Asturias, 33011 Oviedo, Spain
Author contributions: García-Flórez LJ, Gómez-Álvarez G, Barneo-Serra L and Fresno-Forcelledo MF contributed to study design; García-Flórez LJ and Frunza AM contributed to data acquisition; García-Flórez LJ and Gómez-Álvarez G contributed to manuscript preparation; García-Flórez LJ, Gómez-Álvarez G, Frunza AM, Barneo-Serra L and Fresno-Forcelledo MF contributed to manuscript editing and review.
Institutional review board statement: The study was reviewed and approved by the HUCA (Hospital Universitario Central de Asturias) Review Board.
Conflict-of-interest statement: There are no conflicts of interest.
Data sharing statement: Dataset available from the corresponding author at: luisjgf@gmail.com.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Luis J García-Flórez, MD, PhD, Associate Professor of Surgery, General and Digestive Surgery Service, Hospital San Agustín, Camino de Heros s/n, 33401 Avilés, Spain. luisjgf@gmail.com
Telephone: +34-985-123000 Fax: +34-985-123010
Received: May 15, 2015
Peer-review started: May 20, 2015
First decision: July 10, 2015
Revised: July 15, 2015
Accepted: August 10, 2015
Article in press: August 11, 2015
Published online: September 27, 2015
Abstract

AIM: To establish the association between lymph node involvement and the response to neoadjuvant therapy in locally advanced rectal cancer.

METHODS: Data of 130 patients with mid and low locally advanced rectal adenocarcinoma treated with neoadjuvant chemoradiation followed by radical surgery over a 5-year period were reviewed. Tumor staging was done by endorectal ultrasound and/or magnetic resonance imaging. Tumor response to neoadjuvant therapy was determined by T-downstaging and tumor regression grading (TRG). Pathologic complete response (pCR) is defined as the absence of tumor cells in the surgical specimen (ypT0N0). The varying degrees TRG were classified according to Mandard’s scoring system. The evaluation of the response is based on the comparison between previous clinico-radiological staging and the results of pathological evaluation. χ2 and Spearman’s correlation tests were used for the comparison of variables.

RESULTS: Pathologic complete response (pCR, ypT0N0, TRG1) was observed in 19 cases (14.6%), and other 18 (13.8%) had only very few residual malignant cells in the rectal wall (TRG2). T-downstaging was found in 63 (48.5%). Mean lymph node retrieval was 9.4 (range 0-38). In 37 cases (28.5%) more than 12 nodes were identified in the surgical specimen. Preoperative lymph node involvement was seen in 77 patients (59.2%), 71 N1 and 6 N2. Postoperative lymph node involvement was observed in 41 patients (31.5%), 29 N1 and 12 N2, while the remaining 89 were N0 (68.5%). In relation to ypT stage, we found nodal involvement of 9.4% in ypT0-1, 22.2% in ypT2 and 43.7% in ypT3-4. Of the 37 patients considered “responders” to neoadjuvant therapy (TRG1 and 2), there were only 4 N+ (10.8%) and the remainder N0 (89.2%). In the “non responders” group (TRG 3, 4 and 5), 37 cases were N+ (39.8%) and 56 (60.2%) were N0 (P < 0.001).

CONCLUSION: Response to neoadjuvant chemoradiation in rectal cancer is associated with lymph node involvement.

Keywords: Response to treatment, Neoadjuvant therapy, Rectal cancer, Chemoradiotherapy, Lymph node involvement

Core tip: The treatment of rectal cancer has evolved significantly in recent decades. The response of the primary tumor to neoadjuvant therapy, measured by tumor regression grading, seems to be a good prognostic factor, although this relationship is controversial. One of the most important prognostic factors is lymph node stage, but its relationship with the response to neoadyuvant therapy has not been studied extensively. In our series the response is correlated with lymph node involvement in the surgical specimens. Tumor regression grading score could therefore have clinical implications in the future in order to provide tailored therapies.