Stage IV Lung Cancer (Stage 4)

About 40% of NSCLC patients are diagnosed when they are in Stage IV. How does this stage differ from other stages? In Stage IV, the cancer has spread, or metastasized, beyond the lungs into other areas of the body. Stage IV presents a bigger challenge to the doctor than the other stages.

In Stage IV, the cancer has spread into both lungs or more distant parts of the body. Stage IV is the diagnosis when one or more of the following is true: (1) there are one or more tumors in both lungs; (2) cancer is found in fluid around the lungs or the heart; and/or (3) cancer has spread to other parts of the body, such as the brain, liver, adrenal glands, kidneys, or bone. In the TNM system, and coding that ends in a 1 (M is 1) is a Stage IV lung cancer.

About 40 percent of all patients with non-small-cell lung cancer are diagnosed at Stage IV. Because lung cancer does not have a distinct group of symptoms, the patient may mistake their early symptoms for other, less serious illnesses. This is why patients are encouraged to discuss with their doctors all possible sources of exposure to materials that cause lung cancer. By the time the patient sees a doctor, the lung cancer may already be well advanced.

Stage IV non-small-cell lung cancer produces symptoms that can include shortness of breath, persistent coughing, coughing up of blood, pain in the upper body, wheezing, hoarseness, and frequent bouts of bronchitis. Patients in the advanced states of lung cancer are also susceptible to pneumonia. These are symptoms of many diseases, so the doctor may not be immediately suspect cancer. Additional symptoms can include problems swallowing, pain in the hips or ribs, vision problems, muscle weakness, headaches, or seizures. Physicians use blood tests and chest imaging to narrow down their search, and a biopsy to establish a definitive cancer diagnosis. Imaging techniques such as X-rays, CT scans, and MRI scans are useful in determining which stage the cancer is in.

Stage 4 of Lung Cancer
Stage TNM (Tumor, Nodes, Metastasis) Definition
IV Any T, any N, M1A

Any T, any N, M1b
TX = Primary tumor cannot be assessed, or tumor proven by the presence of malignant cells in sputum or bronchial washings but not visualized by imaging or bronchoscopy.

T0 = No evidence of primary tumor.

Tis = Carcinoma in situ.

T1 = Tumor =3 cm in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic evidence of invasion more proximal than the lobar bronchus (i.e., not in the main bronchus).

T1a = Tumor =2 cm in greatest dimension.

T1b = Tumor >2 cm but =3 cm in greatest dimension.

T2 = Tumor >3 cm but =7 cm or tumor with any of the following features (T2 tumors with these features are classified T2a if =5 cm): involves main bronchus, =2 distal to the carina, invades visceral pleura (PL1 or PL2) or is associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung.

T2a = Tumor >3 cm but =5 cm in greatest dimension.

T2b = Tumor >5 cm but =7 cm in greatest dimension.

T3 = Tumor >7 cm or one that directly invades any of the following: parietal pleura (PL3) chest wall (including superior sulcus tumors), diaphragm, phrenic nerve, mediastinal pleura or parietal pericardium.

Tumor in the main bronchus (<2 cm distal to the carina but without involvement of the carina).

Associated atelectasis or obstructive pneumonitis of the entire lung or separate tumor nodule(s) in the same lobe.

T4 = Tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina or
separate tumor nodule(s) in a different ipsilateral lobe.

NX = Regional lymph nodes cannot be assessed.

N0 = No regional lymph node metastasis.

N1 = Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension.

N2 = Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s).

N3 = Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene or supraclavicular lymph node(s).

M0 = No distant metastasis.

M1 = Distant metastasis.

M1a = Separate tumor nodule(s) in a contralateral lobe tumor with pleural nodules or malignant pleural (or pericardial) effusion.

M1b = Distant metastasis.


Doctors consider the age and overall health of the patient when choosing a treatment plan. Treatment options for Stage IV non-small-cell lung cancer may include radiation therapy, chemotherapy, and targeted therapy. Radiation therapy is used mainly for palliative purposes, rather than an intention to cure. The five-year relative survival rate for Stage IV non-small-cell lung cancer is about 2 percent. However, this rate should not be taken as a prediction for any individual, because there are many factors that can affect a person's individual outlook. In addition, because the survival rate data was taken from patients treated five or more years ago, current treatments may result in a higher survival rate.

Compensation information is available for those diagnosed with lung cancer in our FREE Lung Cancer Information Packet or by calling toll-free 1-800-258-1054.

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