Chest
Volume 136, Issue 1, July 2009, Pages 260-271
Journal home page for Chest

Special Feature
Special Feature
The New Lung Cancer Staging System

https://doi.org/10.1378/chest.08-0978Get rights and content

The International Association for the Study of Lung Cancer (IASLC) has conducted an extensive initiative to inform the revision of the lung cancer staging system. This involved development of an international database along with extensive analysis of a large population of patients and their prognoses. This article reviews the recommendations of the IASLC International Staging Committee for the definitions for the TNM descriptors and the stage grouping in the new non-small cell lung cancer staging system.

Section snippets

Fundamentals of the UICC/AJCC Staging System

The NSCLC stage classification is based on the TNM system, which is used for most cancers. The T descriptor defines the extent of the primary tumor, the N descriptor the extent of involvement of regional lymph nodes, and the M descriptor the extent of spread to distant sites. The staging system is based solely on the anatomic extent of disease. Other factors, such as clinical symptoms or molecular biological characterization of the tumor, have not been included. Increasing T status reflects

Development and Methodology of the IASLC Staging System

A proposal to develop an international effort to inform a future revision of the TNM staging classification for lung cancer originated in 1996 at a workshop sponsored by IASLC. An international committee was established and work began in 1999. An unrestricted grant from Eli Lilly and Company enabled the establishment of a database (Eli Lilly and Company played no role in the data collection, analysis, or recommendation development process). The database was developed in cooperation with Cancer

T Descriptor

The IASLC International Staging Committee analyzed the effect of tumor size in detail, in part because there were many patients in whom reliable information was available. The size threshold of 3 cm was confirmed as a significant cutpoint and retained as a definition of a T1 vs a T2 tumor. In addition, significant cutpoints were identified at 2, 5, and 7 cm. Tumors > 7 cm had survival that tracked with other definitions of T3 (ie, invasion or central location) and are therefore placed within

N Descriptor

Analysis of the prognostic influence of the N descriptor resoundingly supported the traditional categorization of N0, N1, N2, and N3, as shown for clinically and pathologically staged patients in Figure 3.3 Therefore, no changes were made in the N descriptor as defined in the 6th edition of the staging manual. Further analyses were done to explore whether particular node stations within an N category had any particular impact. No such relationship could be identified.3 Specifically, there was

M Descriptor

The committee on the M descriptor considered patients traditionally classified as M0 or M1 (distant metastases), but it also considered patients with a malignant pleural effusion or with additional tumor nodules in the lung.4 After analysis and discussion, patients with an additional tumor nodule in the primary tumor lobe or a different ipsilateral lobe were redefined along with other aspects of the T descriptor (see “T Descriptor” section). The remaining cohorts categorized by the M descriptor

Stage Grouping

The IASLC International Staging Committee has defined stage groupings. Despite the recognition of many new subdivisions of the T and M descriptor, the stage grouping has not added any new subdivisions. However the definition of the stage groups has become more complex due to the additional T and M descriptor subgroups. Two different representations of the stage grouping scheme are shown in Table 4 and Figure 6. Survival curves for the stage groupings based on clinical and pathologic staging are

Discussion

The development of the new NSCLC staging system represents an astounding amount of work. This extends from the careful detailed analysis as summarized in this article, back through the establishment of a database (with the necessary definitions, quality controls, and data cleansing), to the individuals and institutions that collected data in the first place with sufficient detail and rigor. An effort of this magnitude as a basis for a staging system is quite unique among types of cancer. The

References (17)

There are more references available in the full text version of this article.

Cited by (810)

  • Chemokines and NSCLC: Emerging role in prognosis, heterogeneity, and therapeutics

    2022, Seminars in Cancer Biology
    Citation Excerpt :

    Chemokines regulate to activate angiogenesis and recruit inflammatory infiltrates in the tumor. The chemokine expression profile surrounding the tumor determines the inflammatory infiltrate, which is an important regulator of angiogenesis and supports the growth and survival of tumors [6–9]. Chemokines and their receptors exhibit bipartite roles, including pro or anti-angiogenic and activating or inhibitory towards tumor growth and survival.

View all citing articles on Scopus

The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/site/misc/reprints.xhtml).

View full text