NCCN Guidelines for Breast Cancer Treatment
The National Comprehensive Cancer Network (NCCN) provides comprehensive, evidence-based recommendations for breast cancer management across all stages, with treatment decisions primarily based on tumor biology, disease extent, and patient factors through a multidisciplinary team approach. 1
Initial Assessment and Staging
- Comprehensive pathology reporting is essential, including determination of histologic type, hormone receptor status, HER2 status, tumor grade, size, and lymph node involvement 1
- For metastatic disease, biopsy of accessible metastatic lesions is recommended to confirm diagnosis and reassess biological markers 1, 2
- PET-CT may be used instead of CT scans and bone scan if available for staging workup 2
- Brain imaging is not routinely recommended in asymptomatic patients, including those with HER2-positive or triple-negative disease 2
Treatment by Breast Cancer Subtype
Hormone Receptor-Positive, HER2-Negative Breast Cancer
- Adjuvant endocrine therapy is recommended to reduce recurrence risk 1
- Endocrine therapy is the preferred first-line treatment for metastatic disease, unless there is concern for endocrine resistance or need for rapid response 2
- For ER-low positive (1-10%) tumors, individualized consideration of risks versus benefits of endocrine therapy is recommended 1
HER2-Positive Breast Cancer
- HER2-directed therapy should be offered to all patients with HER2-positive breast cancer 1
- Trastuzumab significantly improves disease-free survival and overall survival in the adjuvant setting 3
- Clinical trials have shown that trastuzumab reduces the risk of recurrence by 52% and the risk of death by 36% when added to standard chemotherapy 3
Triple-Negative Breast Cancer
- Chemotherapy is the mainstay of treatment for triple-negative breast cancer 1, 2
- Sequential single-agent chemotherapy is generally preferred over combination chemotherapy for metastatic disease, unless there is need for rapid symptom control 2
Preoperative Systemic Therapy
- Preoperative systemic therapy can facilitate breast conservation, render inoperable tumors operable, and provide prognostic information based on response to therapy 1
- Ideal candidates include patients with inoperable breast cancer, HER2-positive disease, or triple-negative breast cancer ≥cT2 or ≥cN1 1
Surgery and Locoregional Treatment
- For early-stage disease, options include breast-conserving surgery with radiation therapy or mastectomy with or without reconstruction 1
- For patients with metastatic disease and intact primary tumor, the primary approach is systemic therapy, with surgery considered for palliation of symptoms or impending complications 1, 2
- Approximately 60-80% of breast cancers are amenable to breast conservation techniques 4
Radiation Therapy
- Whole breast radiation therapy is recommended after breast-conserving surgery 1
- Post-mastectomy radiation is indicated for patients with high-risk features 1
- Re-irradiation to limited areas may be considered in previously irradiated patients after careful risk-benefit assessment 4
Systemic Therapy for Metastatic Disease
- The primary goals of treatment for metastatic breast cancer are palliating symptoms, prolonging survival, and maintaining or improving quality of life 1, 2
- For hormone receptor-positive metastatic disease, endocrine therapy is preferred unless there is concern for endocrine resistance or need for rapid response 2
- For HER2-positive metastatic disease, HER2-directed therapy should be incorporated 1
- For triple-negative metastatic disease, chemotherapy is the mainstay of treatment 1, 2
- Sequential single-agent chemotherapy is generally preferred over combination chemotherapy, unless there is need for rapid symptom control or management of life-threatening visceral metastases 2
Monitoring Response to Treatment
- Evaluation of response to therapy should occur every 2-4 months for endocrine therapy and after 2-4 cycles for chemotherapy in the metastatic setting 1, 2
- Tumor markers may aid in evaluating response, particularly in patients with non-measurable disease 2
Special Considerations
- A small subset of patients with oligometastatic disease or highly chemosensitive disease may achieve complete remission with a multimodal approach 2
- Early introduction of expert palliative care, including effective pain control, should be a priority 2
- Fertility preservation options should be discussed with younger patients before initiating systemic treatments 4
- Older patients should not be denied effective therapy based solely on age 1, 2
Common Pitfalls to Avoid
- Do not withhold effective therapy based solely on patient age 2
- Do not rely on tumor markers alone to initiate a change in treatment 2
- Avoid unnecessary surgery for the primary tumor when systemic disease control is the priority 2
- Do not neglect psychosocial support from trained professionals, which should be available at all stages of the cancer journey 4