Lung cancer happens when cells divide within the lungs uncontrollably. This causes tumors to develop. These can reduce a person’s ability to breathe and unfold to other parts of the body.
What is lung cancer?
Cancer causes changes in cells that are otherwise healthy. The cells grow too quickly, without dying off.
Normal cells in the body usually die at a certain stage in their life cycle, thereby preventing a buildup of too many cells. In cancer, however, the cells continue to grow and multiply. As a result, tumors develop.
The two main types of lung cancer are small cell lung cancer and non-small cell lung cancer, depending on how they appear under a microscope. Non-small cell lung cancer is more common than small cell lung cancer.
Anyone can develop lung cancer, but cigarette smoking and having exposure to smoke, inhaled chemicals, or other toxins can increase the risk.
The main types of lung cancer are non-small cell lung cancer and small cell lung cancer. They differ in the size of cell, as seen under a microscope.
Non-small cell lung cancer
Around 84%Trusted Source of lung cancer cases in the U.S. are non-small cell. There are three subtypes:
- squamous cell cancer
- large cell carcinoma
Small cell lung cancer
Around 13%Trusted Source of lung cancer cases in the U.S. are small cell. This type tends to grow more quickly than non-small cell lung cancer.
Symptoms and signs
People with lung cancer may not have any symptoms until a later stage. If symptoms do appear, they can resemble those of a respiratory infection.
Some possible symptomsTrusted Source include:
- changes to a person’s voice, such as hoarseness
- frequent chest infections, such as bronchitis or pneumonia
- swelling in the lymph nodes in the middle of the chest
- a lingering cough that may start to get worse
- chest pain
- shortness of breath and wheezing
In time, a person may also experience more severe symptoms, such as:
- severe chest pain
- bone pain and bone fractures
- coughing up blood
- blood clots
- appetite loss and weight loss
The staging of cancer describes how far it has spread through the body and how severe it is. Staging helps healthcare professionals and individuals decide on a suitable course of treatment.
The most basic form of staging is as follows:
- localized, wherein the cancer is within a limited area
- regional, wherein the cancer has spread to nearby tissues or lymph nodes
- distant, wherein the cancer has spread to other parts of the body
Similar to this is the TNM stagingTrusted Source system. Healthcare professionals assess the tumor for size and spread, whether or not it affects the lymph nodes, and whether or not it has spread elsewhere.
There are also specific ways of staging non-small cell and small cell lung cancer.
Stages of non-small cell lung cancer
Healthcare professionals typically use tumor size and spread to describe the stages of non-small cell lung cancer, as followsTrusted Source:
- Occult, or hidden: The cancer does not show up on imaging scans, but cancerous cells might appear in the phlegm or mucus.
- Stage 0: There are abnormal cells only in the top layers of cells lining the airways.
- Stage 1: A tumor is present in the lung, but it is 4 centimeters (cm) or under and has not spread to other parts of the body.
- Stage 2: The tumor is 7 cm or under and might have spread to nearby tissues and lymph nodes.
- Stage 3: The cancer has spread to lymph nodes and reached other parts of the lung and surrounding area.
- Stage 4: The cancer has spread to distant body parts, such as the bones or brain.
Stages of small cell lung cancer
Small cell lung cancer has its own categoriesTrusted Source. The stages are known as limited and extensive, and they refer to whether the cancer has spread within or outside the lungs.
In the limited stage, the cancer affects only one side of the chest, though it might already be present in some surrounding lymph nodes.
Around one-third of people with this type find out that they have cancer when it is in the limited stage. Healthcare professionals can treat it with radiation therapy as a single area.
In the extensive stage, the cancer has spread beyond the one side of the chest. It may affect the other lung or other parts of the body.
Around two-thirds of people with small cell lung cancer find out that they have it when it is already in the extensive stage.
According to the American Cancer SocietyTrusted Source, the chances of surviving for 5 years or longer after receiving a diagnosis of lung cancer are as follows.
The percentages reflect the chances of a person surviving with lung cancer compared with the chances of a person surviving without lung cancer.
Non-small cell lung cancer
Small cell lung cancer
Undergoing regular screening may be a good idea for people with a high risk of developing lung cancer. Screening is with a low-dose CT scan.
The American Lung Association recommend screening if a person meets all the following criteria:
- is aged 55–80 years
- has a history of heavy smoking (30 pack years, which is one pack per day for 30 years or two packs per day for 15 years)
- currently smokes or has quit smoking within the past 15 years
Insurance will often cover this screening if a person is aged 55–80 years and has private health insurance or is aged 55–77 years, has Medicare, and meets all the other criteria.
However, people should check with their insurance company before signing up for lung cancer screening.
If a person has any symptoms that could indicate lung cancer or if screening shows something unusual, a healthcare professional will likely recommend some diagnostic testsTrusted Source.
An X-ray, CT, MRI, or PET scan might reveal areas of lung tissue with cancer.
If the cancer has spread, imaging tests can also reveal changes to bones and other organs. Scans can also help track the progress of treatment.
A healthcare professional may wish to take a biopsy to check for cancer cells. They will do this using a fine needle or a bronchoscope.
A bronchoscope is a thin, lighted scope with a camera on the end that enters the lungs through the mouth or nose. A healthcare professional can use it to look for lesions and take samples.
For less accessible lesions, they may use a more invasive surgical procedure, such as thoracoscopy or video-assisted thoracic surgery, to remove lung tissue.
Laboratory tests can also reveal whether or not cancer is present in the:
- pleural effusion, which is the fluid that collects around the lungs
This information can help confirm if cancer is present and, if it is, determine its type and stage.
TreatmentTrusted Source will depend on various factors, including:
- the type of cancer
- the location and stage
- the person’s overall health
- their individual preferences
All the treatment options can have adverse effects. A person should speak with their healthcare professional about the most suitable choice for them, including the pros and cons of each option.
Some treatment options include:
- surgery to remove part or all of a lung
- chemotherapy, which refers to a drug treatment that can kill cancer cells and shrink tumors
- radiation therapy, which uses high energy rays to kill cancerous cells
- radiofrequency ablation, wherein a healthcare professional inserts a thin needle and uses an electric current to destroy cancer cells
- targeted therapy, which targets a specific behavior to prevent tumor growth
- immunotherapy, which helps the body fight cancer cells
- palliative therapy, including pain relief, oxygen therapy, and other help that a person may need to manage their symptoms
A healthcare professional will work with the individual and adjust their treatment plan as their needs change.
Lung cancer can be fatal, but emerging treatments mean that many people now survive and recover from lung cancer, especially if they receive an early diagnosis.
Some factors affecting the likelihood of a positive outcome include:
- a person’s overall health
- their age
- the stage of cancer at diagnosis
- the type of cancer they have
It is not possible to predict exactly how cancer will affect an individual, but a healthcare professional can help a person understand what they may be able to expect by looking at the results of tests and other factors.
Lung cancer is a potentially fatal type of cancer, but people who receive an early diagnosis often have a good chance of survival.People with a high risk of developing lung cancer may wish to consider undergoing regular screening. This can detect the early signs and allow for treatment before the cancer spreads.
Anyone who has concerns about their risk of lung cancer should talk with their healthcare professional.