It is now more common for women with a personal or family history of breast cancer to be familiar with the genetic mutations – BRCA1 and BRCA2. Both increase the risk of developing cancer. Knowing whether you have one of these genetic mutations or not is valuable information for patients and their health care providers. Patients who have been diagnosed with breast cancer before the age 45, have multiple family members with breast cancer, or male breast cancer, or who at risk of having the mutation - if a family member either had or may have had the gene, are screened for BRCA1 and BRCA2. These genetic mutations, unfortunately, can affect generations. Parents have a 50/50 chance of passing the mutation onto their children.
But what if you test negative for both? Does your risk of developing breast cancer drop to the average woman’s overall risk of 13 percent? Not necessarily, researchers say. Even more important they add, the risk for some women maybe just as substantial and life threatening as those with BRCA1 or BRCA2. A third, lesser-known genetic mutation, PALB2, is now raising as much concern among health care providers. Reported this month, researchers say PALB2 may increase the risk of developing breast cancer as much as the other two genetic mutations.
While current genetic testing includes screening for PALB2, the extent to which this genetic mutation increased the risk of breast cancer alone was not well known. Researchers at the University of Cambridge looked at patients without BRCA1 or BRCA2, who had PALB2, to better understand the isolated risk. Studying 362 family members of 154 families with PALB2, 229 of 311 women with the PALB2 mutation had breast cancer, while seven of 51 men with the PALB2 mutation had breast cancer. From this study, researchers say having the PALB2 genetic mutation increases the risk of developing breast cancer from 12 percent to 35 percent by the age of 70. This is lower than the risk for those with BRAC1, 50 to 70 percent, and BRAC2, 40 to 60 percent.
Researchers also found having this genetic mutation was especially risky for younger women. Those under the age of 40 with PALB2 had an increased breast cancer risk eight to nine times higher than the general population. Data indicated this genetic mutation also carried the distinction of increasing the risk of developing “triple negative” breast cancer – often resistant to hormone treatment, more aggressive and more likely to return compare to other breast cancer subtypes.
When risk factors are present, patients and their health care providers need to talk be about the increased risk of breast cancer, even when patients test negative for BRCA1 and BRCA2. Not only is it possible to discover the mutation and know the risk is elevated, but health care providers can follow guidelines to bring the risk down to that of the general population. Patients are advised to make an appointment and discuss their concerns with their primary care physician or a breast specialist if they have any questions about their personal risk.
Today, guidelines for screening do not indicate testing for these genetic mutations for everyone, unless there is a personal history of breast cancer that falls within the guidelines or a family history that meets guidelines. For those who have tested negative for BRCA1 and BRCA2 with a family history, they should talk to their health care provider about screening for PALB2.