Metastatic lung cancer – Stages and their treatment

The development of cancer starts from a specific organ in the body, known as the primary site. Unlike other body cells, cancer cells break away from the primary site at later stages of cancer and affect other body parts. They move within the body through the bloodstream or the lymph system, which is made up of vessels responsible for carrying fluids throughout the body. These vessels are important for supporting the immune system. When cancer cells start traveling to other organs of the body, then it is said to reach the metastasis phase.

Metastatic lung cancer is a fatal condition that begins developing when cancer in some other affected body part starts reaching to lungs. Cancer at the primary site makes metastatic tumors, capable of metastasizing to the lungs. Bladder cancer, breast cancer, colon cancer, kidney cancer, neuroblastoma, prostate cancer, sarcoma, and Wilms’ tumor are primary tumors that spread to the lungs. Thus, people having other types of severe cancers are more likely to develop metastatic lung cancer. There are no visible symptoms of the disease at early stages, hence making it difficult to detect.

Symptoms
Not in all cases does metastatic lung cancer cause symptoms.

• Bloody phlegm/coughing blood
• Chest pain
• A persistent cough
• Shortness of breath
• Sudden weight loss
• Weakness
• Wheezing
• Stages

Metastatic lung cancer is identified by means of two types of staging process – small cell lung cancer staging, and non-small cell lung cancer staging.

Small Cell Lung Cancer Staging – It is typically caused by tobacco or smoking. It makes up roughly about less than 20 percent of all lung cancer cases. It starts in the bronchi, before spanning out to other parts of the body, including the lymph nodes. Small cell lung cancer is classified into two distinct stages:

• Limited stage – Cancer is found only in one lung, including neighboring lymph nodes.
• Extensive stage – Cancer is spread to the other lung, other parts of the body, and to the fluid around the lung.

Non-Small Cell Lung Cancer Staging – It makes use of the TNM system, where T (Tumor) describes size of the tumor, N (Lymph Node) describes whether cancer has affected the lymph nodes or not, M (Metastasis) describes whether cancer has spread to other body parts, such as bones, brain, and liver.

An overall stage to the cancer is assigned only after TNM scores are assigned. Various stages of non-small cell lung cancer are:

• Occult stage – No tumor is found in the lung using bronchoscopy or imaging tests. Cancer cells are found only in sputum.
• Stage 0 – Cancer is small in size and hasn’t yet spread to deeper lung tissues or outside the lungs.
• Stage I – Cancer is present in the underlying lung tissues. However, the lymph nodes are unaffected.
• Stage II – Cancer has spread to the chest wall or nearby lymph nodes.
• Stage III – Metastatic lung cancer is continuing to spread to the lymph nodes or the nearby structures and organs, including esophagus, heart, and trachea, from the lungs.
• Stage IV – Cancer has spread throughout the body and severely affects liver, bones or brain.

Treatment for metastatic lung cancer
The treatment for metastatic lung cancer depends on the stage of cancer and the original site of cancer. Medication involved in treating lung cancer is focused towards metastases. Drug therapy is used to treat various lung cancer cases in which cancer has spread to the liver area. In case cancer has affected the brain, various treatments, ranging from steroids to radiation therapy, are used.

Surgery is also an option in various cases of lung cancer. However, it is limited to only pre-expressive stages of the disease, i.e., in which cancer hasn’t spread to parts other than the lungs. Drug therapy is avoided in cases where severe pain is experienced, or there is an excessive risk of bone breakage. In lung cancer cases where bones have gone too fragile and severe pain is experienced, radiation therapy is used.

Life expectancy
Early detection of metastatic lung cancer can be beneficial in prolonging life, i.e., increasing life expectancy. Lung cancer cases belonging to stage I and stage II can be treated effectively with about 100% life expectancy for five years. Advanced stages of lung cancer have low life expectancy rates. For instance, a person treated in stage IV of metastatic lung cancer has a life expectancy of less than 50% for five years. Therefore, it’s important to detect the disease early to have a greater life expectancy rate for patients.