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

Background: Controversy exists regarding internal mammary lymph nodes (IMNs ) in the staging and treatment of breast cancer, Sentinel lymph node identi fication with radiocolloid can map drainage to IMNs and directed biopsy can be performed with minimal morbidity. Furthermore, recent studies suggest t hat IMN drainage of breast tumors may be underestimated. To gain further in sight into the prognostic value of IMNs, we reviewed the outcome of patient s in whom the IMN status was routinely assessed. Methods: A retrospective review of 286 patients with breast cancer who unde rwent IMN dissection between 1956 and 1987 was conducted. Results: Median follow-up is 186 months, age was 52 years (range, 21-85 yea rs), tumor size was 2.5 cm, and number of IMNs removed was 5 (range, 1-22); 44% received chemotherapy, 16% endocrine therapy, and 5% radiotherapy. Pre sence of IMN metastases correlated with primary tumor size (P < .0001) and number of positive axillary nodes (P < .0001) but did not correlate with pr imary tumor location or age. Overall, the 20-year disease-free survival is significantly worse for the 25% of patients with IMN metastases (P < .0001) . In patients with positive axillary nodes and tumors smaller than 2 cm, th ere was a significantly worse survival (P < .0001) in the patients with IMN metastases. This difference in survival was not seen in women with turners larger than 2 cm, Conclusions: Patients with IMN metastases. regardless of axillary node stat us, have a highly significant decrease in 20-year disease-free survival. Tr eatment strategies based on knowledge of sentinel IMN status may lead to im provement in survival, especially for patients with small tumors. Ar presen t, sentinel IMN biopsies should be performed in a clinical trial setting.