Overview
Definition:
Prophylactic mastectomy, also known as risk-reducing mastectomy, is a surgical procedure to remove one or both breasts in individuals with a significantly elevated lifetime risk of developing breast cancer, aiming to prevent the disease
This is particularly relevant for individuals identified as carriers of germline mutations in BRCA1 or BRCA2 genes, which confer a substantially increased risk of breast and ovarian cancers.
Epidemiology:
BRCA1 and BRCA2 mutations account for approximately 5-10% of all breast cancers
Women with a BRCA1 mutation have a 55-72% lifetime risk of developing breast cancer, while those with a BRCA2 mutation have a 45-69% risk
These mutations also increase the risk of ovarian, prostate, and pancreatic cancers
Prophylactic mastectomy is a highly effective risk-reduction strategy, decreasing the risk of breast cancer by up to 90-95% in mutation carriers.
Clinical Significance:
For DNB and NEET SS surgical residents, understanding prophylactic mastectomy in BRCA carriers is crucial for managing high-risk patients
It involves complex ethical considerations, detailed pre-operative counseling, meticulous surgical planning, and comprehensive post-operative care
This procedure significantly impacts patient quality of life and cancer survivorship, making it a vital topic for board examinations.
Counseling And Risk Assessment
Genetic Counseling:
Comprehensive genetic counseling is paramount
It involves detailed family history assessment, discussion of genetic testing options (BRCA1/BRCA2), interpretation of results, and explanation of associated cancer risks (breast, ovarian, prostate, pancreas)
Understanding the inheritance patterns and implications for family members is also key.
Risk Communication:
Clearly communicate the absolute and relative risk reduction achieved by prophylactic mastectomy
Discuss the residual risk of breast cancer (e.g., occult malignancy at time of surgery, new primary tumors in remaining tissue if not total mastectomy, risk of contralateral breast cancer if unilateral)
Explain the increased risk of other BRCA-associated cancers and the role of other risk-reducing strategies (e.g., salpingo-oophorectomy).
Shared Decision Making:
Engage in shared decision-making with the patient
Discuss the pros and cons of prophylactic mastectomy versus surveillance
Address patient preferences, concerns, and expectations regarding surgical outcomes, aesthetics, body image, sexual function, and psychological impact
Explore alternatives like chemoprevention and intensive surveillance.
Psychosocial Support:
Assess and address the psychosocial impact of genetic mutation diagnosis and the decision for prophylactic surgery
Offer resources for emotional support, including psychological counseling, support groups, and patient advocacy organizations
Patients often experience anxiety, grief, and fear related to cancer risk.
Surgical Technique
Indications For Prophylactic Mastectomy:
Confirmed pathogenic germline mutation in BRCA1 or BRCA2
Strong family history of breast/ovarian cancer with suspected hereditary predisposition
Personal history of breast cancer with contralateral prophylactic mastectomy recommended
Certain other high-risk genetic mutations (e.g., TP53, PTEN, ATM).
Preoperative Preparation:
Detailed pre-operative assessment including physical examination, imaging (mammography, ultrasound, MRI) to rule out occult malignancy, and laboratory investigations
Surgical marking of nipple-areolar complex and skin incisions
Discussion of reconstruction options (immediate vs
delayed, implant-based vs
autologous flap)
Smoking cessation is strongly advised due to impaired wound healing.
Mastectomy Approaches:
Total (simple) mastectomy is the most common approach, removing all glandular tissue, nipple, and areola
Skin-sparing mastectomy (SSM) and nipple-sparing mastectomy (NSM) are increasingly utilized, preserving more skin and often the nipple-areolar complex (NAC) respectively, allowing for better aesthetic outcomes and immediate reconstruction
NSM is contraindicated in cases of extensive Paget's disease or significant nipple retraction/involvement.
Reconstruction Options:
Immediate reconstruction can be performed concurrently with mastectomy
Implant-based reconstruction involves placement of tissue expanders followed by breast implants
Autologous flap reconstruction (e.g., TRAM, DIEP flap) uses the patient's own tissue from other body areas
Delayed reconstruction is an option for patients who prefer to defer surgery or require adjuvant therapy first
The choice depends on patient preference, surgeon expertise, and oncologic safety.
Intraoperative Considerations:
Meticulous hemostasis is crucial
Careful dissection to achieve adequate margins while preserving viability of skin flaps, especially in SSM and NSM
Placement of drains
Management of the nipple-areolar complex: in NSM, careful dissection to avoid devascularization of the NAC and careful placement of the graft
Sentinel lymph node biopsy (SLNB) is generally NOT performed in prophylactic mastectomy unless there is suspicion of occult cancer, as the goal is risk reduction, not treatment of existing disease.
Postoperative Care And Follow Up
Immediate Postoperative Care:
Pain management using multimodal analgesia
Drain management: monitoring output and timing of removal (typically when output is <30 mL/24 hours)
Wound care: ensuring flap viability, monitoring for signs of infection or hematoma
Compression garment application for implant-based reconstruction to minimize seroma and optimize implant positioning.
Complications Management:
Common complications include hematoma, seroma, infection, skin flap necrosis, and implant-related issues (rupture, capsular contracture)
Prompt identification and management, including wound exploration, drainage, and antibiotic therapy, are essential
Reconstruction-specific complications also need vigilant monitoring.
Long Term Follow Up:
Regular clinical breast examinations (frequency determined by risk and guidelines)
Mammography of the remaining breast tissue (if unilateral mastectomy) and chest wall is typically not required unless there is a history of prior breast cancer or specific concerns
Ovarian cancer screening (transvaginal ultrasound, CA-125) and risk-reducing salpingo-oophorectomy (RRSO) are critical components of management for BRCA carriers, usually recommended after childbearing is complete.
Surveillance For Other Brca Cancers:
Discussion of surveillance for other BRCA-associated cancers, including prostate cancer in men, and pancreatic cancer in both men and women, based on family history and updated guidelines
Genetic counseling for at-risk family members.
Key Points
Exam Focus:
High-yield facts include the lifetime risk of breast cancer in BRCA carriers (e.g., 55-72% for BRCA1, 45-69% for BRCA2), the percentage risk reduction from prophylactic mastectomy (up to 90-95%), indications for genetic counseling and testing, and the importance of shared decision-making
Recall common complications and follow-up protocols.
Clinical Pearls:
In NSM, ensure adequate vascular pedicle to the nipple-areolar complex
Always discuss reconstruction options thoroughly with the patient pre-operatively
Sentinel lymph node biopsy is typically omitted unless occult malignancy is suspected
Emphasize the importance of RRSO for ovarian cancer risk reduction in BRCA carriers.
Common Mistakes:
Failure to offer adequate genetic counseling or discuss all risk-reducing options
Performing NSM without assessing the suitability of the nipple-areolar complex
Undertaking prophylactic mastectomy without a clear plan for contralateral risk reduction (including RRSO) or for other BRCA-associated cancers
Inadequate psychosocial support for patients.