Ovarian Cancer Risks
All women have some risk for ovarian cancer and this risk increases with age. The lifetime risk for ovarian cancer in the general population is about 1 in 70 (1.5%). Women with a BRCA mutation have a much higher lifetime risk and a tendency to develop ovarian cancer at a younger age.
When experts speak of ovarian cancer, they also include two related cancers: fallopian tube cancer and primary peritoneal cancer. Both are staged and treated similarly to ovarian cancer. Estimates for ovarian cancer in BRCA mutation carriers also include the risk for fallopian tube and primary peritoneal cancer. Experts don’t know the exact lifetime risk for women with mutations and usually present a risk range from 10% -60% lifetime risk.
In families with a strong history of ovarian cancer but no known BRCA mutation the risk is higher than in the general population but the exact risk is unknown. It is important for women in these families to consult with a cancer genetics expert. Researchers are looking for other causes of cancer in these families. Visit our page on research to determine whether your family qualifies for a research study to identify cancer risk in BRCA-negative families.
Research will improve experts' ability to pinpoint ovarian cancer risk. It is important to consult with a cancer genetics specialist when determining your risk for ovarian cancer and making risk-management decisions. Stay in contact with a genetics expert for updates on current knowledge.
Confronting your personal cancer risk can be confusing and isolating. If you're high-risk and trying to make risk-management decisions, you need as much support as possible. It helps to speak with other women in the FORCE community who have faced these risks.
In women with a BRCA mutation who have never had a diagnosis of cancer, the lifetime risk for ovarian cancer is high. Experts don't agree on the exact risk but estimates range from 10% - 60% lifetime risk for depending on the mutation and other factors.
A study of women with one of the BRCA1 or BRCA2 mutations common in Jewish populations indicated a lifetime ovarian cancer risk of 54% in women with BRCA1 mutations and 23% in women with BRCA2 mutations. This Power Point slide shows the study’s decade-by-decade breakdown for ovarian cancer risk compared to the general population. A different study of multiple families with BRCA mutations (not specifically Jewish families) found a comparatively lower risk: 39% for BRCA1 carriers, compared to 11% of BRCA2 carriers by age 70. Another study combined multiple studies to determine an average risk for ovarian cancer. This "meta-analysis" determined the average lifetime risk to be 55% in BRCA 1 mutation carriers and 31% in BRCA 2 mutation carriers. All the studies show the risk for ovarian cancer in BRCA carriers begins after age 30, and most of the risk occurs after age 40.
Breast cancer survivors who have a BRCA mutation or hereditary breast cancer are at higher risk for ovarian cancer than breast cancer survivors with sporadic breast cancer. A research study on ovarian cancer risk in breast cancer survivors with a BRCA mutation found a 12.7% risk in BRCA1 carriers and 6.8% risk in BRCA2 carriers within 10 years of the breast cancer diagnosis.
Women with a family history of breast and ovarian cancer but no identified BRCA mutation have an elevated risk of ovarian cancer after breast cancer, but the exact risk is unknown. Survivors with a family history of breast cancer only, (no ovarian cancer in the family) but no known mutation in the family, may not have an elevated ovarian cancer risk. A study on women from families with an extensive history of breast cancer but without a BRCA mutation found the risk for ovarian cancer was similar to women in the general population.
Genetics experts can help breast cancer survivors who have a BRCA mutation, a family history of cancer, or other indicators of hereditary cancer determine their risk for ovarian cancer and develop a risk management plan.
The “peritoneum” is a layer of cells lining the inside of the abdomen. These cells are similar to the cells lining the ovaries. Cancer of this lining is called “primary peritoneal cancer” (PPC). Primary peritoneal cancer is treated in a similar manner as stage III ovarian cancer. Carriers of BRCA1 or BRCA2 gene mutations or one of the genes that cause HNPCC are at higher risk for primary peritoneal cancer than women in the general population. The risk for primary peritoneal cancer is low in mutation carriers: one study estimated the lifetime risk in BRCA carriers to be 1.3%, while another study found the risk to be 3.5%.
The fallopian tubes are the passages that carry a woman's eggs from her ovaries to her uterus. In the general population, fallopian tube cancer is very rare. Carriers of BRCA mutations or one of the genes that cause HNPCC have a higher risk for fallopian tube cancer than women in the general population. One study estimated the lifetime risk to be less than 1% in BRCA1 and BRCA2 mutation carriers however a recent study on 122 BRCA positive women undergoing prophylactic oophorectomy found that about 6% of these women had cancer at the time of prophylactic surgery. All of the women had cancers originating in their fallopian tube. The study suggests that much of the ovarian cancer in BRCA carriers may begin in the fallopian tubes.
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