Circulating tumor cells in metastatic inflammatory breast cancer

Background: Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. Circulating tumor cells (CTCs) are an independent prognostic factor in metastatic breast cancer. The aim of this study was to assess the prognostic value of baseline CTCs in metastatic IBC patients. Patients and methods: This retrospective study included 42 metastatic IBC and 107 metastatic non-IBC patients treated with first- or second-line chemotherapy from January 2004 to December 2007 at MD Anderson Cancer Center. CTCs were detected and enumerated before patients started chemotherapy using the CellSearch™ system. Results: Ten (23.8%) IBC patients versus 48 (44.9%) non-IBC patients had baseline CTCs ≥5 per 7.5 ml of peripheral blood. IBC patients had a lower mean ± SEM CTCs than non-IBC patients (7.6 ± 2.9 versus 34.2 ± 9.1; P = 0.02). The estimated median overall survival was 26.5 versus 18.3 months (P = 0.68) in IBC patients and 37.4 versus 18.3 months (P = 0.016) in non-IBC patients with CTCs <5 and CTCs ≥5, respectively. Conclusions: Metastatic IBC patients had a lower prevalence and fewer CTCs in comparison to metastatic non-IBC patients. Survival of metastatic IBC patients with <5 CTCs was not significantly better than that of patients with ≥5 CTCs. Further research is warranted with prospective assessment of CTCs in IBC patients and their biological characterization.