Lung adenocarcinoma is the most common type of lung cancer in the United States. It makes up about 40 percent of lung cancers.

Lung adenocarcinoma falls into a group of cancers called non-small cell lung cancers. They’re named for the way their cells appear under a microscope.

Lung adenocarcinoma progresses more slowly than other lung cancers. It occurs more often in women.

In this article, we take a look at how lung adenocarcinoma is treated, what causes it, and how to recognize its symptoms.

Lung adenocarcinoma doesn’t usually cause obvious symptoms in the early stages. The tumor may develop over quite some time until you experience general symptoms such as:

Most of these symptoms can have many potential causes. It’s a good idea to visit a healthcare professional any time you develop any of these symptoms to rule out lung cancer.

Late stage symptoms

As lung cancers progress, symptoms tend to get worse and lead to a rapid decline in quality of life. In the late stages, lung cancer may cause symptoms such as:

  • extreme tiredness
  • delirium and restlessness
  • coma
  • trouble tolerating food
  • severe breathing difficulty
  • reduced vital signs
  • rattling or gurgling sounds when breathing
  • pain

It’s not entirely clear why some people develop lung adenocarcinoma and others don’t. Researchers think that a combination of environmental and genetic factors contribute to its development.

Smoking or exposure to smoke is a primary risk factor

Smoking cigarettes is the greatest risk factor for developing any lung cancer. About 80 to 90 percent of lung cancer deaths are associated with smoking tobacco.

Smoking is strongly associated with the development of adenocarcinoma, but adenocarcinoma is also the most common type of lung cancer in people who’ve never smoked.

Other risk factors for lung adenocarcinoma

Other risk factors include:

  • Family history. Your risk of developing adenocarcinoma is higher if a close family member develops it. Some genetic markers, such as variations in chromosome 5p15.33, are linked to a higher risk of lung adenocarcinoma.
  • Sex. Adenocarcinoma is more common in women than men.
  • Age. The most common age range for diagnosis with lung adenocarcinoma is 80 to 84. However, adenocarcinoma occurs more often in young people than other types of lung cancer.
  • Exposure to pollution. A 2014 research review found that exposure to pollution is linked to the development of lung adenocarcinoma and squamous cell carcinoma.
  • Exposure to occupational hazards. Exposure to the following occupational hazards is linked to the development of adenocarcinoma:
    • secondhand smoke
    • silica
    • diesel exhaust
    • asbestos
    • radon

In a 2016 study, researchers compared the risk factors of developing lung adenocarcinoma with lung squamous cell carcinoma. They found that compared with people who have squamous cell carcinoma, people with adenocarcinoma were more likely to:

Treatment options for lung adenocarcinoma depend on factors such as your overall health, the stage of your cancer, and your treatment preference.

The following treatments may be used alone or in combination with other treatments:

  • Surgery. Surgery is often recommended for early stage tumors that haven’t spread to other parts of your body. A lobectomy, or the removal of an entire lobe of your lung, is considered the most effective surgery.
  • Radiation therapy. Radiation therapy uses concentrated beams of energy to damage the genetic information of cancer cells and keep them from replicating.
  • Chemotherapy. Chemotherapy is a drug therapy that uses chemicals to kill cancer cells as well as healthy cells in your body that replicate quickly. Chemotherapy is often administered with radiation therapy if cancer spreads beyond your lungs.
  • Targeted therapies. Targeted drug therapies specifically kill cancer cells rather than killing all quickly dividing cells in your body like chemotherapy does.
  • Immunotherapy. Immunotherapy stimulates your immune system to fight cancer cells. Four types of immunotherapy drugs are Food and Drug Administration approved for treating non-small cell lung cancers.
  • Angiogenesis inhibitors. Angiogenesis inhibitors help keep tumors from creating new blood vessels and starve cancer cells of oxygen and essential nutrients.

Clinical trials for lung adenocarcinoma

Over the years, the survival rate of people with lung adenocarcinoma has improved due to advancements in treatment. According to the National Cancer Institute, the survival rate rose from 20.8 percent in the year 2000 to 26.7 percent in 2013.

Researchers constantly search for more effective treatments by running clinical trials where participants are either given new treatments or standard treatments. If new treatments are found to be more effective, they eventually become standard treatments.

If you’re interested in joining a clinical trial, you can talk with your healthcare team about trials available in your region. You can also search for trials online from: