Cancer is a disease which is characterized by the abnormal growth of cells in any body part. Genetics plays a role in the development of cancer by influencing the likelihood that a person will develop certain types of cancer.
Genetic mutations can be inherited from a person’s parents, or they can occur spontaneously. Some genetic mutations may increase the risk of developing cancer, while others may protect against it. Understanding the genetic factors that contribute to cancer can help in the development of more targeted and effective treatments.
Genetic changes that cause cancer
There are several types of genetic changes that can lead to cancer. Some of the most common include:
Oncogenes: These are genes that promote cell growth and division. When these genes are activated (or “turned on”) when they shouldn’t be, they can lead to the development of cancer.
Tumor suppressor genes: These are genes that help to prevent the growth of cancer cells. When these genes are inactivated (or “turned off”) by mutations, they can no longer perform their normal function, which can lead to the development of cancer.
Chromosomal changes: Cancer can also be caused by changes in the structure or number of chromosomes, the structures that carry genetic material. These changes can result in the loss or gain of genetic information, which can contribute to the development of cancer.
DNA repair genes: These are the genes that are responsible for repairing damage to the DNA. When these genes are mutated, DNA damage may not be repaired properly and can lead to the development of cancer.
It’s important to note that most cancers are not caused by a single genetic change, but by multiple genetic mutations and epigenetic changes over time.
Relationship between cancer and genetics
The relationship between cancer and genetics is complex, with both genetic and environmental factors playing a role in the development of the disease.
Some cancers are caused by inherited genetic mutations, while others develop as a result of genetic mutations that occur spontaneously during a person’s lifetime.
Inherited genetic mutations can increase a person’s risk of developing certain types of cancer, such as breast, ovarian, colon, and prostate cancer. For example, mutations in the BRCA1 and BRCA2 genes are associated with a high risk of developing breast and ovarian cancer.
Similarly, Lynch syndrome, caused by mutations in genes such as MLH1, MSH2, MSH6, and PMS2, increases the risk of colon, endometrial and other types of cancer.
On the other hand, most cancers are not caused by inherited genetic mutations, but by genetic mutations that occur spontaneously during a person’s lifetime. These mutations can be caused by exposure to certain environmental factors, such as tobacco smoke, ultraviolet radiation, and certain chemicals.
Understanding the genetic changes that lead to cancer can help in the development of more targeted and effective treatments. Genetic testing can also be used to identify people who are at an increased risk of developing certain types of cancer, allowing for earlier detection and prevention.
Types of cancer that occur due to genetic changes
There are several types of cancer that are known to occur as a result of genetic changes. Some examples include:
Hereditary breast and ovarian cancer: These types of cancer are caused by inherited mutations in genes such as BRCA1 and BRCA2. People with these mutations have an increased risk of developing ovarian and breast cancer.
Hereditary colon cancer: Colon cancer can occur due to inherited mutations in genes such as APC, MUTYH, and DNA mismatch repair genes. Lynch syndrome, caused by mutations in genes such as MLH1, MSH2, MSH6, and PMS2, increases the risk of colon and other types of cancer.
Hereditary melanoma: Melanoma is a type of skin cancer that can be caused by inherited mutations in genes such as CDKN2A, CDK4, and BAP1.
Hereditary Retinoblastoma: Retinoblastoma is a rare eye cancer that occurs in children, it is caused by inherited mutations in the RB1 gene.
Hereditary Adrenocortical carcinoma: ACC is rare cancer that starts in the outer layer (cortex) of the adrenal gland, it can be caused by inherited mutations in the PRKAR1A gene.
It’s important to note that not all cases of these cancers are caused by inherited genetic mutations, and most of these cancers also have a significant environmental component.
How can you tell if you are at risk of hereditary cancer?
There are several ways to determine if you may be at risk for hereditary cancer:
Family history: A personal or family history of cancer, particularly at a young age, can indicate an increased risk of hereditary cancer. If several family members have been diagnosed with the same type of cancer or related cancers, it may be an indication of hereditary cancer syndrome.
Genetic testing: Genetic testing can be used to identify specific genetic mutations that are associated with an increased risk of developing certain types of cancer. For example, genetic testing for mutations in the BRCA1 and BRCA2 genes can be used to identify a person’s risk of developing breast and ovarian cancer.
Genetic counseling: A genetic counselor can help you assess your risk of hereditary cancer by reviewing your family history and discussing the potential benefits and limitations of genetic testing. Genetic counseling can also help you understand and make decisions about genetic testing and management options.
It’s important to note that not all people with an inherited genetic mutation will develop cancer.
Factors such as lifestyle, environment, and chance also play a role in the development of cancer, and not all cancers are inherited. Genetic testing and counseling can help you to understand your risk and take steps to help reduce it.