Detection of circulating epithelial cells after surgery for benign breast disease

Background: Cytokeratins are predominantly expressed in epithelial cells and their malignant counterparts. Ultrasensitive methods for cytokeratin messenger RNAs (mRNAs) can detect rare circulating tumor cells consistent with hematogenous dissemination in epithelial-derived malignancies, including breast carcinomas. Intraoperative tumor-cell shedding may contribute to this process; this hypothesis is based on the assumption that only tumor cells can be mobilized during surgical manipulation. Methods and Results: The present study addresses this issue by using cytokeratin 19 mRNA detection by reverse transcription-polymerase chain reaction (RT-PCR) in preoperative and postoperative blood samples from 54 patients undergoing excisional biopsy for benign breast disease; 22 healthy volunteers represented the control group. No cytokeratin RT-PCR positivity was found in the control or pre operative samples. Cytokeratin RT-PCR positivity was found in 21 postoperative samples (39%). Conclusions: This finding shows that benign epithelial cells can be mobilized during breast surgery; this effect of surgical manipulation warrants caution in the interpretation of RT-PCR positivity for cytokeratin mRNA in the peripheral blood of patients undergoing surgery for breast cancer.