Significance of Circulating Tumor Cells Detected by the CellSearch System in Patients with Metastatic Breast Colorectal and Prostate Cancer

The increasing number of treatment options for patients with metastatic carcinomas has created a concomitant need for new methods to monitor their use. Ideally, these modalities would be noninvasive, be independent of treatment, and provide quantitative real-time analysis of tumor activity in a variety of carcinomas. Assessment of circulating tumor cells (CTCs) shed into the blood during metastasis may satisfy this need. We developed the CellSearch System to enumerate CTC from 7.5 mL of venous blood. In this review we compare the outcomes from three prospective multicenter studies investigating the use of CTC to monitor patients undergoing treatment for metastatic breast (MBC), colorectal (MCRC), or prostate cancer (MPC) and review the CTC definition used in these studies. Evaluation of CTC at anytime during the course of disease allows assessment of patient prognosis and is predictive of overall survival

Parallel probing of drug uptake of single cancer cells on a microfluidic device

Drug resistance is frequently developing during treatment of cancer patients. Intracellular drug uptake is one of the important characteristics to understand mechanism of drug resistance. However, the heterogeneity of cancer cells requires the investigation of drug uptake at the single cell level. Here, we developed a microfluidic device for parallel probing of drug uptake. We combined a v-type valve and peristaltic pumping to select individual cells from a pool of prostate cancer cells (PC3) and place them successively in separate cell chambers in which they were exposed to the drug. Six different concentrations of doxorubicin, a naturally fluorescent anti-cancer drug, were created in loop-shaped reactors and exposed to the cell in closed 2 nL volume chambers. Monitoring every single cell over time in 18 parallel chambers revealed increased intracellular fluorescence intensity according to the dose of doxorubicin, as well as nuclear localization of the fluorescent drug after 2 h of incubation. The herein proposed technology demonstrated a first series of proof of concept experiments and it shows high potential to use for probing drug sensitivity of single cancer cell

Significance of Circulating Tumor Cells Detected by the CellSearch System

The increasing number of treatment options for patients with metastatic carcinomas has created a concomitant need for new methods to monitor their use. Ideally, these modalities would be noninvasive, be independent of treatment, and provide quantitative real-time analysis of tumor activity in a variety of carcinomas. Assessment of circulating tumor cells (CTCs) shed into the blood during metastasis may satisfy this need. We developed the CellSearch System to enumerate CTC from 7.5 mL of venous blood. In this review we compare the outcomes from three prospective multicenter studies investigating the use of CTC to monitor patients undergoing treatment for metastatic breast (MBC), colorectal (MCRC), or prostate cancer (MPC) and review the CTC definition used in these studies. Evaluation of CTC at anytime during the course of disease allows assessment of patient prognosis and is predictive of overall survival

Circulating tumor cells, disease recurrence and survival in newly diagnosed breast cancer

Introduction The presence of circulating tumor cells (CTC) is an independent prognostic factor for progression-free survival and breast cancer-related death (BRD) for patients with metastatic breast cancer beginning a new line of systemic therapy. The current study was undertaken to explore whether the presence of CTC at the time of diagnosis was associated with recurrence-free survival (RFS) and BRD. Methods In a prospective single center study, CTC were enumerated with the CellSearch system in 30 ml of peripheral blood of 602 patients before undergoing surgery for breast cancer. There were 97 patients with a benign tumor, 101 did not meet the inclusion criteria of which there were 48 patients with DCIS, leaving 404 stage I to III patients. Patients were stratified into unfavorable (CTC ≥1) and favorable (CTC = 0) prognostic groups. Results ≥1 CTC in 30 ml blood was detected in 15 (15%) benign tumors, in 9 DCIS (19%), in 28 (16%) stage I, 32 (18%) stage II and in 16 (31%) patients with stage III. In stage I to III patients 76 (19%) had ≥1 CTC of whom 16 (21.1%) developed a recurrence. In 328 patients with 0 CTC 38 (11.6%) developed a recurrence. Four-year RFS was 88.4% for favorable CTC and 78.9% for unfavorable CTC (P = 0.038). A total of 25 patients died of breast cancer-related causes and 11 (44%) had ≥1 CTC. BRD was 4.3% for favorable and 14.5% for unfavorable CTC (P = 0.001). In multivariate analysis ≥1 CTC was associated with distant disease-free survival, but not for overall recurrence-free survival. CTC, progesterone receptor and N-stage were independent predictors of BRD in multivariate analysis. Conclusions Presence of CTC in breast cancer patients before undergoing surgery with curative intent is associated with an increased risk for breast cancer-related death

Importance of circulating tumor cells in newly diagnosed colorectal cancer

Background: The presence of circulating tumor cells (CTC) is associated with poor prognosis in patients with metastatic colorectal cancer (CRC). This study was conducted to determine if the presence of CTC prior to surgery and during follow-up in patients with newly diagnosed non-metastatic CRC identifies patients who are at risk for disease recurrence. Methods: In a prospective single center study 183 patients with newly diagnosed non-disseminated CRC scheduled for surgery were enrolled from 2003 till 2008 and followed up for a median of 5.1 years. CTC were enumerated with the CellSearch System in 4 aliquots of 7.5 ml of peripheral blood before and after surgery (1-26 weeks), after adjuvant therapy and 1, 2, 3 and 4 years after surgery. Findings: ≥1 CTC/ 30ml of blood were detected in 44 (24%) patients before surgery. CTC frequency did not change significantly at the time points after surgery. Patients with CTC before surgery had a significant decrease in Recurrence Free Survival (RFS, logrank test p=0.014) and Colon Cancer Related Survival (CCRS, p=0.002). Five year RFS dropped from 75% to 61% and five year CCRS from 83% to 69% for patients with CTC before surgery. In a multivariate analysis of CTC, T-Stage and N-stage, the presence of CTC and N-stage remained as significant factors for RFS and CCRS. Surprisingly the presence of CTC after surgery was not significantly associated with RFS and CCRS whereas CTC 2-3 years after surgery was again significantly associated with RFS and CCRS. Interpretation: The presence of CTC in patients with stage I-III CRC before surgery is associated with a significant reduction RFS and CCRS. Although similar amounts of CTC were detected within 3 months after surgery they were not associated with RFS or CCRS. In contrast CTC were again highly significant for RFS and CCRS 2-3 years after surgery. These findings suggest a role of CTC detection, to assess which patients need adjuvant treatment. To implement CTC detection in the non-metastatic setting a validated CTC detection technology is needed with increased sensitivity and specificity