Lung cancer - causes, risks and common misconceptions

In the UK, around 48,500 people are diagnosed with lung cancer each year making it the third most common form of cancer.¹ It’s also considered to be one of the most serious.²

It can start in any part of the lungs or airways, or it can spread from another part of the body. Cancer that spreads from elsewhere is called secondary lung cancer, but the information in this article is predominantly about cancer which begins in the lungs – primary lung cancer.

What is lung cancer?

Lung cancer can start developing in the trachea (windpipe), the main airway or within the lungs themselves. It develops as a result of abnormal cells growing uncontrollably and forming tumours.

There are two main kinds of primary lung cancer:

• Non-small-cell lung cancer – the more common of the two, accounting for around 80% to 85% of cases.²
• Small-cell lung cancer – a less common form of cancer which usually spreads faster than non-small-cell lung cancer.

Lung cancer is more common in older people, with around 45% of diagnoses being among those aged 75 and older. And smoking is by far the most common cause, with over 70% of UK lung cancer cases being caused by smoking. Passive smoking can also increase the risk.¹

Survival rates and prognoses vary depending on different factors, from a person’s age to the stage of their cancer. There aren’t any definitive UK-wide statistics for lung cancer survival, but early detection is key. However, there’s still a worrying lack of awareness and plenty of misconceptions around lung cancer.

Warning signs and symptoms

As with many forms of cancer, early detection can make it easier to treat. It also offers the best chance of survival. However, during the early stages of lung cancer, there may not be any noticeable symptoms, which means that people can live with lung cancer for a while before it’s discovered.

Symptoms tend to develop as the condition progresses. Some of the most common symptoms include:

• a new cough that lasts longer than three weeks
• a long-standing cough that doesn’t go away or gets worse
• getting out of breath more easily than you’re used to
• recurring chest infections, or a chest infection that won’t get better
• coughing up phlegm with blood in it
• aches or pains when you breathe or cough
• an ache or pain in the chest or shoulder
• being persistently breathless
• chronic fatigue or lack of energy
• a loss of appetite or unexplained weight loss.

Other, less common symptoms include swelling in the face or neck, changes in the appearance of your fingers (such as becoming more curved or ‘clubbed’), wheezing, hoarseness and difficulty swallowing.

Visit Cancer Research UK or the NHS website for more details on lung cancer symptoms.

Don’t ignore it

The severity, size and spread of lung cancer is indicated using a scale that goes from stage 1 to stage 4.

While data for lung cancer survival by stage is limited, statistics for people diagnosed in England between 2016 and 2020 indicates that almost 65% of people with stage 1 lung cancer will survive their cancer for five or more years after diagnosis. For stage 4 lung cancer, it’s only around 5%.³

So, even this very broad data shows how important it can be to identify lung cancer as soon as possible. The longer it goes undetected, the more chance there is for it to grow, spread and progress through the stages. If you notice any of the above symptoms, make an appointment to see your GP as soon as you can.

When to see a GP

We understand that, as a lot of the symptoms can also be associated with other more common conditions like asthma or the flu, going to the GP may not feel like the natural first step. But it’s better to be safe than sorry.

Particularly if you think any of these causes and risk factors particularly apply to you:

• Smoking tobacco. This is the biggest single cause of lung cancer in the UK and can also exacerbate some of the below risks.
• Working with or exposure to dangerous substances / chemicals, including asbestos, silica and diesel exhaust fumes.
• Exposure to air pollution.
• Previous lung diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).
• Family history of lung cancer in your immediate family (ie. parent or sibling).
• Exposure to radon gas.
• High doses of beta-carotene (if you smoke or used to smoke).

See Cancer Research UK’s Risks and causes of lung cancer for a more detailed overview.

Common misconceptions

Despite being one of the most common forms of cancer in the UK, there are still a number of misconceptions surrounding it. Let’s debunk some of the most common myths.

Myth 1 – It’s only caused by smoking

No. While smoking is the most common direct cause, it’s not the only cause. So, you mustn’t assume you’re safe if you don’t smoke. Lung cancer can be caused by genetics and other risk factors, as outlined above. Though it’s also important to note that, if you do smoke, quitting will significantly reduce your risk.

Myth 2 – It mostly affects men

The number of lung cancer cases in the UK is split fairly evenly between men and women. According to Cancer Research UK, around 25,300 men and 23,300 women are diagnosed in the UK each year.¹ 48% of lung cancer cases in the UK are in females, and 52% are in males.⁴

Myth 3 – Younger people don’t get lung cancer

It’s true that old age is a significant risk factor. The highest incidence rates are in older people, with 45% of new cases in the UK being among those aged 75 and older.¹

However, it’s still possible to get lung cancer when you’re younger, with age-specific incidence rates starting to rise steeply from around age 45-49 and a handful of cases among those in their 20s and 30s.⁵

Myth 4 – If I have lung cancer, there’s no point quitting smoking

It’s never too late to quit. In fact, even if you are diagnosed with lung cancer, quitting can help improve your prognosis and give you a better chance of responding well to treatment. It could also help reduce the risk of developing other diseases, including around 14 other forms of cancer.

Myth 5 – All lung cancer is the same

As mentioned before, there are two main kinds of primary lung cancer – non-small-cell lung cancer and small-cell lung cancer. And within these, there are different ways the cancer can start or develop. For more details, see Cancer Research UK’s overview of the Types of lung cancer.

Myth 6 – All treatment is the same

Just as there are many different types of lung cancer, there are many possible treatment paths. These include radiotherapy, surgery and chemotherapy, or a combination. It all depends on where the cancer is, what type it is and how much it has spread.

Myth 7 – The symptoms are easy to spot

Unfortunately, particularly in the early stages, there may not be any noticeable symptoms or they can be very mild. That’s why it’s so important to be aware of the risk factors as well as the symptoms as this is a very preventable form of cancer. It’s thought that as many as 79% of lung cancer cases in the UK are preventable.⁶

What to do if you think you may be at risk

If you think you fall into any of the risk categories, or if you notice any of the symptoms, make an appointment to see your GP as soon as you can.

They’ll ask about your lifestyle, overall health and any symptoms. They may also check your lung function by getting you to breathe into a device called a spirometer, and they might do a blood test to rule out other possible causes for certain symptoms.

Then, to diagnose lung cancer, doctors usually order a chest X-ray to begin with. If there are signs of lung cancer, or if tests and scans are inconclusive, you’ll be referred to a specialist for further examination and testing. This could involve a CT and / or PET-CT scan and a biopsy, however, just as lung cancer varies, so too does the way in which it’s diagnosed.

Your specialist will guide you through the process and outline possible treatment routes, which could involve surgery, radiation and/or chemotherapy.

If you do receive a cancer diagnosis, the news can feel overwhelming and you’ll have a lot of questions. Explore our cancer care articles for more information. If you're a member with AXA Health, here's more information on dedicated cancer support you may have access to.

References:

1. What is lung cancer? - Cancer Research UK
2. Lung cancer overview - NHS
3. Survival for lung cancer - Cancer Research UK  
4. Lung cancer incidence statistics - Cancer Research UK
5. Lung cancer incidence statistics - Cancer Research UK
6. Lung cancer risk - Cancer Research UK