BACKGROUND AND PURPOSE:

• There are few studies exploring whether the location of lymph node metastasis in breast cancer impacts the survival of patients
• Pan et al. (JAMA, 2021) assessed the survival of patients with distant lymph node metastases (DLNM) versus ipsilateral supraclavicular lymph node metastases (ISLM) in stage IV breast cancer

METHODS:

• Cohort study
• Data source
  • SEER database
• Participants
  • Patients diagnosed with breast cancer between January 1, 2010 and December 31, 2014
  • Three groups of patients were included
    • ISLM without any distant metastasis
    • DLNM
    • Distant metastasis (DLNM excluded)
• Exposures
  • Surgery for primary tumor
  • Surgery for distant lymph nodes
  • Radiotherapy
• Primary outcomes
  • Overall survival (OS)
  • Breast cancer-specific survival (BCSS)

RESULTS:

• 2033 women
  • Mean age: 62.03 years; 74% White
  • ISLM: 10.4%
  • DLNM: 27.0%
  • Distant metastases: 72.6%
• 3-year breast cancer specific survival rates
  • ISLM: 63.24%
  • DLNM: 64.54%
  • Distant: 41.20%
•  3-year overall survival rates
  • ISLM: 53.46%
  • DLNM: 62.67%
  • Distant: 38.21%
• Compared with patients with ISLM, patients with DLNM had similar survival rates, but patients with distant metastases had significantly poorer outcomes
  • Patients with DLNM
    • BCSS: Hazard ratio (HR) 0.81 (95% CI, 0.52 to 1.25; P = 0.34)
    • OS: HR 0.73 (95% CI, 0.51 to 1.05; P = 0.09)
  • Patients with distant metastases
    • BCSS: HR 1.99 (95% CI, 1.43 to 2.78; P < 0.001)
    • OS: HR 1.79 (95% CI, 1.35 to 2.38; P < 0.001)
• Locoregional treatment: For DLNM, primary surgery and radiotherapy were associated with improved overall survival rates
  • Primary surgery: HR 0.21 (95% CI, 0.12 to 0.39; P < 0.001)
  • Radiotherapy: HR 0.46 (95% CI, 0.25 to 0.87; P = 0.02)

CONCLUSION:

• Distant lymph node metastases of breast cancer might be a regional disease and have survival rates similar to ipsilateral supraclavicular lymph node metastases
• The authors recognize a significant limitation to this study is the retrospective design
• The authors conclude that although more studies are needed to confirm their findings

…breast cancer with DLNM may be a curable disease, similar to N3c disease, with a significantly better prognosis than other types of stage IV disease

Locoregional treatment was associated with significantly improved survival for patients with DLNM

Learn More – Primary Sources:

Comparison of Survival Outcomes Among Patients With Breast Cancer With Distant vs Ipsilateral Supraclavicular Lymph Node Metastases

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