N2 describes ipsilateral mediastinal or subcarinal lymph node(s) [5]. N3 includes contralateral mediastinal or hilar lymph node(s) and any supraclavicular or scalene node on either side [5]. M Descriptor The presence of metastatic lung cancer lesions constitutes stage IV disease. Many patients with SCLC present with metastatic disease [9], and the treatment of stage IV cancers depends on the location and number of lesions. M0 disease is consistent with no distant metastases [5]. The M1 classification is subdivided into three categories: M1a includes satellite nodule(s) in the contralateral lung and cytology proven malignant pleural or pericardial effusion [5]. M1b indicates a single extrathoracic metastasis. This category also includes metastasis in a single nonregional lymph node, considered nodes not in the N descriptor, such as axillary, internal mammary, or abdominal lymph node(s) [5,6]. M1c indicates multiple extrathoracic metastases in one or more organs [5]. Modified VALSG Staging Under the modified VALSG staging classification, SCLC is considered LS disease when it is confined to a single hemithorax (although local extension may be present); the primary tumor and regional nodes can be addressed by a single radiation port; and ipsilateral supraclavicular nodes can be included in the same radiation field as the primary tumor. Contralateral mediastinal lymph nodes and ipsilateral pleural effusion are also considered LS- SCLC [51,52]. ES-SCLC includes disease that is not confined to a single radiation port, malignant pericardial effusion, contralateral pleural effusion, and distant hematogenous metastases [51,52]. The classification of contralateral supraclavicular or hilar lymph nodes is controversial. These nodes should be assessed on a case-by-case basis as to whether they may be feasibly included within a single radiation port [51,52].
Noninvasive Clinical Staging of Primary Lung Cancer PCAs. N2 describes ipsilateral mediastinal or subcarinal lymph node(s) [5]. N3 includes contralateral mediastinal or hilar lymph node(s) and any supraclavicular or scalene node on either side [5]. M Descriptor The presence of metastatic lung cancer lesions constitutes stage IV disease. Many patients with SCLC present with metastatic disease [9], and the treatment of stage IV cancers depends on the location and number of lesions. M0 disease is consistent with no distant metastases [5]. The M1 classification is subdivided into three categories: M1a includes satellite nodule(s) in the contralateral lung and cytology proven malignant pleural or pericardial effusion [5]. M1b indicates a single extrathoracic metastasis. This category also includes metastasis in a single nonregional lymph node, considered nodes not in the N descriptor, such as axillary, internal mammary, or abdominal lymph node(s) [5,6]. M1c indicates multiple extrathoracic metastases in one or more organs [5]. Modified VALSG Staging Under the modified VALSG staging classification, SCLC is considered LS disease when it is confined to a single hemithorax (although local extension may be present); the primary tumor and regional nodes can be addressed by a single radiation port; and ipsilateral supraclavicular nodes can be included in the same radiation field as the primary tumor. Contralateral mediastinal lymph nodes and ipsilateral pleural effusion are also considered LS- SCLC [51,52]. ES-SCLC includes disease that is not confined to a single radiation port, malignant pericardial effusion, contralateral pleural effusion, and distant hematogenous metastases [51,52]. The classification of contralateral supraclavicular or hilar lymph nodes is controversial. These nodes should be assessed on a case-by-case basis as to whether they may be feasibly included within a single radiation port [51,52].