Dr. Mary-Claire King, who discovered the BRCA1 gene, to speak at UCSB
If a woman learns she has the BRCA1 or BRCA2 gene, that knowledge can save her life.
Dr. Mary-Claire King, the scientist who discovered the BRCA1 gene and whose work resulted in the discovery of the BRCA2 gene, stressed that point. Those are genes related to hereditary breast and ovarian cancers.
“Women can now learn if they carry cancer-causing mutations in BRCA1 or BRCA2,” she told the News-Press, answering questions by email.
“If they do carry damaging mutations, they can undertake risk-reducing surgery, removal of the ovaries and fallopian tubes and for some women, preventive mastectomy,” Dr. King said.
She added that the discovery of BRCA1, BRCA2 and other genes have led to the development of therapeutic options for patients with cancer due to mutations in those genes. “The best known examples are medications called PARP inhibitors, now in widespread use.”
Dr. King will discuss genetics and breast and ovarian cancer in a free UCSB Arts & Lectures talk at 7:30 p.m. Thursday at UCSB Campbell Hall.
The 73-year-old Evanston, Ill., native earned her bachelor’s in mathematics in 1966 at Carleton College in Northfield, Minn., and her doctorate in genetics in 1973 at UC Berkeley. That was followed by a post-doctorate fellowship from 1974 to 1976 at UC San Francisco.
Dr. King said she worked from 1974 to 1990 to prove the existence of the BRCA1 gene.
“I began with mathematical theory, then worked with DNA from members of families severely affected with breast cancer who were referred to me by their physicians,” said Dr. King, professor of genome science and medicine (medical genetics) at the University of Washington in Seattle. She also holds the title of American Cancer Society professor.
Today, the cancer society reports that about 5 to 10 percent of all cancers result from an abnormal gene inherited from a parent.
The society noted the presence of BRCA1 or BRCA2 greatly increases the risk of breast and ovarian cancer.
“On average, a woman with a BRCA1 or BRCA2 gene mutation has up to a 7 in 10 chance of getting breast cancer by age 80,” the society said on its website, www.cancer.org.
The society said the lifetime ovarian cancer risk is estimated to be between 35 and 70 percent for women with the BRCA1 mutation. “This means that if 100 women had a BRCA1 mutation, between 35 and 70 of them would get ovarian cancer.”
The risk of ovarian cancer for women with BRCA2 mutation is estimated at between 10 and 30 percent by age 70, according to the society.
The society said that compares to a less than 2 percent risk of lifetime ovarian cancer for the general population.
In the U.S., BRCA mutations are more common in Jewish people of Ashkenazi (Eastern Europe) origin than in other racial and ethnic groups, but people of any racial and ethnic background can have them, according to the cancer society.
Dr. King told the News-Press that movie star Angelina Jolie, who tested positive for the BRCA1 gene, was correct in her decision to reduce her risk with a double mastectomy and surgery to remove her ovaries and fallopian tubes. (Ms. Jolie had a family history of ovarian and breast cancer.)
“She has saved her life, and other women can do the same. Thousands have,” Dr. King said.
She added that much has been learned since her discovery of the BRCA1 gene.
“It is now clear that BRCA1 has several ‘sister genes’ that can also harbor mutations that predispose to breast cancer or ovarian cancer,” Dr. King said. “We know how to identify mutations in these genes as well.
“We’ve also learned that mutations in these genes increase the risk of prostate cancer in men, fortunately not to the same degree of breast cancer in women, but enough to warrant increased surveillance,” she said.
Unfortunately, genetic engineering is unlikely to ever remove mutations for breast and ovarian cancer, Dr. King said. “This class of genes does not lend itself to successful genetic manipulation.”
But research continues.
“We are trying to learn of other classes of mutations that occur in BRCA1 and her sister genes, in order to explain families that are clearly affected with breast cancer but thus far with no mutation found.”