Lung cancer can can develop within the airways or deep within the lungs. During cancer development, mutated lung cells proliferate out of control, giving rise to millions of daughter cells and forming tumors within the lung. As the cancer progresses, the lung cancer cells gain invasive properties, allowing the cells to migrate into new tissues and spread cancer growth. Stage IV advanced lung cancer occurs when cancer grows extensively within the lungs as well as distant tissues throughout the body. This advanced form of lung cancer can lead to a number of complications that can ultimately prove fatal.
Severe Lung Damage
A potentially fatal complication of stage IV lung cancer is extensive lung damage. During cancer growth, tumor cells seek out and destroy healthy lung tissue along the margins of the tumor. As the cancer grows, the lungs accumulate more and more tissue damage, diminishing lung capacity and leading to difficulty breathing. According to the Merck Manual, patients with severe lung cancer may suffer from pleural effusions, pools of fluid around the lungs that make it difficult to breath. Although cancer growth in the lung may be slowed with surgery or radiation treatment, progressive damage to the lungs can prove incapacitating or fatal.
Liver Damage
Stage IV lung cancer commonly spreads to the liver, causing the complication of liver damage and shutdown. Under normal conditions, the liver helps remove toxins from the body and secretes chemicals that aid in metabolism and digestion. Lung cancer growth in the liver harms healthy liver tissue, leading to scarring and progressive liver damage. Medline Plus indicates that patients with liver metastases experience pain in the upper right abdomen, fatigue and a loss of appetite. As the cancer progresses, ducts leading from the liver to the gallbadder become blocked with cancer growth, causing liver secretions to leak into the blood. At these late stages of liver damage, patients may develop a yellowing of the skin and eyes as bile salts from the liver travel through the bloodstream and deposit in tissues near the skin. Over time, this liver damage prevents the liver from detoxifying the body and can cause death.
Brain Damage
Another possible complication of stage IV lung cancer is brain damage. Harvard University indicates that lung cancer commonly metastasizes to the brain, where cancer growth damages nerve cells. An early symptom of lung cancer metastasis to the brain is the development of abnormal headaches that may be very frequent or severe. As the cancer continues to grow, the tumor increases intracranial pressure, placing excess pressure on the entire brain. Over time, this increased pressure can lead to seizures and scarring within the brain. Harvard indicates that stage IV lung cancer patients with brain complications may respond to radiation therapy, slowing the progression of cancer in the brain.
