Should the esophageal cancer staging system be revised

See related article on page 1103. A ccurate TNM staging plays a pivotal role in cancer management and research. The TNM staging system for esophageal cancer is frequently viewed with discontent by thoracic surgeons. Yet, the sixth editions of the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer (UICC) staging manuals, published in 2002, offered minimal changes in the chapter on esophageal staging.1,2 The AJCC chapter notes the remarkable epidemiologic shift that has occurred in this disease with a rapid increase in the number of adenocarcinomas of the distal esophagus and gastroesophageal junction. The location of the lymph nodes involved by gastroesophageal junction tumors was added to the section on nodal descriptors, and a lymph node map previously proposed by Casson and colleagues3 was added to encourage uniform nomenclature of lymph nodes removed at surgery. However, the TNM descriptors and stage classifications were not changed from the previous editions of the staging manuals. The lack of change in the esophageal staging system frustrates many surgeons who believe that it does not stratify patients appropriately for prognosis. However, a staging system must be evidence-based, prognostically accurate, easy to use, and internationally accepted. The AJCC task force for the chapters on lung and esophageal cancer staging that I chaired1 strongly considered changing the staging system for esophageal cancer, but in conjunction with the editors of the manual ultimately did not do so because, unfortunately, there was insufficient published data to support a proposal for a new system. In addition, the AJCC and the UICC coordinate acceptance of changes in staging systems to maintain international concordance. Proposed changes must be based on data considered persuasive by representatives from all of the countries participating in the UICC. Such data did not exist at the time the manual was being written. In the current issue of the Journal, Rice and his colleagues4 at The Cleveland Clinic proposed a revised staging system for esophageal cancer. In terms more familiar to statisticians than to clinicians, their elegantly analyzed study examined the “monotonicity, distinctiveness, and homogeneity of survival in the context of current TNM classifications and stage groupings” based on a prospective 18-year database of 480 patients treated solely by esophageal resection. Otherwise stated, their analysis attempted to develop a staging system that reflects decreasing survival across increasing tumor stages, distinct differences in survival for each of the stage classifications, and no significant differences in survival among the TNM subsets included within each stage category. Rice and coworkers modeled their study on the pioneering approach used by Balch and colleagues5 in analyzing a large international database to propose a new staging system for malignant melanoma—a system that has just been adopted by the AJCC and UICC in the sixth editions of the staging manuals. Balch’s approach set a new standard for the development of evidencebased staging systems and has prompted similar efforts for other malignancies, including a study recently initiated by the International Association for the Study of Lung Cancer, aimed at achieving a comprehensive revision of the lung cancer staging system. Relative to the current staging system, the salient features of the system proposed by Rice and coworkers include the following: the separation of T1 tumors into T1a (intramucosal) and T1b (submucosal) with T1a and high-grade dysplasia grouped together as stage I; a complete revision of the nodal descriptors based solely on the number of involved lymph nodes (0 to 2 vs 3 or more) rather than anatomic lymph From the Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.