From the Guidelines
Bilateral mastectomy is a treatment option for ductal carcinoma in situ (DCIS), but it is generally considered more aggressive than necessary for most cases. DCIS is a non-invasive breast cancer confined to the milk ducts that hasn't spread to surrounding breast tissue. Most patients with DCIS are effectively treated with breast-conserving surgery (lumpectomy) followed by radiation therapy, which offers excellent survival rates with less extensive surgery.
- The choice of treatment strategy is based on biology and tumour extent/location as well as on the age, body habitus and general health status of the patient and her/his preferences 1.
- Bilateral mastectomy may be considered in specific situations: for patients with extensive DCIS that involves multiple areas of the breast, those with strong genetic predisposition like BRCA mutations, patients with previous radiation to the chest, or those who strongly prefer mastectomy due to anxiety about recurrence or desire to avoid radiation.
- The decision should be individualized and made after thorough discussion with healthcare providers about the risks, benefits, and alternatives, as bilateral mastectomy is irreversible and carries more surgical risks and longer recovery compared to less extensive procedures, without necessarily improving survival for most DCIS patients.
- According to the most recent guidelines, risk-reducing surgery with prophylactic bilateral mastectomy and reconstruction may be offered to women with a very high risk of breast cancer, such as those carrying the BRCA1 or BRCA2 gene mutations or those with previous chest irradiation for lymphoma, with a reduction in the risk for both subsequent breast cancer incidence and mortality by 90%–95% 1.
- It's also important to note that total mastectomy with clear margins in DCIS is curative, and radiation therapy is not recommended, with the possibility of considering tamoxifen to decrease the risk of contralateral breast cancer in patients who are at a high risk of new breast tumours 1.
From the Research
Treatment Options for Ductal Carcinoma In Situ (DCIS)
- Bilateral mastectomy is not normally indicated for patients with unilateral DCIS, as stated in the study by 2.
- Treatment options for DCIS include mastectomy, wide-excision breast-conserving surgery (BCS) plus radiotherapy, or BCS alone, according to 2.
- The decision to undergo bilateral mastectomy should be made on a case-by-case basis, considering factors such as the size and location of the tumor, patient preference, and medical history.
Risks and Benefits of Bilateral Mastectomy
- The risk of contralateral breast cancer (CBC) is relatively low, with 5- and 10-year Kaplan-Meier CBC rates of 3.2 and 6.4%, respectively, as reported in 3.
- Bilateral mastectomy may not be necessary for patients with DCIS, as the risk of CBC is not significantly associated with factors that increase the risk of ipsilateral breast tumor recurrence (IBTR), according to 3.
- Radiotherapy is effective in reducing the risk of local recurrence, with a summary recurrence rate of 8.9% for CS + RT, compared to 22.5% for CS alone, as shown in 4.
Current Recommendations
- The American Cancer Society and other organizations recommend that patients with DCIS discuss their treatment options with their doctor and consider factors such as the size and location of the tumor, patient preference, and medical history.
- Patients with DCIS should be informed about the risks and benefits of each treatment option, including bilateral mastectomy, and make an informed decision based on their individual circumstances.
- Further research is needed to determine the optimal treatment approach for patients with DCIS, including the use of radiotherapy and the role of bilateral mastectomy, as noted in 5 and 6.