A study found that between the years 1995 and 2005 the number of women choosing to have a healthy breast removed to minimize future breast cancer risk has been increasing. When a mastectomy is done to reduce the risk of future breast cancer, the surgery is called prophylactic mastectomy. When a mastectomy is done to remove a breast cancer, the surgery is called therapeutic mastectomy. These research findings agree with those from other studies looking at trends in prophylactic mastectomy.
The researchers reviewed the medical records of nearly 70,000 women from New York state who had mastectomies performed during the years 1995 through 2005. Overall during all 11 years, nearly 9% of these mastectomies were prophylactic mastectomies. The rest were therapeutic mastectomies. But the researchers found that the proportions of prophylactic and therapeutic mastectomies changed over the course of these 11 years.
- In 1995 only 5.6% of the mastectomies performed in that year were prophylactic, while the other 94.4% were therapeutic mastectomies
- By 2005 the proportion of prophylactic mastectomies increased to 14.1%, while the proportion of therapeutic mastectomies decreased to 85.9%
Most women who have prophylactic mastectomy choose to do so after being diagnosed with early breast cancer in one breast. In this study, 81% of the prophylactic mastectomies were performed in women who had been diagnosed with breast cancer in the opposite breast. To minimize their risk of a recurrence in the same breast or the future development of a new breast cancer in the same or opposite breast, these women chose to have both breasts removed -- therapeutic for the breast with the cancer, and prophylactic for the opposite, healthy breast. Much less commonly, women who have never been diagnosed with breast cancer but are, or believe they are, at high risk for breast cancer choose to have both breasts removed prophylactically, to minimize their risk of ever developing breast cancer. Having both breasts removed is called bilateral mastectomy. In this study, 19% of the prophylactic mastectomies (bilateral) were performed in women who had never been diagnosed with breast cancer.
In this research, much of the increase in prophylactic mastectomies was among women who had already been diagnosed with breast cancer, but year after year a small number of women chose to have bilateral prophylactic mastectomy even though they had not ever been diagnosed with breast cancer.
The researchers found that prophylactic mastectomy was more commonly chosen by younger women, and by women who were Caucasian and who had private insurance. They speculated that the actual numbers of prophylactic mastectomies might actually have been higher than what they observed in their study, since in some cases prophylactic mastectomies may have been recorded as therapeutic. Some insurance companies will cover therapeutic, but not prophylactic, mastectomy.
This study didn't pinpoint why, over time, more women are choosing prophylactic mastectomy. For women already diagnosed with breast cancer it's likely they chose this surgery because they were concerned about developing breast cancer in the other breast. Being diagnosed with breast cancer does increase the risk of developing a new, different breast cancer in the future. For women who've been diagnosed with breast cancer but who don't have an abnormal BRCA1 or BRCA2 gene, the risk of developing a new breast cancer in the other breast is about 1% a year. After 10 years, this risk is about 10%. For women who have an abnormal BRCA1 or BRCA2 gene, the risk of developing a new breast cancer in the other breast is higher. Their risk can be 3 to 4% per year (30% to 40% over 10 years).
For the women in this study who had not ever been diagnosed with breast cancer, they presumably chose to have bilateral prophylactic mastectomy based on knowing -- or believing -- that their breast cancer risk is significantly increased (for example, based on family history and/or genetics).
Every woman diagnosed with breast cancer and every woman who is considered at high risk for breast cancer has to ask herself this question: for me, how much risk is enough to make a decision to remove one or both healthy breasts? Because each woman's situation is unique, every woman will have a different answer to the question.
Whether or not you have been diagnosed with breast cancer, if you're considering prophylactic mastectomy to reduce future risk, here are some things to consider:
- What's your real risk of developing a second breast cancer? This is an important discussion to have with your doctor. Generally speaking, women tend to overestimate their risk of breast cancer. This may be an unintended effect of greater breast cancer awareness. Before making any decisions about surgery, it's worth taking the time to understand your unique situation and the risk associated with it. This allows you to base your decision on facts.
- What are your plans, if any, for breast reconstruction after surgery? To achieve a balanced appearance, some women may need or want cosmetic surgery on the healthy breast after reconstruction. Also, some types of reconstruction may be performed only once. This could limit reconstruction choices for women who may need a second mastectomy if breast cancer is diagnosed in the future in the other breast. Because of this, some women may opt to have a double mastectomy and reconstruction of both breasts at the same time. Your medical team, including a plastic surgeon, can help you make the decision that's best for you.
- Do you have an abnormal BRCA1 or BRCA2 gene? Some women may make decisions assuming they have an abnormal gene because someone in their family had breast cancer -- without having genetic testing and counseling themselves. Having an abnormal BRCA1 or BRCA2 gene makes a big difference in the risk of developing a future breast cancer. If you're considering prophylactic mastectomy because you MIGHT have an abnormal gene based on family history, talk to your doctor about whether genetic testing and counseling are right for you. You may still decide to have a double mastectomy, but it's better to make that decision based on facts, not assumptions.
- Can medicine lower my risk of a future breast cancer? Removing a healthy breast may reduce the risk of future breast cancer in that breast by 90%, according to the National Cancer Institute. Medicines that lower the risk of breast cancer don't offer the same certainty, but they're another option to consider.
Talk to your medical team about all your options and make your decisions based on the best information available for you and your unique situation.