Those of you with hereditary breast cancer (confirmed by the finding that you carry a breast-cancer gene), please listen up.
If you develop breast cancer, your diagnosis will likely be made a decade earlier than were the diagnoses of your relatives in the previous generation. The MD Anderson Center at the University of Texas has completed a study (published in the online September 2011 edition of Cancer) that shows that women who have an inherited gene are commonly diagnosed today 6 years to 10 years earlier than, say, their mothers were.
Subtracting a Decade
This is one of the reasons why, when a woman is diagnosed with hereditary breast cancer, we take a look at her age at diagnosis, and then subtract 10 years from it. We then consider this second number--if it is below 40--to be the age at which the next generation of the woman's family should begin some form of breast screening and monitoring.
For example, say that a mother is diagnosed with breast cancer at age 45, and she is known to be positive for the BRCA gene. This means that we will strongly recommended that her daughter, rather than waiting until the usual age of 40, begin yearly breast screenings, including imaging, at age 35 (that is, 45 years minus 10 years).
One Caveat With This Guideline
It is important to note, however, that performing imaging studies on very young women--those still in their teens and 20s--has not yielded much benefit, since their breast tissue is naturally very dense. Still, if anyone in the previous generation was diagnosed in her 30s, then the new generation of girls should begin doing self-breast exams and having clinical breast exams by the physician that much earlier.