What is Lung Cancer?

Rhoda Baer, National Cancer Institute

Lung cancer is the leading cause of cancer deaths in the United States.Those who smoke are at the greatest risk of developing lung cancer. This risk increases with the number of cigarettes smoked and the length of this behavior. Quitting smoking reduces the risk of developing lung cancer significantly. In the early stages of lung cancer, there are usually no symptoms or signs. However, in the later stages of the cancer, the patient may experience a chronic “smoker's cough”, shortness of breath, chest pain, coughing up blood, wheezing, bone pain, headache, hoarseness, and weight loss.

Smokers and those who are exposed to secondhand smoke are the most at risk for lung cancer. However, lung cancer also occurs in those who have never smoked before and those who never had a prolonged exposure to smoke. For these particular cases, there is not exact cause of the lung cancer. Smoking damages the cells that line the lungs, and when you inhale cigarette smoke, carcinogens damages and changes the lung tissue immediately- this causes lung cancer. In the early stages of smoking and secondhand smoking, the lung is able to repair this cell damage. However, after repeated exposure over a prolonged period of time, the normal cells become more damaged. This damage can cause the lung cells to act abnormally, and cancer may develop as a result. There are two types of lung cancer depending on the appearance of the lung cancer cells. Doctors will decide on treatment plans based on the type of lung cancer.

The first type of lung cancer is small cell lung cancer. This type of cancer occurs exclusively in heavy smokers. The second type of lung cancer is non-small cell lung cancer. This type of cancer consist of different types of lung cancers that behave in a similar way such as squamous cell carcinoma, large cell carcinoma, and adenocarcinoma.

There are many things that can increase one's risk for lung cancer. Exposure to dangerous levels of certain substances can also increase the risk for this cancer. Examples include:

  • radon gas (a breakdown of uranium in water, rock, and soil that can end up in the air)

  • asbestos

  • other carcinogens (such as nickel, arsenic, and chromium)

Smoking exponentially increases the chances of developing lung cancer. The likelihood of a smoker developing lung cancer depends on the longevity of this behavior and the quantity of cigarettes smoked. Quitting smoking at any time significantly lowers the risk of lung cancer. Exposure to secondhand smoke increases the risk for lung cancer as well. Those with a past family history of lung cancer are at more of a risk for lung cancer.

There are four stages of lung cancer. In State I, the cancer is only present in the lung, and it has not spread to the lymph nodes. Usually, the tumor is smaller than 2 inches at this stage. In Stage II, the tumor can be larger than 2 inches or it can be a small tumor that spread to the nearby structures and organs such as the diaphragm, lymph nodes, pleura, and chest walls.

In Stage III, the tumor can be very large and has invaded nearby organs. The tumor can also be a small tumor that is accompanied by cancerous cells in the lymph nodes. In State IV, the cancer has metastasized beyond the lung to different parts of the body.

There are many surgical and non-surgical treatments for lung cancer. Many of the surgical procedures involves removing the cancerous parts of the lung. Surgeons can perform a wedge resection, a segmental resection, a pneumonectomy, or a lobectomy. Non-surgical treatments include chemotherapy, radiation therapy, targeted drug therapy, clinical trials, and palliative care.

Continue Reading