Angelina Jolie's announcement earlier this year to undergo a preventative double mastectomy failed to increase the public's understanding of a person's genetic risk for breast cancer.

This is according to a University of Maryland survey of more than 2,500 Americans in which 75 percent said they were aware of Jolie's story. Of this number, less than 10 percent correctly answered either questions about the BRCA gene mutation that prompted her to undergo the procedure, or an average person's risk of developing breast cancer. 

The BRCA1 and BRCA2 genes are tasked with producing tumor suppressor proteins that repair damaged DNA. When mutations hinder the genes' protein production or functioning, DNA damage may go unattended, leaving cells vulnerable to additional genetic alterations that can ultimately lead to cancer.

Jolie wrote that because of the BRCA1 gene she inherited from her mother, who died from cancer at age 56, doctors estimated she had an 87 percent risk of breast cancer - a risk that prompted her to undergo the procedure.

"We often speak of 'Mommy's mommy,' and I find myself trying to explain the illness that took her away from us," Jolie wrote in the May 14 op-ed published by The New York Times. "[My children] have asked if the same could happen to me."

Today, her doctors estimate Jolie has less than a 5 percent chance of developing breast cancer. "I can tell my children that they don't need to fear they will lose me to breast cancer," she said.

"I wanted to write this to tell other women that the decision to have a mastectomy was not easy," she continued. "But it is one I am very happy that I made."

Eight months later, however, Jolie's decision to take her procedure public appears to have done little to raise public understanding of breast cancer risk, the researchers report in the journal Genetics in Medicine.

According to the National Cancer Institute, approximately 12 percent of women in the general population will develop breast cancer during their lifetimes. In contrast, between 55-65 percent with a harmful BRCA1 mutation and 45 percent with a harmful BRCA2 mutation will develop the disease by the time they reach 70.

Of those interviewed for the study, roughly half could remember Jolie's estimated risk for breast cancer before surgery, but fewer than 10 percent were able to interpret a woman's risk without the mutation relative to Jolie's risk.

There were even signs that exposure to Jolie's story led to increased confusion on the matter, with about 50 percent of participants wrongly believing that a lack of family history of cancer was linked to a lower-than-average personal risk of developing the disease. 

"Since many more women without a family history develop breast cancer each year than those with, it is important that women don't feel falsely reassured by a negative family history," said Dr. Debra Roter, co-author of the study and director of the Center for Genomic Literacy and Communication at the Johns Hopkins Bloomberg School of Public Health.

Other findings included 57 percent of women who had heard the story saying they would elect for a similar surgery if they carried the faulty BRCA gene, while 72 percent of men said they felt Jolie was right to publicly announce her decision to do so.

"Ms. Jolie's health story was prominently featured throughout the media and was a chance to mobilize health communicators and educators to teach about the nuanced issues around genetic testing, risk, and prophylactic surgery," explained lead author Dina Borzekowski, a research professor in UMD's Department of Behavior and Community Health. "It feels like it was a missed opportunity to educate the public about a complex but rare health situation."

A spokesman for Jolie told Nature World News the actress "is not giving any further statements" on the subject.