Progress in using circulating tumor cell information to improve metastatic breast cancer therapy. J Oncol. 2013;2013:702732. [PMID: 23589716 PMCID: PMC3621388 DOI: 10.1155/2013/702732]

Potential of Liquid Biopsies for Breast Cancer Screening, Diagnosis, and Response to Treatment

Cancer therapy decisions are often made according to the histopathological-molecular profile of tumor tissue obtained from surgery or biopsy. It has been shown that tumor profiles change with time and treatment, and that tumor tissue is heterogeneous. Thus, other approaches that are easily accessible and less invasive than surgery or biopsy to monitor responses to treatment and predict relapses are urgently needed. In the last few years, the term "liquid biopsies" has been introduced to represent multifunctional circulating biomarkers in the peripheral blood and other physiological fluids of patients with cancer. Liquid biopsies are a noninvasive alternative to tissue biopsies, but they have not been implemented in routine clinical practice for breast cancer. In addition, liquid biopsies seem to be a promising approach for personalized medicine, which enables the prediction, monitoring, and rational selection of appropriate therapy for individual patients. In this review, we outline recent progress and current challenges with liquid biopsies in clinical practice for breast cancer diagnosis, treatment choices, and responses to therapy from a clinician's perspective.

Monitoring disease progression and treatment efficacy with circulating tumor cells in esophageal squamous cell carcinoma: A case report

This study investigated whether changes in circulating tumor cell (CTC) numbers reflect tumor progression and treatment efficacy in esophageal squamous cell carcinoma (ESCC). A 47-year-old male patient with ESCC is presented in this case study. The patient was evaluated for a series of serum tumor markers and subjected to radiological examinations before and after surgery and during follow-up over the course of five years. In addition, the CTCs in 7.5 mL of peripheral blood were enriched by magnetic-activated cell sorting negative selection and identified by immunofluorescence staining. Serum tumor markers remained within normal ranges and were discordant with imaging scans during the follow-up. Initially, one CTC was detected in the peripheral blood sample, and 14 were observed seven days after the operation. After 12 wk, subcutaneous metastases and bone metastases occurred, and the number of CTCs increased to 84. After 48 wk, lung metastases were noted, and the CTC level was 21. At 104 wk, the number of CTCs was 14, and disease recurrence was detected by positron emission tomography-computed tomography. The CTC counts were in accord with the imaging studies at several time points. The additional information provided by CTC enumeration could thus facilitate monitoring of disease status and treatment efficacy and provide support for treatment decisions.

Toll-like receptor (TLR) expression of immune system cells from metastatic breast cancer patients with circulating tumor cells

The risk posed by breast cancer represents a complex interaction among factors affecting tumor immunity of the host. Toll-like receptors (TLRs) are members of the innate immune system and generally function to attract host immune cells upon activation. However, the good intentions of TLRs are sometimes not transferred to positive long-term effects, due to their involvement in exacerbating inflammatory effects and even contributing to continued inflammation. Chronic inflammatory states are considered to favor an increased predisposition to cancer, with continuous activation of inflammatory cytokines and other hallmarks of inflammation exerting a deleterious effect. Circulating tumor cells (CTCs) are neoplastic cells present in the peripheral blood circulation that have been found to be an indicator of disease progression and long-term survival. In the present study, we examined the expression of TLRs on dendritic cells, which play a major role in eliciting anti-tumor immunity, in metastatic breast cancer patients with CTCs. Flow cytometric data showed significant differences between circulating tumor cell (CTC) positive patients and CTC negative patients in their expression of TLR2 by CD8 positive cytotoxic T cells and TLR2, TLR4, TLR3, and TLR8 by CD11c positive dendritic cells (p<0.05). Expression of TLR2, TLR4, and TLR8 was increased in CTC positive patients, whereas TLR3 expression was decreased in the dendritic cell population.

Circulating tumor cell data: integration with imaging and serum tumor markers for metastatic breast cancer patient management

Management of metastatic breast cancer is critical to maximizing survival with good quality of life. Circulating tumor cell (CTC) levels in the peripheral blood hold promise for enabling improved patient care. We describe a case of a 47-year-old female with infiltrating ductal carcinoma who developed metastatic disease. Serum tumor markers were discordant with imaging studies at several time points. CTC levels were used to support decision making in light of the discordant data. The use of this tool enabled prompt changes in therapy with progressive disease and supported suspending therapy to enable recovery from treatment adverse effects when a significant response was detected by imaging and CTCs were absent from the peripheral circulation. The additional information provided by CTC enumeration helped clarify disease status and provided support for treatment decisions.

Clinical value of circulating liver cancer cells for the diagnosis of hepatocellular carcinoma: A meta-analysis

This meta-analysis was conducted to evaluate the clinical value of circulating tumor cells (CTCs) for liver tumor size, clinical stage and metastasis. The clinical studies on CTCs and liver cancer were electronically and manually retrieved and Review Manager 5.1 software was used to evaluate the quality of the obtained studies, extract data and conduct a meta-analysis. A total of 5 studies including 535 liver cancer patients were identified. The results of the meta-analysis revealed that the odds ratio (OR) values of CTCs-positive rates between large and small tumor size, tumor stage I/II and III/IV, as well as metastatic and non-metastatic groups were 12.12 (95% CI: 7.84-18.74), 0.10 (95% CI: 0.07-0.16) and 0.09 (95% CI: 0.05-0.15), respectively, which demonstrated a significant difference. In conclusion, the detection of CTCs in the peripheral blood was clearly associated with tumor size, clinical stage and metastasis.

Circulating tumor cells (CTCs) from metastatic breast cancer patients linked to decreased immune function and response to treatment

We aimed to examine the use of circulating tumor cells (CTCs) as an effective measure of treatment efficacy and immune system function in metastatic breast cancer patients. CTCs are believed to be indicators of residual disease and thus pose an increased risk of metastasis and poorer outcomes to those patients who are CTC-positive. We obtained peripheral blood samples from 45 patients previously diagnosed with metastatic disease originating in the breast. Using TLR agonists that bind TLR ligands and upregulate immune effects versus unstimulated cells, we calculated a percent specific lysis using chromium-51 assay to illustrate the functional abilities of patient natural killer (NK) cells. We found those with greater than 5 CTCs per 7.5 mL blood had significantly decreased responses by their immune cells when compared with those patients who had 5 CTCs or less. We furthermore found a correlation between disease progression and CTC-positive patients, indicating that those who have a positive test should be closely monitored by their clinician. CTCs represent an exciting new clinical opportunity that will ideally utilize their low invasiveness and quick turnaround time to best benefit clinical scenarios.