Cancer in Our Communities
Members of the Jewish community who trace their roots to Central or Eastern Europe are known as Ashkenazi Jews. Although today members of this community are found around the world, Ashkenazi Jews for centuries were a geographically isolated population. The isolation experienced by this population means its members can trace their ancestry back to a small number of members known as “founders.”
Over time, the genetic traits of these early Ashkenazi “founders” have been passed down through generations, including a greater frequency of carrying certain changes in genes known as BRCA1 and BRCA2, which are associated with an increased risk of cancer. Everyone has two copies of each of these genes, one that is inherited from their mother, and one from their father.
Some specific changes, or mutations, in BRCA1 and BRCA2 occur more frequently in Ashkenazi Jews than in the general population. These mutations increase the risk of certain types of cancer, including breast and ovarian in women and breast and prostate in men. About one out of every 40 individuals of Ashkenazi Jewish ancestry have a mutation in the BRCA1 or BRCA2 gene, as compared to one out of every 800 members of the general population, according to the Centers for Disease Control.
Although these genetic mutations increase the risk of developing some cancers, not everyone who carries a gene mutation will develop cancer. And, despite these genetic abnormalities, prevention and lifestyle strategies can still be helpful in preventing cancer.
The BRCA1 and BRCA2 genes are part of the body’s normal mechanism to fix mistakes that occur in the DNA when cells go through normal division. However, abnormal copies of either of these genes – which are inherited from parents – do not perform naturally and as a result make a carrier more susceptible to breast and ovarian cancer.
In particular, there are three mutations (two in BRCA1 and one in BRCA2) that account for the majority of the BRCA mutations seen in persons of Ashkenazi Jewish ancestry. Women with a mutated BRCA1 or BRCA2 gene have a lifetime risk of between 36 percent and 85 percent of developing breast cancer by age 70. The average woman in the United States has about a 12 percent risk of developing breast cancer over a 90-year life span.
Women with a BRCA1 or BRCA2 gene mutation have a lifetime risk of 15 to 40 percent for developing ovarian cancer. By comparison, women who do not have a BRCA mutation have a 1.8 percent risk of developing ovarian cancer.
Just as Ashkenazi women have an increased risk of inheriting a mutated BRCA1 and BRCA2 gene from one or both of their parents, so do Ashkenazi men. These mutations result in a higher risk of developing certain types of cancer, including male breast cancer and prostate cancer.
Men who inherit an abnormal BRCA1 or BRCA2 gene have approximately a 6 percent risk for developing breast cancer during their lifetime. That risk is 80 percent greater than the lifetime risk of men without an abnormal BRCA1 or BRCA2 gene.
Men carrying abnormal versions of these genes may also be three to seven times more likely than average to develop prostate cancer. Other cancer risks, such as cancer of the skin or digestive tract, may also be somewhat higher among men with BRCA1 or BRCA2 mutations. But, as with women, the risk increases for these cancers are much lower than the increase in risk for breast cancer.