Introduction

Early detection of metastasis is important for improving overall survival in breast cancer (BC) patients. Circulating tumor cells (CTCs) play a role in detecting minimal residual disease (MRD). In an ongoing cohort, we evaluated the association between CTC dynamics before and after surgery performed with curative intent. Additionally, we assessed cancer-related worry in post-surgical BC patients.

Methods

A total of 75 CTC tests were performed on 55 female BC patients, of whom 20 were follow-up cases. In an ongoing IEC-approved clinical cohort, 10 BC patients were enrolled using a quantitative, non-probability purposive sampling method. CTC counts, including clusters, were measured both pre-surgery and 24 hours post-surgery. PD-L1 expression on CTCs was assessed using the CDSCO-approved OncoDiscover platform. Patient-reported outcome measures (PROMs) were evaluated using the Breast-Q Cancer Worry scale, a validated subscale reflecting fear of recurrence and related concerns. Statistical analysis compared PROM scores with CTC patterns, including increase, persistence, or clearance. A paired sample t-test was applied to compare pre- and post-operative PROM scores to evaluate changes in cancer-related worry in relation to CTC counts.

Results

Among the 75 tests performed in 55 BC patients, 84.5% were CTC-positive, with a mean of 1.43 CTCs per test. In longitudinal monitoring of 10 female BC patients who underwent surgery, six received neoadjuvant chemotherapy (NACT) followed by breast-conserving surgery, while four underwent surgery without prior chemotherapy. Overall, 40% (4/10) showed a reduction in CTC counts, and 20% (2/10) achieved complete CTC clearance after surgery. Patients with increased post-surgery CTC counts reported a significant increase in cancer-related worry. The mean pre-surgery score was 43.9, which increased to 51.8 after surgery. These findings suggest the need for targeted emotional and psychological support in the post-surgical period and highlight the role of CTC monitoring in assessing MRD.

Conclusions

Monitoring CTCs strengthens their potential as an early indicator of residual disease by providing important clinical insights into tumor activity during the operative phase. Further validation is warranted to support more integrated, patient-centered care approaches aimed at reducing the burden of advanced cancer.