Lung Cancer: About Lung Cancer

According to the American Cancer Society, more than 115,000 men and 110,000 women are diagnosed each year with cancer of the lungs and bronchi (the air tubes leading to the lungs). The incidence of lung cancer has been declining among men over the past two decades and has recently begun to drop in women. Studies have shown that on a per-cigarette basis, female smokers may be more likely to develop lung cancer than male smokers, and that the disease may behave differently in men than in women.

Types of Lung Cancer

There are two major types of primary lung cancer: non-small cell and small cell. Each arises from different types of cells in the lung, and each grows and spreads in different ways. As such, treatments for these two types of primary lung cancer vary.

A diagnosis will include not only the type of lung cancer but the stage, a term that is used to describe the extent and spread of the disease at the time of diagnosis. Tumors found in the lungs sometimes originate from cancers elsewhere in the body. These tumors are called lung metastases.

Non-Small Cell Lung Cancer

Non-small cell lung cancer is the most common type of lung cancer. It begins when epithelial cells, which form the lining of the lungs, become abnormal and start to grow uncontrollably. These cells can develop into a mass called a tumor. A cancerous tumor is a collection of a large number of cancer cells that have the ability to spread to other parts of the body. The spread of cancer from a primary site to a secondary site is called metastasis.

Types of Non-Small Cell Lung Cancer

There are three main types of non-small cell lung cancer:

  • Adenocarcinoma begins in cells that line the alveoli, which exchange oxygen and carbon dioxide near the outer walls of the lungs.
  • Squamous cell carcinoma begins in cells that line the bronchial tubes in the center of the lungs.
  • Large cell carcinoma, also called undifferentiated lung cancer, is the name given to about 5 percent of non-small cell lung cancers that do not belong to either of the first two types.

Differences among these three types of cancer mean that there are differences in the drugs that are most effective for treating them. Different drugs are recommended for squamous and non-squamous cell carcinoma, although many medicines help with both. Treatments that are effective for adenocarcinoma are also generally effective in treatment of large cell carcinoma.

Non-small cell lung cancer tumors can be further subcategorized based on specific genetic mutations that can take place in cancer cells. Doctors at Memorial Sloan Kettering can identify these mutations during your diagnostic testing and use this information to determine what treatments might be most effective. Learn more about how we use personalized medicine to guide treatment decisions.

Symptoms

Many people with non-small cell lung cancer have no noticeable symptoms. Often the first sign of the disease is an abnormal spot that appears on a chest x-ray or CT scan for another medical condition. Sometimes, however, people notice one or more of the following symptoms:

  • Cough
  • Shortness of breath
  • Chest pain
  • Loss of appetite
  • Coughing up phlegm or mucus
  • Coughing up blood
  • Fatigue

Lung cancer can spread within the lung itself as well as to the lymph nodes in the chest, the bones, brain, liver, adrenal glands, and elsewhere. If it does, you may experience pain or discomfort in other parts of the body.

Although these symptoms are associated with non-small cell lung cancer, they can also develop as a result of medical conditions not related to cancer. If you experience one or more of these symptoms, talk with your doctor.

Small Cell Lung Cancer

Small cell lung cancer is believed to originate when specialized cells called neuroendocrine cells in areas surrounding the bronchi (the air tubes that lead from the trachea to the lungs) become abnormal and start to grow uncontrollably. These cells can develop into a mass called a tumor. A cancerous, or malignant, tumor is a collection of a large number of cancer cells that has the ability to spread to other parts of the body (metastasize).

Small cell lung cancer is less common than non-small cell lung cancer. Small cell lung cancer accounts for about 13 percent of all lung cancer cases, or approximately 30,000 cases per year in the United States. It develops in equal numbers among men and women.

Small cell lung cancer also behaves differently than non-small cell lung cancer. Small cell lung cancer tends to metastasize quickly to lymph nodes in the chest and to other parts of the body. This means that when the cancer is identified, it has often already begun to spread. For these and other reasons, diagnosis and treatment for small cell lung cancer is different from that of non-small cell lung cancer.

Symptoms

Many people with small cell lung cancer have no noticeable symptoms. Often the first sign of the disease is an abnormal spot that appears on a chest x-ray or CT scan for another medical condition. Sometimes, however, people notice one or more of the following symptoms:

  • Cough
  • Shortness of breath
  • Chest pain
  • Loss of appetite
  • Coughing up phlegm or mucus
  • Coughing up blood
  • Fatigue

Lung cancer can spread within the lung itself as well as to the lymph nodes in the chest, the bones, brain, liver, adrenal glands, and elsewhere. If it does, you may experience pain or discomfort in other parts of the body.

Although these symptoms are associated with small cell lung cancer, they can also develop as a result of medical conditions not related to cancer. If you experience one or more of these symptoms, talk with your doctor.