Elin Borgen

Detection of Isolated Tumor Cells in Bone Marrow Is an Independent Prognostic Factor in Breast Cancer

PURPOSE This study was performed to disclose the clinical impact of isolated tumor cell (ITC) detection in bone marrow (BM) in breast cancer. PATIENTS AND METHODS BM aspirates were collected from 817 patients at primary surgery. Tumor cells in BM were detected by immunocytochemistry using anticytokeratin antibodies (AE1/AE3). Analyses of the primary tumor included histologic grading, vascular invasion, and immunohistochemical detection of c-erbB-2, cathepsin D, p53, and estrogen receptor (ER)/progesterone receptor (PgR) expression. These analyses were compared with clinical outcome. The median follow-up was 49 months. RESULTS ITC were detected in 13.2% of the patients. The detection rate rose with increasing tumor size (P =.011) and lymph node involvement (P <.001). Systemic relapse and death from breast cancer occurred in 31.7% and 26.9% of the BM-positive patients versus 13.7% and 10.9% of BM-negative patients, respectively (P <.001). Analyzing node-positive and node-negative patients separately, ITC positivity was associated with poor prognosis in the node-positive group and in node-negative patients not receiving adjuvant therapy (T1N0). In multivariate analysis, ITC in BM was an independent prognostic factor together with node, tumor, and ER/PgR status, histologic grade, and vascular invasion. In separate analysis of the T1N0 patients, histologic grade was independently associated with both distant disease-free survival (DDFS) and breast cancer-specific survival (BCSS), ITC detection was associated with BCSS, and vascular invasion was associated with DDFS. CONCLUSION ITC in BM is an independent predictor of DDFS and BCSS. An unfavorable prognosis was observed for node-positive patients and for node-negative patients not receiving systemic therapy. A combination of several independent prognostic factors can classify subgroups of patients into excellent and high-risk prognosis groups.

A concept for the standardized detection of disseminated tumor cells in bone marrow from patients with primary breast cancer and its clinical implementation

Numerous single‐institutional studies and a large pooled analysis have demonstrated that the presence of disseminated tumor cells (DTCs) in the bone marrow (BM) from patients with primary, nonmetastatic breast cancer (Stages I‐III) is associated with impaired prognosis. To date, sampling of BM and assessment of DTCs is not considered a routine procedure in the clinical management of breast cancer patients; however, emerging data suggest a future role for risk stratification and monitoring of therapeutic efficacy. Because these clinical options need to be evaluated in trials to verify the principle of this concept in the clinical setting, agreement on the standardized detection of DTCs is necessary. Consequently, the German, Austrian, and Swiss Societies for Senology recently formed a panel 1) to review and discuss the existing methodologies, 2) to find a consensus for a standardized detection of DTCs, and 3) to explore the options for its clinical implementation. Cancer 2006.

Isolated tumor cells in bone marrow three years after diagnosis in disease-free breast cancer patients predict unfavorable clinical outcome

Purpose: The aim of the study was to explore the value of analyzing bone marrow (BM) for the presence of isolated tumor cell(s) (ITCs) in disease-free breast cancer patients 3 years after diagnosis. Experimental Design: ITCs in BM at operation was found to be an independent prognostic factor in 817 breast cancer patients. Among these, 356 disease-free patients were analyzed with a second BM after 3 years follow-up (median 40 months, SD 3 months, range 29–52). ITC was detected by immunocytochemistry with anticytokeratine antibodies (AE1/AE3). Results: The population consisted of 70% T1 and 72% node-negative patients. ITC in BM was detected in 15%. At a median of 25 months since the second BM aspiration (66 months since diagnosis), 32 patients had developed relapse, 12 local and 20 systemic. Of the patients with ITC in BM, 21% relapsed compared with 7% of the ITC-negative patients (P < 0.001). Ten patients died of breast cancer. Survival analyses showed that ITC in BM predicted reduced distant disease-free survival (DDFS) and breast cancer specific survival (BCSS; P < 0.001, log-rank test). Uni-and multivariate analyses of the prognostic value of N, T, estrogen receptor/progesterone receptor, and BM status, histological grade, vascular invasion, p53-, c-erb-B2-, and cathepsin D expression were performed. BM status was the only independent prognostic factor for both DDFS and BCSS, whereas c-erbB-2 and N status were independent for BCSS and vascular invasion and T status for DDFS. Conclusions: ITC in BM 3 years after diagnosis in disease-free breast cancer patients is an independent prognostic factor. Detection of residual disease by BM analysis at follow-up may unravel insufficient adjuvant treatment. The clinical implications should be further explored.

Persistence of Disseminated Tumor Cells in the Bone Marrow of Breast Cancer Patients Predicts Increased Risk for Relapse—A European Pooled Analysis

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. Clin Cancer Res; 17(9); 2967–76. ©2011 AACR.

Immunocytochemical detection of isolated epithelial cells in bone marrow: non‐specific staining and contribution by plasma cells directly reactive to alkaline phosphatase

Detection of isolated tumour cells (TCs) in bone marrow (BM) from epithelial cancer patients by immunocytochemical (ICC) analysis seems to predict future relapse, but the reported percentages of positive BMs among patients with localized cancer show large variations and the number of detected TCs is low. This emphasizes the importance of thoroughly testing the methods in use. This study was performed to clarify to what extent positive staining of haematopoietic cells (HCs) interferes with the ICC detection of epithelial cells in BM. BM mononuclear cells (MNCs) from normal donors and stage I–II breast cancer patients were stained with anti‐cytokeratin (CK) and isotype control monoclonal antibodies (MAbs) followed by alkaline phosphatase (AP)‐based visualization of immunolabelled cells. In the ICC staining of normal donors by the anti‐CK MAbs AE1/AE3 or A45‐B/B3, rare immunoreactive cells were detected in 7/20 and 8/19 BMs, respectively. Morphological examination recognized all these cells as typical HCs. In the breast cancer patients (n=257), anti‐CK‐positive cells were detected in 26·6 per cent, excluding cells with HC morphology. Using the same morphological criteria, isotype control‐positive cells were detected in 5·4 per cent of patients. Some of the false‐positive events were further analysed and cells with strong reactivity against the AP enzyme alone were detected. Double ICC staining recognized the majority of these AP directly‐reactive cells as CD45‐negative and human Ig kappa/lambda‐positive, in accordance with the phenotype of mature plasma cells. Morphological evaluation and adequate controls are important to ensure the diagnostic specificity of micrometastases in BM. It is recommended that the number of BM MNCs included in negative controls should equal the number of cells in the diagnostic specimens.

Comparison of the clinical significance of occult tumor cells in blood and bone marrow in breast cancer

Immunocytochemical (ICC) detection of disseminated tumor cells (DTC) in bone marrow (BM) in early breast cancer is an independent prognostic factor. The significance of circulating tumor cells (CTC) in peripheral blood (PB) needs further exploration and comparison to DTC detection. PB and BM were prospectively collected from 341 breast cancer patients median 40 months after operation. PB samples were analyzed for tumor cells by a negative immunomagnetic technique (10 × 106 cells/test). BM aspirates were analyzed by standard ICC (2 × 106 cells/test). CTC were present in 10% of the patients and DTC in 14%. Thirty‐seven relapses and 14 breast cancer deaths have occurred at median 66 months after diagnosis. Both CTC‐status and DTC‐status were significantly associated with disease free survival (DFS) (event rate: CTC‐positive 26.5% vs. CTC‐negative 9.1%; DTC‐positive 29.2% vs. DTC‐negative 7.8%) (p < 0.001/p < 0.001, log rank) and breast cancer specific survival (event rate: CTC‐positive 17.6% vs. CTC‐negative 2.6%; DTC‐positive 12.5% vs. DTC‐negative 2.7%) (p < 0.001/p < 0.001). The presence of both CTC and DTC (n = 8) resulted in an especially poor prognosis (p < 0.001). In node negative patients, DTC‐status, but not CTC‐status, predicted differences in DFS (p = 0.006 vs. p = 0.503). Excluding 23 patients with breast cancer‐related events prior to the sample collections, CTC detection was not significantly associated with DFS/distant‐DFS (p = 0.158/0.193), in contrast to DTC detection (p < 0.001/<0.001). Presence of CTC and absence of DTC did not affect DFS (p = 0.516). Applied to early stage disease, CTC analysis of increased volumes of PB appears less sensitive and prognostic than standard DTC analysis. Currently, this does not support an exchange of BM with PB for analysis of occult tumor cells.

Genomic architecture characterizes tumor progression paths and fate in breast cancer patients

This study demonstrates the relation among structural genomic alterations, molecular subtype, and clinical behavior and shows that an objective score of genomic complexity can provide independent prognostic information in breast cancer. Form and Malfunction Breast cancer is an iniquitous disease with a panoply of predisposing genetic and environmental causes, the details of which have yet to be fully understood. One of every four women will be diagnosed with breast cancer, hence the early and accurate identification of specific tumor features that may affect overall survival is imperative in achieving an optimal prognosis. A widely appreciated taxonomy in the breast cancer field has enabled the molecular discernment of five pathological subtypes; however, as research dives deeper into the chromosomal underpinnings of the disease, new classifiers are needed to augment what is known with key structural details to create a more vivid tumor landscape. Now, Russnes and colleagues have generated new algorithms that can estimate the specific genomic region as well as the architectural type of rearrangement—gains or losses of chromosome arms. A cohort of breast tumors was scored using this method, and all tumors with complex rearrangements had more whole chromosome arms affected than those without complex rearrangement. Moreover, there was an overlapping correlation with the molecular subtyping features of the tumors, and the score could confer prognostic power. Distinct molecular subtypes of breast carcinomas have been identified, but translation into clinical use has been limited. We have developed two platform-independent algorithms to explore genomic architectural distortion using array comparative genomic hybridization data to measure (i) whole-arm gains and losses [whole-arm aberration index (WAAI)] and (ii) complex rearrangements [complex arm aberration index (CAAI)]. By applying CAAI and WAAI to data from 595 breast cancer patients, we were able to separate the cases into eight subgroups with different distributions of genomic distortion. Within each subgroup data from expression analyses, sequencing and ploidy indicated that progression occurs along separate paths into more complex genotypes. Histological grade had prognostic impact only in the luminal-related groups, whereas the complexity identified by CAAI had an overall independent prognostic power. This study emphasizes the relation among structural genomic alterations, molecular subtype, and clinical behavior and shows that objective score of genomic complexity (CAAI) is an independent prognostic marker in breast cancer.

Presence of bone marrow micrometastasis is associated with different recurrence risk within molecular subtypes of breast cancer

Expression profiles of primary breast tumors were investigated in relation to disseminated tumor cells (DTCs) in bone marrow (BM) in order to increase our understanding of the dissemination process. Tumors were classified into five pre‐defined molecular subtypes, and presence of DTC identified (at median 85 months follow‐up) a subgroup of luminal A patients with particular poor outcome (p=0.008). This was not apparent for other tumor subtypes. Gene expression profiles associated with DTC and with systemic relapse for luminal A patients were identified. This study suggests that DTC in BM differentially distinguishes clinical outcome in patients with luminal A type tumors and that DTC‐associated gene expression analysis may identify genes of potential importance in tumor dissemination.

Increased sensitivity for detection of micrometastases in bone- marrow/peripheral-blood stem-cell products from breast-cancer patients by negative immunomagnetic separation

Immunocytochemical detection (ICC) of isolated tumor cells in bone marrow (BM) is currently the most established method for monitoring early dissemination in epithelial cancer. However, the low sample size that can practically be analyzed restricts the sensitivity and reliability of the ICC method. To be able to analyze larger samples, a negative immunomagnetic separation (IMS) technique, utilising anti‐CD45‐conjugated Dynabeads, has been developed. Tumor‐cell enrichment by depletion of CD45‐expressing mononuclear cells (MNC) is followed by ICC for detection of the cytokeratin (CK)‐positive (+) epithelial cells. In this study, bone‐marrow samples (n = 165) and peripheral‐blood‐progenitor‐cell (PBPC) apheresis products (n = 22) from breast‐cancer patients were analyzed. The negative IMS analysis of 1 to 2 × 107 MNC was compared with ICC analysis of 2 × 106 unseparated MNC. Negative IMS resulted in 85% mean depletion of MNC. The results showed that 11.7% of the samples were positive by ICC analysis of unseparated MNC, as compared with 23.5% after negative IMS. In samples presenting >10 CK+ cells, a 4‐fold higher number of positive cells was detected by the negative IMS technique. Moreover, there was no evidence for general enrichment of false‐positive cells. Altogether our results show that negative IMS is an efficient enrichment method for sensitive detection of CK+ cells in BM/ PBPC products from breast‐cancer patients. This opens the possibility for further characterization of micrometastatic tumor cells. Int. J. Cancer 78:556–560, 1998.

The Prognostic Value of Isolated Tumor Cells in Bone Marrow in Breast Cancer Patients: Evaluation of Morphological Categories and the Number of Clinically Significant Cells

Purpose/Experimental Design: Immunocytochemical detection of isolated tumor cells (ITCs) in the bone marrow (BM) is a prognostic factor in breast cancer. However, hematopoietic cells (HCs) can occasionally be stained by the techniques used. Morphological evaluation improves the specificity of ITC detection, but optimal separation of ITCs from false-positive HCs needs to be determined. Here, predetermined morphological categories of immunocytochemically (ICC)-positive cells in the BM and the number of detected ITCs were analyzed for association with clinical outcome in 817 early-stage breast cancer patients (median 49 months of follow-up). All ICC+ cells detected were categorized into one of the following groups: (a) tumor cell (TC); (b) uninterpretable cell (UIC); (c) probable HC; or (d) HC. Results: Among the TC+ patients, 30.6% and 25.9% experienced systemic relapse (SR) and breast cancer death (BCD), respectively, as compared with 13.3% and 8.5% of patients without TCs in the BM (survival analyses: P < 0.001, log-rank). The SR and BCD rate was 19.7% and 15.8% for TC−/UIC+ patients versus 12.5% and 7.4% for TC−/UIC− patients. Survival analyses confirmed that the UIC+ group contained clinically significant cells (P = 0.018, log-rank). No difference in clinical outcome was observed, regardless of whether probable HCs or HCs were present. Analyzing the number of ITC+ cells, SR and BCD occurred in 12.4% and 7.4% of patients with 0 ITCs present, 21.3% and 18.5% of patients with 1 ITC present, 19.4% and 16.7% of patients with 2 ITCs present, and 42.5% and 32.5% of patients with ≥3 ITCs present. Conclusions: Morphological categorization of ICC+ cells improves the clinical value of ITC detection in the BM. The presence of only one ITC reduces survival, and a greater number of ITCs further aggravates the prognosis.