Lung cancer

August 1st is World Lung Cancer Day, an annual global initiative that aims to support people with lung cancer, raise awareness, promote screening for those at risk, and educate people about the risk factors for this common, and often deadly disease.

In this blog, we will join that initiative and look at what lung cancer is, who is at risk of developing the disease and what treatments are available.

What is lung cancer?

Lung cancer is a type of cancer that affects the lungs. It is one of the most common types of cancer, and the leading cause of death from cancer globally. Over 43,000 people are diagnosed with lung cancer every year in the UK.

Cancer that starts in the lungs is called primary lung cancer. A cancer growth (tumour) can start in the trachea (windpipe), bronchus (main airway) or lung tissue. Cancerous cells can also spread from another part of the body to the lungs. This is known as secondary lung cancer.

This blog will focus on primary lung cancer.

Types of lung cancer

There are two main types of primary lung cancer:

• Non-small-cell lung cancer (NSCLC) - this is the most common type and accounts for over 80% of cases. There are three types of non-small-cell lung cancer; squamous cell carcinoma, adenocarcinoma and large-cell carcinoma
• Small-cell lung cancer (SCLC) - is a less common type of lung cancer that grows faster and can be harder to treat than non-small-cell lung cancer

Metastatic lung cancer

Metastatic lung cancer occurs when the primary cancer grows and spreads (metastasises) from where it started in your lung to another part of your body. It is also known as advanced lung cancer.

There's no cure for metastatic lung cancer, but treatment may help to control it, reduce your symptoms and improve your quality of life.

What causes lung cancer?

The majority (seven out of ten) cases of primary lung cancer are caused by smoking tobacco products such as cigarettes, cigars and pipes.

Tobacco smoke contains 60 substances that are known carcinogens (cancer-causing substances). Your risk of developing lung cancer from smoking increases according to how much and how long you smoke.

What are the risk factors for lung cancer?

Risk factors for developing lung cancer include:

• smoking
• exposure to second-hand smoke (passive smoking)
• ageing - lung cancer is most common in people aged 75 and over
• a family history of lung cancer
• chronic lung disease
• exposure to harmful substances such as radon, asbestos, diesel exhaust, uranium, silica, coal products and air pollution
• having a weakened immune system due to medication or diseases like HIV/AIDS
• previous radiotherapy treatments to your chest area, such as for breast cancer or lymphoma

What are the symptoms of lung cancer?

Lung cancer often doesn't have any symptoms in the early stages of the disease. This means it is often diagnosed later when the disease has progressed and may be more difficult to treat.

Early symptoms of lung cancer may include:

• a cough that lasts for three weeks or more, or is getting worse
• shortness of breath
• chest pain when breathing or coughing
• persistent chest or shoulder pain
• recurrent chest infections
• a hoarse voice

Other symptoms may include:

• unexplained weight loss
• coughing up blood (haemoptysis)
• fatigue
• loss of appetite
• difficulty swallowing (dysphagia) or pain when swallowing
• nail clubbing (changes in the appearance of your fingernails)
• wheezing (noisy breathing)
• a smaller pupil and drooping eyelid in one eye with little or no sweating on that side of your face (Horner's syndrome)
• swelling of your face, neck, arms or upper chest (superior vena cava syndrome)

When to see a consultant

Make an appointment with your consultant if you have any of the above symptoms of lung cancer such as a persistent cough or shortness of breath for three weeks or more.

How is lung cancer diagnosed?

To diagnose lung cancer, your consultant will ask you about your symptoms, general health and medical history. They will perform a physical examination and may check how well your lungs are working using a test called a spirometer. This is a quick, non-invasive test where you breathe as hard as you can into a mouthpiece connected to a spirometry machine to measure the volume of air you breathe in and out.

Your consultant may order blood tests to check for other causes of your symptoms such as a chest infection.

Further tests to diagnose lung cancer include:

Chest X-ray

A chest X-ray is usually the first test for suspected lung cancer. A chest X-ray cannot definitively diagnose lung cancer, as abnormalities such as a mass may be due to other conditions. If lung cancer is suspected, your consultant will order further tests to confirm your diagnosis.

CT (computerised tomography) scan

A CT scan is a non-invasive, painless procedure that provides detailed images of the inside of your body using X-rays and a computer. Before your scan, you'll be given an injection called contrast medium, a special dye which helps make the images clearer. A CT scan normally takes between 10 and 30 minutes.

PET-CT (positron emission tomography-computerised tomography) scan

A PET-CT scan allows your consultant to examine your lungs in more detail and shows the activity of the cells within your lungs. This allows your consultant to make a more detailed diagnosis and decide on the best course of treatment. Before your PET-CT scan, you'll be injected with a slightly radioactive material called a tracer. A PET-CT scan is a painless, non-invasive procedure and takes about 30 to 90 minutes.

Bronchoscopy and biopsy

A bronchoscopy is a procedure to examine your airways using a bronchoscope (a thin tube with a camera) and take a sample of cells (biopsy). Before the procedure, you'll be given medication to make you feel sleepy and relaxed and a local anaesthetic to numb your throat. Once the medication has taken effect, your consultant will pass the bronchoscope through your mouth or nose and into your airways. A bronchoscopy normally takes around 30 to 40 minutes.

Endobronchial ultrasound scan (EBUS)

This is a newer procedure that combines a bronchoscopy with an ultrasound scan. It involves using a bronchoscope with an ultrasound probe attached to locate the lymph nodes in your lungs and take a tissue sample (biopsy). The tissue sample is sent to the laboratory to check for the presence of cancerous cells and establish what type they are. An endobronchial ultrasound scan takes around 90 minutes.

Lung cancer treatment

Treatment for lung cancer depends on several factors including the type of lung cancer you have, the size and location of the cancer, whether your cancer has spread, and your general health. A single treatment or a combination of treatments may be used to treat lung cancer.

The most common treatment options for lung cancer include:

• surgery
• chemotherapy
• radiotherapy

Surgery

Your consultant may recommend surgery if you have non-small-cell lung cancer (NSCLC) in only one of your lungs and you are in good overall health. You may also have a course of chemotherapy to destroy any cancer cells that remain after surgery.

There are 3 main types of lung cancer surgery:

• Segmentectomy (wedge resection) - involves removing a small piece of your lung and may be suitable if you have early-stage cancer that is small and has not spread
• Lobectomy - one section of your lung, called a lobe, is removed. It may be used if your cancer is limited to one lobe of one of your lungs.
• Pneumonectomy - is the removal of your entire lung. This type of surgery is performed if your cancer is located in the middle of your lung or has spread throughout your lung

Chemotherapy

Chemotherapy is a type of medication that kills cancer cells. It works by stopping cancer cells from reproducing and spreading in your body. Chemotherapy is the main treatment for small cell lung cancer which has often spread beyond the lung by the time it is diagnosed. As the medication circulates in your bloodstream, it can also treat cancer cells that have spread to other parts of your body.

Chemotherapy can also be used to treat non-small cell lung cancer either before or after surgery, before, after or with radiotherapy, or in combination with immunotherapy.

Radiotherapy

Radiotherapy uses high-energy X-rays to destroy cancer cells. Depending on factors such as your general health, the stage of your cancer and the results of any surgery, you may have radiotherapy on its own, after surgery, after chemotherapy or in combination with chemotherapy (chemoradiotherapy).

Other treatments

Other treatments for lung cancer include:

• immunotherapy - is a group of medications that stimulate your immune system to target and kill cancer cells
• targeted therapies (biological therapies) - are usually used to treat non-small cell lung cancer. They work by targeting the differences in cancer cells by interrupting their growth and how they function
• radiofrequency ablation - uses high-energy radio waves to heat and destroy cancer cells
• photodynamic therapy (PDT) - involves having an injection that makes your body cells sensitive to light. 24 to72 hours later, a laser is targeted at your tumour and the light-sensitive cancer cells are destroyed
• cryotherapy - may be used if your cancer starts to block your airways, making breathing difficult. A cold-generating device called a cryoprobe is placed against the tumour causing it to shrink

Can lung cancer be prevented?

Lung cancer can't always be prevented, but there are some things you can do to reduce your risk, including:

• don't smoke or quit smoking if you do. The risk of developing lung cancer reduces every year you don't smoke and after 15 years you have the same risk as someone who has never smoked
• avoid exposure to second-hand smoke and other substances that may be harmful to your lungs
• follow a healthy, nutritious diet
• take regular exercise
• maintain a healthy weight

Lung cancer screening

In 2021, The American College of Chest Physicians (CHEST) released a new clinical guideline containing 16 recommendations for screening at-risk groups for lung cancer. The guideline includes:

• Annual screening for individuals aged 50 to 80 without symptoms who have smoked for 20 years or more and either continue to smoke or have quit within the past 15 years
• Provision of smoking cessation treatment for individuals eligible for screening who continue to smoke

In 2023, a lung cancer screening programme was introduced in England. The screening programme targets 55 to 74-year-olds with a GP record that includes a history of smoking. Eligible participants will be assessed and offered screening and smoking cessation services.

Summary

Lung cancer is a common and serious type of cancer that is usually caused by smoking. In many cases, people with lung cancer do not have any symptoms until the disease is advanced and may be harder to treat. The best way to reduce your risk of lung cancer is to stop smoking. If you smoke or used to smoke and have a high risk of developing lung cancer, talk to your consultant about lung cancer screening.

You can learn more about lung cancer at:

NHS: Overview. Lung cancer

Macmillan Cancer Support: Lung cancer

Cancer Research UK: Lung cancer