What is the treatment plan for a patient with carcinoma (Ca) of the breast?

Treatment Plan for Breast Cancer

The treatment of breast cancer requires a stage-specific, multimodal approach that begins with tissue diagnosis and biomarker assessment, followed by surgery (breast-conserving therapy with radiation or mastectomy), and adjuvant systemic therapy tailored to hormone receptor, HER2, and nodal status. 1, 2

Initial Diagnostic Workup

All patients must undergo core needle biopsy to confirm histological diagnosis and obtain complete biomarker profiling, including ER, PR, HER2 status, and Ki67 proliferation markers. 1, 3

• Staging workup includes complete blood count, comprehensive metabolic panel with liver enzymes and alkaline phosphatase, bilateral mammography, chest imaging, and clinical examination with axillary assessment 1, 3, 2
• Axillary ultrasound is mandatory for all clinically node-negative patients, with biopsy confirmation of any suspicious nodes 1
• For metastatic disease, minimum imaging includes CT chest/abdomen and bone scintigraphy, or alternatively 18F-FDG PET-CT 3
• Abdominal ultrasound, CT scan, and bone scan should only be performed if suspicious symptoms or abnormal laboratory findings are present 3, 2

A critical pitfall is failing to reassess biomarkers in metastatic/recurrent disease, as tumor biology can change—always biopsy accessible metastatic sites when technically feasible. 3

Surgical Management by Stage

Early Stage Disease (Stage I-II)

For T2 tumors, two surgical options exist with equivalent survival: breast-conserving surgery with whole-breast radiation, or mastectomy. 1, 4, 5

• Sentinel lymph node biopsy is the standard approach for clinically node-negative patients 1, 6
• Axillary lymph node dissection may be omitted if only 1-2 positive sentinel nodes are identified and breast-conserving therapy with radiation is planned 1
• Breast-conserving surgery requires wide local excision with negative margins and mandatory whole-breast radiation 2, 5
• Mastectomy with immediate reconstruction should be offered to patients who require or prefer mastectomy 2

Locally Advanced Disease (Stage III)

Stage III breast cancer typically requires neoadjuvant chemotherapy to downsize the tumor before definitive surgery. 5

• For HER2-positive T2 or larger tumors, neoadjuvant chemotherapy with dual HER2 blockade (pertuzumab plus trastuzumab) and taxane-based chemotherapy for at least 9 weeks preoperatively achieves pathologic complete response rates of 57-66% 1, 7
• Post-mastectomy radiation to the chest wall and regional nodes is mandatory for patients with ≥4 positive axillary nodes 1

Inflammatory breast cancer requires induction chemotherapy followed by mastectomy (not breast-conserving surgery), axillary lymph node dissection, and chest wall radiation. 5

Radiation Therapy

Whole-breast radiation is mandatory after breast-conserving surgery for all invasive breast cancers. 1, 2, 5

• Post-mastectomy radiation should be considered for high-risk features, even with negative lymph nodes 2
• Regional nodal irradiation may improve disease-free survival in patients with high-risk node-negative disease 2

Systemic Therapy by Tumor Biology

Hormone Receptor-Positive Disease

Endocrine therapy is mandatory for all hormone receptor-positive breast cancers, with chemotherapy added for tumors larger than 1 cm or high-grade disease. 2, 4

• For adjuvant treatment of node-positive breast cancer, docetaxel 75 mg/m² can be administered 1 hour after doxorubicin 50 mg/m² and cyclophosphamide 500 mg/m² every 3 weeks for 6 courses 8
• Postmenopausal women should be offered postoperative bisphosphonates 4
• For metastatic disease, start with endocrine therapy (third-generation aromatase inhibitors for postmenopausal patients) unless biologically aggressive disease mandates rapid response 9

HER2-Positive Disease

For HER2-positive breast cancer, trastuzumab must be added to chemotherapy for a total of one year in the adjuvant setting. 2, 7

• Trastuzumab is FDA-approved for adjuvant treatment of HER2-overexpressing node-positive or high-risk node-negative breast cancer as part of doxorubicin/cyclophosphamide followed by paclitaxel or docetaxel, or with docetaxel/carboplatin, or as monotherapy following multi-modality anthracycline-based therapy 7
• For metastatic HER2-positive disease, trastuzumab in combination with paclitaxel is indicated for first-line treatment 7
• Critical warning: Avoid anthracyclines with trastuzumab due to cardiotoxicity risk—evaluate LVEF prior to and during treatment, and discontinue for clinically significant decrease in left ventricular function. 7, 9

Triple-Negative Breast Cancer

Adjuvant chemotherapy is the standard of care for triple-negative breast cancer, with chemotherapy (with or without immune checkpoint inhibitor therapy according to PD-L1 status) recommended for metastatic disease. 2, 3

• PD-L1 status should be assessed as part of routine clinical practice in triple-negative breast cancer 3

Metastatic Disease (Stage IV)

The primary treatment goal for metastatic breast cancer is palliation to maintain and improve quality of life, using systemic therapy tailored to hormone receptor and HER2 status. 9

• For hormone receptor-positive metastatic disease, start with endocrine therapy unless rapid response is needed 9
• For hormone receptor-negative or aggressive disease, sequential single-agent chemotherapy produces equivalent overall survival to combination regimens with significantly less toxicity 9
• Palliative radiotherapy should be used for bone metastases, brain metastases, and symptomatic soft tissue masses 9
• Consider surgical removal of the primary tumor for limited metastatic presentations, as retrospective data suggest a survival benefit 9

Multidisciplinary Team Requirements

Treatment must be provided by a specialized team including at least one surgeon, radiation oncologist, medical oncologist, radiologist, and pathologist with breast cancer expertise. 2, 9

• Treatment decisions should be extensively discussed with the patient, taking into account patient preferences 2
• For metastatic disease, include palliative care specialists and psychosocial support from treatment initiation 9

Follow-Up Protocol

Clinical examination every 3-6 months for 3 years, then every 6-12 months thereafter, with annual mammography for surveillance. 1, 2, 3

• For patients on tamoxifen with intact uterus, annual gynecologic assessment is required 2
• For patients on aromatase inhibitors, bone mineral density determination at baseline and periodically thereafter 2
• Monitor patients on chemotherapy frequently (every 1-2 cycles), and those on endocrine therapy every 2-3 months 9

A common pitfall is over-surveillance with imaging—routine staging scans are not recommended unless clinically indicated by symptoms or laboratory abnormalities. 3, 2