Are malignant cells displaced by large-gauge needle core biopsy of the breast?

OBJECTIVE. The purpose of this paper is to determine the rate of tumor displacement resulting from large-gauge needle core biopsy in patients with breast carcinoma. MATERIALS AND METHODS. Three hundred fifty-two cancer excisions in patients who had undergone large-gauge needle core biopsy were evaluated for evidence of tumor displacement. Three needle procedures were compared: vacuum-assisted, automated gun, and core biopsy guided by palpation. Needle track visualization, presence and amount of tumor displacement, tumor morphology, and interval between core biopsy and surgical excision were recorded for each case. RESULTS. Seventy-six cases showed tumor displacement of one or two cell clusters, and 38 cases showed displacement of multiple tumor fragments. Tumor displacement was identified in 37% of automated gun specimens, 38% of specimens obtained with palpable guidance, and 23% of specimens obtained with a vacuum-assisted needle. Tumor displacement was seen in 42% of patients with an interval between biopsy and excision of less than 15 days, in 31% of patients with an interval of 15-28 days, and in 15% of tumors excised more than 28 days after core biopsy (p < .005). CONCLUSION. Tumor cell displacement was observed in 32% of patients who had undergone large-gauge needle core biopsy. The incidence and amount of tumor displacement was inversely related to the interval between core biopsy and excision. This relation suggests that tumor cells do not survive displacement.