Changes in Circulating Tumor Cell Detection in Patients with Localized Breast Cancer Before and After Surgery

Abstract

Few data exist on the potential role of circulating tumor cells (CTCs) in patients with operable breast cancer. If the presence of CTCs in early breast cancer could predict an increased risk for relapse, it might be an early marker for treatment efficacy and could help in deciding treatment continuation. Thirty milliliters of peripheral blood was taken from 56 breast cancer patients before surgery and again 5 days after surgery, and the presence of CTCs was evaluated. In case of positivity of one of the perioperative samples, another sample was taken after 30 days. The presence of CTCs was assessed with the CellSearch System (Veridex, Warren, NJ). One to three CTCs were found in 16 (29%) of 56 patients before surgery, in 14 (30%) of 47 patients at day 5, and in 8 (30%) of 27 at day 30. No association with pathological characteristics was found, apart a borderline significant association between presence of CTCs at baseline and vascular invasion (P = 0.07). When we looked at concordance between CTCs at baseline and after day 5 (47 patients), we found 40% discordant samples (10 negative at baseline and positive at day 5, and 9 vice versa). This study provides evidence of the presence of CTCs in approximately 30% of patients with localized breast cancer both before and after surgery, with change from positive to negative and vice versa in 40% of cases. No association with the pathological variables was found, except for vascular invasion and presence of preoperative CTCs. Long-term follow-up will be required to understand the significance of these data.