Journal of Thoracic Oncology:
Letters to the Editor
Goldstraw, Peter MB, FRCS; Rusch, Valerie W. MD; Sobin, Leslie MD
Royal Brompton Hospital; Imperial College; London, United Kingdom; email@example.com (Goldstraw)
Memorial Sloan-Kettering Cancer Center; New York (Rusch)
Armed Forces Institute Of Pathology; Washington, DC (Sobin)
Disclosure: Eli Lilly and Company provided funding to support the International Association for the Study of Lung Cancer (IASLC) Staging Committee’s work to establish a database and to suggest revisions to the 6th Edition of the TNM classification for Lung Cancer (staging) through a restricted grant. Lilly had no input into the committee’s analysis of the data, nor in their suggestions for revisions to the staging system.
We thank Drs Raj, Coulden, and Entwistle for their interest in the International Association for the Study of Lung Cancer (IASLC) Staging Project, their kind comments and insightful questions.
Our recommendations for the 7th Edition of tumor, node, metastasis (TNM)1 were based upon the largest database ever accumulated for the study of Lung Cancer.2 It was a global effort with colleagues from 46 data sources in over 19 countries contributing data on cases treated by all modalities of care, enrolled over a relatively short period from 1990 to 2000. However, when collecting data retrospectively to build a large database as quickly as possible one has to take what data is available. Much of the data with which we were provided had been collected for other purposes, such as clinical trials, and the staging data collected was often limited to those fields shown to be important in earlier editions of TNM. Consequently, there were many issues that we would have wished to evaluate on which we had no data. Many of these areas will be included in the prospective database intended as the next phase in this project. The amount of detail that we can collect will be dependent upon the level of funding we obtain and upon identifying appropriate collaborators who are able to supply the minimum dataset.
We agree that the issue of lymphangitis identified by Raj and colleagues is inadequately covered by the “optional descriptors” for lymphatic invasion presently offered in the 6th Edition of either the International Union Against Cancer (UICC) TNM Classification of Malignant Tumors3 or the American Joint Committee on Cancer (AJCC) Manual of Cancer Staging.4 We hope to study this in more detail in the prospective data base.
Our N-descriptors subcommittee has reported the results of exploratory analyses covering the prognostic role of involvement of individual lymph nodes and various combinations of nodal stations.5 In addition, this group has developed an “IASLC” nodal chart, about to be submitted to the Journal of Thoracic Oncology, which for the first time will reconcile the differences between the “Naruke” nodal chart6 and that of “Mountain and Dressler.”7 These developments should allow our prospective data base better to unravel the prognostic interaction between the position and bulk of involved lymph nodes. We intend also to collect data on the size of the most relevant nodal deposit in our prospective data base.
Sadly in clinical staging the decision as to how much of a bulky tumor mass represents primary tumor and how much is due to nodal disease will remain a judgment call. General rule 4, however, suggests that “if there is doubt concerning the correct T, N, or M category to which a particular case should be allotted, then the lower (i.e., less advanced) category should be chosen. This will also be reflected in the stage grouping.”
Positron emission tomography scanning was not widely available during the period of our data collection. The European Lung Cancer Working Party, on our behalf, undertook a meta-analysis of the prognostic significance of the maximum standardized uptake value in the primary tumor at presentation, recently published in the Journal of Thoracic Oncology.8 Our prospective database will allow much more thorough assessment of the prognostic information available with positron emission tomography scanning.
Finally, we would like to take this opportunity to inform our colleagues in the lung cancer community of the TNM Helpdesk available by following the links at www.uicc.org. This resource allows one to direct questions to experts in the field of staging and lung cancer, and is monitored by the UICC for proposals for future revisions.
The project was also supported by the AJCC grant “Improving AJCC/UICC TNM Cancer Staging.”
Peter Goldstraw, MB, FRCS
Royal Brompton Hospital
London, United Kingdom
Valerie W. Rusch, MD
Memorial Sloan-Kettering Cancer Center
Leslie Sobin, MD
Armed Forces Institute Of Pathology
1. Goldstraw P, Crowley JJ, Chansky K, et al. The IASLC Lung Cancer Staging Project: proposals for revision of the stage groupings in the forthcoming (seventh) edition of the TNM classification for lung cancer. J Thorac Oncol
2. Goldstraw P, Crowley J, Chansky K, et al. The IASLC International Staging Project on Lung Cancer. J Thorac Oncol
3. UICC International Union Against Cancer. TNM Classification of Malignant Tumours, 6th Ed. New York: Wiley-Liss, 2002.
4. Greene FL, Page DL, Fleming ID, et al. AJCC Cancer Staging Manual, 6th Ed. New York: Springer, 2002.
5. Rusch VR, Crowley JJ, Giroux DJ, et al. The IASLC Lung Cancer Staging Project: proposals for revision of the N descriptors in the forthcoming (seventh) edition of the TNM classification for lung cancer. J Thorac Oncol
6. Naruke T, Suemasu K, Ishikawa S. Lymph node mapping and curability at various levels of metastasis in resected lung cancer. J Thor Cardiovasc Sur
7. Mountain CF, Dresler CM. Regional lymph node classification for lung cancer staging. Chest
8. Berghmans T, Dusart M, Paesmans M, et al. Primary tumour standardized uptake value (SUV max) measured on florodeoxyglucose emission tomography (PDG-PET) is of prognostic value for survival in non-small cell lung cancer (NSCLC): a systematic review and meta-analysis (MA) by the European lung cancer working party for the IASLC lung cancer staging project. J Thorac Oncol