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.

Background. Although there are many reported prognostic indicators for pulmonary adenocarcinoma, the clinicopathologic characteristics and prognostic factors of early stage adenocarcinoma have not been evaluated fully, except for several studies of nonmucinous and sclerosing bronchioloalveolar carcinoma. Method. Two hundred thirty‐six surgically resected small peripheral adenocarcinomas measuring 2 cm or less in greatest dimension were reviewed using a simple histologic classification of six types based on tumor growth patterns. Results. Type A (localized bronchioloalveolar carcinoma [LBAC]) (n = 14) revealed replacement growth of alveolar‐lining epithelial cells with a relatively thin stroma. In type B (LBAC with foci of structural collapse of alveoli) (n = 14), fibrotic foci due to alveolar collapse were observed in tumors of LBAC. Type C (LBAC with foci of active fibroblastic proliferation) (n = 141) was the largest group in this study, and foci of active fibroblastic proliferation were evident. Type D (poorly differentiated adenocarcinoma), type E (tubular adenocarcinoma) and type F (papillary adenocarcinoma with a compressive growth pattern) (n = 61) showed compressive and expanding growth. Types A and B showed no lymph node metastasis and the most favorable prognosis (100% 5‐year survival) of the six types. Conclusion. Histologic types A and B are thought to be in situ peripheral adenocarcinoma, whereas type C appears to be an advanced stage of types A and B. Conversely, types D, E, and F are small advanced adenocarcinomas with a less favorable prognosis. Cancer 1995;75:2844–52.

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.

Pulmonary resection for patients with lung cancer with interstitial lung diseases may provoke acute exacerbation at a substantially high rate and has high associated mortality. Surgical procedures that proved to be a risk factor for acute exacerbation should be chosen cautiously for these high-risk patients.

In terms of prognosis, large cell neuroendocrine carcinoma is distinctly different from other non-small cell lung cancers. The prognosis of large cell neuroendocrine carcinoma was poor, even for early stage disease; the prognosis of the stage I disease of large cell neuroendocrine carcinoma was poorer than that of the same stage of other non-small cell lung cancers. Because of its aggressive clinical behavior and poor prognosis, large cell neuroendocrine carcinoma should be recognized as one of the poorest prognostic subgroups among primary lung cancers, and therefore novel therapeutic approaches should be established.