Lung cancer is a serious condition that affects the lungs. It is one of the most common cancer diagnoses worldwide.

Scientists estimate that lung cancer accounts for 12.4% of cancers worldwide. As with all types of cancer, lung cancer comes from gene mutations. However, there are different types of gene mutation that can lead to the condition.

This article will provide information about gene mutations and lung cancer. It will discuss the main gene mutations that lead to lung cancer and what these mutations mean for lung cancer treatment and outlook.

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Millions of cells make up the body. Different kinds of cell play different roles. Our cells are themselves made up of smaller components, which also have different functions.

Genes are the body’s way of making sure that this incredibly complex system keeps working properly. Genes behave like instructions for our cells, telling them when to grow, when to divide, and when to die.

Gene mutations occur when some of the genes in a person’s body become different from the version of those genes in the general population. When this happens, the genes can give unusual instructions to certain cells.

As the National Cancer Institute explain, some gene mutations can lead to harmful changes in the body’s cells. For example, gene mutations could cause cells to form incorrectly or to grow too large.

Lung cancer occurs when gene mutations cause unusual cell growth in the lungs.

Around 5–10% of these mutations are inherited, according to the National Cancer Institute. However, most lung cancer mutations are due to exposure to carcinogens. Carcinogens are substances that have the potential to cause dangerous gene mutations.

The most common cause of lung cancer is tobacco smoking. In fact, scientists believe that this is the cause of around 90% of lung cancer cases.

Although there are many kinds of lung cancer mutation, some are more frequent than others. This section will look at some of the more common lung cancer mutations.

EGFR mutations

EGFR genes are responsible for controlling cell growth and division. When EGFR genes mutate, it can cause cells to grow and divide at unusual rates.

Scientists have found that EGFR mutations are more common in certain kinds of lung cancer than in others.

For example, EGFR mutations occur in around 34% of all lung adenocarcinomas. However, they are even more common in the lung adenocarcinomas of people who do not smoke and of people of Asian descent.

EGFR mutations are less common in lung squamous cell carcinoma (SCC), which is another form of lung cancer. They occur in around 6% of lung SCC tumors.

TP53 mutations

TP53 is a gene that functions to make sure that cells do not grow too quickly. When it mutates, it can lose its ability to control unusual cell growth.

TP53 mutations arise in around 43% of lung SCCs and in around 35% of lung adenocarcinomas.

KRAS mutations

KRAS is a gene that controls cell division and growth. It also controls cell specialization by telling the cell which sorts of jobs to do.

Around 19% of people with lung adenocarcinomas have KRAS mutations, whereas only 5% of people with lung SCCs have these mutations.

PIK3CA mutations

PIK3CA is a gene that helps regulate cell function and control cell survival.

Scientists have detected PIK3CA mutations in around 4% of lung adenocarcinomas and in around 6% of lung SCCs.

Doctors often treat lung cancers with a mixture of surgery and chemotherapy. In some cases, they may also use radiation therapy.

With surgery, healthcare professionals remove large concentrations of cancer cells, or tumors. The method of chemotherapy works by suppressing the growth of the leftover cancer cells.

However, the type of treatment a doctor uses will vary depending on the kind of lung cancer mutation a person has.

For example, one study notes that EGFR mutations respond less well to certain drugs, such as gefitinib and erlotinib, than to others, such as EGFR tyrosine kinase inhibitors.

Other lung cancer mutations, such as KRAS mutations, make a person’s lung cancer more difficult to treat with chemotherapy.

Although scientists still have a lot to learn about different lung cancer mutations, their current knowledge helps doctors treat lung cancers as well as they can.

The National Cancer Institute list several symptoms of lung cancer. These include:

  • a persistent or worsening cough
  • chest pain or discomfort
  • breathing difficulties or wheezing
  • coughing up blood
  • appetite loss or weight loss
  • difficulty swallowing
  • feeling very tired

Although these symptoms are shared with other conditions, lung cancer is a very serious illness. Anyone with the above symptoms should contact a doctor as soon as they can.

As with all cancers, lung cancer develops in stages. The more advanced a person’s lung cancer, the less likely they are to recover.

Around 70% of people with stage 1 lung cancer survive for another 5 years if they undergo surgical treatment. However, this number falls to 2–13% in people with stage 4 lung cancer.

Scientists also know that different lung cancer mutations can affect a person’s chances of recovery. Although researchers debate the exact figures, some patterns are beginning to emerge.

For example, one study notes that the TP53 mutation may cause more aggressive tumors. It also states that the PIK3CA mutation may lead to faster disease progression.

In recent decades, scientists have greatly advanced our knowledge of lung cancer and of the different genetic mutations that can cause it.

With this improvement in understanding, doctors are able to treat lung cancers in more effective ways.