Dynamic changes of CTCs in patients with metastatic HR(+)/HER2(-) breast cancer receiving salvage treatment with everolimus/exemestane

PURPOSE

Detection of CTCs represents a poor prognostic factor in patients with early and metastatic breast cancer (mBC) and treatment with everolimus-exemestane (E/E) is an established effective treatment in hormone receptor-positive/HER2-negative mBC patients. The effect of E/E on CTCs in mBC patients was prospectively investigated.

METHODS

CTCs from 50 pre-treated patients with mBC receiving E/E were analyzed using the CellSearch (CS) platform and triple immunofluorescence (IF) staining for cytokeratin, M30 and Ki67 expression to assess their proliferative and apoptotic status.

RESULTS

CTCs (by CS) were detected in 64% of patients before treatment and E/E administration resulted in their decreased prevalence [(n = 18; 36%, p = 0.004) and (n = 7; 19.4%, p = 0.019) post-1st and post-3rd treatment cycle, respectively] whereas it was significantly increased at disease progression (PD: 61%) compared to post-1st and post-3rd cycle (p = 0.049 and p = 0.021, respectively). Ki67-positive CTCs were detected in 60%, 60%, 17% and 50% of patients before treatment, post-1st, post-3rd cycle and at PD, respectively, while the opposite was observed for M30-positive CTCs (0% at baseline, 10% after the 1st cycle, 50% after the 3rd cycle and 0% at PD). The detection of even ≥ 1 CTC/5 ml after one cycle was associated with decreased PFS (3.3 vs 9.0 months, p = 0.025) whereas the detection of even ≥ 2 CTCs at PD was associated with decreased OS (32.4 vs 19.5 months; p = 0.009).

CONCLUSIONS

The combination of E/E resulted in early elimination of proliferating CTCs in mBC patients and this effect was associated with a favorable clinical outcome.

Using a systemic approach to address the requirement for Integrated Water Resource Management within the Water Framework Directive

Sustainable management of water resources calls for integration of ideas and approaches and revolves around assessment of causal-effect relationships as tools towards defining informed mitigation options and planning. The current paper presents a new holistic approach developed within the Globaqua Coordination Project that combines indicator-based well-established and tested concepts towards developing informed Programmes of Measures and River basin management plans: a. The DPSIR framework that has been engaged as central instrument to address the Water Framework Directive requirements and the concepts embedded in the Integrated Water Resource Management; b. The Ecosystem Services Approach emphasizing on the links between ecosystem services, changes in ecosystems and human well-being, c. Scenario assessment for valuation of future conditions to ensure the sustainability in the use of water resources. The implementation of the new combined framework in two river basins, Ebro in Spain and Evrotas in Greece, stressed the need for revised options targeting elimination of water pollution, measures to ensure water supply that covers the demand even under conditions of climate change and increased water stress and the need for improved valuation of environmental and resource use costs.

Dynamic changes of phenotypically different circulating tumor cells sub-populations in patients with recurrent/refractory small cell lung cancer treated with pazopanib

The aim of the study was to investigate the effect of 2^nd-line pazopanib on the different CTCs subpopulations in SCLC patients and evaluate the clinical relevance of their changes. Different CTCs subpopulations were evaluated before pazopanib initiation (n = 56 patients), after one-cycle (n = 35) and on disease progression (n = 45) by CellSearch and double immunofluorescence using anti-CKs and anti-Ki67, anti-M30 or anti-Vimentin antibodies. Before treatment, CTCs were detected in 50% of patients by CellSearch whereas 53.4%, 15.5% and 74.1% patients had CK⁺/Ki67⁺, CK⁺/M30⁺ and CK⁺/Vim⁺ CTCs, respectively. One pazopanib cycle significantly decreased the number of CTCs as detected by CellSearch (p = 0.043) as well as the number of CK⁺/Ki67⁺ (p < 0.001), CK⁺/M30⁺ (p = 0^.015) and CK⁺/Vim⁺ (p < 0^.001) cells. On disease progression, both the incidence and CTC numbers were significantly increased (CellSearch, p = 0.027; CK⁺/Ki67⁺, p < 0.001; CK^+/M30⁺, p = 0.001 and CK⁺/Vim⁺, p < 0^.001)^. In multivariate analysis, the detection of CK⁺/Vim⁺ CTCs after one treatment cycle (HR: 7.9, 95% CI: 2.9–21.8; p < 0.001) and CTCs number on disease progression, as assessed by CellSearch, (HR: 2.0, 95% CI: 1.0–6.0; p = 0.005) were emerged as independent factors associated with decreased OS. In conclusion, pazopanib can eliminate different CTC subpopulations in patients with relapsed SCLC. The analysis of CTCs could be used as a dynamic biomarker of treatment efficacy.

A Comparison of Three Methods for the Detection of Circulating Tumor Cells in Patients with Early and Metastatic Breast Cancer

BACKGROUND

We directly compared CTC detection rates and prognostic significance, using three different methods in patients with breast cancer (BC).

METHODS

Early (n=200) and metastatic (n=164) patients were evaluated before initiating adjuvant or first-line chemotherapy, using the CellSearchTM System, an RT-qPCR for CK-19 mRNA detection and by double immunofluorescence (IF) microscopy using A45-B/B3 and CD45 antibodies.

RESULTS

Using the CellSearchTM System, 37% and 16.5% of early BC patients were CTC-positive (at ≥1 and ≥2 CTCs/23 ml of blood), 18.0% by RT-qPCR and 16.9% by IF; no agreement was observed between methods. By the CellSearchTM 34.8% and 53.7% (at≥ 5 and ≥ 2 CTCs/7.5 ml) of metastatic patients were CTC-positive, 37.8% by RT-qPCR and 28.5% by IF. A significant agreement existed only between the CellSearchTM and RT-qPCR. In 60.8% of cases, differential EpCAM and CK-19 expression on CTCs by IF could explain the discrepancies between the CellSearchTM and RT-qPCR. CTC-positivity by either method was associated with decreased overall survival in metastatic patients.

CONCLUSION

A significant concordance was observed between the CellSearchTM and RT-qPCR in metastatic but not in early BC. Discordant results could be explained in part by CTC heterogeneity. CTC detection by all methods evaluated had prognostic relevance in metastatic patients.

TTF-1- and/or CD56-positive Circulating Tumor Cells in patients with small cell lung cancer (SCLC)

The aim of the study was to evaluate the phenotypic CTCs heterogeneity (TTF-1⁺ and/or CD56⁺) in SCLC patients and correlate it with the CellSearch. Peripheral blood was obtained from 108 consecutive patients. CTCs were detected by CellSearch and double-immunofluorescence using anti-CD45, anti-TTF-1 and anti-CD56 antibodies. Before chemotherapy TTF-1⁺/CD45⁻, CD56⁺/CD45⁻ and TTF-1⁺/CD56⁺ CTCs were detected in 66(61.1%), 55(50.9%) and 46(42.6%) patients, respectively; 60.2% of patients were CellSearch⁺. Among the 22 patients with 0 CTCs/7.5 ml on CellSearch, TTF-1⁺/CD45⁻, CD56⁺/CD45⁻ and TTF-1⁺/CD56⁺ CTCs were detected in 8(36.4%), 6(27.3) and 6(27.3%) patients, respectively; no CK⁺/EpCAM⁺ or TTF1⁺/EpCAM⁺ CTCs were detected in these patients. One-chemotherapy cycle decreased both the number of positive patients (p < 0.001) and their CTC number (p < 0.001), irrespectively of their phenotype and the detection method. The incidence and number of the different CTC subpopulations on PD, was significantly increased at their baseline levels. Multivariate analysis revealed that the increased number of CTCs at baseline and on PD were significantly associated with decreased PFS (p = 0.048) and OS (p = 0.041), respectively. There is an important CTC heterogeneity in such patients according to the expression of TTF-1 and CD56 which could detect EpCAM⁻ CTC subpopulations and, thus, undetectable by CellSearch. These CTC subpopulations are dynamically correlated with treatment efficacy and disease-progression.

Abstract 373: Analytical and clinical validation of an EpCAM-independent assay for CTC detection in peripheral blood of early breast cancer patients based on Cytokeratin-19 (CK-19) RT-qPCR

Introduction: The aim of our study was to evaluate the prognostic significance of our previously developed EpCAM independent RT-qPCR assay for CK-19 mRNA (Stathopoulou et al, Int J Cancer 2006) and validate its analytical and clinical performance in early breast cancer.

Methods: Quality control on analytical sensitivity and specificity, linearity, intra- and inter-assay reproducibility, and stability of the external standard used for the preparation of the calibration curves was performed. Reproducibility of the assay between our labs was evaluated by analyzing 26 cDNAs. The prognostic significance of the assay in respect to DFI and OS was evaluated by analysing peripheral blood of 179 patients with stage I/II breast cancer postoperatively, before the administration of adjuvant chemotherapy.

Results: The limit of detection (LOD) is 3 copies/reaction and limit of Quantitation (LOQ) 10 copies/reaction. The linear range of the calibration curve was 10-105copies/reaction and the intra- and inter-assay reproducibility are shown below:

CK19 transcriptsReproducibility of the assay (n = 3)copies/reactionIntra-assay RSD (%)Inter-assay RSD (%)101.973.151020.932.241030.450.861040.122.581050.11.52

The inter-lab reproducibility of the assay was evaluated by analyzing 26 cDNA samples in both labs and there was a 100% concordance. During the follow up period (8 years) 32/179 (17.9%) patients relapsed and 18/179 (10%) patients died from the disease. 45/179 (25.1%) samples were found positive for CK-19 and 134/179 (74.9%) negative. In the group of CK-19 positive patients 15/45(33.3%) relapsed and 9/45(20.0%) died while in the group of CK-19 negative patients 17(12.7%) patients relapsed and 9(6.7%) died. Kaplan-Meier analysis showed that CK-19 mRNA positivity was significantly associated with DFI (P = 0.014) and OS (P = 0.051).

Conclusions: This EpCAM independent assay can be used for a high-throughput detection of CTCs in peripheral blood and has prognostic significance in early breast cancer.

Citation Format: Areti Strati, Athina Markou, Aliki Stathopoulou, Stella Apostolaki, Dimitris Mavroudis, Vasilis Georgoulias, Evi S. Lianidou. Analytical and clinical validation of an EpCAM-independent assay for CTC detection in peripheral blood of early breast cancer patients based on Cytokeratin-19 (CK-19) RT-qPCR. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 373. doi:10.1158/1538-7445.AM2015-373

Abstract P4-01-13: CTC enumeration and characterization has predictive and prognostic implications in patients with metastatic breast cancer treated with exemestane plus the mTOR inhibitor everolimus

Background: The utility of CTC enumeration in predicting patient (pt) outcome has been demonstrated in metastatic breast cancer (MBC) treated with chemotherapy or endocrine therapy. In this study we evaluated the clinical impact of CTC assessment in terms of both enumeration and characterization in breast cancer pts treated with exemestane plus everolimus. Patients and methods: Thirty-nine pts with hormone receptor (HR)-positive, HER2-negative MBC, received exemestane plus everolimus. CTC enumeration in peripheral blood (7.5 ml) was performed before treatment (n=39), post cycles 1 (n=39) and 3 (n=29), on disease re-evaluation and on relapse, whichever occurred first, using the CellSearch System. CTC characteristics were determined at the same time points by immunofluorescence (IF) analysis of PBMC cytospins (106 cells), triple stained with pancytokeratin (CK) antibody along with Ki67 and M30 as proliferation and apoptosis markers, respectively, using the Ariol System. Patients were assessed by CT scans and bone scan, every 3 months or as clinically indicated. Results: At the cut-off of ≥ 1 CTC, 25 of 39 (64%) pts had detectable CTCs at baseline, 12 (31%) of 39 post-1st and 10 (34.5%) of 29 post-3rd cycle. Ten (25.6%) pts remained CTC(+) and 12 (30.8%) CTC(-) both at baseline and post-1st cycle; 15 (38.5%) CTC(+) pts turned to CTC(-) and 2 (5%) CTC(-) turned to (+). CTC positivity after the first cycle was associated with shorter median progression-free survival (PFS) compared to CTC(-) status (3.9 vs 8 mo, p=0.031). Shorter PFS was also recorded for pts that remained CTC(+) at both time points compared to all other (p=0.02). At the cut-offs of ≥ 2 and ≥ 5 CTCs, 16 (41%) and 9 (23%) pts were CTC(+) at baseline, respectively; post-1st cycle, 7 (18%) and 4 (10%) pts were CTC(+) (at ≥ 2 and ≥ 5 CTCs, respectively). Post-3rd cycle the positivity rate was 17% for both cut-offs and these pts had significantly shorter PFS compared to CTC(-) pts (3.7 vs 8.7 months, p=0.048). Efficacy assessment revealed partial response in 3 (7.7%) pts, stable disease in 27 (69.23%) and progressive disease (PD) in 8 (20.5%); 1 pt was non-evaluable for response. Among pts determined CTC(+) post-1st cycle (cut-off ≥ 2 CTCs), 57% progressed compared to 13% of CTC(-) pts (p=0.02). In addition, at the post-3rd cycle evaluation, pts with PD had significantly higher CTC counts compared to non-progressors (mean ± SEM; 10 ± 5.78/pt vs 1.62±0.83/pt, p=0.027). By the use of IF 43%, 44% and 40% of CTC(+) pts had proliferative [Ki67(+)/M30(-)] CTCs at baseline, post -1st and -3rd cycles, respectively (cut-off ≥ 1 CTC); 67%, 50% and 50% of those pts, respectively, experienced PD. Apoptotic [Ki67(-)/M30(+)] CTCs were detected in 14%, 22% and 60% of CTC(+) pts at baseline, post -1st and -3rd cycles, respectively; none of the pts with apoptotic CTCs experienced PD. Conclusions: CTC enumeration and characterization in terms of proliferation and apoptosis during the course of treatment has significant predictive and prognostic implications in patients with MBC receiving the combination of exemestane plus everolimus.

Citation Format: Sofia Agelaki, Dimitris Mavroudis, Maria Spiliotaki, Eleni Politaki, Maria A Papadaki, Stella Apostolaki, Christos Nikolaou, Vassilis Georgoulias. CTC enumeration and characterization has predictive and prognostic implications in patients with metastatic breast cancer treated with exemestane plus the mTOR inhibitor everolimus [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-01-13.

Effect of front-line chemotherapy on circulating CK-19 mRNA-positive cells in patients with metastatic breast cancer

PURPOSE

To evaluate the effect of front-line chemotherapy on CK-19mRNA+ circulating tumor cells (CTCs) and their relevance in patients with metastatic breast cancer (MBC).

PATIENTS AND METHODS

The presence of CK-19mRNA+ CTCs was assessed using a real-time RT-PCR assay in 298 previously untreated patients with MBC before and after the administration of front-line chemotherapy.

RESULTS

CK-19mRNA+ CTCs were detected in the blood of 199 (66.8 %) and 148 (49.7 %) patients before and after chemotherapy, respectively. There was no correlation between the detection of CK-19mRNA+ CTCs after chemotherapy and the various known clinicopathologic parameters except with HER2 status. The incidence of detection of CK-19mRNA+ CTCs was significantly decreased after the administration of 3 (47.8 %; p < 0.001) or 6 (44.3 %; p = 0.001) chemotherapy cycles. The persistent detection of >2.25 CK-19mRNA+ CTCs both before and after chemotherapy (persistently high group) was associated with a significantly (p = 0.003) decreased overall survival. In addition, chemotherapy-induced decrease of CK-19mRNA+ CTCs (≤2.25 CTCs) was associated with a better survival (47 vs 34 months; p < 0.001). Failure of chemotherapy to decrease the CK-19mRNA+ CTCs ≤2.25 was associated with decreased overall survival (HR 1.405, 95 % CI 1.044-1.891; p = 0.025) whereas in multivariate analysis the persistence of >2.25 CTCs both before and after chemotherapy was emerged as an independent prognostic factor (HR 1.661, 95 % CI 1.070-2.579; p = 0.024).

CONCLUSION

Detection of CK-19mRNA+ CTCs after the completion of front-line chemotherapy in patients with MBC is associated with poor survival and may be a useful tool for the evaluation of front-line chemotherapy.

KRAS genotypic changes of circulating tumor cells during treatment of patients with metastatic colorectal cancer

INTRODUCTION

Circulating tumor cells (CTCs) could represent a non-invasive source of cancer cells used for longitudinal monitoring of the tumoral mutation status throughout the course of the disease. The aims of the present study were to investigate the detection of KRAS mutations in CTCs from patients with metastatic colorectal cancer (mCRC) and to compare their mutation status during treatment or disease progression with that of the corresponding primary tumors.

MATERIALS AND METHODS

Identification of the seven most common KRAS mutations on codons 12 and 13 was performed by Peptide Nucleic Acid (PNA)-based qPCR method. The sensitivity of the assay was determined after isolation of KRAS mutant cancer cells spiked into healthy donors' blood, using the CellSearch Epithelial Cell kit. Consistent detection of KRAS mutations was achieved in samples containing at least 10 tumor cells/7.5 ml of blood.

RESULTS

The clinical utility of the assay was assessed in 48 blood samples drawn from 31 patients with mCRC. All patients had PIK3CA and BRAF wild type primary tumors and 14 KRAS mutant tumors. CTCs were detected in 65% of specimens obtained from 74% of patients. KRAS mutation analysis in CTC-enriched specimens showed that 45% and 16.7% of patients with mutant and wild type primary tumors, respectively, had detectable mutations in their CTCs. Assessing KRAS mutations in serial blood samples revealed that individual patient's CTCs exhibited different mutational status of KRAS during treatment.

CONCLUSIONS

The current findings support the rationale for using the CTCs as a dynamic source of tumor cells which, by re-evaluating their KRAS mutation status, could predict, perhaps more accurately, the response of mCRC patients to targeted therapy.

Detection of circulating cytokeratin-19 mRNA-positive cells in the blood and the mitotic index of the primary tumor have independent prognostic value in early breast cancer

BACKGROUND

Previous studies showed that molecular detection of CK-19 mRNA in peripheral blood and the mitotic index of primary tumors have prognostic value in early breast cancer. The aim of this study was to assess the association between these variables.

PATIENTS AND METHODS

The primary tumors of 223 operable breast cancer patients (92 premenopausal and 131 postmenopausal) were evaluated for the MAI classified as either ≤ 5 per 10, 6 to 10 per 10 and > 10 per 10 or < 10 per 10 and ≥ 10 per 10 mitoses per high power field using a standardized protocol previously reported. Peripheral blood was also collected before and after the end of adjuvant chemotherapy for detection of CK-19 mRNA-positive cells using reverse transcription polymerase chain reaction previously described.

RESULTS

After a median follow-up of 118 months, 75 patients (33.6%) experienced disease relapse and 56 (25.1%) died of breast cancer. MAI was strongly associated with disease-free survival (DFS) and overall survival (OS) (P < .001 for DFS and OS together). Detecting CK-19 mRNA-positive cells in the peripheral blood before but not after adjuvant chemotherapy was associated with marginally worse DFS (P = .055) and OS (P = .059). Cox regression analysis revealed that MAI and CK-19 mRNA-positive cell detection before adjuvant chemotherapy were independent variables associated with decreased DFS (P < .001 and P = .038, respectively) and OS (P < .001 and P = .029, respectively). There was no significant interaction between MAI and detection of CK-19 mRNA-positive cells.

CONCLUSION

MAI of the primary tumor and detection of CK-19 mRNA-positive cells in the blood before adjuvant chemotherapy in early breast cancer patients are 2 independent prognostic factors associated with clinical outcome.

International study on inter-reader variability for circulating tumor cells in breast cancer

Introduction

Circulating tumor cells (CTCs) have been studied in breast cancer with the CellSearch® system. Given the low CTC counts in non-metastatic breast cancer, it is important to evaluate the inter-reader agreement.

Methods

CellSearch® images (N = 272) of either CTCs or white blood cells or artifacts from 109 non-metastatic (M0) and 22 metastatic (M1) breast cancer patients from reported studies were sent to 22 readers from 15 academic laboratories and 8 readers from two Veridex laboratories. Each image was scored as No CTC vs CTC HER2- vs CTC HER2+. The 8 Veridex readers were summarized to a Veridex Consensus (VC) to compare each academic reader using % agreement and kappa (κ) statistics. Agreement was compared according to disease stage and CTC counts using the Wilcoxon signed rank test.

Results

For CTC definition (No CTC vs CTC), the median agreement between academic readers and VC was 92% (range 69 to 97%) with a median κ of 0.83 (range 0.37 to 0.93). Lower agreement was observed in images from M0 (median 91%, range 70 to 96%) compared to M1 (median 98%, range 64 to 100%) patients (P < 0.001) and from M0 and <3CTCs (median 87%, range 66 to 95%) compared to M0 and ≥3CTCs samples (median 95%, range 77 to 99%), (P < 0.001). For CTC HER2 expression (HER2- vs HER2+), the median agreement was 87% (range 51 to 95%) with a median κ of 0.74 (range 0.25 to 0.90).

Conclusions

The inter-reader agreement for CTC definition was high. Reduced agreement was observed in M0 patients with low CTC counts. Continuous training and independent image review are required.

Abstract P1-04-12: Prognostic value of CTC detection by RT-PCR and the CellSearch system before first-line chemotherapy in metastatic breast cancer

Background: CTCs have significant prognostic role in patients with breast cancer. Several techniques developed for CTC detection might help in monitoring treatment efficacy. The CellSearch System is the only clinically validated for use in patients with metastatic breast cancer (MBC). We have previously shown a concordance between RT-PCR for cytokeratin 19 (CK-19) and CellSearch System in the detection of CTCs in MBC. In this study we aimed to evaluate the prognostic value of CTC detection using these assays in the same cohort of patients. Methods: Blood was obtained from patients with MBC before the initiation of first-line chemotherapy. Different aliquots of the same blood sample were evaluated for the presence of CTCs by RT-PCR for CK-19 mRNA and by the CellSearch System. Disease progression and response to treatment were determined using standard clinical and imaging criteria. Results: In 142 patients with available clinical data, CTC evaluation was performed using both methods. Median age was 60.7 years (range, 23-82), 74.6% were post-menopausal and 16.9% were HER2-positive. CTCs were detected in 52.1% and 36.6% of patients by the CellSearch System (cut-offs ≥2 and ≥5 CTCs/7.5 ml, respectively) and in 38.7% by RT-PCR; 27.5% (cut-off ≥2) and 20.4% (cut-off ≥5) of patients were CTC-positive by both methods. Response rate was 40% in patients with CTCs detected by CellSearch (cut-off ≥2) vs 62% in CTC-negative patients; there was no difference in objective responses using the ≥5 cut-off, or using RT-PCR for CTC detection. Median PFS was 9.0 (cut-off ≥2) and 7.5 months (cut-off ≥5) for CTC-positive versus 20.0 (cut-off ≥2) and 18.7 months (cut-off ≥5) for CTC-negative patients using the CellSearch System (p = 0.0001). No significant difference in PFS was evident according to CTC detection by RT-PCR (10.0 vs 13.1 months, p = 0.253). Median survival was 24.7 vs 57.3 (cut-off ≥2) and 18.5 vs 53.7 (cut-off ≥5) months for CTC-positive vs CTC-negative patients using the CellSearch System (p = 0.0001); by RT-PCR, median survival was 30.3 and 50.1 months for CTC-positive and CTC-negative patients, respectively (p = 0.021). Conclusions: The detection of CTCs before first-line chemotherapy using either the CellSearch System or RT-PCR for CK-19 mRNA has significant prognostic value in patients with MBC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-04-12.

Differential effect of adjuvant taxane-based and taxane-free chemotherapy regimens on the CK-19 mRNA-positive circulating tumour cells in patients with early breast cancer

Background:

To determine the effect of adjuvant taxane-free and taxane-based chemotherapy regimens on the elimination of circulating tumour cells (CTCs) in patients with early breast cancer.

Methods:

The presence of CK-19 mRNA-positive CTCs in the peripheral blood was evaluated before and after chemotherapy, using a real-time RT–PCR assay, in a historical comparison of two cohorts of women with stage I–III breast cancer treated with adjuvant taxane-free (N=211; FE₇₅C or E₇₅C) and taxane-based (N=334; T/E₇₅C or T/E₇₅) chemotherapy.

Results:

Taxane-based chemotherapy resulted in a higher incidence of CTCs' elimination than taxane-free regimens since 49.7% (74 of 149) and 33.0% (29 of 88) of patients with detectable CTCs before chemotherapy, respectively, turned negative post-chemotherapy (P=0.015). Patients treated with taxane-free regimens had a significantly lower disease-free survival (DFS) (P=0.035) than patients treated with taxane-based regimens; this difference was observed in patients with but not without detectable CTCs before chemotherapy (P=0.018 and P=0.481, respectively). The incidence of deaths was significantly higher in the taxane-free cohort of patients with but not without detectable CTCs before chemotherapy compared with that of the taxane-based cohort (P=0.002). Multivariate analysis revealed that the chemotherapy regimen was significantly associated with prolonged DFS (HR: 2.00; 95% CI=1.20–3.34).

Conclusion:

Elimination of CK-19 mRNA-positive CTCs during adjuvant chemotherapy seems to be an efficacy indicator of treatment and is associated with a favourable clinical outcome of patients with detectable CTCs before chemotherapy.

Clinical relevance of circulating CK-19mRNA-positive tumour cells before front-line treatment in patients with metastatic breast cancer

BACKGROUND

To investigate the clinical relevance of CK-19mRNA-positive circulating tumour cells (CTCs) detected before the initiation of front-line treatment in patients with metastatic breast cancer (MBC).

METHODS

The presence of CTCs was detected in 298 patients with MBC using a real-time PCR (RT-PCR assay. In 44 patients, the detection of CTCs was evaluated by both the CellSearch and the RT-PCR assay. Interaction with known prognostic factors and association of CTCs with clinical outcome were investigated.

RESULTS

There was a strong correlation between the detection of CTCs by both assays. CK-19mRNA-positive CTCs were detected in 201 (67%) patients and their detection was independent of various patients' clinico-pathological characteristics. The median progression-free survival (PFS; 9.2 vs 11.9 months (mo), P=0.003) and the overall survival (OS; 29.7 vs 38.9 mo, P=0.016) were significantly shorter in patients with detectable CK-19mRNA-positive CTCs compared with patients without detectable CTCs. Multivariate analysis demonstrated that oestrogen receptor status, performance status and detection of CTCs were emerged as independent prognostic factors associated with decreased PFS and OS.

CONCLUSION

The detection of CK-19mRNA-positive CTCs in patients with MBC before front-line therapy could define a subgroup of patients with dismal clinical outcome.

Trastuzumab decreases the incidence of clinical relapses in patients with early breast cancer presenting chemotherapy-resistant CK-19mRNA-positive circulating tumor cells: results of a randomized phase II study

BACKGROUND

Since the detection of circulating tumor cells (CTCs) which express HER2 is an adverse prognostic factor in early breast cancer patients, we investigated the effect of trastuzumab on patients' clinical outcome.

PATIENTS AND METHODS

Seventy five women with HER2 (-) breast cancer and detectable CK19 mRNA-positive CTCs before and after adjuvant chemotherapy, were randomized to receive either trastuzumab (n=36) or observation (n=39). CK19 mRNA-positive CTCs were detected by RT-PCR and double stained CK(+)/HER2(+) cells by immunofluorescence. The primary endpoint was the 3-year disease-free survival rate.

RESULTS

Fifty-one (89%) of the 57 analyzed patients had HER2-expressing CTCs. After trastuzumab administration, 27 of 36 (75%) women became CK19 mRNA-negative compared to seven of 39 (17.9%) in the observation arm (p=0.001). After a median follow up time of 67.2 months, four (11%) and 15 (38%) relapses were observed in the trastuzumab and observation arm, respectively (p=0.008); subgroup analysis indicated that this effect was mainly confined to women with >3 involved axillary lymph nodes (p=0.004). The median DFS was also significantly higher for the trastuzumab-treated patients (p=0.008).

CONCLUSION

Administration of trastuzumab can eliminate chemotherapy-resistant CK19 mRNA-positive CTCs, reduce the risk of disease recurrence and prolong the DFS.

P5-01-16: The Detection of Circulating CK19 mRNA-Positive Cells in the Blood and the Mitotic Index of the Primary Tumor Have Independent Prognostic Value in Early Breast Cancer

Background: Previous studies have shown that the molecular detection of CK-19 mRNA in peripheral blood and the mitotic index of primary tumor have prognostic value in early breast cancer. The aim of the present study was to assess the association between these variables. Patients and Methods: The primary tumors of 223 operable breast cancer patients (92 premenopausal and 131 postmenopausal) were evaluated for the mitotic activity index (MAI) classified either as &lt;5/10, 6–10/10 and &gt;10/10 or &lt;10/10 and &gt;10/10 mitoses/hpf using a standardized protocol as previously reported (Baak JP et al, Breast Cancer Res Treat 2009, 115:241–254). Peripheral blood was also collected before the start and after the end of adjuvant chemotherapy for detection of CK-19 mRNA-positive cells by RT-PCR as previously described (Stathopoulou et al, Clin Cancer Res 2003, 9:5145–5151). Results: After a median follow-up of 118 months, 75 (33.6%) patients have experienced disease relapse and 56 (25.1%) have died of breast cancer. MAI was strongly associated with disease-free survival (DFS) and overall survival (OS) (p&lt;0.001 for both DFS and OS). Detection of CK19 mRNA-positive cells in the peripheral blood before but not after adjuvant chemotherapy was marginally associated with worse DFS (p=0.055) and OS (p=0.059). There was no correlation between MAI and CK19 mRNA detection before chemotherapy. Cox regression analysis revealed that both MAI and CK19 mRNA-positive cell detection before adjuvant chemotherapy were independent variables associated with decreased DFS (p&lt;0.001 and p=0.038, respectively) and OS (p&lt;0.001 and p=0.029, respectively). The interaction test showed no significant association between MAI and detection of CK19 mRNA-positive cells.

Conclusion: MAI of the primary tumor and detection CK-19 mRNA-positive cells in the blood before the start of adjuvant chemotherapy in women with early breast cancer are two independent prognostic factors associated with clinical outcome.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-01-16.

P4-07-21: A Comparison of Two Methods for the Detection of Circulating Tumor Cells (CTCs) in Patients (pts) with Early and Metastatic Breast Cancer (BC): RT-PCR for Cytokeratin (CK) −19 mRNA Versus the CellSearch System

Background: Different methods are available for the detection of CTCs in pts with BC, however, the variable performance of these assays, the heterogeneity of CTCs, and the possible treatment-induced alteration of the markers evaluated, imply that no ideal method currently exists. We compared the efficiency of two methods to detect CTCs in pts with BC.

Patients and Methods: Blood was obtained from 200 pts with early and 164 with metastatic BC before the start of adjuvant or first-line chemotherapy, respectively. Different aliquots of the same sample were evaluated by RT-PCR for CK-19 mRNA and by the CellSearch System. Blood samples were available after the end of adjuvant or first-line therapy in 99 and 93 pts, respectively. CTCs in 23 and 7.5 ml of blood were enumerated by CellSearch, in adjuvant and metastatic pts, respectively. Cut-off values of ≥1 and ≥2 CTCs/23 ml and ≥2 and ≥5 CTCs/7.5 ml were used. Twenty ml of blood were obtained for mRNA extraction in all RT-PCR experiments.

Results: In early BC, 18.0% of samples were positive prior to therapy by RT-PCR and 37.0% (CTC≥1) and 16.5% (CTC≥2) by CellSearch. No significant correlation was shown for the detection of CTCs between methods. Overall (positive and negative) concordance was 62% for CTC≥1 and 73.5% for CTC≥2 (Chi-Square, p=0.161 and p=0.307). Post-chemotherapy, the positivity rate was 33.6% (CTC≥1) and 18.8% (CTC≥2) by CellSearch and 11.6% by RT-PCR (Spearman, R=-0.031, p=0.761). Overall agreement was 60.6% (CTC≥1) and 71.4% (CTC≥2) (Chi-Square, p=0.771 and p=0.708). In the metastatic setting, 37.8% of the samples were positive by RT-PCR, and 50% (CTC≥2) or 32.3% (CTC≥5), by CellSearch (Spearman, R=0.373, p=0.0001). Overall agreement was 70.0% for CTC≥5 (Chi-Square, p=0.0001). Post-chemotherapy, 21% were positive by RT-PCR and 13.7% and 8.4% by CellSearch for CTC≥2 and ≥5, respectively (Spearman, R=0.194, p=0.063). Overall concordance for CTC≥5 was 79.6% (Chi-Square, p=0.017). Agreement was also observed for CTC≥2, pre-and post-chemotherapy (Chi-Square, p=0.0001 and p=0.010). The concordance rates in the adjuvant and metastatic settings are shown in Table 1.

Cytokeratin-19 mRNA-positive circulating tumor cells during follow-up of patients with operable breast cancer: prognostic relevance for late relapse

BACKGROUND

The detection of cytokeratin-19 (CK-19) mRNA-positive circulating tumor cells (CTC) before and/or after adjuvant chemotherapy in patients with operable breast cancer is associated with poor clinical outcome. Reliable prognostic markers for late disease relapse are not available. In this study we investigated the value of CTC detection during the first five years of follow-up in predicting late disease relapse.

METHODS

Blood was analyzed from 312 women with operable breast cancer who had not experienced disease relapse during the first two years of follow-up. A real-time reverse transcriptase polymerase chain reaction (RT-PCR) for CK-19 mRNA was used to detect CTC three months after the completion of adjuvant chemotherapy and every six months thereafter for a follow-up period of five years.

RESULTS

Eighty patients (25.6% of the study population) remained CTC free throughout the five-year period. A change in CTC status was observed in 133 patients (42.6%); 64 patients (20.5%) with initially CK-19 mRNA-positive CTC during the first 24 months turned CTC-negative afterwards while 69 (22.1%) who were initially CTC-negative became CTC-positive. Ninety-nine patients (31.7%) remained persistently CK-19 mRNA-positive. After a median follow-up period of 107 months (range: 38 to 161 months), the persistently CTC-positive patients with either hormonal receptor positive or negative tumors, had a higher risk of late-disease relapse compared to the persistently CTC-negative patients (36.4% versus 11.2%, P <0.001). Multivariate analysis revealed that persistently CTC-positive patients also had a shorter disease-free (P = 0.001) and overall survival (P = 0.001).

CONCLUSIONS

Persistent detection of CK-19 mRNA-positive CTC during the first five years of follow-up is associated with an increased risk of late relapse and death in patients with operable breast cancer and indicates the presence of chemo-and hormonotherapy-resistant residual disease. This prognostic evaluation may be useful when deciding on subsequent adjuvant systemic therapy.

Abstract PD04-04: Cytokeratin-19 mRNA Positive Circulating Tumor Cells during Follow-Up of Patients with Early Breast Cancer: Prognostic Relevance for Late Relapse

PURPOSE: We reported previously that the detection of CK-19 mRNA-positive circulating tumor cells (CTCs) after adjuvant chemotherapy in patients with early breast cancer is associated with poor clinical outcome. Reliable prognostic markers for late disease relapse are not available. In this study we investigated the prognostic value of CTCs’ detection during the first 5 years of follow-up in predicting late disease relapse. PATIENTS AND METHODS: Blood was obtained from 281 patients with early breast cancer who had not experienced disease relapse during the first two years of follow up. CTCs were detected using a real-time reverse transcriptase polymerase chain reaction for CK 19 mRNA after the completion of adjuvant chemotherapy and every six months thereafter for a 5-year follow up period. Patients were classified into four groups based on the CTCs’ status during the first two years and the subsequent three years of follow up (persistently negative, persistently positive, negative turned to positive and the opposite).

RESULTS: The vast majority of patients (92.9%) received some kind of hormonal therapy in addition to chemotherapy. Sixty-nine (24.6%) patients remained CTCs-free throughout the 5-year period. A change in CK-19 mRNA status was observed in 126 (44.9%) patients; 60 (21.4%) patients with initially CK-19 mRNA-positive CTCs during the first 24 months turned CTC-negative afterwards while 66 (23.5%) patients who were initially CTC-negative became CTC-positive. Eighty-six (30.6%) patients remained persistently CK-19 mRNA-positive for the entire 5 years. After 94 months of median follow up (range: 51-147), the relapse rate for each of the above groups of patients is illustrated in the following table.

Table 1: CTCs’ detection status and risk of late disease repapse.

Compared to the persistently negative, only the group of CK-19 mRNA-persistently positive patients had a statistically significant higher risk of relapse (38.4% versus 7.2%, p&lt; 0.001), shorter progression-free survival (not reached vs 135 months, P&lt;0.001) and significant difference in overall survival (not reached vs 146 months, p=0.045).

CONCLUSION: Persistent detection of CK-19 mRNA-positive CTCs in the blood during the first 5 years of follow up after adjuvant chemotherapy is associated with an increased risk of late disease relapse indicating the presence of chemotherapy-and hormonetherapy-resistant residual disease. This prognostic evaluation may be useful when deciding on subsequent adjuvant systemic therapy.

Prognostic significance of the detection of peripheral blood CEACAM5mRNA-positive cells by real-time polymerase chain reaction in operable colorectal cancer

PURPOSE

To evaluate the clinical relevance of circulating CEACAM5mRNA-positive cells in patients with operable colorectal cancer (CRC).

METHODS

Peripheral blood was obtained from 265 patients with operable CRC before the initiation of adjuvant systemic therapy from 96 normal donors and RNA prepared from the Lovo and ARH-77 CRC and leukemic cell lines, respectively, was used as positive and negative controls. The detection of CEACAM5mRNA-positive cells was done using a real-time PCR assay. The association with known prognostic factors and the effect of CEACAM5mRNA-positive cells on patients' prognosis was investigated.

RESULTS

The analytical detection limit of the method was found to correspond to 0.7 Lovo cell equivalence/5 μg RNA, with a sensitivity of 1 tumor cell/10(5) normal cells and a specificity of 97%. Ninety-eight (37%) patients had detectable circulating CEACAM5mRNA-positive cells. Detection of CEACAM5mRNA-positive cells was significantly associated with higher relapse rate (P < 0.001), decreased disease-free survival (DFS; P < 0.001), higher death rate (P = 0.017), and decreased median overall survival (P = 0.025). Multivariate analysis revealed that the detection of circulating CEACAM5mRNA-positive cells was an independent prognostic factor for decreased DFS [HR = 3.4; 95% CI: 2.0-5.9; P < 0.001].

CONCLUSIONS

Detection of peripheral blood CEACAM5mRNA-positive cells is an adverse prognostic factor correlated with poor clinical outcome in patients with operable CRC.

Cytokeratin-19 mRNA-positive circulating tumor cells after adjuvant chemotherapy in patients with early breast cancer

PURPOSE

To evaluate the prognostic significance of cytokeratin-19 (CK-19) mRNA-positive circulating tumor cells (CTCs) in peripheral blood of women with early-stage breast cancer after the completion of adjuvant chemotherapy.

PATIENTS AND METHODS

Blood was obtained from 437 patients with early breast cancer before the start and after the completion of adjuvant chemotherapy, and the presence of CK-19 mRNA-positive CTCs was assessed by real-time reverse transcriptase polymerase chain reaction. Interaction with known prognostic factors and association of CTCs with clinical outcome were investigated.

RESULTS

CK-19 mRNA-positive CTCs were detected before chemotherapy in 179 patients (41.0%). After adjuvant chemotherapy, a significant change in CK-19 status was observed, as status for 51% of patients with initially CK-19 mRNA-positive disease turned negative, and status for 22% of patients with initially CK-19 mRNA-negative disease became positive (McNemar test P = .004). The detection of CK-19 mRNA-positive CTCs postchemotherapy was associated with involvement of more than three axillary lymph nodes (P = .026). Clinical relapses and disease-related deaths were significantly increased in patients with detectable postchemotherapy CK-19 mRNA-positive CTCs (both P < .001, respectively). Disease-free and overall survival were significantly reduced in patients with detectable CK-19 mRNA-positive CTCs postchemotherapy (P < .001 and P = .001, respectively). In multivariate analysis, the detection of CK-19 mRNA-positive CTCs before and after adjuvant chemotherapy was an independent factor associated with reduced disease-free survival (P < .001) and overall survival (P = .003).

CONCLUSION

The detection of CK-19 mRNA-positive CTCs in the blood after adjuvant chemotherapy is an independent risk factor indicating the presence of chemotherapy-resistant residual disease.

Prognostic value of the molecular detection of circulating tumor cells using a multimarker reverse transcription-PCR assay for cytokeratin 19, mammaglobin A, and HER2 in early breast cancer

PURPOSE

To investigate the prognostic value of the molecular detection of circulating tumor cells (CTCs) using three markers [cytokeratin 19 (CK19), mammaglobin A (MGB1), and HER2] in early breast cancer.

EXPERIMENTAL DESIGN

CK19mRNA+, MGB1mRNA+, and HER2mRNA+ cells were detected using real-time (CK19) and nested (MGB1 and HER2) reverse transcription-PCR in the peripheral blood of 175 women with stage I to III breast cancer before the initiation of adjuvant chemotherapy. The detection of CTCs was correlated with clinical outcome. In 10 patients, immunofluorescence staining experiments were done to investigate the coexpression of cytokeratin, MGB1, and HER2 in CTCs.

RESULTS

CK19mRNA+, MGB1mRNA+, and HER2mRNA+ cells were detected in 41.1%, 8%, and 28.6% of the 175 patients, respectively. Patients had one of the following molecular profiles: CK19mRNA+/MGB1mRNA+/HER2mRNA+ (n = 8), CK19mRNA+/MGB1mRNA+/HER2mRNA- (n = 1), CK19mRNA+/MGB1mRNA-/HER2mRNA+ (n = 42), CK19mRNA+/MGB1mRNA-/HER2mRNA- (n = 21), CK19mRNA-/MGB1mRNA+/HER2mRNA- (n = 5), and CK19mRNA-/MGB1mRNA-/HER2mRNA- (n = 98). Double-immunofluorescence experiments confirmed the following CTC phenotypes: CK+/MGB1+, CK+/MGB1-, CK-/MGB1+, CK+/HER2+, CK+/HER2-, MGB1+/HER2-, and MGB1+/HER2+. In univariate analysis, the detection of CK19mRNA+, MGB1mRNA+, and HER2mRNA+ cells was associated with shorter disease-free survival (DFS; P < 0.001, P = 0.001, and P < 0.001, respectively), whereas the detection of CK19mRNA+ and MGB1mRNA+ cells was associated with worse overall survival (P = 0.044 and 0.034, respectively). In multivariate analysis, estrogen receptor-negative tumors and the detection of CK19mRNA+ and MGB1mRNA+ cells were independently associated with worse DFS.

CONCLUSION

The detection of peripheral blood CK19mRNA+ and MGB1mRNA+ cells before adjuvant chemotherapy predicts poor DFS in women with early breast cancer.

Different prognostic value of cytokeratin-19 mRNA positive circulating tumor cells according to estrogen receptor and HER2 status in early-stage breast cancer

PURPOSE

To examine the prognostic value of cytokeratin-19 (CK-19) mRNA-positive circulating tumor cells (CTCs) in early-stage breast cancer patients focusing on clinically relevant subgroups based on estrogen receptor (ER) and HER2 expression.

PATIENTS AND METHODS

CK-19 mRNA-positive CTCs were detected by real-time reverse transcriptase polymerase chain reaction in the blood of 444 consecutive, stage I-III, breast cancer patients before initiation of adjuvant chemotherapy. The association between detection of CK-19 mRNA-positive CTCs and clinical outcome was analyzed for patients with ER-positive, ER-negative, triple-negative, HER2-positive, and ER-positive/HER2-negative tumors.

RESULTS

CK-19 mRNA-positive CTCs were detected in 181 (40.8%) of 444 patients; 109 (41.9%) of 260 patients with ER-positive tumors; 71 (40.6%) of 175 patients with ER-negative tumors; 27 (35%) of 77 patients with triple-negative tumors; 35 (39.8%) of 88 patients with HER2-positive tumors; and 82 (44.1%) of 186 patients with ER-positive/HER2-negative tumors. After a median follow-up of 53.5 months, patients with CK-19 mRNA-positive CTCs experienced reduced disease-free survival (DFS; P < .001) and overall survival (OS; P < .001); this was mainly observed in patients with ER-negative (P < .001 and P < .001, respectively) but not ER-positive tumors (P = .172 and P = .425, respectively) and in patients with triple-negative (P = .008 and P = .001, respectively) and HER2-positive (P = .023 and P = .040, respectively) but not ER-positive/HER2-negative tumors (P = .210 and P = .578, respectively). In multivariate analysis, the interaction between CK-19 mRNA-positive CTCs and ER status was the strongest independent prognostic factor for reduced DFS (hazard ratio [HR], 3.808; 95% CI, 2.415 to 6.003; P < .001) and OS (HR, 4.172; 95% CI, 2.477 to 9.161; P < .001).

CONCLUSION

Detection of CK-19 mRNA-positive CTCs before adjuvant chemotherapy predicts poor clinical outcome mainly in patients with ER-negative, triple-negative, and HER2-positive early-stage breast cancer.

Different prognostic value of cytokeratin-19 mRNA-positive circulating tumor cells according to estrogen receptor status in early breast cancer

10500

Background: We have previously shown that the detection of cytokeratin-19 (CK-19) mRNA-positive circulating tumor cells (CTCs) predicts poor clinical outcome in node-negative breast cancer patients. Here, we examined the prognostic value of CK-19 mRNA-positive CTCs in early breast cancer patients focusing on clinically relevant subgroups based on estrogen receptor (ER) status. Methods: We analysed peripheral blood from 448 consecutive patients with stage I-III breast cancer after surgery and before the initiation of any adjuvant treatment for the presence of CK-19 mRNA-positive CTCs using a real-time RT-PCR assay. The effect of CK-19 mRNA-positive CTCs on clinical outcome of patients with ER-positive, ER-negative, and triple-negative (ER/PR/HER2-negative) tumors was investigated. Results: CK-19 mRNA-positive CTCs were detected in 181 (40.4%) of the 448 patients; 109 (41.5%) of 263 patients with ER-positive, 71 (40.6%) of 175 patients with ER-negative and 27 (35%) of 77 patients with triple-negative tumors. There was no significant difference in the proportion of patients with detectable CK-19 mRNA-positive CTCs in the ER-negative and ER-positive subgroups (p=0.856). After a median follow-up of 53 months, patients with CK-19 mRNA-positive CTCs experienced reduced disease-free survival (DFS) (p<0.0005) and overall survival (OS) (p<0.0005); this was mainly observed in patients with ER-negative (p<0.0005 and p<0.0005, respectively) and triple-negative (p=0.008 and p=0.001, respectively) but not with ER-positive (p=0.174 and p=0.364, respectively) tumors. In multivariate analyses, detection of CK-19 mRNA-positive CTCs was the strongest independent prognostic factor associated with reduced DFS and OS in the entire cohort (p<0.0005 and p=0.009, respectively), in ER-negative (p<0.0005 and p=0.003, respectively) and triple-negative (p=0.020 and p=0.022, respectively) but not in ER-positive tumors (p=0.350 and p=0.621, respectively). Conclusions: Detection of CK-19 mRNA-positive CTCs predicts poor clinical outcome at five years follow-up, only in patients with ER-negative and triple-negative, but not with ER-positive, early breast cancer.

No significant financial relationships to disclose.

Clinical relevance of circulating CK-19 mRNA-positive cells detected during the period of adjuvant tamoxifen treatment in patients with early breast cancer

10534

Background: To evaluate the effect of adjuvant treatment with tamoxifen on the CK-19 mRNA+ circulating tumor cells (CTCs) in patients with early-stage breast cancer. Methods: CTCs were prospectively and longitudinally detected using a specific real-time PCR for CK-19 mRNA in 119 patients with estrogen and/or progesterone receptor-positive tumors during the period of tamoxifen administration. Results: Twenty-two (18.5%) patients had detectable CK-19 mRNA+ CTCs after the completion of adjuvant chemotherapy and in 15 (68.2%) of them adjuvant tamoxifen could not eliminate these cells (persistently positive). In 68 (57.1%) patients no CK-19 mRNA+ CTCs could be detected throughout the follow up period (persistently negative). Seven (46.7%) of the 15 persistently positive and six (8.8%) of the 68 persistently negative patients developed disease recurrence (p=0.00026). Persistence of CK-19 mRNA+ CTCs was associated with a significantly shorter median disease-free interval (p=0.0001) and overall survival (0.0005). Multivariate analysis revealed that the detection of CK-19 mRNA+ CTCs during the administration of tamoxifen was associated with an increased risk of relapse (HR=22.318, p=0.00006) and death (HR=13.954, p< 0.00001). Conclusions: The detection of CK-19 mRNA+ CTCs throughout the period of adjuvant tamoxifen treatment is an independent poor prognostic factor in patients with early breast cancer.

No significant financial relationships to disclose.

Clinical relevance of circulating CK-19 mRNA-positive cells detected during the adjuvant tamoxifen treatment in patients with early breast cancer

BACKGROUND

The purpose of this study was to evaluate the effect of adjuvant treatment with tamoxifen on the CK-19 mRNA+ cells in patients with early-stage breast cancer.

PATIENTS AND METHODS

CK-19 mRNA+ cells were prospectively and longitudinally detected using a specific real-time PCR assay for CK-19 mRNA in 119 patients with estrogen and/or progesterone receptor-positive tumors during the period of tamoxifen administration.

RESULTS

Twenty-two (18.5%) patients had detectable CK-19 mRNA+ cells after the completion of adjuvant chemotherapy and in 15 (68.2%) of them adjuvant tamoxifen could not eliminate these cells (persistently positive). In 68 (57.1%) patients, no CK-19 mRNA+ cells could be detected throughout the follow-up period (persistently negative). Seven (46.7%) of the 15 persistently positive and six (8.8%) of the 68 persistently negative patients developed disease recurrence (P = 0.00026). Persistency of CK-19 mRNA+ cells was associated with a significantly lower median disease-free interval (P = 0.0001) and overall survival (P = 0.0005). Multivariate analysis revealed that the detection of CK-19 mRNA+ cells during the administration of tamoxifen was associated with an increased risk of relapse [hazard ratio (HR) = 22.318, P = 0.00006] and death (HR = 13.954, P < 0.00001).

CONCLUSIONS

The detection of CK-19 mRNA+ cells throughout the period of adjuvant tamoxifen treatment is an independent poor prognostic factor in patients with early breast cancer.

Circulating HER2 mRNA-positive cells in the peripheral blood of patients with stage I and II breast cancer after the administration of adjuvant chemotherapy: evaluation of their clinical relevance

BACKGROUND

The purpose of this study was to evaluate the prognostic value of circulating tumor cells (CTCs) expressing HER2 messenger RNA (mRNA) after the administration of adjuvant chemotherapy in women with operable breast cancer.

PATIENTS AND METHODS

HER2 mRNA-positive CTCs were detected by nested RT-PCR in the peripheral blood of 214 patients with stage I and II breast cancer after the completion of adjuvant chemotherapy.

RESULTS

HER2 mRNA-positive CTCs were detected in 45 (21%) patients. Adjuvant chemotherapy could eliminate HER2 mRNA-positive CTCs in 16 (30.2%) prechemotherapy-positive patients. Moreover, HER2 mRNA-positive CTCs were detected in eight (5%) of 161 prechemotherapy-negative patients. The detection of HER2 mRNA-positive CTCs after chemotherapy was associated with reduced disease-free interval (DFI) (P = 0.006) but not with overall survival (P = 0.2); this effect was mainly observed in node-negative patients (P = 0.04) and to a lesser extent in node-positive (P = 0.06). Multivariate analysis revealed that the detection of HER2 mRNA-positive CTCs was an independent predictive factor for DFI (hazard ratio 3.238, P < 0.0005).

CONCLUSIONS

The detection of HER2 mRNA-positive CTCs after the completion of adjuvant chemotherapy may provide clinically useful information concerning the efficacy of treatment and the prognosis of patients with operable breast cancer.

Central nervous system relapse in patients with breast cancer is associated with advanced stages, with the presence of circulating occult tumor cells and with the HER2/neu status

Introduction

To evaluate the incidence of central nervous system (CNS) involvement in patients with breast cancer treated with a taxane-based chemotherapy regimen and to determine predictive factors for CNS relapse.

Methods

The medical files of patients with early breast cancer (n = 253) or advanced stage breast cancer (n = 239) as well of those with other solid tumors (n = 336) treated with or without a taxane-based chemotherapy regimen during a 42-month period were reviewed. HER2/neu overexpression was identified by immunohistochemistry, whereas cytokeratin 19 (CK-19) mRNA-positive circulating tumor cells (CTCs) in the peripheral blood were identified by real-time PCR.

Results

The incidence of CNS relapse was similar in patients suffering from breast cancer or other solid tumors (10.4% and 11.4%, respectively; P = 0.517). The incidence of CNS relapse was significantly higher in breast cancer patients with advanced disease (P = 0.041), visceral disease and bone disease (P = 0.036), in those who were treated with a taxane-containing regimen (P = 0.024), in those with HER2/neu-overexpressing tumors (P = 0.022) and, finally, in those with detectable CK-19 mRNA-positive CTCs (P = 0.008). Multivariate analysis revealed that the stage of disease (odds ratio, 0.23; 95% confidence interval, 0.007–0.23; P = 0.0001), the HER2/neu status (odds ratio, 29.4; 95% confidence interval, 7.51–101.21; P = 0.0001) and the presence of CK-19 mRNA-positive CTCs (odds ratio, 8.31; 95% confidence interval, 3.97–12.84; P = 0.001) were independent predictive factors for CNS relapse.

Conclusion

CNS relapses are common among breast cancer patients treated with a taxane-based chemotherapy regimen, patients with HER2/neu-positive tumor and patients with CK-19 mRNA-positive CTCs.

A highly specific real-time RT-PCR method for the quantitative determination of CK-19 mRNA positive cells in peripheral blood of patients with operable breast cancer

The aim of the present study was to decrease the incidence of false positives and to better characterize marginally cytokeratin-19 (CK-19) mRNA positive peripheral blood samples from patients with early stage breast cancer. A new set of highly specific primers for CK-19, which avoids amplification of contaminating genomic DNA, was designed and evaluated to improve the specificity and sensitivity of the previously described methodology. The primers were specifically designed to avoid amplification of contaminating genomic DNA and CK-19 pseudogenes. The breast cancer cell line MCF-7 was used as positive control for the development and analytical evaluation of the assay, while peripheral blood samples from 62 healthy female individuals and 160 patients with early breast cancer were used for the evaluation of the sensitivity and specificity of the new primer pair. The novel designed primer pair was highly sensitive, as it detects up to 1 MCF-7 cell, and specific as none of the healthy individuals had detectable CK-19 mRNA positive cells in their peripheral blood. CK-19 mRNA positive cells were detected in 33 out of 160 (20.6%) patients with early breast cancer. Results obtained by the proposed optimized real-time RT-PCR protocol correlated well with those obtained in the same samples by our previously reported quantitative real-time RT-PCR [concordance in 198/222 (89.2%), p = 0.0022, McNemar test]. The improved method eliminates the incidence of false positives and is highly sensitive and specific. The method could be used in a clinical setting in the near future for continuous monitoring and quantification of circulating epithelial cells in the peripheral blood of patients with operable breast cancer, provided that a quite larger number of clinical samples with a known follow-up will be analyzed.

Effect of adjuvant treatment on the circulating CK-19 mRNA-positive tumor cells in patients with early stage breast cancer

20012

Background: To evaluate the effect of adjuvant treatment on the peripheral blood CK-19 mRNA circulating tumor cells (CTCs) in patients with early-stage breast cancer. Methods: CTCs were detected by real-time RT-PCR assay, in 119 patients with estrogen or/and progesterone receptors-positive tumors at the following time points: before the initiation and after the completion of adjuvant chemotherapy and every 3 or 6 months during the period of adjuvant tamoxifen administration. Results: Adjuvant chemotherapy failed to “eliminate” the CTCs in 17 (47%) out of 36 patients with detectable cells in pre-chemotherapy samples; in addition, adjuvant tamoxifen failed to “eliminate” the CTCs in 8 (36.4%) of 22 patients displaying detectable cells in post-chemotherapy samples. The incidence of clinical relapse was significantly (p = 0.017) higher for patients with post-chemotherapy detectable CTCs as well as for patients with persistently detectable CTCs throughout the follow-up period compared with those who did not (65.3% vs 7.3%, respectively; p < 0.001). In multivariate analysis, post-chemotherapy detection of CTCs and their persistence throughout the follow-up period were significantly associated (p = 0.001 and 0.003, respectively) with early relapse. Conclusions: The detection of CK-19 mRNA+ CTCs after adjuvant chemotherapy and during tamoxifen administration is an independent prognostic factor associated with unfavorable outcome.

No significant financial relationships to disclose.

Predictive and prognostic value of peripheral blood cytokeratin-19 mRNA-positive cells detected by real-time polymerase chain reaction in node-negative breast cancer patients

PURPOSE

To evaluate the predictive and prognostic value of peripheral blood cytokeratin-19 (CK-19) mRNA-positive cells in axillary lymph node-negative breast cancer patients.

PATIENTS AND METHODS

Peripheral blood was obtained from 167 node-negative breast cancer patients before the initiation of any systemic adjuvant therapy, and was analyzed for the presence of CK-19 mRNA-positive cells using a real time polymerase chain reaction assay. The association with known prognostic factors and the effect of CK-19 mRNA-positive cells on patients' prognosis was investigated.

RESULTS

CK-19 mRNA-positive cells were detected in the blood of 36 (21.6%) of the 167 patients. There was no correlation between the detection of CK-19 mRNA-positive cells in the peripheral blood and the various known pathologic and clinical prognostic factors; only overexpression of HER2 receptor (score 2+/3+) on the primary tumor was associated with a higher incidence of CK-19 mRNA-positive cell detection (P = .033). Multivariate analysis revealed that detection of peripheral blood CK-19 mRNA-positive cells was associated with early clinical relapse (P < .00001) and disease-related death (P = .008).

CONCLUSION

Detection of peripheral-blood CK-19 mRNA-positive cells is an independent predictive and prognostic factor for reduced disease-free interval and overall survival, respectively, in node-negative breast cancer patients.

Trastuzumab Administration Can Effectively Target Chemotherapy-Resistant Cytokeratin-19 Messenger RNA–Positive Tumor Cells in the Peripheral Blood and Bone Marrow of Patients With Breast Cancer

PURPOSE

The detection of disseminated occult breast cancer cells in peripheral blood and bone marrow is associated with poor prognosis. Since a high proportion of these cells express the HER-2 receptor, we evaluated the effectiveness of the anti-HER-2 antibody trastuzumab (Herceptin) administration to eliminate them.

EXPERIMENTAL DESIGN

Thirty patients with prior chemotherapy exposure were recruited to the study on the basis of having detectable cytokeratin-19 (CK-19) mRNA transcripts by nested reverse transcription (RT)-PCR in the peripheral blood and/or bone marrow. There were 13 patients with stage I, II, or III breast cancer and 17 with stage IV disease. They were treated in two cohorts with either 4 to 8 weekly infusions of trastuzumab at 2 mg/kg (4 mg/kg loading dose; 20 patients) or 2 to 3 infusions every 3 weeks at 6 mg/kg (8 mg/kg loading dose; 10 patients). All of the patients' samples were also analyzed for HER-2 by nested RT-PCR, but detectable HER-2 messenger RNA (mRNA) was not required for inclusion in the study. After trastuzumab infusions, patients were closely monitored by nested RT-PCR and real-time RT-PCR for the detection of CK-19 mRNA-positive cells.

RESULTS

Before trastuzumab infusions, CK-19 mRNA-positive cells were detected in the peripheral blood (n = 10), bone marrow (n = 14), or both (n = 6). In 25 of 30 patients (83%), HER-2 mRNA expression was detected by nested RT-PCR in the pretrastuzumab CK-19-positive sample. After trastuzumab infusions, overall, 28 of 30 (93%) patients became CK-19 mRNA negative by nested RT-PCR and 20 of 30 (67%) by real-time RT-PCR. After a median follow-up of 6 months (range 2 to 22+), the median duration of CK-19 mRNA negativity by nested RT-PCR was 9, 12, and 6 months for stage I/II, III, and IV disease, respectively.

CONCLUSIONS

Therapy-resistant CK-19 mRNA-positive cells in the peripheral blood and bone marrow can be effectively targeted by trastuzumab administration. Further studies are needed to evaluate the prognostic significance of the disappearance of these cells.

Real-time quantification of CK-19 mRNA-positive cells in peripheral blood of breast cancer patients using the lightcycler system

PURPOSE

The purpose of this research was to develop a quantitative real-time reverse transcription-PCR (RT-PCR) for CK19-mRNA and evaluate its clinical potential for the molecular detection of occult carcinoma cells in the peripheral blood of breast cancer patients.

EXPERIMENTAL DESIGN

The method is based on real-time monitoring during PCR of fluorescently labeled specific hybridization probes for CK19-mRNA. The breast cancer cell line MCF-7 was used for the development and analytical evaluation of the assay. We analyzed blood samples from 89 healthy blood donors, 77 patients with early breast cancer (stage I-II) postoperatively, and 47 patients with previously untreated metastatic disease (stage IV) before and after chemotherapy. All of the samples were also analyzed by nested RT-PCR.

RESULTS

The method is highly sensitive and specific, because only 2 of 89 (2.2%) of the healthy control subjects had detectable CK19-mRNA+ cells. In 77 patients with early breast cancer, CK19-mRNA+ cells were detected in 24 (31.2%) before and 5 (6.5%) after adjuvant chemotherapy, and their levels differed significantly (P < 0.001, Wilcoxon test). In 47 patients with verified metastases 19 (40.4%) and 20 (42.6%) were found positive before and after chemotherapy, and no significant difference in CK19-mRNA+ cell levels was observed (P = 0.96, Wilcoxon test). Results obtained by the proposed real-time RT-PCR method correlated well with those obtained for the same samples by nested RT-PCR [concordance in 312 of 337 (92.6%); P = 0.69, McNemar test].

CONCLUSIONS

The developed method is highly sensitive and specific, and can be used for high-throughput continuous monitoring and quantification of circulating epithelial cells in the peripheral blood of breast cancer patients.

Peripheral blood circulating cytokeratin-19 mRNA-positive cells after the completion of adjuvant chemotherapy in patients with operable breast cancer

BACKGROUND

The purpose of this study was to evaluate the prognostic significance of the molecular detection of cytokeratin 19 (CK-19) mRNA-positive cells in the peripheral blood of women with operable breast cancer after the completion of adjuvant chemotherapy.

PATIENTS AND METHODS

Blood from 161 patients with stage I and II breast cancer, obtained after the completion of adjuvant chemotherapy, was tested by nested RT-PCR for CK-19 mRNA detection. Using univariate and multivariate analyses possible interactions with other prognostic factors and association of CK-19 mRNA detection with risk of relapse, disease-free interval (DFI) and overall survival were investigated.

RESULTS

After completion of adjuvant chemotherapy, 27.3% of patients had peripheral blood CK-19 mRNA-positive cells; there was no association of this finding with any other prognostic factors or the type of chemotherapy regimen used. For patients with less than four involved axillary lymph nodes the risk of relapse was 3.81 [95% confidence interval (CI) 1.06-13.71] times higher, and the DFI was significantly reduced (P = 0.028) if CK-19 mRNA-positive cells were detectable in the blood after the completion of adjuvant chemotherapy. In contrast, for patients with four or more involved lymph nodes, the presence of CK-19 mRNA-positive cells after adjuvant chemotherapy did not significantly affect the risk of relapse or DFI. Furthermore, the risk of relapse was higher (hazards ratio 3.70; 95% CI 1.09-13.89) and the DFI was reduced (P = 0.022) for patients with detectable CK-19 mRNA-positive cells following adjuvant cyclophosphamide, methotrexate and 5-fluorouracil (CMF) as compared with epirubicin, cyclophosphamide and 5-fluorouracil (FEC) or sequential taxotere-epirubicin and cyclophosphamide (T/EC) chemotherapy.

CONCLUSIONS

The detection of CK-19 mRNA-positive cells in the peripheral blood after adjuvant chemotherapy may be of clinical relevance for patients with early breast cancer and less than four involved axillary lymph nodes.