Iatrogenic displacement of tumor cells to the sentinel node after surgical excision in primary breast cancer

Isolated tumor cells (ITC) are more common in the sentinel node (SN) after needle biopsy of a breast cancer, indicating iatrogenic displacement of tumor cells. We here investigate whether similar iatrogenic displacement occurs after surgical excision of a breast tumor. We compared the incidence of ITC in the SN of 414 breast cancer patients with recent surgical excision to a group of 16,960 patients without recent surgical procedure in a multivariate analysis by linking data from the Danish Breast Cancer Cooperative Group database and the Danish National Health Register. Moreover, the incidence of spread to non-SNs in patients with ITC in the SN after recent surgical excision was analyzed. We found an adjusted odds ratio on 3.73 (95% CI 2.57-5.43; P