Lung cancer is the most common cancers globally and causes more deaths than any other type of cancer. It is an often an aggressive cancer and early diagnosis is essential for successful treatment and management. While lung cancer is more common among tobacco smokers, it can also affect non-smokers. Exposure to smoke on a regular basis, as well as certain air pollutants and other inhaled carcinogens increases the risk of developing lung cancer.
Facts About Lung Cancer
It is important to understand the basic facts about lung cancer. The general term lung cancer is broadly applied to different types of malignant (cancerous) tumors in the lungs. Technically it can only be considered lung cancer when the malignancy arises from cells of the lung tissue. This cancer can then spread (metastasize) to other parts of the body. Sometimes cancer that starts elsewhere in the body, like cancer of the kidney, can spread to the lungs and other organs.
What are the types of lung cancer?
There are broadly two types of lung cancer:
- Small cell lung cancer (SCLC)
- Non-small cell lung cancer (NSCLC)
Non-small cell lung cancer includes several sub-types such as:
- Squamous cell carcinoma
- Large cell carcinoma
How common is lung cancer?
Lung cancer is the most common type of cancer across the world. Every year there are about 220,000 new cases of lung cancer diagnosed in the United States and around 155,000 Americans die from lung cancer annually. This means that about 1 in 4 deaths due to cancer are associated with lung cancer. Non-small cell lung cancer (NSCLC) is the more common type of lung cancer, accounting for about 85% of lung cancer cases.
Does lung cancer only occur in smokers?
In some types of lung cancers, 90% of cases occur in tobacco smokers. The heavier the smoker, the greater the risk of developing lung cancer. However, lung cancer does not only affect tobacco smokers. People who are non-smokers may also develop lung cancer if they are exposed to:
- Secondhand smoke
- Radon gas
- Carcinogens like asbestos
A family history of lung cancer is also a risk factor. However, there are cases where lung cancer occurs in a person who had no previous exposure to these cancer-causing chemicals mentioned above.
Is lung cancer curable?
Yes. Lung cancer is curable if the cancer can be removed or destroyed completely with no remaining cancer cells in the lung tissue. This can be achieved with chemotherapy, radiation therapy and surgery. However, this is dependent on early diagnosis and intervention. When cancer spreads beyond the lungs and surrounding lymph nodes, it may reach various other organs simultaneously (like the bone, brain, kidneys) and a cure is highly unlikely at that point.
What are the Signs of Lung Cancer?
Lung cancer is a serious and deadly condition. However, the symptoms may not be as severe in the early stages. In fact at the outset there may be little to no symptoms. A person could have lung cancer and not know that it is present. It may only be discovered upon routine investigations like with a chest x-ray.
Always consult with a medical professional if lung cancer is suspected. Tobacco smokers in particular need to be cautious and immediately seek medical attention if there even a few signs and symptoms of lung cancer, especially long term and heavy smokers.
Read more on how to spot lung cancer.
Coughing is the most common symptom that is present in most cases of lung cancer. However, there are a few lung cancer cases where there is no persistent cough. Patients report the onset of a “new cough” that is ongoing. Smokers may also report a persistent “smokers” cough which is worsening over time. Eventually there may be other symptoms that accompany the cough such as bloody sputum, chest pain and shortness of breath.
The sputum that is expectorated with coughing may be blood-tinged and eventually there is coughing up of blood entirely (hemoptysis). Often this is the symptom that prompts a person to seek medical attention. In the early stages, blood may only be seen after bouts of coughing. As the condition progresses, whole blood may be coughed up with little effort. This is a symptom that is also seen with certain lung infections like tuberculosis (TB).
Another symptom of lung cancer is chest pain when breathing. This may be more noticeable with deep breathing, particularly with inhalation. Over time the chest pain may be persistent irrespective of the depth of breathing. The pain becomes severe as the tumor infiltrates the surrounding tissue. When the nervous system is infiltrated then there may be additional symptoms like muscle weakness depending on the area that is supplied by these nerves.
Shortness of Breath
Shortness of breath eventually develops in lung cancer and varies in severity. Initially it may only be noticed with physical activity. As the condition progresses there is difficulty breathing even at rest. It may also be accompanied by chest pain with breathing. As with other symptoms, shortness of breath may be due to many different conditions apart from lung cancer. On it own, shortness of breath is not a conclusive indicator of lung cancer.
Abnormal breathing sounds like wheezing and stridor may also occur with lung cancer, particularly when the airways are involved. Wheezing may be missed as a symptom of lung cancer if there is a history of asthma. Furthermore wheezing can occur with tumors in the mediastinum (the middle compartment of the chest) even if the lungs are not involved. Therefore abnormal breathing sounds on its own are not a reliable sign of lung cancer.
Lung nodules are masses that may be seen in the lung tissue on an x-ray or CT scan. These masses can be non-cancerous tumors and other growths that may occur with other lung diseases like tuberculosis (TB). However, when a nodule is larger than 3 centimeters (about 1.2 inches) in diamater, irregularly shaped and partly solid then it is more likely to be due to cancer.
Read more on what is a lung nodule.
Other Signs and Symptoms
- Unintentional weight loss
- Enlarged lymph nodes
- Recurrent lung and airway infections
- Hoarse voice
- Bone pain