Is Lung Cancer Hereditary?

Lung cancer is a serious health condition that affects many people worldwide. It is the leading cause of cancer-related deaths in both men and women. There are several risk factors associated with lung cancer, including smoking, exposure to environmental toxins, and genetic factors. 

While hereditary lung cancer is rare and inherited mutations are still being explored, patients with first-degree relatives with the disease are at an increased risk of developing lung cancer themselves and should take precautions where possible.

What Is Lung Cancer?

Lung cancer is one of the most common types of cancer, with a generally poor prognosis. For this reason it is important that we take lung cancer seriously, educating ourselves and prioritising preventative measures where possible.

Lung cancer begins in the cells of the lungs. As with all forms of cancer, a mutation or change in the genetic material of the cell causes cells which grow and divide uncontrollably and can eventually accumulate to form a tumour. Lung cancer can also spread (metastasize) to other parts of the body, creating secondary cancers.

There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC is the most common type of lung cancer, while SCLC is much less common but tends to be more aggressive. NSCLC comes in three forms, adenocarcinoma (the most common subtype), squamous cell carcinoma, and large-cell carcinoma.

What Causes Lung Cancer?

Acquired gene mutations can occur during your life, due to errors in normal cell processes or influences from your environment, changing normal cells into cancer cells.

In lung cancer, the leading cause of changes to the normal lung cells is smoking. 

Tobacco smoke contains many chemicals that can damage the DNA in lung cells and lead to cancer, and the longer and more often you smoke, the higher your risk of developing lung cancer. 

However, around 10-20% of those who develop lung cancer have never smoked, which means that we need to consider other causes too. 

Lung cancer in non-smokers is sometimes treated as if it were a separate disease because it has different characteristics to lung cancer in smokers. Causes are not yet certain, but lung cancer in non-smokers or never-smokers may be associated with environmental factors as well as family history. 

Exposure to environmental toxins such as radon and air pollution, as well as chemicals that may be found in certain occupations (asbestos, diesel fumes, cadmium, chromium, nickel, silica, arsenic, beryllium), have been found to increase the risk of developing lung cancer. 

Can I Inherit Lung Cancer?

You cannot inherit cancer, but you can inherit genetic mutations from your parents, and these mutations could increase your risk of developing cancer. 

Environmental factors  are the primary causes of lung cancer, smoking in particular. This means that lung cancer is not generally hereditary. However, in a small number of cases inherited genetic mutations may be to blame for an increased risk of developing the disease. 

While research has not clearly answered the question of heredity, a family history of lung cancer has been found to increase lung cancer risk. Those with first-degree relatives (parents, siblings, children) who have or have had lung cancer, are at about a 50% higher risk for developing lung cancer themselves, compared to those without this family history. The reason for this could be inherited genetics, environment, or both. 

While results of research into inherited gene changes and lung cancer have been inconsistent, the exploration is ongoing. 

When it comes to hereditary cancer susceptibility syndromes (inherited risk for the development of several different cancers that is higher than the general population),  Li-Fraumeni syndrome (LFS) increases the risk of several cancers, including lung cancer. This syndrome involves an inherited mutation in the TP53 tumour-suppressor gene, which prevents the gene from fulfilling its normal job of controlling cell growth and preventing cancer. 

You inherit two copies of every gene from your parents, one from your mother and one from your father. A gene mutation inherited in one of your TP53 genes causes LFS. This mutation can also be acquired during your life (a new mutation), which then could possibly be passed on to your children.  

Family cancer syndromes can cause several family members to develop a type of cancer (often younger than non-inherited cancers) or multiple types of cancer in one person.

How Can I Find Out My Lung Cancer Risk?

If you have a family history of lung cancer, you may be concerned about your risk of developing the disease. It's important to talk to your doctor about your family history and any other risk factors you may have. 

Some signs that could indicate hereditary cancer include family members diagnosed at a younger age than in the general population, cancer in multiple family members and multiple generations, more than 1 cancer in a family member, and rare cancers in family members. 

Your doctor may recommend genetic testing to determine if you have any inherited mutations, such as LFS, that increase your risk of developing cancer. 

Genetic testing may also assist in finding a treatment suited to your lung cancer characteristics. Almost all NSCLCs are analysed using genetic sequencing in an attempt to discover mutations that may be helpful for treatment actions. For example, some patients with NSCLC have mutations in the EGFR and KRAS genes, for which some treatment options have been developed (e.g. Tyrosine kinase inhibitors).

However, it is important to note that the hereditary aspect of lung cancer is still being explored and genetic testing options may be limited, if available at all. 

Even if you are able to get tested, having a genetic mutation associated with lung cancer does not necessarily mean that a person will develop the disease. Other factors, such as smoking and environmental exposures, can also play a role in the development of lung cancer. 

What Can I Do To Reduce My Risk Of Lung Cancer?

If you are concerned about your risk of developing lung cancer, there are several steps you can take to reduce your risk:

• Don't smoke: If you smoke, quitting is the most important thing you can do to reduce your risk of lung cancer. Even if you have smoked for many years or have already been diagnosed, quitting will have a big impact. Because smoking has such a strong influence on lung health there are many available resources that can assist you in this process.
• Avoid exposure to environmental toxins: Try to avoid exposure to substances such as radon, asbestos, and air pollution. If you work in an environment with potential lung cancer-causing agents, take appropriate safety precautions. You may also be able to test your living and work spaces for the presence of harmful chemicals.
• Live a healthy lifestyle: Maintain a healthy diet, exercise regularly, and take steps to manage your stress levels. These lifestyle factors can help support overall health and reduce the risk of cancer.

Will I Get Lung Cancer If My Parents Had It?

While smoking and environmental factors remain the primary causes of lung cancer, there seems to be a small genetic component to the disease which is still being explored. 

If you have a family history of lung cancer, it is important to discuss your concerns with a healthcare professional, who can help assess your risk and provide appropriate guidance and recommendations.