Cancer is characterized by the abnormal and unmitigated growth of cells. The cells form into masses, cysts, and lesions, and when left unchecked, they may grow into various areas of the body. Advanced lung cancer, as with other forms of cancer, has the ability to metastasize to other tissues, organs, and organ systems.

If you have been diagnosed with lung cancer, understanding the spread of lung cancer may help you and your healthcare provider better tackle your cancer and develop a proper treatment plan. Where and how does lung cancer spread? Read on to find out.

Understanding Lung Cancer

Lung cancer refers to any cancer that originates in the cells and lung tissue. Secondary lung cancer occurs when cancerous cells from somewhere else in the body enter the lungs.

As mentioned, cancers are characterized by the sudden abnormal growth of cells. This is a result of a cellular mutation, though the primary cause of this mutation is not well known or understood. Doctors do know that cancer is not isolated to its organ or tissue of origin. The growing tumor can crowd into nearby organ structures, forcing cells to spread directly into adjacent tissue. As the tumor grows, cancerous cells can obstruct blood vessels, which prevents the blood and oxygen flow into healthy tissue. Without that blood and oxygen, the tissue eventually dies, allowing the cancer to spread further.

Alternately, lung cancer cells can detach from their primary tumor and move their way through the blood or lymph nodes to areas that are relatively far from the point of origin. More advanced stages of lung cancer can speed up its metastatic process. Lung cancer cells can stick and move inside the walls of blood vessels and lymph nodes into nearby organ tissues, eventually growing and forming into tumor cells that may continue to spread.

Where Does Lung Cancer Spread?

Due to the nature of cancer and its ability to travel through blood vessels, metastatic lung cancer can technically spread to just about any area of the human body, including other vital organs. However, there are some common areas where lung cancer may metastasize. 

Lymph Nodes

Your lymph nodes are part of your immune system and play a role in bacterial and viral infections. Lung cancers that do spread almost always grow into the lymph nodes in the chest and neck first. This usually does not present with any noticeable symptoms, though cancers that spread to lymph nodes beyond the chest area may result in lumps in the neck or armpits. It should be noted that lung cancer that expands to the lymph nodes does not necessarily mean that it is metastatic.

Bones

Lung cancer will spread to the bones near the chest in up to 40 percent of patients with advanced forms of the disease. This usually affects the pelvis, spine, and upper bones in the arms and legs. The symptoms can vary, but an instantaneous feeling of pain or discomfort in the bones is the most prevalent sign. This pain can present as a minor strain or muscle ache before progressing to more severe and consistent pain.

Tumor cells can also weaken and break down the bones. This can result in sudden fractures and bone breaks occurring with minor trauma or during everyday activities. That break down can also cause calcium to leak into the blood, leading to muscle weakness, a loss of appetite, and other symptoms. Cancerous cells pressing against the spine may present an actual emergency.

Brain

Up to 40 percent of those with lung cancer will develop brain metastases at some point. About 20 to 35 percent of patients with non-small cell lung cancer will develop brain metastases. In about 44 percent of people, the spread of lung cancer into the brain does not present any noticeable symptoms. For others, the degradation of brain tissue and increased physical pressure from swelling and inflammation can result in various symptoms that may include:

  • Headaches
  • A loss of balance and coordination
  • Confusion
  • Memory loss
  • Changes to vision
  • Nausea
  • Fatigue
  • Weakness on one side of the body

Liver

Metastatic lung cancer that has spread to the liver usually does not present any symptoms. If the metastases are large enough or if there are numerous tumors on the liver, symptoms may include nausea after meals, a loss of appetite, and pain under the right ribs. If the cancer obstructs the ducts of your liver, you may experience jaundice.

Due to the general lack of early signs of lung cancer, the spread of lung cancer can occur before the disease actually gets diagnosed. If you encounter any unusual symptoms, please consult your doctor immediately for a diagnosis to determine the right targeted therapy plan for you.

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January 17, 2020