The IASLC Staging and Prognostic Factors Committee has collected a new database of 94,708 cases donated from 35 sources in 16 countries around the globe. This has now been analysed by our statistical partners at Cancer Research And Biostatistics and, in close collaboration with the members of the committee proposals have been developed for the T, N, and M categories of the 8th edition of the TNM Classification for lung cancer due to be published late 2016. In this publication we describe the methods used to evaluate the resultant Stage groupings and the proposals put forward for the 8th edition.

This article proposes codes for the primary tumor categories of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) and a uniform way to measure tumor size in part-solid tumors for the eighth edition of the tumor, node, and metastasis classification of lung cancer. In 2011, new entities of AIS, MIA, and lepidic predominant adenocarcinoma were defined, and they were later incorporated into the 2015 World Health Organization classification of lung cancer. To fit these entities into the T component of the staging system, the Tis category is proposed for AIS, with Tis (AIS) specified if it is to be distinguished from squamous cell carcinoma in situ (SCIS), which is to be designated Tis (SCIS). We also propose that MIA be classified as T1mi. Furthermore, the use of the invasive size for T descriptor size follows a recommendation made in three editions of the Union for International Cancer Control tumor, node, and metastasis supplement since 2003. For tumor size, the greatest dimension should be reported both clinically and pathologically. In nonmucinous lung adenocarcinomas, the computed tomography (CT) findings of ground glass versus solid opacities tend to correspond respectively to lepidic versus invasive patterns seen pathologically. However, this correlation is not absolute; so when CT features suggest nonmucinous AIS, MIA, and lepidic predominant adenocarcinoma, the suspected diagnosis and clinical staging should be regarded as a preliminary assessment that is subject to revision after pathologic evaluation of resected specimens. The ability to predict invasive versus noninvasive size on the basis of solid versus ground glass components is not applicable to mucinous AIS, MIA, or invasive mucinous adenocarcinomas because they generally show solid nodules or consolidation on CT.

We confirm the prognostic value of clinical and pathological TNM staging in patients with SCLC, and recommend continued usage for SCLC in relation to proposed changes to T, N, and M descriptors for NSCLC in the eighth edition. However, for M descriptors, it remains uncertain whether survival differences in patients with SSM in the brain simply reflect better treatment options rather than better survival based on anatomic extent of disease.

https://www.wileyhealthlearning.com/acs.aspx The revision for the eighth edition of the tumor, node, and metastasis (TNM) classification of lung cancer was based on analyses of the International Association for the Study of Lung Cancer database, which included 77,156 evaluable patients diagnosed with lung cancer from 1999 to 2010. Among tumor (T) descriptors, the following new tumor‐size groups were created: T1a, ≤1 cm; T1b, >1 to 2 cm; T1c, >2 to 3 cm; T2a, >3 to 4 cm; T2b, >4 to 5 cm; T3, >5 to 7 cm; and T4, >7 cm. Tis and T1mi were introduced for adenocarcinoma in situ and minimally invasive adenocarcinoma, respectively. Endobronchial tumors located <2 cm from the carina have better prognosis than those with any other T3 descriptor and were classified as T2. Total atelectasis/pneumonitis was classified as a T2 descriptor, because it has a T2 prognosis. Diaphragmatic invasion is now T4. Visceral pleural invasion remains unchanged, and mediastinal pleura invasion, which is seldom used, disappears as a T descriptor. The lymph node (N) component descriptors are unchanged, but the number of involved nodal stations has prognostic impact. For the metastasis (M) component, M1a (intrathoracic metastases) remains unchanged, but extrathoracic metastases are divided into a single extrathoracic metastasis (new M1b) and multiple extrathoracic metastases in a single organ or multiple organs (M1c). Stage IA is now divided into IA1, IA2, and IA3 to accommodate T1a, T1b, and T1cN0M0 tumors, respectively; all N1 disease is stage IIB except for T3‐T4N1M0 tumors, which are stage IIIA; a new stage IIIC is created for T3‐T4N3M0 tumors; and stage IV is divided into IVA (M1a and M1b) and IVB (M1c). This revision enhances our capacity for prognostication and will have an important impact in the management of patients with lung cancer and in future research. CA Cancer J Clin 2017;67:138–155. © 2017 American Cancer Society.

Lung cancer continues to be a major global health problem; the disease is diagnosed in more than 1.6 million new patients each year. However, significant progress is underway in both the prevention and treatment of lung cancer. Lung cancer therapy has now emerged as a "role model" for precision cancer medicine, with several important therapeutic breakthroughs occurring during 2015. These advances have occurred primarily in the immunotherapy field and in treatments directed against tumors harboring specific oncogenic drivers. Our knowledge about molecular mechanisms for oncogene-driven tumors and about resistance to targeted therapies has increased quickly over the past year. As a result, several regulatory approvals of new agents that significantly improve survival and quality of life for patients with lung cancer who have advanced disease have occurred. The International Association for the Study of Lung Cancer has gathered experts in different areas of lung cancer research and management to summarize the most significant scientific advancements related to prevention and therapy of lung cancer during the past year.

An extensive analysis has produced stage classification proposals for lung cancer with a robust degree of discriminatory consistency and general applicability. Nevertheless, external validation is encouraged to identify areas of strength and weakness; a sound validation should have discriminatory ability and be based on an independent data set of adequate size and sufficient follow-up with enough patients for each subgroup.

Clinical and pathologic (i.e., after resection) criteria are presented to identify two foci as separate primary lung cancers versus a metastasis. Few features are definitive; many commonly used characteristics are suggestive but associated with a substantial rate of misclassification. Careful review by a multidisciplinary tumor board, considering all available information, is recommended.

We propose to tailor TNM classification of multiple pulmonary sites of lung cancer to reflect the unique aspects of four different patterns of presentation. We hope that this will lead to more consistent classification and clarity in communication and facilitate further research in the nature and optimal treatment of these entities.