CHEST Special Features Seventh Edition of the Cancer Staging Manual and Stage Grouping of Lung Cancer Quick Reference Chart and Diagrams Omar Lababede, MD ; Moulay Meziane, MD ; and Thomas Rice, MD, FCCP Lung cancer remains the most common cause of cancer-related death in the United States. TNM staging, which is an important guide to the prognosis and treatment of lung cancer, has been revised recently. In this article, we propose a quick reference chart and diagrams that consolidate TNM staging information in a simple format. The current classification of lymph node stations and zones is illustrated as well. CHEST 2011; 139(1):183 189 Abbreviations: M 5 metastases; N 5 regional lymph node involvement; T 5 primary tumor Lung cancer is the leading cause of cancer mortality in both men and women in the United States. 1 Staging plays a critical role in guiding treatment selection and determining prognosis of cancer. Additionally, the evaluation of the response to treatment and the clinical research of cancer are facilitated by a universal system. TNM staging provides a consistent, reproducible description of cancers based on the extent of anatomic involvement. This is achieved by defining the characteristics of the primary tumor (T), regional lymph node involvement (N), and metastases (M). The seventh edition of TNM staging for lung tumors has been released recently. The revisions in the new edition were recommended by the International Association for the Study of Lung Cancer staging project and were accepted by both the International Union Against Cancer and the American Joint Committee on Cancer. 2-6 TNM staging of lung cancer is complex, and many variables must be considered ( Tables 1, 2 ). It can be Manuscript received April 27, 2010; revision accepted June 14, 2010. Affiliations: From the Imaging Institute (Drs Lababede and Meziane) and the Department of Thoracic and Cardiovascular Surgery (Dr Rice), Cleveland Clinic, Cleveland, OH. Correspondence to: Omar Lababede, MD, Imaging Institute, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195; e-mail: lababeo@ccf.org 2011 American College of Chest Physicians. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians ( http://www.chestpubs.org/ site/misc/reprints.xhtml ). DOI: 10.1378/chest.10-1099 difficult to use and remember. We have designed a chart and two diagrams to present the new staging system in a simple, but nevertheless comprehensive, format. The comparative characteristics of the primary tumor are listed in the vertical columns of the chart ( Fig 1 ). These features include size and extent (endobronchial location, local invasion, and satellite nodule[s]). The horizontal columns describe regional lymph node involvement. The different stage groupings are color coded and can be found at the intersections of appropriately matched horizontal and vertical columns. Stages with unique characteristics such as stages 0 and IV are defined in separate boxes. The basic design of the chart is based on our previously published reference chart of the fifth edition of lung cancer staging. 7 The diagrams ( Fig 2 ) illustrate the same information in a more concise visual format. The recently adopted revisions of TNM staging are reflected in our chart and diagrams. These changes include the following: TNM system application to small cell lung carcinoma and carcinoid tumor of the lung (the previous system was applicable to non-small cell lung carcinoma only) Redefinition of the primary tumor classification based on size: T1 is subdivided into T1a and T1b T2 is subdivided into T2a and T2b Cancer larger than 7 cm is reclassified as T3. www.chestpubs.org CHEST / 139 / 1 / JANUARY, 2011 183
Table 1 Seventh Edition of TNM Staging of Lung Tumors: Definition of T, N, and M 2-6 Descriptor Definition Primary tumor (T) Tx Tumor that cannot be assessed or is not detected radiologically or bronchoscopically but is proven histopathologically (malignant cells in bronchopulmonary secretions) T0 No evidence of primary tumor Tis Carcinoma in situ T1 Tumor with the following characteristics: Size 3 cm Airway location: in lobar bronchus or more distal airways Local invasion: none, surrounded by lung or visceral pleura Subdivisions: T1a (size 2 cm) and T1b (2 cm, size 3 cm) T2 Tumor with size. 3 cm but 7 cm or tumor with any of the following characteristics: Airway location: involvement of the main bronchus (distance to the carina is 2 cm) or presence of atelectasis or obstructive pneumonitis that extends to hilar region but does not involve the entire lung Local invasion: involvement of visceral pleura Subdivisions: T2a (3 cm, size 5 cm) and T2b (5 cm, size 7 cm) T3 Tumor. 7 cm in size or tumor with any of the following: Airway location: tumor in the main bronchus (within 2 cm of the carina), or tumor with atelectasis or obstructive pneumonitis of the entire lung Local invasion: direct invasion of chest wall (including superior sulcus tumors), diaphragm, phrenic nerve, mediastinal pleura, or parietal pericardium Satellite tumor nodule(s) in the same lobe as the primary tumor T4 Tumor of any size invading any of the following: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, or carina; or tumor with satellite tumor nodule(s) in a different lobe, ipsilateral to that of the primary tumor Lymph nodes (N) Nx Regional lymph nodes cannot be assessed N0 Absence of regional lymph node involvement N1 Presence of metastasis to ipsilateral peribronchial and/or ipsilateral hilar lymph nodes (including direct extension to intrapulmonary nodes) N2 Presence of metastasis to ipsilateral mediastinal and/or subcarinal lymph nodes N3 Presence of metastasis to any of the following lymph node groups: contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular nodes Distant metastasis (M) M0 Absence of distant metastasis M1 Presence of distant metastasis Subdivisions: M1a (satellite tumor nodule(s) in a contralateral lobe to that of the primary tumor or tumors with malignant pleural or pericardial effusion) M1b (distant metastasis) The uncommon superficial spreading tumor of any size with its invasive component limited to the bronchial wall is classified as T1a even in the case of extension to main bronchus. Satellite nodule(s) in the same lobe as the primary tumor will now classify the tumor as T3 (previously T4), whereas their presence in a different lobe of the same lung is reclassified as T4 (previously M1). Table 2 Seventh Edition of TNM Staging of Lung Tumors: Stage Grouping 2-6 Occult carcinoma (TxN0M0) Stage 0 (TisN0M0) Stage IA (T1a/bN0M0) Stage IB (T2aN0M0) Stage IIA (T1a/bN1M0, T2aN1M0,T2bN0M0) Stage IIB (T2bN1M0, T3N0M0) Stage IIIA (T(1-3)N2M0, T3N1M0, T4N(0-1)M0) Stage IIIB (T4N2M0, T(1-4)N3M0) Stage IV (Any T, any N, M1) Redefinition of metastases (M): subdivision of M into M1a and M1b. M1a includes both satellite nodule(s) in the contralateral lung and malignant pleural and pericardial effusions. Malignant pleural and pericardial effusions were classified previously as T4 N0 Mx. Changes to stage groupings, including T4N0M0 and T4N1M0 tumors are reassigned from stage IIIB to stage IIIA. The newly defined T2b tumors with no lymph node or distant metastases (T2bN0M0) are grouped under IIA instead of IB. The newly defined T2a tumors with N1 lymph node but without distant metastases (T2aN1M0) are grouped under IIA rather than IIB. 184 Special Features
Figure 1. Reference chart for 2009 TNM staging system of lung cancer. M 5 metastases; N 5 regional lymph node involvement; T 5 tumor. Although regional lymph node (N) classifications have not changed, a unified map of lymph node stations was adopted by the International Association for the Study of Lung Cancer. 2,3,8 The new map reconciles discrepancies among previous nodal mapping proposals and introduces the concept of lymph node zones ( Table 3 ). Figures 3A and 3B demonstrate the new lymph nodes stations. www.chestpubs.org CHEST / 139 / 1 / JANUARY, 2011 185
Figure 2. Reference diagrams for 2009 TNM staging system of lung cancer. The T classification can be defined by evaluating the size first (upper left), then upgrading the classification (if necessary) based on the presence of the other criteria of primary tumor invasion/extent (A, B, and C). The criteria of extent should not be used to assign a lower classification. The lower diagram can be used to define the N and M classification and to determine the corresponding stage. Note that N1, N2, N3, and the separate tumor nodule of M1a were depicted in the lower illustration based on a right-sided tumor (T). For left lung tumors, a mirror image of these descriptors should be used. Additionally, the endobronchial extension and local invasion (A and B of the criteria of extent) were shown in the upper illustration based on a left-sided tumor to simplify the drawing. See Figure 1 legend for expansion of abbreviations. 186 Special Features
Table 3 IASLC Lymph Node Definition 2,3,8 Definition Nodal Zone Nodal Station Nodes Description Upper Border Lower Border Other Supraclavicular 1 (R and L) Low cervical, supraclavicular and sternal notch Upper mediastinal 2R 2L Right upper Left upper Lower margin of cricoid cartilage Apex of right lung and pleural cavity and upper border of the manubrium Apex of left lung and pleural cavity and upper border of the manubrium Clavicles and upper border of the manubrium Intersection of caudal margin of the innominate vein and trachea Upper limits of the aortic arch Midline of the trachea defines R and L Left lateral margin of the trachea defines R and L 3a Prevascular Apex of chest Level of carina a 3p Retrotracheal Apex of chest Level of carina... 4R Right lower Intersection of caudal margin of the innominate vein and trachea Lower border of the azygos vein Left lateral margin of the trachea defines R and L 4L Left lower Upper limits of the aortic arch Upper rim of the left main pulmonary artery Aortopulmonary 5 Subaortic (aortopulmonary window) 6 Paraaortic (ascending aorta or phrenic) Lower border of the aortic arch Upper rim of the left main pulmonary artery Line tangential to the upper limits of the aortic arch Lower border of the aortic arch Subcarinal 7 Subcarinal The carina Upper border of lower lobe bronchus on the left and lower border of the bronchus intermedius on the right Lower mediastinal 8 (R and L) Paraesophageal Upper border of lower lobe bronchus on the left and lower border of the bronchus intermedius on the right Diaphragm Lateral to ligamentum arteriosum...... The midline defines R and L 9 (R and L) Pulmonary ligaments The inferior pulmonary vein Diaphragm Within the pulmonary ligament Hilar/interlobar 10 (R and L) Hilar Lower rim of the azygos on the right and upper rim of the left main pulmonary artery on the left Interlobar regions b 11 (R and L) Interlobar Between the origin of the lobar bronchi c Peripheral 12 (R and L) Lobar Adjacent to the lobar bronchi 13 (R and L) Segmental Adjacent to the segmental bronchi 14 (R and L) Subsegmental Adjacent to the subsegmental bronchi IASLC 5 International Association for the Study of Lung Cancer; L 5 left; R 5 right. a The posterior sternum forms the anterior border of the prevascular nodes, whereas the posterior border is limited by the anterior border of the superior vena cava on the right side and the left carotid artery on the left side. b Includes nodes adjacent to the main stem bronchi and hilar vessels, including the proximal aspects of the pulmonary arteries and veins. c Can be subdivided on the right into 11s (between the right upper lobe and bronchus intermedius) and 11i (between the middle and lower lobe bronchi). www.chestpubs.org CHEST / 139 / 1 / JANUARY, 2011 187
Figure 3. The International Association for the Study of Lung Cancer lymph node map depicted on views of the chest. A, right lateral view. B, left lateral view. The lymph node stations are color coded and grouped into zones. The colored arrows define the anatomic limits of certain color-matching stations. AA 5 aortic arch; AAo 5 ascending aorta; Ao 5 aorta; AzV 5 azygos vein; BI 5 bronchus intermedius; C 5 carina; E 5 esophagus; IPV 5 inferior pulmonary vein; IV 5 innominate vein; L 5 left; LLLB 5 left lower lobe bronchus; LPA 5 left main pulmonary artery; PA 5 main pulmonary artery; PUL. LIG. 5 pulmonary ligament; R 5 right; RLLB 5 right lower lobe bronchus; SVC 5 superior vena cava; T 5 trachea. 2,3,8 188 Special Features DownloadedFrom:htp:/journal.publications.chestnet.org/byaLoyolaUniversityMedicalCenterUseron08/08/2012
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