Ovarian Cancer Genetics and Heredity, Essay Example

Introduction

Ovarian cancer is the fifth principal cause of cancer death in the United States, respectively to the second leader breast cancer. The ratio is that 1:70 women in the United States will eventually contract ovarian cancer. There is a predisposition ratio of 3:1 with at least one first degree relative. An offspring of the parent has a predisposition of 50:50 to inherit the predisposition from the parent.  This does not mean that the person will inherit the cancer because of incomplete penetrance or gender-related expression. The predisposition does not discriminate by gender. Both males and females can pass the gene to their offspring. “The syndrome associated with the cancer is called BRCA1 or BRCA2 mutation syndromes. Ovarian cancer has also been associated with Lynch syndrome, basal cell nevus (Gorlin) syndrome (OMIM), and multiple endocrine neoplasia type 1 (MEN1) (OMIM).” (“Genetics of Breast and Ovarian Cancer”).

Models for Prediction of the Likelihood of a BRCA1 or BRCA2 Mutation are used to establish if there is a link between family genetics and the occurrence of ovarian cancer. “Personal characteristics associated with an increased likelihood of a BRCA1 or BRCA2 mutation include the following:

• “Breast cancer diagnosed at an early age.”
• “Bilateral breast cancer.”
• “A history of both breast and ovarian cancer.”
• “The presence of breast cancer in one or more male family members.” (“Genetics of Breast and Ovarian Cancer”).

Research shows that there is a likelihood of an increase to carry the BRCA1 or BRCA2 Mutation if the following family characteristics are evident: more than one person in the family has ovarian cancer, both breast and ovarian cancer is present in the family history, more than one family member has cancer and there is an established background of Ashkenazi Jewish background.

Limitations to Genetic Testing

Genetic tests are not designed to detect the complexities that could cause a disease but they do help to calculate the risks, identify management perspectives with relation to the disease and help to decipher the tests results with relevance given to past history. High risks do not express the gene has passed on but infers the possibility of mutation.

Research shows there is a correlation between gene tracing and susceptibility to the disease and relation to breast disease. Further 5-10% of women who inherit either ovarian or breast cancer have a higher chance of inheriting the disease because of a family history of the gene. Research has already proven that alteration to the BRCA1 gene can tremendously increase the chance of both breast and ovarian cancer. Diagnostic testing is available for early detection but it is certainly more difficult to screen for ovarian cancer, though the use of ultrasound technology is currently being used.

It is very interesting to note that only 10% of women that have ovarian cancer have a predisposition for the cancer as compared to 90% that contract the cancer sporadically. “The proportion of women with cancer due to genetic mutation actually decreases with age by about 14% with those diagnosed in the fourth decade and dropping to 7% with those diagnosed in the sixth decade. Certain ethnic groups, such as Ashkenazi Jews, have high rates of specific mutations of these genes.” (“Molecular Basis of Hereditary Predisposition to Ovarian Cancer”).

When mutations or changes occur in cell structure cells begin to grow out of context and the result is cancer. If our body is not able to repair the cell damage often cancer is what happens as a result of the cell change. When the change happens in a singe copy of a protective gene pair the risk for cancer often increases due to the rapid change in the cell structure. Risks occur according to the exact mutation that was inherited by the parents. Heredity cancer syndrome is often used to describe the inherited gene mutation that increases the risk for the development of cancer. Cancers are believed to be of a sporadic nature hence even if it does not run in the family a person has a chance of contacting cancer in his/her lifetime. “Again to reiterate only 10-15% of cancers are of hereditary nature.” (Hereditary Cancer and Cancer Genetics”).  BRCA mutations do not seem to play a significant role in the development of mucinous or borderline ovarian tumours,

Prevention

Genetic testing is becoming increasingly popular and is recommended by physicians and insurance companies. DNA sequencing tests are available to those who want to test for the BRCA1 and BRCA2 genes, though “researchers estimate that it still overlooks 5 to 15 percent of the mutations that can occur within these two genes.” (Fergus, 2008).  Preventative medications and prophylactic surgery is an option for those who test positive for the genes. “Women with a family history including 2 or more first- or second-degree relatives with either ovarian cancer alone or both breast and ovarian cancers should undertake prophylactic oophorectomy immediately after childbearing has been completed to reduce the risk of ovarian cancer.” (Prat, 2003).

Endometrial cancer carcinoma is the most common gynaecologic cancer known to women and is cancer of the lining of the uterus. Adenocarcinoma accounts for more that 75% of endometrial cancers. It commences in the uterus, spreads to the cervix and eventually makes its way through the wall of the uterus, “the parametrium and to the bladder and the rectum. It can further spread by the lymphatic system to the vagina, fallopian tubes, ovaries, the pelvic and aortic lymph nodes and to the lymph nodes in the groin and above the collarbone.” (Stern, 2007).  As with other cancers there is no known cause for the cancer but the use of birth control pills can greatly reduce the chance to contract the cancer. There are several different stages of the cancer but it is important to note this cancer with relation to ovarian cancer because of the fact it can spread to the ovaries.

Conclusion

Approximately 55% of all women diagnosed with ovarian cancer will die from the cancer. That is an astonishing 14,200 women in the United States. Though much research has been conducted on ovarian cancer in the states, academians state that more deaths will be reported in Northern Europe due to ovarian cancer than in the United States. The key to surviving ovarian cancer is early examinations for the treatment of such cancer. If a person has a predisposition to the cancer through family history it is suggested they undergo genetic testing to determine if they are a carrier to take preventative medication or have surgery.

Keeping in mind there are also other risk factors to consider a person with a strong family history of cancer might want to take proactive measures to protect his/herself from the increasing killer in women. Research shows that women who take hormone therapy for a combination of ten or more years have extremely high risk factors of contracting ovarian cancer.

References

Genetics of Breast and Ovarian Cancer (2009) Genetics of Breast and Ovarian Cancer Retrieved September 30, 2009 from, http://www.cancer.gov/cancertopics/pdq/genetics/breast-and-ovarian/HealthProfessional/page2#Section_11

Molecular Basis of Hereditary Predisposition to Ovarian Cancer (2009) Molecular Basis of Hereditary Predisposition to Ovarian Cancer Retrieved September 30, 2009 from, http://www.ovariancancer.jhmi.edu/hereditary.cfm

Hereditary Cancer and Cancer Genetics (2008) Hereditary Cancer and Cancer Genetics Retrieved September 30, 2009 from, http://www.facingourrisk.org/hereditary_cancer/hereditary_cancer_and_genetics.html

Fergus, K. (2008) Considering Genetic Testing Retrieved September 30, 2009 from, http://www.genetichealth.com/BROV_Genetic_Testing_for_Breast_and_Ovarian_Cancer.shtml#Anchor1

Prat, J. (2003) Ovarian Cancer Heredity Retrieved September 30, 2009 from, http://www.ncbi.nlm.nih.gov/pubmed/16112002

Stern, J. (2007) Uterus: Endometrial Carcinoma Retrieved September 30, 2009 from, http://womenscancercenter.com/info/types/uterus.html