Usefulness of CTC and DTC-BM Detection for Adjuvant Therapy Effects and Prognosis Prediction in Early Breast Carcinoma: Results of 8–11 Years of Follow-up Evaluation

Circulating tumor cells (CTCs) reportedly have been detected in the peripheral blood of more than 50% of breast carcinoma cases with distant metastases. Moreover, the survival period is shorter for patients who had more than five CTCs after a single chemotherapy treatment. However, a few data show the relationships between CTCs and expressions of disseminated tumor cells in the bone marrow (DTCs-BM), including treatment effects and prognoses in early breast carcinomas.In this study, CTCs and DTC-BMs were measured by the CellSearch System for 20 patients with stages 1-3 carcinomas, who were followed for 8-11 years.CTCs in 2 (10%) of 20 breast carcinomas, more than 1 CTC was detected before adjuvant therapy, and both cases showed a decrease to 0 after chemotherapy. DTC-BMs in 19 (95%) of the 20 primary cases, more than 1 cell was found in the BM. After adjuvant therapy, 16 cases showed a decrease to 0-10 cells, 2 cases to 11-20 cells, and 2 cases to more than 21 cells. Six patients experienced recurrence. One of the two CTC-positive cases (21 cells) had bone and liver metastasis within 11 months. Among the DTC-BM cases, only 1 (16.7%) of the 6 primary patients with 11-20 cells had recurrence, whereas 4 (80%) of the 5 patients with more than 21 cells had recurrence 3-6 years later.Detection of DTC-BMs is useful for observing adjuvant therapy effects and for predicting relatively late-phase metastasis. The cluster status of CTCs suggests early relapsing.