Advertisement

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Electronic Letters to:

Gastrointestinal Imaging: Antonella Filippone, Roberta Ambrosini, Maurizio Fuschi, Tiziana Marinelli, Domenico Genovesi, and Lorenzo Bonomo Preoperative T and N Staging of Colorectal Cancer: Accuracy of Contrast-enhanced Multi–Detector Row CT Colonography—Initial Experience Radiology 2004; 231: 83-90 [Abstract] [Full text] [PDF]

eLetters: Submit a response to this article

Electronic letters published:

TNM Classification Correction

Didier J.M.L.E. Bielen, MD   (28 June 2005)

TNM Classification Correction 28 June 2005
Didier J.M.L.E. Bielen, MD, Abdominal radiologist University Hospital Gasthuisberg Leuven Belgium Send letter to journal: Re: TNM Classification Correction didier.bielen{at}uz.kuleuven.ac.be Didier J.M.L.E. Bielen, MD	Editor: The topic addressed in the article by Filipponi et al (1) is very relevant. Unfortunately, in the Material and Methods section, the authors misinterpreted the TNM definition for lymph node classification. For colon and rectum (ICD-0 C18-C20), both the fifth and sixth editions of the TNM classification (the authors refer to the fifth edition in their reference 14) deals with NX (local-regional lymph nodes cannot be assessed) to N2 (metastases in four or more regional lymph nodes). For these types of tumors, pelvic lymph nodes should be classified as either N1 or N2 (depending on their number and only if occurring in the local-regional lymph node groups) or as M1 (metastasis in nodes other than those listed above is classified as distant metastasis). For anal tumors (ICD0 C21.1) the N3 classification is used for metastasis in perirectal and inguinal lymph nodes and/or bilateral internal iliac and/or bilateral inguinal lymph nodes. Therefore, authors should specify whether they examined just colon and rectum tumors (TNM staging NX to N2) or if they included anal tumors (TNM staging NX to N3). Reference 1. Filippone A, Ambrosini R, Fuschi M, Marinelli T, Genovesi D, Bonomo L. Preoperative T and N staging of colorectal cancer: accuracy of contrast-enhanced multi-detector row CT colonography—initial experience. Radiology 2004; 231:83-90. Drs Filippone and Genovesi respond: We thank Dr Bielen for his interest in our article and appreciate his comment. We totally agree that, according to the fifth edition of the TNM classification (1) of colorectal tumors, regional lymph nodes should be classified as N1 and N2, while involvement of nonregional lymph nodes are classified as distant metastases (M1). However, as has been recently pointed out by Compton et al (2), a colorectal cancer may involve more than one site by continuous longitudinal extension. In these cases the lymph nodes are defined as those of all involved sites and subsites. In some cases, the regional nodes of the primary tumor site are free of malignancy, while the nodes in the drainage area of an organ directly invaded by the primary tumor contain metastases. In this circumstance, the lymph nodes of the invaded site are considered the primary site nodes and are classified in the N category (3). Therefore, the N3 stage was considered for advanced low rectal cancer with direct invasion of the anal canal. Although we could have been more rigorous in the description of the N3 stage in the Materials and Methods section, we did not observe any metastatic involvement of nonregional lymph nodes in our population, and so the results of our study are not affected. References 1. Sobin LH, Wittekind CH, eds. UICC TNM classification of malignant tumors. 5th ed. New York, NY: Wiley, 1997. 2. Compton CC, Greene FL. The staging of colorectal cancer: 2004 and beyond. CA Cancer J Clin 2004; 54: 295-308. 3. Wittekind C, Greene FL, Henson DE (eds). TNM supplement: a commentary on uniform use. 3rd ed. New York, NY; Wiley-Liss; 2003.