What is lung cancer?

Lung cancer is the growth of cancerous cells in the tissues of the lungs or airways. This is a serious form of cancer that is often not detected until later stages of the disease when treatment is less likely to be effective. Because of the absence of symptoms and the failure of early detection, nearly 90% of lung cancer is fatal.

Lung cancer is often categorized as a carcinoma. Carcinomas are cancers that start in the tissues or the lining of the organs. There are two basic types of lung cancer:

  • Small Cell Lung Cancer (SCLC). This form of cancer is rarer than others. It begins in the chest or bronchi and spreads quickly.
  • Non-Small Cell Lung Cancer (NSCLC). This form of cancer makes up 85-90% of lung cancer diagnoses. There are three main types of NSCLC: Adenocarcinoma (the most common type of lung cancer), squamous cell carcinoma, and large cell carcinoma.

The stage of a cancer refers to how far the cancer has spread, the size of the tumor, whether the lymph nodes or other organs are affected. There are just two stages of small-cell lung cancer: limited and extensive. Limited small cell lung cancer is in only one lung and may or may not have spread to the lymph nodes. Extensive small cell lung cancer is in both lungs or has spread the surrounding area. NSCLC (non-small cell lung cancer) has several stages that are defined as the following:

  • Occult. In this stage, the mucus or fluid of the lungs contains cancer cells and there are no visible tumors.
  • Stage 0. Cancerous cells are in the air passages or bronchi but not in the tissues of the lungs.
  • Stage I. Cancer is in the tissue of one lung but has not spread to any other organs or lymph nodes.
  • Stage II. Cancer may have spread beyond the lung to surrounding tissues and lymph nodes.
  • Stage III. Cancer has spread beyond the lung to nearby organs and lymph nodes.
  • Stage IV. Cancer has spread to the other lung, fluid around the heart, or distant organs like the brain or liver.

Early detection plays a vital role in the better outcomes for lung cancer, and earlier stages of the disease respond well to treatment.

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When to See a Doctor

If you are experiencing any of the symptoms above, especially if you are a smoker or have smoked previously, you should contact your doctor to get screened for lung cancer. While some of the symptoms can be signs of a common illness, prolonged cough and breathing problems may be a warning sign of a more serious condition.