The diagnosis and prognosis of lung cancer includes the following:

Review of Medical History

The doctor will ask about your symptoms and medical history. He or she will ask when you first noticed the symptoms and how they may have progressed. The doctor will also ask about anything that may increase your risk of lung cancer, including:

  • Smoking history
  • Exposure to environmental and occupational substances
  • Family history of cancer

Physical Exam

The doctor will perform a physical exam, listen to your lungs, and assess your general health. Your overall health may affect your treatment plan. Abnormalities in other parts of the body may indicate spread of the cancer. The doctor will check for signs of fluid in the neck, armpits, and shoulder areas. Such swelling may be associated with lung cancer pressing on the superior vena cava, a major blood vessel connecting the lungs and heart. Your abdomen will be checked for signs that the liver is affected as well. The doctor will also check the skin for nodules (bumps).

Diagnostic Tests

To help your doctor make a diagnosis of lung cancer, some of the following tests may be done:

Chest x-ray – a series of standard x-ray images of your chest to check for abnormal areas on the lungs.

CT scan – a type of x-ray that uses a computer to produce cross-sectional images of the inside of the body, in this case the lungs. A special spiral or helical low dose CT scan may identify smaller tumors than a regular x-ray.

Sputum cytology – examination of a sample of mucus from the lungs to check for cancer cells.

Biopsy – removal of a sample of lung tissue to be tested for cancer cells. Methods of lung biopsy include the following:

Bronchoscopy – a visual examination of the lungs and air passages with a bronchoscope—an instrument with a lighted tip. The doctor can remove tissue samples or wash the tissues with saline (a procedure called lavage) to obtain cells to check for cancer.

Needle aspiration – a needle is inserted through the chest to remove a sample of tissue from the tumor. This tissue is checked for cancer cells.

Thoracentesis – a needle is inserted through the chest to remove a sample of the fluid from around the lungs to check for cancer cells.

Placement of Thoracentesis Needle

Placement of Thoracentesis Needle
© 2009 Nucleus Medical Art, Inc.

Pulmonary function tests – this series of tests is done to see how well your lungs work. The findings from these tests help your doctor determine what kind of treatments may be appropriate for you.

Positron emission tomography (PET) scan - assesses metabolic activity in the tissue. Cancer cells typically generate more activity than non-cancerous cells. A PET scan can be performed on a variety of body tissues. A nurse or technologist administers a radioactive substance. This may be done through an injection, or in some cases, you will be asked to breathe in a gas with the substance. The compound travels through the blood to the area of the body under study. It takes between 30 and 90 minutes for the substance to be absorbed by the tissue under study. You lie on a table and are moved into a machine that looks like a large, square-shaped doughnut. This machine detects and records the energy levels emitted from the substance that was injected earlier. The images are viewed on a nearby computer monitor.

Cytology

Cytology is the study of cells. The cytology of cancer cells differs significantly from normal cells, and physicians use the unique cellular features seen on biopsy samples to determine the diagnosis and assess the prognosis of a cancer.

To diagnose lung cancer, the cytology of cells from sputum, bronchial washings or brushings, and/or tissue from a biopsy are examined.

Staging

Staging is the process by which physicians determine the prognosis of a cancer that has already been diagnosed. Staging is essential for making treatment decisions (e.g., surgery vs. chemotherapy). Several features of the cancer are used to arrive at a staging classification, the most common being the size of the original tumor, extent of local invasion, and spread to distant sites (metastasis). Low staging classifications (0 – 1) imply a favorable prognosis, whereas high staging classifications (4 – 5) imply an unfavorable prognosis.

Additional tests to determine staging may include:

Blood tests - testing of a blood sample may help determine possible cancer spread to other parts of the body.

CT scan – a type of x-ray that uses a computer to produce cross-sectional images of the inside of the body, to look for areas where the cancer may have spread.

MRI scan – a test that uses magnetic waves to produce images of the inside of the body. Using a large magnet, radio waves, and a computer, an MRI produces two-dimensional and three-dimensional pictures. It is used to help determine if the cancer has spread.

Bone or liver scans – tests that look for evidence of tumors in these organs. A radioactive substance is injected into the bloodstream and tracked by a scanning machine. Cancerous areas absorb more of the radioactive substance than normal tissue and show up as “hot spots.”

Lymph node biopsy - your doctor removes all or part of one of your lymph nodes. A pathologist examines this tissue sample under a microscope. The biopsy can show whether or not there is cancer and the type of cancer cells present.

Mediastinoscopy – a test performed in the hospital to check lymph nodes in the chest for cancer cells. The doctor inserts an instrument through a small incision into the chest to remove lymph node tissue, which is then checked for cancer cells.

Stages of Lung Cancer

Lung cancer staging considers three categories: tumor, lymph nodes, and metastases.

Your doctor considers the following factors to determine the stage of lung cancer:

  • The size of the tumor and how close it is to the windpipe
  • Your ability to carry on activities of daily living without assistance
  • Whether the disease has spread to your lymph nodes
  • Whether the disease has spread to the bone, liver, or other places outside the lung
  • How many body systems the cancer has affected

Lung Cancer Tumor (T) Stages:

Stage Tis (in situ) - cancer cells are found in the sputum but cannot be seen in the airways or the lung.

Stage T1 - the tumor is 3 centimeters (cm) or smaller, has not spread to the skin or pleura (membrane) that surround the lungs, and is not affecting the main branches of the airways (bronchi).

Stage T2 - the cancer has one or more of the following characteristics:

  • It is larger than 3 cm.
  • It involves the main bronchus but is not closer than 2 cm to where the windpipe branches left and right.
  • It has spread to the pleura that surround the lungs.
  • It may block part of the airway and can cause some collapse of the lung, but has not caused the entire lung to collapse.

Stage T3 - the cancer has one or more of the following characteristics:

  • It has spread to the chest wall, diaphragm, or pleura surrounding the space between the lungs or the membranes surrounding the heart.
  • It involves a main bronchus and is closer than 2 cm to where the windpipe branches left and right.
  • It has grown into the airway and caused a lung to collapse or pneumonia in the entire lung.

Stage T4 - the cancer has one or more of the following characteristics:

  • It has spread to structures inside the chest other than the lung (spinal bones, heart, esophagus, large blood vessels).
  • Two or more separate tumors in the same lobe.
  • Cancer cells in the space surrounding the lungs.

Lung Cancer Lymph Node (N) Stages:

Stage NO - the cancer has not spread to the lymph nodes.

Stage N1 - the cancer has spread to lymph nodes in the lung or the area where the bronchus meets the lung, and affected the lymph nodes on the same side of the body as the cancer.

Stage N2 - the cancer has spread to the lymph nodes where the windpipe branches left and right, or to lymph nodes in the space between the chest bone and heart. The affected lymph nodes are on the same side of the body as the cancer.

Stage N3 - the cancer has spread to lymph nodes near the collarbone on either side or to the opposite side of the lung from where the lung cancer is located.

Lung Cancer Metastatic (M) Stages:

Stage MO - the cancer has not spread.

Stage M1 - the cancer has spread to other parts of the body beyond the chest, other lobes of the lung, or lymph nodes beyond those considered in the N stages.

Overall Cancer Stage

Overall Lung Cancer Stages, Based on T, N, and M Stages
Overall StageT StageN StageM Stage
Stage 0TisN0M0
Stage IAT1N0M0
Stage IBT2N0M0
Stage IIAT1N1M0
Stage IIBT2N1M0
T3N0M0
Stage IIIAT1N2M0
T2N2M0
T3N1 or N2M0
Stage IIIBAny TN3M0
T4Any NM0
Stage IVAny TAny NM1

Prognosis

Prognosis is a forecast of the probable course and/or outcome of a disease or condition. Prognosis is most often expressed as the percentage of patients who are expected to survive over five or ten years. Cancer prognosis is a notoriously inexact process. This is because the predictions are based on the experience of large groups of patients suffering from cancers at various stages. Using this information to predict the future of an individual patient is always imperfect and often flawed, but it is the only method available. Prognoses provided in this monograph and elsewhere should always be interpreted with this limitation in mind. They may or may not reflect your unique situation.

The 5-year cause-specific survival rates for non-small cell lung cancer, by stage:
Stage5-year survival rate
Stage I85%
Stage II70%
Stage III35%
Stage IV5%

These rates may vary depending on other prognostic factors. About half of patients with non-small cell lung cancer that is found and treated before it has spread live five or more years. But lung cancer is found at this early stage in only about 17% of patients.

For patients with small cell lung cancer, five-year survival rates are 25% to 30% for early disease and 10% for advanced, metastatic disease.