Healthy cells grow when they receive signals and undergo repair or die when they are damaged or old. When cells begin to grow and multiply uncontrollably, it leads to cancer. The DNA has specific information for cell growth and division. If the genes go through changes during cell division, it is known as a mutation and can affect cell growth and increase cancer risk. Let’s look at how genetics and cancer are associated.

1. Is cancer a genetic disease?
Today, only about 5-10 percent of all cancer cases are directly caused by genetic defects, and research has linked mutations in specific genes to over 50 hereditary cancer syndromes that increase the risk of certain cancers.

2. What is the link between genetics and cancer?
Changes in the genes can be inherited or acquired due to various factors throughout one’s lifetime. A child might inherit a particular gene mutation from a parent. A genetic mutation that occurs at the time of conception elevates a child’s risk of developing a specific type of cancer. Inherited genetic mutations increase the risk, but it does not mean that an individual with these mutations will develop the disease.
Genetic mutation can also occur due to external triggers like cigarette smoking, dietary habits, and environmental factors.

3. What are the types of genetic mutations?
Two types of genetic mutations can cause cancer: germline mutations and acquired mutations.

• Germline mutations
  Mutations occur in a sperm cell or egg cell and are passed from a parent to child at the time of conception. Since the mutation is present in the reproduction cells, the genes are passed from one generation to other. Germline mutations are rare causes of cancer, and they lead to inherited cancers.
• Acquired mutations
  Gene mutations or damage to a particular cell during a person’s lifetime are called acquired mutations, and they can cause several types of cancer. Cancer caused by acquired mutations is called sporadic cancer. Tobacco usage, exposure to UV radiation, increasing age, and viruses are the leading causes of acquired mutations.

4. Which genes are linked to cancer?
Mutations in the following types of genes can lead to cancer:

• Tumor suppressor genes
  Mutations in these genes cause uncontrollable cell growth and division, leading to tumors.
• Oncogenes
  Mutations in oncogenes turn healthy cells into cancer cells.
• DNA repair genes
  These genes repair mistakes made while copying DNA during cell division. Mutations in these genes cause errors in the DNA to remain unfixed and become mutations that can cause cancer.

5. What is genetic testing for cancer risk?
Genetic testing searches for mutations in genes, chromosomes, or proteins that elevate cancer risk. That said, genetic testing cannot tell whether an individual will develop cancer for sure and can only determine if they are at a higher risk.