Risk Reducing Surgery for Breast Cancer

What is Mastectomy Surgery?

Mastectomy surgery is performed in two ways. The first is bilateral mastectomy, which is performed on women at high risk for breast cancer (women with a family history of breast/ovarian cancer, BRCA1 and BRCA 2 carriers, women with TP53 and PTEN gene mutations, etc.). Both breasts are removed. The second is performed on women diagnosed with unilateral breast cancer. This is called Contralateral Prophylactic Mastectomy. A mastectomy is performed on the other breast to reduce the risk.

Who Can Undergo Risk-Reducing Surgery in Breast Cancer (Prophylactic Mastectomy)?

Risk-reducing surgery in breast cancer can be performed in the following situations:

• Those with BRCA1 or BRCA2 gene mutations
• Those with a strong family history of breast cancer
• Individuals with conditions such as lobular carcinoma in situ (LCIS) or atypical ductal hyperplasia (ADH) found during breast biopsy
• Those who have previously received cancer treatment for one of their breasts
• Individuals with mutations in high-penetrance genes such as PTEN or TP53

What is Bilateral Prophylactic Mastectomy?

Bilateral prophylactic mastectomy is the most commonly performed type of risk-reducing surgery. Bilateral prophylactic mastectomy involves the complete removal of both breasts. This procedure can be performed in two ways. The first method involves the complete removal of the areola and nipple. The second method removes the breast tissue while leaving the nipple in place. The procedure in which the nipple is left in place is called subcutaneous mastectomy. In subcutaneous mastectomy, since the skin and nipple are preserved, reconstruction (adding new tissue) methods are also used. This allows the surgical procedure to be performed without altering the original appearance of the breast.

Methods of Risk-Reducing Surgery in Breast Cancer

Methods of risk-reducing surgery in breast cancer are divided into bilateral prophylactic mastectomy and contralateral prophylactic mastectomy. Even if breast cancer is diagnosed in one breast, protective mastectomy surgery is performed on the other breast. This surgery is called contralateral prophylactic mastectomy. Bilateral prophylactic mastectomy is further divided into total mastectomy, where the breast cancer risk is reduced more than in bilateral subcutaneous mastectomy. This is because total mastectomy can remove more breast tissue. Additionally, hormonal treatments such as tamoxifen and raloxifene can be used in women at high lifetime risk of developing breast cancer.

What is the Risk of Developing Breast Cancer and the Risk Reduction Rate?

The risk of developing breast cancer and the risk reduction rate are as follows:

• In individuals with clinically significant mutations in the BRCA1 and BRCA2 genes, the risk of breast cancer decreases by up to 95%.
• In women with a high family risk, the risk decreases by up to 90%.
• Women with mutations in the BRCA1 gene have a lifetime risk of breast cancer of approximately 55-65% by age 70.
• In those with a mutation in the BRCA2 gene, this rate is around 45-47%.
• In patients with Li-Fraumeni syndrome who have a mutation in the TP53 gene, the lifetime risk of developing breast cancer is approximately 49-60%.
• In patients with mutations in the PTEN gene and Cowden syndrome, the risk is between 55-65%.
• The lifetime risk of breast cancer in American women is 12%.

Risks of Risk-Reducing Surgery in Breast Cancer

The risks of risk-reducing surgery in breast cancer include complications such as bleeding, pain, scar tissue formation, and infection. Surgical methods used in breast cancer are irreversible.