IASLC Staging Articles
- 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).
- It can be difficult to distinguish between a second primary and a metastasis in patients with lung cancer who have more than one pulmonary site of cancer.
- Application of tumor, node, and metastasis (TNM) classification is difficult in patients with lung cancer presenting as multiple ground glass nodules or with diffuse pneumonic-type involvement. Clarification of how to do this is needed for the forthcoming eighth edition of TNM classification.
- Separate tumor nodules with the same histologic appearance occur in the lungs in a small proportion of patients with primary lung cancer. This article addresses how such tumors can be classified to inform the eighth edition of the anatomic classification of lung cancer. Separate tumor nodules should be distinguished from second primary lung cancer, multifocal ground glass/lepidic tumors, and pneumonic-type lung cancer, which are addressed in separate analyses.
- Patients with lung cancer who harbor multiple pulmonary sites of disease have been challenging to classify; a subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee was charged with developing proposals for the eighth edition of the tumor, node, and metastasis (TNM) classification to address this issue.
- In the 2003 Supplement for tumor, node, metastasis (TNM) Staging classification it states that TNM staging “applies to all types of carcinoma including small cell carcinoma; however, it does not apply to carcinoids.” Despite this caveat, most publications on typical and atypical carcinoids use the TNM staging system for nonsmall cell carcinoma and are able to demonstrate prognostic significance for the different stages. For this reason, as the next TNM Staging proposal is being considered, we sought to investigate the carcinoid cases submitted to the International Association for the Study of Lung Cancer (IASLC) database, as well as the National Cancer Institute Surveillance Epidemiology and End Results (SEER).