Introduction

Lung cancer incidence and mortality continue to increase worldwide. It is estimated that there are 2.2 million new lung cancer cases worldwide and 1.8 million deaths from lung cancer [1]. In Europe, there are estimated to be four million new cases of cancer and 1.9 million cancer-­ related deaths as of 2020. Lung cancer accounted for 11.8% of new cancer diagnoses and 380,000 deaths, or approximately onefth of all cancer-­ related deaths [2]. As of 2018, the incidence of lung cancer in the United States was 121,680 for

men and 112,350 for women with a total of 234,030 new cases for the year. Lung cancer is the second most common cancer in both men and women, but accounts for the most cancer deaths in the United States [3]. With the NELSON trial demonstrating reduced lung cancer mortality in high-risk individuals who underwent low radiation dose computed tomography (CT) screening and the update to the United States Preventative Services Task Force (USPSTF) 2021 [4, 5], the incidence of imaging detected lung nodules/lung cancer will undoubtedly increase [5]. Accurate staging of lung cancer is crucial as this will guide treatment. The eighth edition of tumor node metastasis (TNM) staging for non-small cell lung cancer (NSCLC) helps categorize tumors on the basis of primary tumor characteristics (T), the presence or absence of regional lymph node involvement (N), and the presence or absence of distant metastases (M) [6]. The eighth edition of the TNM staging system had major changes to T and M classi cations and was adopted as of January 1, 2018 (Fig. 28.1). If disease is isolated within the thorax, mediastinal and hilar lymph node staging becomes critical for determining the best approach for curative intent treatment. In addition to accurate staging, samples should be

Fig. 28.1  TNM lung cancer staging 8th edition