7.1. Non Small Cell Lung Cancer Staging: The Numbered Staging System: Stage 1 to 4 (or I to IV)
This section summarizes the current non small cell lung cancer staging systems and for small cell lung cancer (SCLC).
At present, two systems are used for staging non small cell lung cancer (NSCLC):
1) The numerical Stage 1, 2, 3 and 4 (or I, II, III, and IV).
2) The TNM (Tumor, Node, Metastasis) staging system.
Staging categories for small cell lung cancer include either ‘limited’ or ‘extensive,’ but the future use of TNM staging is under review.
7.1. Non Small Cell Lung Cancer Staging System: Numbered: Stages 1 to 4 (or I to IV)
When a cancer is ‘staged‘ an indication is given of the tumor size and how far it has spread. The stage of a cancer (with the tumor type and tumor grade) indicates to the physician and surgeon which type of treatment is required.
Lung cancer staging is done using imaging techniques, supported by biopsy. In some cases, there may be a requirement for surgery to stage the cancer.
Stage 1 – the lung cancer is small and is localized in one area of the lung.
Stage 1A – the lung cancer is small (up to 3cm).
Stage 1B – the lung cancer is between 3cm to 5cm in size, and it may have spread into adjacent structures (the main bronchus or the pleura) or the lung may have partly collapsed (‘consolidated’).
Figure 7.1 Diagram. Non Small Cell Lung Cancer Staging:
Stage 1 Lung Cancer
Stage 2 – the lung cancer is larger and may have started to invade into the surrounding lung tissues, and there may be cancer cells in the lymph nodes (locally advanced).
Stage 2A – the lung cancer is between 5cm and 7cm in size, but there is no lymph node involvement.
Or, the lung cancer is 5cm or less, and there are cancer cells in the most proximal lymph nodes.
Stage 2B – the lung cancer is between 5cm and 7cm in size, and there are cancer cells in the most proximal lymph nodes.
Or, the lung cancer is larger than 7cm but there are no lymph node metastases.
Or, there are no lymph node metastases but the lung cancer has spread to the chest wall or the diaphragm, or the pleura or there is lung collapse due to bronchial obstruction.
Or, the lung cancer is of any size but there is more than one tumor in the same lobe of the lung.
Figure 7.2 Diagram: Non Small Cell Lung Cancer Staging:
Stage 3 – the lung cancer is locally invasive, with regional lymph node involvement (by metastasis).
Stage 3A is a varied category – the lung cancer is larger than 7 cm and has metastasized to the proximal lymph nodes.
Or, the lung cancer has spread to the chest wall or the diaphragm, or the pleura.
Or, the lung cancer has spread to proximal lymph nodes on the same side as the affected lung.
Or, the lung cancer is of any size but has invaded another structure in the chest, such as the heart, the trachea, the oesophagus, the laryngeal nerve, the spine, or a main blood vessel.
Or, there is lung cancer spread to more than one lobe of the same lung with proximal lymph node metastases.
Stage 3B is a varied category – the lung cancer has metastasized to lymph nodes on the other side of the chest.
Or, the lung cancer has metastasized to mediastinal lymph nodes and to other structures, including the chest wall, the pleura, the diaphragm, the pericardium, the heart, the trachea, the esophagus or a main blood vessel.
Figure 7.3 Diagram: Non Small Cell Lung Cancer Staging:
Figure 7.4 Diagram: Non Small Cell Lung Cancer Staging:
Figure 7.5 Diagram: Non Small Cell Lung Cancer Staging:
Stage 4 – the lung cancer has spread by metastasis to other parts of the body (liver, bone, brain, adrenals).
Or, the lung cancer is in both lungs.
Or, there is pleural fluid (malignant pleural effusion), or pericardial fluid (malignant pericardial effusion) that contains cancer cells.
Figure 7.6 Diagram: Non Small Cell Lung Cancer Staging:
The purpose of staging is to guide patient management, but studies have shown that cancer staging has prognostic importance. Prognosis in cancer is usually given as ‘5-year survival,’ as a percentage of patients who are alive, 5 years on from the initial diagnosis.
Table 7.1 5-Year Survival Rates in NSCLC
According to Stage
American Joint Committee on Cancer (AJCC). (2009). Lung Cancer Staging. 7th Edition. (Retrieved 26th Feb 2015): http://cancerstaging.org/references-tools/quickreferences/documents/lungmedium.pdf
Detterbeck FC, Boffa DJ, Tanoue LT. (2009). The new lung cancer staging system. Chest 136(1), 260. (Retrieved 26th Feb 2015): https://www.ncbi.nlm.nih.gov/pubmed/19584208
American Cancer Society How is Non-Small Cell Lung Cancer Staged? (Retrieved 30th April 2015): http://www.cancer.org/cancer/lungcancer-non-smallcell/detailedguide/non-small-cell-lung-cancer-staging
National Cancer Institute Cancer Staging Fact Sheet. (Retrieved 30th April 2015): http://www.cancer.gov/cancertopics/diagnosis-staging/staging/staging-fact-sheet