Should internal mammary nodes be sampled in the sentinel lymph node era?

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Internal mammary lymph nodes (IMNs) play a debated role in breast cancer staging and treatment.
• Sentinel lymph node biopsy can assess IMN drainage with minimal morbidity.
• Recent data suggest IMN drainage from breast tumors may be underestimated.

Purpose of the Study:

• To investigate the prognostic significance of internal mammary lymph node status in breast cancer patients.
• To evaluate the impact of IMN metastases on long-term disease-free survival.

Main Methods:

• Retrospective review of 286 breast cancer patients who underwent IMN dissection between 1956 and 1987.
• Analysis of patient outcomes, including 20-year disease-free survival.
• Correlation of IMN metastases with tumor size, axillary node status, and patient demographics.

Main Results:

• IMN metastases were found in 25% of patients and significantly correlated with primary tumor size and positive axillary nodes.
• Patients with IMN metastases had significantly worse 20-year disease-free survival (P < .0001).
• This survival difference was pronounced in patients with tumors smaller than 2 cm, irrespective of axillary node status.

Conclusions:

• IMN metastases are a strong negative prognostic indicator for breast cancer patients, significantly reducing 20-year disease-free survival.
• Incorporating sentinel IMN status into treatment strategies may enhance survival, especially for early-stage tumors.
• Sentinel IMN biopsies are recommended within a clinical trial framework for further validation.