Lung cancer occurs when cells within the lungs develop genetic mutations that causes them to grow abnormally. This can be due to exposure to certain things in the environment--such as tobacco smoke, radon, and asbestos--or due to hereditary genetic mutations. One of the hallmarks of late-stage lung cancer is the spread of the tumor, which is also known as metastasis. These tumors may also have undergone further changes that causes them to abnormally secrete hormones.
Signs in the Lung
Late-stage lung cancer can cause many symptoms within the lungs, including a cough that does not go away. Often, late-stage lung cancer will cause the person to cough up blood. It may also cause severe chest pain, shortness of breath and wheezing. Another sign of late-stage lung cancer that is typical of many late-stage cancers is sudden weight loss and a lack of appetite.
Signs of Cancer Spread
The signs that cancer has spread to different organs depends on the location of the metastases. Lung cancer will often spread to the bones, where it can cause bone pain. If the cancer spreads to the brain, it can cause headaches, numbness, seizures and dizziness, as well as weakness of a limb. Some cancers will cause jaundice, which is a yellowing of the skin and eyes. This is a result of liver metastases. If the cancer has spread to the lymph nodes, then lumps will be seen near the skin surface.
Horner's Syndrome
Horner's syndrome is a group of symptoms that can be caused by tumors at the top part of the lungs, causing damage to a nerve that runs very near that area. Horner's syndrome can cause one eyelid to droop or be weak. It can cause the pupil in the affected eye to be smaller. In addition, the affected side of the face will have little or no sweating.
Paraneoplastic Syndrome
Some late-stage lung cancers develop the ability to secrete hormones. Because these cells are already growing abnormally, they can cause unnaturally high levels of these hormones, resulting in paraneoplastic syndrome. Paraneoplastic syndrome can result in extremely high levels of calcium in the blood, abnormally high levels of water retension by the kidneys and high production of cortisol.
Signs on Medical Tests
Late-stage lung cancer will generally be confirmed via multiple diagnostic tests. Late-stage lung cancer will generally appear on a chest X-ray as either a large mass or several smaller dark spots in the lungs. A CT scan will often not only show the initial lung tumor but also some of the metastases. Spread of the lung cancer to the brain or spinal cord can be observed using an MRI.
