Lessons from Angelina: The Tricky Calculus of Cancer Testing Alastair Grant / AP Angelina Jolie leaves a G8 Foreign Ministers meeting on sexual violence against women in London, on April, 11, 2013. Angelina Jolie deserves praise for her decision to reveal in a New York Times op-ed that she recently underwent a preventive double mastectomy. She had the surgery after discovering she carried a gene mutation that gave her a high risk of developing breast and ovarian cancers. As an engaged and informed patient taking control over her own health, Jolie is a role model. But it would be a mistake to view the actress's experience as instructive for most women who live in fear of developing breast cancer, a disease that claims the lives of some 40,000 American women every year. Jolie's disclosure comes at a time when more and more breast cancer patients who don't have a high genetic risk factor are opting for single or double mastectomies, even though those surgeries don't necessarily increase their chances of survival. It also comes after decades of breast cancer awareness campaigns have heightened anxiety of the disease to unprecedented levels. Otis Brawley, chief medical officer for the American Cancer Society, salutes Jolie for her carefully and responsibly worded essay, but fears other American women may not proceed with the same caution. He says one thought that came to mind as he read Jolie's essay, was ""Oh no, there's going to be a rush to get this screening test that's really going to be a bad thing for a lot of people."" MORE: Angelina Jolie's Double Mastectomy: It's Not the Only Option Women with a family history of early onset ovarian or breast cancers, with close family members who've developed such cancers or who've already tested positive for the mutation affecting Jolie, known as the BRCA gene, should talk to their doctor and possibly a genetic counselor about undergoing testing. Jolie was prompted to do so after her mother died of ovarian cancer at 56. The mutation means a woman is far more likely to develop breast cancer - Jolie says her doctors estimated she had an 87% chance of getting breast cancer and a 50% chance of getting ovarian cancer, which is also linked to BRCA mutations. But the gene mutation itself is very rare. Less than 1% of American women have it and hereditary mutations like BRCA are linked to just 5%-10% of all breast cancer cases. In her essay, Jolie urged women, "especially if you have a family history of breast or ovarian cancer, to seek out the information and medical experts who can help you through this aspect of your life." But in the absence of risk factors or medical advice that testing is warranted, there's good evidence that, for some, it could actually be harmful. The U.S. Preventive Services Task Force, a government panel that writes clinical guidelines based on empirical evidence, recommends against population-wide BRCA testing in part because it could lead to false positives or test results that show mutations of an "unknown significance." If carried out on a massive scale, the test, according to the task force, could lead to unnecessary "prophylactic surgery, chemoprevention, or intensive screening...The potential harms of routine referral for genetic counseling or BRCA testing in these women outweigh the benefits." A better approach is for women like Jolie, whose personal family history already indicates she might have the mutation, to confer with a doctor and follow medical advice. MORE: The Genetic Calculus of Angelina Jolie's Double Mastectomy It doesn't always happen that way. Brawley remembers receiving a call several years ago from a woman who, although she had no family history that put her at increased risk for breast cancer, "was just worried and she heard that there was this test and she happened to have the money to pay for it." The testing revealed she had a mutation of "unknown significance" that researchers have since determined is not associated with an increased risk for cancer. But for this woman it was too late, says Brawley. She freaked out and had a bilateral mastectomy. Brawley says the "the pinking of America," the high-profile campaigns to raise awareness about the risk of breast cancer may have contributed to responses like this. We have over-emphasized and scared people too much. New research may back him up. In a study presented at an American Society for Clinical Oncology symposium in 2012, researchers found found that that 70% of women who underwent double mastectomies after developing cancer in one breast were clinically at very low risk for developing cancer in the other breast. Lead author Sarah Hawley says women with breast cancer that's treated are overestimating their risk of developing cancer in the future. "They're thinking of doing these things that several years ago they may not have even considered," she says. MORE: Hard Choices Angelina Jolie Faces About Testing Her Kids for Cancer The trend of more frequent aggressive surgery following breast cancer diagnoses is a reversal of course. In the 1970s, after a near century of standard care that included removal of entire breasts, muscle and surrounding lymph nodes, doctors and women began moving toward less invasive procedures like lumpectomies. On Jolie's decision to have a double mastectomy after discovering she had a mutated BRCA gene, Hawley says, "I think what she did made sense and was appropriate, but a lot of people are going to get that confused and think, "If I get a diagnosis of cancer I'm going to do the same thing."" PHOTOS: Angelina Jolie: Humanitarian The ultimate check on too much BRCA testing - and subsequent overtreatment - may be financial. Insurance company guidelines for covering BRCA screening vary, but many large insurers cover testing for women who meet evidence-based criteria, often using recommendations from the USPSTF and the National Comprehensive Cancer Network (NCCN), a non-profit that writes guidelines for many of the largest cancer hospitals in the U.S. Mary Daly, who chairs NCCN's genetic familial high risk assessment panel for breast and ovarian cancers, says insurer decisions about whom to cover fall along a continuum. On one end are women with breast cancer and family members who have already tested positive for the BRCA mutation, putting them at high risk, and who are likely to receive insurance coverage for testing. Insurers who cover BRCA testing will often also cover preventive double mastectomies and reconstructive surgery for women who test positive. A woman without cancer who has a close family member who's tested positive for BRCA might fall somewhere near the middle in terms of risk and likelihood of coverage. Someone like Jolie, who is cancer free and who had a family member who had cancer but isn't alive to be tested for the BRCA mutation, may not receive insurance coverage for testing, which can cost up to $3,000. MORE: Angelina Jolie's Public-Image Turnaround Under the Affordable Care Act, which kicks in fully in 2014, insurers are required to pay 100% of the cost of BRCA testing for women with a qualifying family history. But it's not completely clear what makes someone qualify. According to the government, this includes "women whose family history is associated with an increased risk for deleterious mutations in the BRCA1 or BRCA2 genes be referred for genetic counseling and evaluation for BRCA testing." The company that makes the common BRCA screening test, Myriad Genetics, applauded this government language. But there may be patient challenges to coverage decisions without more explicit guidelines about what kind of family history constitutes an increased risk. "Genetic testing is not a discrete event - it's a process," says Daly, pointing out that one woman's decision to get tested could affect her entire family. In addition, the research is ongoing. In Angelina's story, she said had an 87 percent chance of developing breast cancer. Why isn't it 100 percent?" asks Daly. Having the mutation is not enough - you need something else in order to get the cancer and we are just at the beginning of studying what that could be. There are a lot of modifiers of these mutations we could learn more about. PHOTOS: When Celebrities Battle Cancer: Photos of 20 Inspiring Survivors