Introduction
Ovarian cancer is a disease that occurs in the ovaries of women. There are different types and subtypes of ovarian cancer, and a few of them have a higher genetic predominance. Any individual can develop ovarian cancer; however, certain risk factors can make some individuals more prone to ovarian cancer.
Genetic mutation is one of the biggest risk factors for ovarian cancer. Research suggests that around one-fifth of ovarian cancers have hereditary susceptibility. Hereditary ovarian cancers can occur due to a gene mutation (changes occurring in the gene) in certain genes, which may be passed down from the parent (mother or father). High-grade serous epithelial ovarian cancer is a type of ovarian cancer that occurs due to gene mutations.
What Is Ovarian Cancer?
Ovarian cancer is a disease affecting the ovaries of women. Ovaries are female reproductive organs where eggs and hormones are produced. Ovarian cancer occurs when some cells in the ovary multiply uncontrollably or abnormally and form a mass or tumor. In the early stages of cancer, it usually shows no noticeable symptoms.
But as cancer progresses, individuals may experience pain in the pelvis or lower abdomen, changes in bowel or urinary habits, or vaginal bleeding between periods or after menopause. As there are fewer noticeable symptoms in the early stages, it is often diagnosed in the late stages, making it the fifth leading cancer that causes death in women. Few ovarian cancers are considered hereditary when ovarian cancers cluster in families. Hereditary ovarian cancer can occur due to inherited gene mutations.
How Is Ovarian Cancer Inherited?
Ovarian cancer can occur due to genetic changes occurring due to lifestyle changes, environmental changes, and others etc., and it is called acquired gene mutations. Another type is hereditary gene mutation, which occurs due to inherited gene mutations. All individuals generally have two copies of each gene in their cells, one inherited from the mother and another from the father.
Hereditary ovarian cancer follows an autosomal dominant inheritance pattern, which means a parent with a gene mutation may pass a normal gene copy or a mutated gene copy to their offspring. So, if a person has a parent with a gene mutation, there is a 50 percent chance of inheriting the condition from the parent. So if a person has ovarian cancer, their sibling or parent who has the mutation also has a chance of inheriting the same mutation.
Which Gene Mutation Is Responsible for Ovarian Cancers?
BRCA1 (Breast Cancer gene 1) and BRCA2 (Breast Cancer gene 2) are well-known genes linked with genetic mutations in ovarian cancer. Mutations in these genes are responsible for 15 to 20 percent of ovarian cancer. BRCA 1 and 2 produce proteins to repair any damage in the DNA (deoxyribonucleic acid).
Every individual will have two copies of these genes, one inherited from the father and one from the mother. Individuals who inherit mutated variants in one of these genes from any of their parents (father or mother) are at high risk of getting several cancers, including ovarian cancer. Also, it is noted that when BRCA1 and BRCA2 mutated genes are inherited from a parent, the individual is more likely to develop cancer at a very young age.
Even if an individual has inherited a harmful variant of BRCA1 or BRCA2 from any one parent, it does not mean that they will develop cancer, but they are at high risk of developing cancer. Because they would have inherited a normal copy of the gene, but when there are variations in the normal copy during that individual's lifetime, it can become cancer.
Lynch Syndrome: Lynch syndrome is also an inherited disease caused by mutations in the genes responsible for DNA mismatch repair (like PMS2, MLH1, MSH2, and MSH6). Lynch syndrome increases the risk of various types of cancer, like colorectal cancer, uterine cancer, prostate cancer, ovarian cancer, etc.
It is mainly well known for its association with colorectal cancer. The level of risk for developing cancer depends on which gene has mutated. Approximately 3 to 17 percent of people with Lynch syndrome have a chance of developing ovarian cancer in their lifetime. Also, in people with Lynch syndrome, cancer can develop at a much younger age than in the normal population.
Other Genetic Susceptibility Genes: Other than the above-mentioned gene mutations, other gene mutations can cause ovarian cancer. Scientists are still discovering many other genes that can elevate ovarian cancer risk. TP53, PTEN, BRIP1, PALB2, STK11, RAD51C, and ATM are some genes that can increase the risk of ovarian cancer. Each of these genes maintains a delicate balance of cellular processes; when any changes occur, they can disrupt this equilibrium, which can develop ovarian cancer.
How to Check for the Risk of Inherited Diseases?
If an individual has a family health history that is most likely to have inherited breast, ovarian, and other cancers, healthcare professionals may recommend genetic counseling and genetic testing. The genetic counselor will take a detailed family health history to check for the possibility of developing cancer risks and will say whether genetic testing is required or not to find out about genetic mutations.
The genetic counselor recommends genetic testing with the help of a panel that checks for mutations in numerous genes, along with BRCA1 and BRCA2. Genetic testing will be most beneficial if it is first performed on individuals who have breast or ovarian cancer in the family.
If a person has BRCA1, BRCA2, or another gene mutation, their relatives can also undergo genetic testing. If their test results are negative, their genetic testing may not be needed for their close relatives. Most ovarian cancer is not hereditary; therefore, genetic testing will not help most women with a family history of ovarian cancer.
Conclusion
Ovarian cancer is one of the most deadly cancers, taking the lives of many women worldwide. It has increased the risk of hereditary inheritance. If an individual inherits mutated genes from their parents, their risks are higher than those of normal individuals. Even if an individual has inherited a harmful variant from any one parent, it does not mean that they will develop cancer. Still, they have an increased risk of developing cancer. Individuals with a family history of cancer can undergo genetic counseling or genetic testing with their healthcare professional's advice to check for any mutation in the gene.
