Management of Breast Cancer
Breast cancer management should be carried out in specialized breast units/centers by a multidisciplinary team consisting of medical oncologists, breast surgeons, radiation oncologists, breast radiologists, breast pathologists, and breast nurses to ensure optimal outcomes for patients. 1
Diagnosis and Assessment
- Pathological diagnosis should be made according to the WHO classification from a surgical specimen obtained by breast-conserving surgery or modified radical mastectomy including axillary lymph node dissection 1
- Routine staging should include complete blood count, routine chemistry including liver enzymes, alkaline phosphatase, calcium, contralateral mammography, clinical examination, and chest X-ray 1
- Postoperative pathological assessment should be made according to the pathological TNM system 1
- Validated gene expression profiles may be used to gain additional prognostic and predictive information to complement pathology assessment and help in adjuvant chemotherapy decision-making 1
- FDG-PET-CT scanning may be useful when conventional methods are inconclusive and may replace traditional imaging for staging in high-risk patients 1
Treatment Strategy Development
- Treatment decisions should be based on tumor burden/location (size and location of primary tumor, number of lesions, extent of lymph node involvement) and biology (pathology, biomarkers, gene expression), as well as patient age, menopausal status, general health status, and preferences 1
- Patients should be provided with the opportunity to be actively involved in all management decisions, with information provided repeatedly both verbally and in writing 1
- Breast cancer is categorized into 3 major subtypes that guide treatment approaches: hormone receptor positive/HER2 negative (70% of patients), HER2 positive (15%-20%), and triple-negative (15%) 2
Surgical Management
- Breast-conserving surgery (BCS) is the preferred local treatment option for most early breast cancer patients, with oncoplastic techniques used when needed to maintain good cosmetic outcomes 1
- Sentinel lymph node biopsy (SLNB), rather than full nodal clearance, is the standard of care for axillary staging in early, clinically node-negative breast cancer 1
- Further axillary surgery following a positive SLNB is not required in cases of low axillary disease burden (micrometastases or one to two SLNs containing metastases) when treated with postoperative tangential breast radiotherapy 1
- When mastectomy is necessary, breast reconstruction should be available and proposed to all women, with immediate reconstruction offered to most patients except those with inflammatory cancer 1
Systemic Therapy
Early Breast Cancer
- Systemic therapy for non-metastatic breast cancer is determined by subtype 2:
- Trastuzumab is indicated for adjuvant treatment of HER2-overexpressing node-positive or high-risk node-negative breast cancer as part of treatment regimens with chemotherapy 3
- Validated gene expression profiles should be used to help in adjuvant chemotherapy decision-making for appropriate patients 1
Metastatic Breast Cancer
- The goal of treatment for metastatic breast cancer is to prolong survival and maintain quality of life 1
- Treatment should be based on tumor biology and disease burden, previous therapies and responses, patient preferences, and performance status 1
- For hormone receptor-positive metastatic disease, endocrine therapy is the preferred option unless rapid response is warranted or endocrine resistance is suspected 1
- HER2-directed therapy should be offered early to all HER2-positive metastatic breast cancer patients, either as a single agent, combined with chemotherapy, or with endocrine therapy 1
- Sequential monochemotherapy is preferred in metastatic breast cancer without rapid clinical progression or life-threatening visceral metastases 1
- Trastuzumab is indicated in combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer 3
Radiation Therapy
- Radiation therapy is an essential component of breast-conserving treatment 1
- Axillary radiation is a valid alternative in patients with a positive sentinel lymph node biopsy, regardless of the type of breast surgery 1
- Radiotherapy is also useful for palliative control of painful bone metastases and central nervous system involvement in metastatic disease 1
Follow-up Care
- Follow-up after curative treatment should include history, eliciting of symptoms, and physical examination every 3-6 months for 3 years, then every 6-12 months thereafter 1
- Patients with metastatic breast cancer should be seen frequently enough to provide optimal palliation of symptoms and maintain quality of life 1
- Patients should have access to effective palliative care throughout their treatment journey 1
Special Considerations
- In younger premenopausal patients, fertility issues and preservation techniques should be discussed before initiating systemic treatment 1
- Age should not be the sole determinant for withholding or recommending treatment but should be considered along with other factors 1
- Patients with isolated local-regional recurrence should be treated with curative intent, including appropriate "secondary" adjuvant treatment modalities 1
Common Pitfalls and Caveats
- Improper assessment of HER2 status can lead to unreliable results and inappropriate treatment selection; testing should be performed by laboratories with demonstrated proficiency 3
- Trastuzumab can result in cardiac toxicity, particularly when combined with anthracycline-containing chemotherapy; left ventricular function should be evaluated in all patients prior to and during treatment 3
- Concomitant chemo-hormonal therapy is discouraged in metastatic breast cancer 1
- A phenomenon of tumor marker flare can occur in the first 6 weeks of effective therapy and must be considered when interpreting serial values 1