Indications for Supraclavicular Lymph Node Radiation in Breast Cancer
Supraclavicular lymph node (LN) radiation is strongly recommended for patients with 4 or more positive axillary lymph nodes, patients with T3-T4 tumors regardless of nodal status, and should be strongly considered in patients with 1-3 positive axillary nodes, especially with additional risk factors. 1
Definite Indications for Supraclavicular LN Radiation
- Patients with 4 or more positive axillary lymph nodes (category 1 recommendation) 1
- Patients with T3-T4 tumors regardless of nodal status 1
- Patients with clinically or pathologically positive supraclavicular lymph nodes (N3c disease) 2
- Patients with clear residual disease after surgery 1
Strong Considerations for Supraclavicular LN Radiation
- Patients with 1-3 positive axillary lymph nodes, especially with additional risk factors: 1
- Tumors greater than 5 cm 1
- Positive or close (<1 mm) pathologic margins 1
- Young age (≤40 years) 1, 3
- Presence of lymphovascular invasion 4, 3
- Extracapsular extension 4
- Involvement of higher axillary node levels (level II or III) 4, 3
- Low number of examined axillary lymph nodes 1
- High lymph node ratio (number of positive nodes/number of nodes examined) 5
Technical Considerations
- According to ESTRO guidelines, the supraclavicular radiation field should include the most caudal lymph nodes surrounding the subclavicular arch and the base of the jugular vein 1, 2
- In high-risk patients, consideration should be given to including lymph nodes in the posterior triangle of the neck (level V) 6
- Standard radiation dose is 50 Gy in fractions of 1.8 to 2.0 Gy 1
- CT-based treatment planning should be used to minimize radiation dose to the heart and lungs 1
Special Considerations
- After axillary lymph node dissection (ALND), the resected part of the axilla should not be irradiated, except in cases of clear residual disease 1
- After a positive sentinel lymph node biopsy (SLNB) without subsequent ALND, regional radiation therapy is advised 1
- For patients undergoing neoadjuvant chemotherapy, decisions regarding radiation therapy should be based on pre-chemotherapy tumor characteristics, regardless of response to treatment 1
Prognostic Implications
- Supraclavicular lymph node metastases (N3c disease) carry significant prognostic implications and require aggressive multimodal therapy 2, 7
- Patients with supraclavicular recurrence have poor prognosis with 5-year survival rates as low as 16% 7
- Most patients with supraclavicular recurrence develop distant metastases within 5 years, suggesting it should be considered an indicator of systemic disease 7
The evidence strongly supports the use of supraclavicular lymph node radiation in high-risk breast cancer patients, particularly those with multiple positive axillary nodes or advanced primary tumors, as it reduces locoregional recurrence and improves overall survival 1.