By Joel Diamond, MD
Yesterday, I saw a new patient – 34-year-old woman in excellent health who was concerned about her risk for developing breast cancer. Her anxiety arose from the fact that she was adopted, and therefore precluded her from knowing a key risk factor– family history. She asked if this meant that she should start having mammograms at an earlier age, with an assumption that her unknown family history of cancer was indeed positive. After much discussion about other risk factors, the overall predictive value of mammography, and the relative risk due to family history, we finally began to discuss the emotional impact of cancer risk, rather than just statistics and science.
The encounter got me thinking about the value of BRCA testing and its implications for both negative and positive results. BRCA1 and BRCA2 mutations are associated with approximately 25% of hereditary breast cancers and 15% of ovarian cancers. More worrisome is that 60% of women who inherit BRCA1 will develop breast cancer, and 39% will develop ovarian cancer; BRCA2 confers about 45% and 15% respectively. In addition, these mutations are associated with other cancers as well, including pancreatic cancer, acute myeloid leukemia as well as male breast cancer and prostate cancer. Even in patients who have the gene but do not develop cancer, 50% of their children will receive the BRCA mutation and inherit the same overall risk for cancer.
Positive BRCA results may suggest starting annual mammography as young as 25, the use of more advanced imaging such as MRI, and prophylactic of drugs such as tamoxifen might decrease risk. Some might even consider elective mastectomy, like actress Angelina Jolie.
So, back to my patient. Would there be emotional value in having true negative BRCA testing result? Perhaps. It might help allay her fears and convince her not to pursue unnecessary or more frequent tests and procedures. It would alleviate concerns of passing an unknown family history risk to her children. Keep in mind however, that science is continuing to learn of new biomarkers (such as PALB2) for inherited cancer. Perhaps a negative BRCA test is really a false sense of security.
Despite all the ambiguity, in the end, our discussion turned out to be helpful and her anxiety was relieved. A frank and comprehensive review of options is always favorable, as is reassuring patients that their physician will continue to keep them up-to-date of new findings and recommendations.