Breast cancer seeding associated with core needle biopsies: a systematic review.

BACKGROUND: Preoperative diagnosis has become the standard in breast cancer (BC) management. Recently, ultrasound guided core needle biopsy (CNB) and stereotactic needle core biopsy have replaced fine needle aspiration cytology. Epithelial cell displacement (DE) occurs frequently after core needle biopsy (CNB) for breast cancer diagnosis. AIM: Systematically review (between 1900 and 2008) the clinical significance of DE after CNB in BC patients, and associated risk factors (delay between biopsy and surgery, needle passes, duration of the procedure, tumor size, histological type, tumor grade, margins, type of surgery, and of adjuvant treatment). MATERIALS AND METHODS: We selected 15 studies: 9 assessed the rate of DE after CNB and 6 the impact of CNB on outcome endpoints. RESULTS: We found 3 prospective and 12 retrospective studies. However these had numerous biases such as insufficient power, confounding factors, selection of cases and controls, surrogate endpoints, heterogeneity of measured displacement. Malignant DE on surgical specimens occurred in 22% of the patients. A short interval between CNB and surgical excision increased the risk of detecting displaced cells. No increase in local recurrence was reported after CNB. Contradictory results were found in terms of sentinel node metastases. Only one study evaluated overall survival data and reported no worse survival in patients with preoperative CNB. CONCLUSION: Although data are limited, no increased morbidity has been associated with iatrogenic seeding after CNB.