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Background: Disseminated tumor cells (DTCs) have potential to predict the effect of adjuvant treatment. The purpose of this study was to compare two methods, reverse transcription quantitative PCR (RT-qPCR) and immunocytochemisty (ICC), for detecting breast cancer DTCs in bone marrow (BM) from early breast cancer patients., Methods: We investigated a subset (n = 313) of BM samples obtained from 271 early breast cancer patients in the "Secondary Adjuvant Taxotere Treatment" (SATT)-trial. All patients in this study had node positive or intermediate/high-risk node negative non-metastatic disease. The DTCs were detected by ICC using AE1-AE3 anti-cytokeratin monoclonal antibodies. Patients with DTCs detected in their BM by ICC after standard adjuvant fluorouracil, cyclophosphamide, epirubicin (FEC) chemotherapy were offered docetaxel treatment. For comparison, 5 × 106 mononuclear cells from the aliquoted BM samples were also analyzed by RT-qPCR using a multimarker (MM) assay based on the tumor cell mRNA markers keratin 19 (KRT19), mammaglobin A (hMAM), and TWIST1. In the MM-assay, a sample was defined as positive for DTCs if at least one of the mRNA markers was positive., Results: The MM RT-qPCR assay identified DTCs in 124 (40%) of the 313 BM samples compared with 23/313 (7%) of the samples analyzed by ICC. The concordance between the MM RT-qPCR and ICC was 61% (Kappa value = 0.04) and twelve of the BM samples were positive by both methods. By RT-qPCR, 46/313 (15%) samples were positive for KRT19, 97/313 (31%) for TWIST1, and 3/313 (1%) for hMAM mRNA. There were no statistically significant associations between the individual mRNA markers., Conclusion: The RT-qPCR based method demonstrated more DTC-positive samples than ICC. The relatively low concordance of positive DTC-status between the two different assessment methods suggests that they may be complementary. The clinical relevance of the methods will be evaluated based on future clinical outcome data., Trial Registration: ClinicalTrials.gov: NCT00248703.

Detection of disseminated tumour cells (DTCs) in bone marrow by immunocytochemistry (ICC) includes morphological evaluation of cytokeratin immunopositive cells. The aim of this study was to disclose the prognostic significance of different morphological categories of ICC-positive cells according to treatment status and tumour subtype. Bone marrow samples (at surgery) were analysed for the presence of cytokeratin-positive DTCs by a standard immunocytochemical method. The immunopositive cells were classified into the following categories, prior to any analysis of the association between DTCs and clinical outcome: tumour cells (TC), uninterpretable cells (UIC), hematopoietic cells (HC), and questionable HC (QHC). The analysis included 747 early breast cancer patients. Median follow-up was 84 months for relapse, and 99 months for death. The categorisation of the ICC positive cells revealed TC in 13.3 % of the patients, whereas 13.1, 17.8, and 21.4 % of the cases were positive for UIC, QHC, and HC, respectively. Analysing all patients, only TC and UIC predicted systemic relapse. Separate analysis of all patients not receiving adjuvant systemic treatment (No-Adj; n = 389) showed that only QHC were associated with reduced survival (DDFS: p = 0.008; BCSS: p = 0.004, log rank) and the presence of QHC also remained significant in multivariate analysis. Primary tumour subgroup analysis (of all patients) by hormone receptors (HR) and HER2, demonstrated that only TC/UIC had prognostic impact in the HR+/HER2- patients, whereas presence of QHC was associated with unfavourable outcome only in triple negative patients (DDFS: p = 0.004; BCSS: p = 0.024). Patients with ≥3HC had improved outcome compared to those with fewer/no HC (DDFS: p = 0.005; BCSS: p = 0.009). Hence, morphological DTC subgroups may differ in clinical significance according to primary tumour subtype and treatment status. This emphasises the importance of DTC characterisation, and separate analyses of DTC categories according to tumour subtype. Hematopoietic ("false positive") cells might predict an immune-related favorable clinical outcome.

Background: Presence of disseminated tumor cells (DTCs) in bone marrow (BM) after completion of systemic adjuvant treatment predicts reduced survival in breast cancer. The present study explores the use of DTCs to identify adjuvant insufficiently treated patients to be offered secondary adjuvant treatment intervention, and as a surrogate marker for therapy response., Methods: A total of 1121 patients with pN1-3 or pT1c/T2G2-3pN0-status were enrolled. All had completed primary surgery and received 6 cycles of anthracycline-containing chemotherapy. BM-aspiration was performed 8-12 weeks after chemotherapy (BM1), followed by a second BM-aspiration 6 months later (BM2). DTC-status was determined by morphological evaluation of immunocytochemically detected cytokeratin-positive cells. If DTCs were present at BM2, docetaxel (100 mg/m², 3qw, 6 courses) was administered, followed by DTC-analysis 1 month (BM3) and 13 months (BM4) after the last docetaxel infusion., Results: Clinical follow-up (FU) is still ongoing. Here, the descriptive data from the study are presented. Of 1085 patients with a reported DTC result at both BM1 and BM2, 94 patients (8.7%) were BM1 positive and 83 (7.6%) were BM2 positive. The concordance between BM1 and BM2 was 86.5%. Both at BM1 and BM2 DTC-status was significantly associated with lobular carcinomas (p = 0.02 and p = 0.03, respectively; chi-square). In addition, DTC-status at BM2 was also associated with pN-status (p = 0.009) and pT-status (p = 0.03). At BM1 28.8% and 12.8% of the DTC-positive patients had ≥2 DTCs and ≥3 DTCs, respectively. At BM2, the corresponding frequencies were 47.0% and 25.3%. Of 72 docetaxel-treated patients analyzed at BM3 and/or BM4, only 15 (20.8%) had persistent DTCs. Of 17 patients with ≥3 DTCs before docetaxel treatment, 12 patients turned negative after treatment (70.6%). The change to DTC-negativity was associated with the presence of ductal carcinoma (p = 0.009)., Conclusions: After docetaxel treatment, the majority of patients experienced disappearance of DTCs. As this is not a randomized trial, the results can be due to effects of adjuvant (docetaxel/endocrine/trastuzumab) treatment and/or limitations of the methodology. The clinical significance of these results awaits mature FU data, but indicates a possibility for clinical use of DTC-status as a residual disease-monitoring tool and as a surrogate marker of treatment response., Trial Registration: Clin Trials Gov NCT00248703.

Introduction: The detection of circulating tumour cells (CTCs) in the peripheral blood and disseminated tumour cells (DTCs) in the bone marrow are promising prognostic tools for risk stratification in early breast cancer. There is, however, a need for further validation of these techniques in larger patient cohorts with adequate follow-up periods., Methods: We assayed CTCs and DTCs at primary surgery in 733 stage I or II breast cancer patients with a median follow-up time of 7.6 years. CTCs were detected in samples of peripheral blood mononuclear cells previously stored in liquid-nitrogen using a previously-developed multi-marker quantitative PCR (QPCR)-based assay. DTCs were detected in bone marrow samples by immunocytochemical analysis using anti-cytokeratin antibodies., Results: CTCs were detected in 7.9% of patients, while DTCs were found in 11.7%. Both CTC and DTC positivity predicted poor metastasis-free survival (MFS) and breast cancer-specific survival (BCSS); MFS hazard ratio (HR) = 2.4 (P < 0.001)/1.9 (P = 0.006), and BCSS HR = 2.5 (P < 0.001)/2.3 (P = 0.01), for CTC/DTC status, respectively). Multivariate analyses demonstrated that CTC status was an independent prognostic variable for both MFS and BCSS. CTC status also identified a subset of patients with significantly poorer outcome among low-risk node negative patients that did not receive adjuvant systemic therapy (MFS HR 2.3 (P = 0.039), BCSS HR 2.9 (P = 0.017)). Using both tests provided increased prognostic information and indicated different relevance within biologically dissimilar breast cancer subtypes., Conclusions: These results support the use of CTC analysis in early breast cancer to generate clinically useful prognostic information.

Background: The prognostic significance of disseminated tumor cells (DTC) in bone marrow (BM) of breast cancer patients at the time of primary diagnosis has been confirmed by a large pooled analysis. In view of the lack of early indicators for secondary adjuvant treatment, we here evaluated whether the persistence of DTCs after adjuvant therapy increases the risk of subsequent relapse and death., Patients and Methods: Individual patient data from 676 women with primary diagnosis of early breast cancer stages I-III from 3 follow-up studies were pooled. During clinical follow-up, patients underwent BM aspiration (BMA) to determine the presence of DTC. Tumor cells were detected by the standardized immunoassays. Univariate and multivariable proportional hazards models were estimated to assess the prognostic significance of DTC for disease-free survival (DFS) and overall survival (OS)., Results: Patients were followed for a median of 89 months. BMA was performed at median 37 months after diagnosis of breast cancer. At follow-up BMA, 15.5% of patients had DTCs. The presence of DTC was an independent indicator of poor prognosis for DFS, distant DFS (DDFS), cancer-specific survival, and OS during the first 5 years following cancer diagnosis (log-rank test P < 0.001 values for all investigated endpoints)., Conclusion: Among breast cancer patients, persistent DTCs during follow-up significantly predicted the increased risk for subsequent relapse and death. Analysis of DTC might serve as a clinically useful monitoring tool and should be tested as an indicator for secondary adjuvant treatment intervention within clinical trials., (©2011 AACR.)