Impact of isolated tumor cells in sentinel lymph nodes detected by immunohistochemical staining

Aim Isolated tumor cells (ITCs) in lymph nodes are defined histologically as node-negative. The clinical impact of ITCs in sentinel lymph nodes (SLNs) remains unclear. We report the prognosis of breast cancer patients with ITC-positive SLNs detected by immunohistochemical staining. Patients and methods One hundred and sixty-five breast cancer patients with histologically negative SLNs were seen between January 1998 and December 2000. In 69 patients, sentinel node biopsy (SNB) was immediately followed by axillary lymph node dissection, and 96 had undergone SNB alone. Permanent sections of 301 SLNs were re-examined after hematoxylin-eosin staining and cytokeratin 19 immunohistochemical staining. Results ITCs were found in 18 SLNs of 17 patients and a micrometastasis was found in one SLN of one patient. As of November 2005, only one patient with ITCs in one SLN had supraclavicular lymph node recurrence. In contrast, 18 of the 147 patients with negative SLNs had tumor recurrence. Surgical management of the axilla had no influence on recurrence-free survival in all of the patients. Conclusion This study shows that breast cancer patients with ITC-positive SLNs should be clinically managed as node-negative patients.