In hopes of avoiding cancer, some high-risk women elect to have both breasts
surgically removed, a procedure called bilateral prophylactic mastectomy. The
surgery would remove all breast tissue that potentially could develop breast
cancer. Preventive breast cancer surgery also may be considered if a woman has
already had breast cancer, because she is at increased risk for developing
breast cancer again in the same or other breast.
How much is the risk reduced?
A recent
study suggests that prophylactic mastectomy may reduce the risk of breast cancer
by at least 90 percent.
Is preventative mastectomy effective?
In
reviewing past studies of prophylactic mastectomy, results vary widely. In some
studies, women had prophylactic mastectomies for a variety of reasons, such as
pain, fibrocystic breast disease, dense breast tissue, cancer phobia, or a family
history of breast cancer. Some women still developed breast cancer even though
they had their breast tissue removed. But, in most studies, patients did not
develop breast cancer after prophylactic mastectomy. However, many of these
patients would not have been predicted to have had a high-risk cancer
development.
There have been arguments made that even for high-risk women, prophylactic
mastectomy is inappropriate because not all breast tissue can be removed during
a surgical procedure. To understand why, we need to know what composes breast
tissue and from where cancer comes.
Physiological challenges of prophylactic mastectomy
Breast
tissue is composed primarily of fat tissue, connective tissue, and glandular
tissue, which produces milk. It is in the glandular tissue of the breast that
breast cancers may develop, specifically in the milk ducts and the milk lobules.
These ducts and lobules are located in all parts of the breast tissue, including
tissue just under the skin. The breast tissue extends from the collar bone to
the lower rib margin, and from the middle of the chest, around the side and
under the arm.
In a mastectomy, it is necessary to remove tissue from just beneath the skin
down to the chest wall and around the borders of the chest. However, even with
very thorough and delicate surgical techniques, it is impossible to remove every
milk duct and lobule, given the extent of the breast tissue and the location of
these glands just beneath the skin.
Who should have surgery?
Does this
mean that every patient should be considered for breast cancer prevention
surgery? The answer is clearly no. The decision to proceed with prophylactic
mastectomy is an individual decision. Such factors as an estimation of
individual breast cancer risk, the ability to monitor the patient for early
breast cancer and, most importantly, the patient’s concerns and feelings, need
to be considered in making this decision.