Purpose The association between pathological complete response (pCR) in patients receiving neoadjuvant chemotherapy
(NAC) for breast cancer and Circulating Tumour Cells (CTCs) is not clear. The aim of this study was to assess whether
CTC enumeration could be used to predict pathological response to NAC in breast cancer as measured by the Miller–Payne
grading system.
Methods Twenty-six patients were recruited, and blood samples were taken pre- and post-NAC. CTCs were isolated using
the ScreenCell device and stained using a modifed Giemsa stain. CTCs were enumerated by 2 pathologists and classifed as
single CTCs, doublets, clusters/microemboli and correlated with the pathological response as measured by the Miller–Payne
grading system. χ2
or ANOVA was performed in SPSS 24.0 statistics software for associations.
Results 89% of patients had invasive ductal carcinoma (IDC) and 11% invasive lobular carcinoma (ILC). At baseline 85%
of patients had CTCs present, median 7 (0–161) CTCs per 3 ml of whole blood. Post-chemotherapy, 58% had an increase
in CTCs. This did not correlate with the Miller–Payne grade of response. No signifcant association was identifed between
the number of CTCs and clinical characteristics; however, we did observe a correlation between pre-treatment CTC counts
and body mass index, p<0.05.
Conclusions Patients with a complete response to NAC still had CTCs present, suggesting enumeration is not sufcient to
aid surgery stratifcation. Additional characterisation and larger studies are needed to further characterise CTCs isolated
pre- and post-chemotherapy. Long-term follow-up of these patients will determine the signifcance of CTCs in NAC breast
cancer patients.
