Everything you need to know about lung cancer

Types of lung cancer

Lung cancer is the third most common cancer and the leading cause of cancer-related deaths in the United States.

According to the American Cancer Society (ACS), it is most common in males. Black males are around 12% more likely to develop it than white males.

The two main types of lung carcinoma are:

• NSCLC: Around 80% to 85% of lung cancer cases in the United States are NSCLC. The three main subtypes are:
  • adenocarcinoma
  • squamous cell carcinoma
  • large cell carcinoma
• SCLC: Around 10% to 15% of lung cancer cases in the U.S. are SCLC. This type tends to grow more quickly than NSCLC.

Symptoms of lung cancer

People with lung cancer do not typically experience symptoms until a later stage, when the cancer has spread. However, potential symptoms include:

• voice changes, such as hoarseness
• frequent chest infections, such as bronchitis or pneumonia
• a lingering cough that may worsen
• coughing up blood
• chest pain
• appetite loss and weight loss
• fatigue
• shortness of breath and wheezing

In time, a person may also experience more severe symptoms, such as:

• bone pain and bone fractures
• headaches
• swelling in the lymph nodes in the middle of the chest

Learn about the early signs of lung cancer.

Lung cancer stages

Cancer staging describes its severity and how far it has spread through the body. Staging helps healthcare professionals and individuals decide on a course of treatment.

The most basic form of staging is as follows:

• Localized: The cancer is within a limited area.
• Regional: The cancer has spread to nearby tissues or lymph nodes.
• Distant: The cancer has spread to other parts of the body.

Similar to this is the TNM staging system. Healthcare professionals assess the tumor’s size, whether it affects the lymph nodes, and whether it has spread elsewhere.

Learn more about lung cancer stages.

NSCLC stages

Healthcare professionals typically use tumor size and spread to describe the stages of NSCLC, as follows:

• Occult or hidden: The cancer does not show 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 body parts.
• 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.

SCLC stages

SCLC stages are known as limited or extensive. These refer to whether the cancer has spread within or outside the lungs.

Limited stage cancer affects one side of the chest, although it might already be present in some surrounding lymph nodes.

The ACS states that around 1 in 3 people with SCLC find out they have cancer during the limited stage. Healthcare professionals can treat it with radiation therapy as a single area.

Extensive stage cancer has spread beyond the one side of the chest. It may affect the other lung or other parts of the body. Around 2 in 3 people with SCLC learn they have it during the extensive stage.

Lung cancer survival rates

The table below outlines the chances of surviving for 5 years or longer after receiving a lung cancer diagnosis, as estimated by the ACS.

The percentages reflect the chances of a person surviving with lung cancer compared with the chances of a person surviving without the condition.

NSCLC

SCLC

Complications of lung cancer

Lung cancer complications may be due to treatment side effects or the spread of cancer. Some possible complications of lung cancer include:

• Superior vena cava syndrome: If tumors obstruct blood flow through the vein carrying blood from the upper body to the heart, superior vena cava syndrome may occur, causing facial swelling, dizziness, and more.
• Metastasis: Metastatic lung cancer has spread to other parts of the body, such as the brain, bones, and adrenal glands.
• Lung infections: People with lung cancer have a higher risk of lung infections, such as pneumonia or bronchitis, due to decreased immune function, which may be due to the cancer or certain cancer treatments, such as chemotherapy.
• Heart blockage: Although extremely rare, lung cancer can spread to the heart and may compress or obstruct the veins and arteries. This can cause issues such as arrhythmias or heart attacks.
• Hypercalcemia: Lung cancer can elevate calcium levels in the blood, which health experts call hypercalcemia. This may lead to nausea, vomiting, excessive thirst, and stomach pain.
• Blood clots: People with lung cancer have an increased risk of deep vein thrombosis, when a blood clot forms in a deep vein. If a blood clot travels to the lungs, it can prevent blood flow and cause a pulmonary embolism, which may be fatal.
• Neuropathy: Pancoast tumors, a type of tumor at the top of the lungs, can affect the nerves in the eyes, face, and shoulders. This can cause pain and Horner’s syndrome, which can cause droopy eyelids and changes in pupil size.
• Spinal cord compression: Cancer can spread from the lungs to the spine, which can compress the vertebrae, causing back pain, weakness, and difficulty walking.

Causes and risk factors

Smoking tobacco is the most common cause of lung cancer, with around 80% of lung cancer deaths stemming from smoking.

However, not everyone with lung cancer smokes, and lung cancer can occur due to other factors, including:

• exposure to chemicals such as:
  • radon
  • diesel exhaust
  • asbestos
• environmental factors, such as air pollution
• inherited or acquired genetic changes
• exposure to secondhand smoke

Lung cancer screening

Regular screening may benefit people with a high risk of developing lung cancer.

The American Lung Association (ALA) recommends screening for people who meet the following criteria:

• people ages 50 to 80 years
• a 20-pack-year history of smoking — which may mean smoking one pack of cigarettes daily for 20 years or two packs daily for 10 years
• they currently smoke or have quit within the past 15 years

Insurance may cover this screening. People can check with their insurance company before signing up for lung cancer screening.

False positive results sometimes occur when screening for lung cancer. The ALA estimates that around 12% to 14% of initial screening scans for lung cancer will have a false positive.

However, advances in screening methods have helped reduce the rate of false positives. Also, regular screening allows physicians to detect changes more easily between scans to prevent false positives.

A person should speak with a doctor about the likelihood of false positives and what to expect after screening.

Lung cancer diagnosis

If a person has lung cancer symptoms or if screening shows something unusual, a healthcare professional may recommend the following diagnostic tests.

Imaging tests

Doctors may use the following imaging tests to reveal areas of lung tissue with cancer:

• X-ray
• CT scan
• MRI
• PET scan

Scans can help track treatment progress and reveal changes to bones and other organs if the cancer has spread.

Tissue sampling

A healthcare professional may wish to take a biopsy using a fine needle or a bronchoscope to check for cancer cells.

For less accessible lesions, they may use a more invasive surgical procedure, such as thoracoscopy or video-assisted thoracic surgery, to remove lung tissue.

Other samples

Laboratory tests can also reveal whether or not cancer is present in the following:

• pleural effusion, which is the fluid that collects around the lungs
• sputum
• blood

This information can help confirm whether cancer is present and, if it is, determine its type and stage.

Lung cancer treatment

Treatment will depend on various factors, including:

• the type of cancer
• the location and stage
• the person’s overall health
• their individual preferences

Some treatment options include:

• surgery to remove part or all of a lung
• chemotherapy, 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, such as pain relief, to manage symptoms

A healthcare professional can explain the pros and cons of each option and will work with the individual to adjust their treatment plan as their needs change.

Preventing lung cancer

Although it is not possible to prevent all lung cancers, the ACS recommends the following steps to reduce the risk:

• quit smoking, if applicable
• avoid secondhand smoke
• avoid radon and other toxins
• eat a balanced diet

Frequently asked questions

Below are some common questions about lung cancer.

Can someone survive with lung cancer that doctors catch early?

According to the ACS, survival rates are generally better for people with a lung cancer diagnosis in the earlier stages. People may also have a better outlook than current survival estimates predict due to treatment progression.

What is the quality of life for someone with lung cancer?

Lung cancer symptoms and treatments can cause distress and a poor quality of life for some people. Factors such as stress, social opportunities, and a patient’s perception of their treatment and condition may affect their quality of life.

People with lung cancer can speak with their healthcare team about improving their quality of life.

Can white phlegm indicate lung cancer?

Coughing up phlegm, which may have blood in it, can indicate lung cancer. People should speak with a healthcare professional if they start to cough up phlegm, especially if they have other symptoms of lung cancer.

Summary

Lung cancer may cause no symptoms until later stages, although some people may experience a chronic cough, changes to the voice, and fatigue.

People with a high risk of developing lung cancer can consider regular screening. This can help detect the early signs and allow for treatment before the cancer spreads.

Anyone with concerns about lung cancer can speak with a healthcare professional.