Lung cancer is cancer that begins in the lungs.

According to the American Cancer Society (ACS), it’s the second most common type of cancer in both males and females.

Lung cancer is also the leading cause of cancer death in both sexes. However, new cases of lung cancer and deaths due to lung cancer have been declining due to decreases in smoking as well as advances in diagnosis and treatment.

Adenocarcinoma of the lung is a type of non-small cell lung cancer and is the most frequently observed type of lung cancer. Keep reading as we dive deeper into adenocarcinoma of the lung, its causes, and how it’s diagnosed and treated,

There are two predominant types of lung cancer:

NSCLC is much more common, making up 80 to 85 percent of all lung cancers.

Adenocarcinoma of the lung is one type of NSCLC. It’s also the most common type of lung cancer, making up over 40 percent of all NSCLC diagnoses.

This cancer begins in the mucus-secreting glands that line the walls of your alveoli, the tiny air sacs in your lungs. It’s often found on the outer parts of the lungs.

Adenocarcinoma of the lung can be further divided into different subtypes, based off of factors like:

  • the size of the tumor
  • how the cancer cells look under a microscope
  • whether the cancer has started to invade surrounding tissues

Lung cancers, including adenocarcinoma of the lung, are often asymptomatic in their early stages. In these situations, a cancer may be found when you’re having a chest X-ray for another condition.

When symptoms are present, they can include:

The outlook for lung cancer is better when it’s found and treated early. If you develop any of the symptoms above, make an appointment with your doctor. They can perform tests to help find what’s causing your symptoms.

Cancer is when cells in your body begin to grow and divide out of control. This is caused by changes in genes, particularly those that manage cell growth and division.

Genetic changes can be inherited, but are often acquired during your lifetime. This can happen due to errors that happen as cells divide or due to damage caused by harmful substances that you encounter in the environment.

In fact, genetic sequencing has found acquired genetic changes in over 70 percent of adenocarcinomas of the lung. As you’d expect, many of these are in genes that have to do with cellular growth and division.

Risk factors for adenocarcinoma of the lung

Risk factors are things that raise your risk of developing a condition. We know of several risk factors for adenocarcinoma of the lung.

Like other types of lung cancer, smoking is the main risk factor for adenocarcinoma of the lung. Tobacco smoke contains thousands of different chemicals and at least 70 of them are known to cause cancer.

However, people who don’t smoke can still get adenocarcinoma of the lung. In fact, it’s the most common type of lung cancer in people who’ve never smoked.

Some additional risk factors for adenocarcinoma of the lung are:

To diagnose adenocarcinoma of the lung, your doctor will first get your medical history. They’ll ask about the symptoms you’re having, if you currently or have previously smoked, and if you have a family history of lung cancer.

They’ll then perform a physical examination. At this time, they’ll get your vital signs and will listen to your lungs as your breathe.

The tests that may be ordered to help diagnose adenocarcinoma of the lung are:

  • Blood tests. Blood tests help your doctor assess your overall health:
    • Blood chemistry can look at certain chemicals in the blood, such as glucose and electrolytes, and can also inform them on how well your liver and kidneys are working.
  • Imaging tests. Imaging tests can be used to help your doctor to get a look at your lungs to check for signs of a tumor. Several types of imaging may be used, including:
    • chest X-ray
  • Bronchoscopy. During a bronchoscopy, your doctor will use a thin, flexible tube with a camera on the end to look inside of your airways for signs of cancer. Tissue samples may also be collected.
  • Sputum cytology. For sputum cytology, a doctor will view a mucus sample under a microscope to look for cancer cells. This test may not be as helpful for adenocarcinoma of the lung since this cancer is often on the outer edges of the lungs.
  • Thoracentesis. If fluid is present in the space between your chest wall and lungs, your doctor will use a needle to remove a sample of this fluid. It can be checked under a microscope to look for cancer cells.

A lung biopsy is the only way to definitively diagnose adenocarcinoma of the lung. If the tests above raise suspicions of lung cancer, a biopsy will be collected from the affected area and examined under a microscope for signs of cancer.

This tissue can also be tested for proteins or genetic changes associated with adenocarcinoma of the lung. If present, these can affect outlook and may also be targets for treatments like targeted therapy and immunotherapy.

Tests for staging

If adenocarcinoma of the lung is diagnosed, some additional tests are done to help determine the cancer’s stage. Staging helps your doctor to know how far the cancer has spread and plays a vital role in treatment recommendations.

The staging of NSCLCs like adenocarcinoma takes three factors into consideration:

  • Tumor (T): the size of the tumor and also whether it’s invaded surrounding tissues
  • Lymph nodes (N): whether the cancer has spread to nearby lymph nodes
  • Metastasis (M): whether the cancer has spread to more distant tissues like the brain and bones

Additional tests that may be used as a part of staging are:

  • Lymph node biopsy. During a lymph node biopsy, all or part of a nearby lymph node is removed to check if the cancer has spread to the lymph nodes.
  • Bone scan. A bone scan can look to see if cancer has spread to the bones.
  • Magnetic resonance imaging (MRI) scan. An MRI scan can determine if cancer has spread to the brain and spinal cord.
  • Endobronchial ultrasound (EBUS). During this procedure, a doctor inserts a thin flexible tube with a small video camera through your mouth and down your windpipe to create images of your lungs and nearby lymph nodes. The camera gives doctors a closer look at areas of concern seen on X-rays or scans. Doctors can also use this method to obtain biopsy tissues or fluid samples.
  • Advanced bronchoscopy. Initial tissue collection can also be done using newer, advanced techniques, such as electromagnetic navigation bronchoscopy (ENB), which uses electromagnetic technology to obtain samples of lung tissue, or robotic-assisted bronchoscopy (RAB), a tool that helps doctors locate and collect tissue samples on the lung or lymph nodes.

If you have adenocarcinoma of the lung, your treatment options will largely depend on the extent, or stage, of your cancer. Other factors that are also important to treatment selection include:

  • your age and overall health
  • how well your lungs are functioning
  • whether certain markers are present on cancer cells
  • your personal preference

The treatments for adenocarcinoma of the lung can include one or a combination of the following:

  • Surgery. Surgery can be used to remove areas affected by cancer. Since this involves removing parts of your lungs, lung function tests will be done beforehand to see if surgery is a good option for you. Nearby lymph nodes may also be removed.
  • Chemotherapy. Chemotherapy may be used when surgery isn’t an option, such as when cancer has spread into nearby tissues or has metastasized. In some cases, it may be combined with radiation therapy. Other times chemotherapy may be used include:
    • prior to surgery in order to shrink a tumor (neoadjuvant therapy)
    • after surgery to help kill any remaining cancer cells (adjuvant therapy)
  • Radiation therapy. Radiation therapy may also be used if surgery isn’t an option due to the extent of the cancer. It can also be used as a neoadjuvant or adjuvant therapy.
  • Targeted therapy. Targeted therapy uses drugs that hone in on specific markers associated with cancer cells. It may be used if your cancer has certain markers that are targets of these drugs. Examples of targeted therapy drugs are:
    • monoclonal antibodies like bevacizumab (Avastin) and ramucirumab (Cyramza)
    • tyrosine kinase inhibitors like erlotinib (Tarceva) and gefitinib (Iressa)
    • kinase inhibitors that target certain gene changes like dabrafenib (Tafinlar), trametinib (Mekinist), and ceritinib (Zykadia)
  • Immunotherapy. Immunotherapy helps your immune system respond to cancer cells. It’s typically used for more advanced adenocarcinoma of the lung. Immunotherapy options for adenocarcinoma of the lung include:

Clinical trials

Doctors and researchers continue to develop newer, more effective treatments for adenocarcinoma of the lung. These can include new targeted therapy or immunotherapy drugs or new ways to use existing treatments.

Before being used on a larger scale, these new treatments need to be tested in clinical trials. If you’re interested in taking part in a clinical trial, talk with your care team. They can help you to find one that you’d be a good candidate for.

You can also consider looking at clinical trials supported by the National Cancer Institute. The LUNGevity Foundation also provides a clinical trial matching service via the phone or an online search tool.

A variety of factors can affect the outlook for adenocarcinoma of the lung. These include:

  • the stage of your cancer
  • the subtype of adenocarcinoma of the lung that you have
  • how well your lungs are functioning
  • whether certain genetic changes are present in the cancer cells
  • your age and overall health

According to the ACS, the outlook for most types of NSCLC are similar. The table below shows the 5-year survival rates in people diagnosed with NSCLC between 2010 and 2016.

Stage of cancer 5-year survival rate
Localized: Cancer hasn’t spread outside the lung. 63 percent
Regional: Cancer has spread to nearby lymph nodes or tissues. 35 percent
Distant: Cancer has spread to more distant tissues like the brain and bones. 7 percent
All combined 25 percent

Two subtypes of adenocarcinoma of the lung, adenocarcinoma in situ and minimally invasive adenocarcinoma, have a better outcome, especially when treated early with surgery. If surgery completely removes the cancer, 5-year survival rates approach 100 percent.

Survival rates are calculated based on data from many people with NSCLC and don’t account for individual factors or recent advances in diagnosis and treatment. Overall, it’s best to discuss your individual outlook with your care team.

Adenocarcinoma of the lung is a type of NSCLC that affects mucus-producing cells. It’s the most commonly diagnosed type of lung cancer.

The main risk factor for adenocarcinoma of the lung is smoking. However, it can also develop in those who’ve never smoked. Additional risk factors include age, a family history of lung cancer, and exposures to certain harmful substances.

Generally speaking, the outlook for adenocarcinoma of the lung is best when it’s diagnosed and treated early. As such, talk with your doctor if you develop symptoms like a persistent cough, shortness of breath, or chest pain.