What are the management options for carcinoma (ca) of the breast?

Management of Breast Cancer

Breast cancer management requires a multidisciplinary approach combining surgery, radiation therapy, and systemic treatments, with specific strategies determined by tumor stage, molecular subtype (hormone receptor and HER2 status), and surgical margin status. 1

Initial Surgical Approach

For Early-Stage Operable Breast Cancer

Breast-conserving surgery (lumpectomy) with axillary dissection and whole breast radiotherapy is the standard treatment for localized tumors that can be completely excised with clear margins and satisfactory aesthetic results. 2

• Sentinel lymph node biopsy is the preferred method for axillary staging in clinically node-negative patients, avoiding the complications of complete axillary dissection such as lymphedema and arm pain 1, 3
• For patients with 1-2 positive sentinel nodes undergoing breast conservation with whole-breast radiation, completion axillary lymph node dissection may be avoided (based on ACOSOG Z0011 criteria) 1
• Axillary dissection should only be performed after invasive carcinoma is confirmed histologically 2
• All tissue margins must be examined pathologically 2

Mastectomy Indications

Modified radical mastectomy is indicated when: 2

• Extensive microcalcifications are present at diagnosis 2
• Positive surgical margins persist with residual microcalcifications after initial excision 2
• Patient refuses breast-conserving treatment 2
• Breast-conserving surgery cannot achieve clear margins with acceptable cosmetic results 2

Immediate breast reconstruction can be offered if the patient desires, with delayed reconstruction as an alternative option 2

Radiation Therapy

After Breast-Conserving Surgery

Whole breast radiotherapy is mandatory following lumpectomy, as it significantly reduces local recurrence rates (Level of Evidence A). 2, 1

• For patients under 50 years old: whole breast radiation PLUS boost to the tumor bed is standard 2
• For patients over 50 years old: boost to tumor bed is optional, recommended only if other risk factors for recurrence are present 2
• Exception: Women aged 70+ with ER-positive, clinically node-negative early breast cancer may omit radiation after lumpectomy if receiving endocrine therapy 1

After Mastectomy

Chest wall and regional nodal irradiation (internal mammary chain, infra- and supraclavicular regions) is indicated when: 2

• ≥4 positive lymph nodes are present (Category 1 recommendation) 1
• 1-3 positive lymph nodes are present (should be strongly considered) 1
• Extensive microcalcifications with lymph node involvement 2

Surgical Margin Management

Margin Adequacy Standards

"No ink on tumor" is the sufficient standard for negative margins in invasive breast cancer, according to the Society of Clinical Oncology consensus 4

• Margins wider than "no ink on tumor" do not significantly decrease ipsilateral breast tumor recurrence (IBTR) rates based on meta-analysis of 28,162 patients 4
• Positive margins (ink on invasive carcinoma or DCIS) double the risk of IBTR compared to negative margins 4
• This increased recurrence risk with positive margins is not mitigated by favorable biology, endocrine therapy, or radiation boost 4

Management of Positive Margins After Initial Excision

When re-excision is feasible (can achieve clear margins with satisfactory cosmesis): 2

• Standard: Re-excision followed by whole breast radiotherapy 2
• Add boost to tumor bed if patient is under 50 years old (standard) or has other risk factors (option) 2

When re-excision is not feasible or margins remain positive: 2

• Modified radical mastectomy is the standard approach 2
• Alternative option: Breast radiotherapy with boost to tumor bed if patient refuses re-excision 2

Special Margin Considerations

• For DCIS: margins >10 mm are widely accepted as negative but may be excessive and compromise cosmetic outcomes 4
• For phyllodes tumors: wide excision means 1 cm surgical margins 4

Systemic Therapy

Hormone Receptor-Positive/HER2-Negative Disease

CDK4/6 inhibitors combined with endocrine therapy are recommended for appropriate patients, showing significant progression-free survival benefits. 1

• For advanced disease, endocrine therapy with targeted agents (CDK4/6 inhibitors, mTOR inhibitors, PI3K inhibitors) is preferred over chemotherapy 1
• Sequential monotherapy is preferred over combination chemotherapy unless rapid clinical progression or life-threatening visceral metastases are present 1

HER2-Positive Disease

For advanced HER2+ disease, trastuzumab with vinorelbine or a taxane is preferred for first-line therapy. 1

• Dual HER2 blockade with trastuzumab and pertuzumab can be combined with docetaxel, weekly paclitaxel, vinorelbine, or nab-paclitaxel 1

Triple-Negative Breast Cancer

Chemotherapy remains the primary systemic treatment option for triple-negative breast cancer. 1

• For previously treated patients with anthracyclines with/without taxanes, carboplatin has shown comparable efficacy with more favorable toxicity profile compared to docetaxel 1

Adjuvant Chemotherapy

Node-positive breast cancer is generally treated systemically with chemotherapy, endocrine therapy (for hormone receptor-positive cancer), and trastuzumab (for ERBB2-overexpressing cancer). 3

• Anthracycline- and taxane-containing regimens are active against breast cancer 3
• Paclitaxel 175 mg/m² as a 3-hour infusion every 3 weeks for 4 courses following AC (doxorubicin/cyclophosphamide) reduces disease recurrence risk by 22% and death risk by 26% in node-positive disease 5

Stage-Specific Approaches

Stage III Breast Cancer

Induction (neoadjuvant) chemotherapy is required to downsize the tumor and facilitate breast-conserving surgery. 3

Inflammatory Breast Cancer

Despite being stage III, inflammatory breast cancer requires aggressive treatment: 3

• Induction chemotherapy
• Mastectomy (NOT breast-conserving surgery)
• Axillary lymph node dissection
• Chest wall radiation

Stage IV (Metastatic) Disease

Treatment goals shift to prolonging survival and maintaining quality of life. 3

• Tumor markers may be used to evaluate response in patients with non-measurable metastatic disease, but should not be used alone to initiate treatment changes 1
• Response evaluation should occur every 2-4 months for endocrine therapy or after 2-4 cycles of chemotherapy 1

Follow-Up Protocol

Structured surveillance includes: 1

• History and physical examination every 3-6 months for 3 years
• Then every 6-12 months thereafter 1

Critical Pitfalls to Avoid

• Never perform frozen section or primary axillary dissection in the absence of a palpable macroscopic lesion 2
• Always perform post-operative mammogram 2 months after surgery if microcalcifications were present to verify absence of residual lesions 2
• Do not pursue wider margins than "no ink on tumor" in invasive cancer, as this compromises cosmetic outcomes without reducing recurrence 4
• Ensure aesthetic results remain satisfactory when performing boost to tumor bed and/or re-excision 2