Lung Cancer

What Is Lung Cancer?

The lungs are 2 sponge-like organs found in the chest. The right lung has 3 sections, called lobes. The left lung has 2 lobes. The left lung is smaller because the heart takes up more room on that side of the body. The lungs bring air in and out of the body, taking in oxygen and getting rid of carbon dioxide gas, a waste product.

The lining around the lungs, called the pleura, helps to protect the lungs and allows them to move during breathing. The windpipe (trachea) brings air down into the lungs. It divides into tubes called bronchi (singular bronchus), which divide into smaller branches called bronchioles. At the end of these small branches are tiny air sacs known as alveoli.

Lung Cancer Picture

Most lung cancers start in the lining of the bronchi, although they can start in other parts of the lung.

Lung cancer often takes many years to develop. First, there may be areas of pre-cancerous changes in the lung. These changes are not a mass or tumor. They can't be seen on an x-ray and they don't cause symptoms. But these changes can be found by special tests of cells in the lining of the airways of lungs damaged by smoke.

As these pre-cancerous areas go on to become true cancer, they may make chemicals that cause new blood vessels to form nearby. These new blood vessels nourish the cancer cells and allow a tumor to form. Finally, the tumor becomes large enough to be seen on an x-ray.

Once lung cancer occurs, cancer cells can break away and spread to other parts of the body in a process called metastasis. Lung cancer is a life-threatening disease because it often spreads in this way before it is found.

Types of Lung Cancer

There are two main types of lung cancer and they are treated differently.

Small cell lung cancer (SCLC)
Non-small cell lung cancer (NSCLC)

If the cancer has features of both types, it is called mixed small cell/large cell cancer.

Small Cell Lung Cancer (SCLC)

About 13% of all lung cancers are of the small cell type. This type of cancer often starts in the bronchi near the center of the chest. Although the cancer cells are small, they can multiply quickly and form large tumors that can spread widely through the body. This is important because it means that treatment must include drugs to kill the widespread disease. This kind of cancer is almost always caused by smoking. It is very rare for someone who has never smoked to have small cell lung cancer.

Non-small Cell Lung Cancer (NSCLC)

The other 87% of lung cancers are of the non-small cell type. There are 3 sub-types within this group. The cells in these sub-types differ in size, shape and chemical make-up.

Squamous cell carcinoma is usually linked to smoking. It tends to be found centrally, near a bronchus.

Adenocarcinoma is usually found in the outer region of the lung.

Large-cell undifferentiated carcinoma can appear in any part of the lung and tends to grow and spread quickly, which can make it hard to treat.

Other types of tumors can grow in the lungs as well. Some of these are not cancer and others are cancerous. Carcinoid tumors, for example are slow-growing and usually cured by surgery. The American Cancer Society has more information about lung carcinoid tumors. To learn about these tumors, see our document "Lung Carcinoid Turmor."

Lung Cancer: The Bad and the Worse There are two major types of lung cancer. One is the Small Cell Lung Cancer (SCLC) mentioned in the previous paragraph. The other is Non-Small Cell Lung Cancer (NSCLC). Non-Small Cell Lung Cancer has three subtypes: Adenocarcinoma, Squamous Cell Carcinoma and Large Cell Undifferentiated Carcinoma. NSCLC is the least "serious" of the two types. In fact, if it is detected early, it is possible that it can be cured with surgery.

Save Yourself From Lung Cancer Three common types of non-small cell lung cancer are squamous cell carcinoma, adenocarcinoma and large cell carcinoma. Squamous cell carcinoma is the most common non-small cell lung cancer.Adenocarcinoma, the primary cause of this non-small cell lung cancer is still a challenge to medical experts. Thus, experts continue to study the major cause of this cancer.

Common Causes of Lung Cancer There are a various risk factors that are linked to lung cancer. The most common known causes are as follows: Cigarette Smoking, Secondhand Smoke, Asbestos Exposure, Radon Gas and Air Pollution

What Are The Stages Of Lung Cancer? Once a diagnosis of lung cancer has been made, the doctor will attempt to determine the stage the lung cancer is at. The staging system is somewhat like a measurement system, with the numbers indicating: whether the cancerous tumors are localized or whether the tumors have spread to other parts of the body; the tumor's size; and whether or not the tumors have spread to the lymph nodes. There are four main stages of lung cancer (Stages 1 - 4) and identification of one of the stages is what helps doctors prescribe an appropriate treatment method.

Steps To Preventing Lung Cancer Did you realize that approximately 10% of lung cancer patients have never in their lives smoked cigarettes? When asked about lung cancer prevention, most people will tell you that the easiest way to prevent lung cancer is to never take up the dangerous habit of cigarette smoking. And while it's true that smoking often leads to lung cancer, the fact that 10% of lung cancer patients are not now nor have ever been smokers cannot be easily explained.

How Smoking Increases The Risk Of Lung Cancer With so many dangers associated with smoking, especially the correlation between smoking and the development of lung cancer, it is amazing to see how many people continue to voluntarily take part in this activity! Why is it that these mostly mature, reasonably intelligent men and women of every nationality allow such a small object to have so much control over their lives? You'd think it would be easy to just say "NO" to this tiny little death machine, but in reality it just isn't so.

Lung Cancer Symptoms, What You Need To Know. Because lung cancer symptoms do not manifest until it is already on its advanced stage, minor lung cancer symptoms are often ignored. This is because minor lung cancer symptom such as frequent coughing is often associated with itchiness in the throat. Smokers believe that this is an ordinary occurrence among smokers, thus they are not alarmed until they feel more severe lung cancer symptoms.