Lung Cancer Symptoms and Causes
Lung cancer is the leading cause of cancer deaths in the United States in both men and women, leading to more deaths than colon, prostate, ovarian, and breast cancers combined. It is also one of the most preventable kinds of cancer.
Early Signs of Lung Cancer
Early stage lung cancer typically presents no symptoms. Signs and symptoms of lung cancer more often occur when the disease has advanced to a later stage. However, some symptoms do present earlier in the disease progression.
The early signs of lung cancer may include:
- A new persistent cough that worsens, or a change in an existing chronic cough
- Coughing up blood
- Pain in the chest, back, or shoulders that worsens during coughing, laughing, or deep breathing
- Shortness of breath or wheezing
- Tiredness or weakness
- Loss of appetite
- Frequent lung infections such as bronchitis or pneumonia
- Unexplained weight loss
Less common symptoms of early stage lung cancer may include:
- Swelling in the face or neck
- Difficulty swallowing or pain while swallowing
- Changes in the appearance of fingers
Although these symptoms are likely to be caused by something other than lung cancer, it’s important to see your doctor. Detecting lung cancer early can mean more available treatment options and better outcomes.
Advanced Lung Cancer Symptoms
When lung cancer spreads to other parts of the body, it is considered in the advanced stage. It may affect the bones, liver, or brain.
Symptoms of advanced stage lung cancer may include:
- Bone pain or fractures
- Swelling of the face, arms, or neck
- Weakness or numbness in the limbs
- Lumps in the neck or collarbone region
- Blood clots
If you experience any of these symptoms, speak with your doctor. Finding lung cancer as early as possible – even if it has already spread to other parts of the body – is key to getting the most effective treatment.
Types of Lung Cancer
Lung cancer typically begins in the walls of the lungs’ airways or air sacs, but it can spread to other parts of the body. There are more than 20 types of lung cancer. The two main types are non-small-cell lung cancer and small-cell lung cancer.
Small-cell lung cancer
About 10 to 15 percent of all lung cancers are small-cell lung cancer. This type of lung cancer tends to grow and spread faster than non-small-cell lung cancer.
There are two stages of small-cell lung cancer: limited and extensive. Each type requires different treatment.
- In the limited stage, cancer is generally found in only one lung. There also may be cancer in nearby lymph nodes on the same side of the chest.
- In the extensive stage, cancer has spread beyond the primary tumor in the lung into other parts of the body.
Although it spreads quickly, this type of cancer generally responds well to chemotherapy and radiation therapy.
Non-small-cell lung cancer
This type is much more common than small-cell lung cancer, accounting for about 85 to 90 percent of lung cancers. The three primary types of non-small-cell lung cancer are named for the type of cells in the tumor:
- Squamous cell carcinoma (also called epidermoid carcinoma) is often found in the bronchi near the middle of the lungs. It begins in the squamous cells, which are flat cells that line the inside of the airways in the lungs. This type is often linked to a history of smoking.
- Adenocarcinoma usually begins along the outer edges of the lungs. It is the most common type of lung cancer in people who have never smoked. It is also more common in women than in men and is more likely to occur in younger people than other types of lung cancer. This type is more likely to be found and diagnosed before it has spread.
- Large-cell carcinoma are a group of cancers with large, abnormal-looking cells. These tumors may begin anywhere in the lungs and tend to grow quickly.
Lung cancer symptoms can vary from person to person and may depend on the type of lung cancer and what part of the lung is affected.
Causes of Lung Cancer
Smoking is the primary cause of lung cancer, with around 90 percent of lung cancers occurring as a result of tobacco use. The risk of lung cancer increases with the number of cigarettes smoked each day and the number of years as a smoker. Quitting at any time lowers the risk of developing lung cancer. However, smoking is not the only cause of lung cancer. Other causes of lung cancer include:
- Second-hand smoke – Even if you do not smoke, exposure to second-hand smoke increases the risk of lung cancer. Studies have shown that nonsmokers who live with a smoker have a 24-percent increased risk for developing lung cancer when compared with other nonsmokers. Each year, there are around 7,300 deaths from lung cancer in the U.S. that are attributed to second-hand smoke.
- Asbestos and other carcinogens - Exposure to asbestos and other substances known to cause cancer – known as carcinogens – such as arsenic, chromium, and nickel can increase your risk of developing lung cancer. The workplace is a common source of exposure to asbestos and other carcinogens. Asbestos fibers can live in the lung tissue for a lifetime following exposure. Asbestos workers who are nonsmokers have a five times greater risk of developing lung cancer than other nonsmokers.
- Radon gas – Radon gas is a natural gas, produced by the breakdown of uranium in soil, rock, and water, and which eventually becomes part of the air you breathe. Unsafe levels of radon can accumulate in buildings through gaps in the foundation, pipes, drains, or other openings, and exposure can increase the risk of developing lung cancer.
- Family or personal history – Lung cancer is more likely to occur in people with a parent, sibling, or child who has had lung cancer. This genetic predisposition can occur in smokers and nonsmokers; however, smokers will have an even greater risk. Survivors of lung cancer are also at a greater risk of developing a second lung cancer.