Biopsy type does not influence sentinel lymph node status

Background: This study sought to determine whether the type of biopsy examination independently affects sentinel lymph node (SLN) status in breast cancer patients. Methods: A prospective multicenter study of patients who had SLN biopsy examination followed by axillary node dissection was analyzed to determine whether the type of biopsy examination influenced SLN status. Results: Of the 3853 patients studied, 32% had a positive SLN. Patients were diagnosed by fine-needle (N = 293), core-needle (N = 2154), excisional (N = 1386), or incisional (N = 20) biopsy procedures. The rates of SLN positivity for these groups were 45%, 32%, 29%, and 65%, respectively (P < .001). Other factors predictive of SLN status included: patient age (P < .001), tumor size (P < .001), tumor palpability (P < .001), number of SLN removed (P < .001), type of surgery (mastectomy vs. lumpectomy) (P < .001), histologic subtype (P = .048), and the use of immunohistochemistry (P < .001). All of these factors remained significant in the multivariate model except for histologic subtype and biopsy examination type. Conclusions: Biopsy examination type does not independently influence the risk for nodal metastasis.