Assessment of the effect of surgery on the kinetics of circulating tumour cells in patients with operable breast cancer based on cytokeratin-19 mRNA detection

The aim of this study was to evaluate the effect of surgery on the kinetics of CTCs in breast cancer patients. The detection of CK-19 mRNA-positive CTCs in the blood by RT-PCR was analysed in 104 stage 0-IIIA patients at 4 time-points: prior to surgery, upon completion, 24 h after surgery and 15 days after surgery. Furthermore, a late sample was assessed prior to initiation of adjuvant chemotherapy in a subgroup of 53 patients. As negative controls, peripheral blood was obtained from 50 female patients undergoing excision of benign breast lesions and from 11 female patients receiving surgery for early-stage colorectal cancer. A significant percentage of blood samples from breast cancer patients (14.4%) were negative for CK-19 preoperatively but turned transiently positive early postoperatively. However, no significant difference in CK-19 mRNA detection was noted among the first 4 examined time-points. There was no significant correlation between CK-19 mRNA-positive cells and classic prognostic factors. A significant increase in CK-19 mRNA-positivity (32.1%) was observed in a late sample of the subgroup of 53 patients before adjuvant chemotherapy after a median of 54 days, postoperatively. Surgery may result in CTC detection in a small proportion of early breast cancer patients. There is no clear correlation to indicate which patients are expected to have detectable CTCs. Although CTCs are detected in a small proportion of patients during the perioperative period, the detection rate may increase over time and with longer follow-up.

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