NR2F1 stratifies dormant disseminated tumor cells in breast cancer patients.

BACKGROUND: The presence of disseminated tumor cells (DTCs) in bone marrow (BM) is an independent prognostic factor in early breast cancer but does not uniformly predict outcome. Tumor cells can persist in a quiescent state over time, but clinical studies of markers predicting the awakening potential of DTCs are lacking. Recently, experiments have shown that NR2F1 (COUP-TF1) plays a key role in dormancy signaling. METHODS: We analyzed the NR2F1 expression in DTCs by double immunofluorescence (DIF) staining of extra cytospins prepared from 114 BM samples from 86 selected DTC-positive breast cancer patients. Samples collected at two or more time points were available for 24 patients. Fifteen samples were also analyzed for the proliferation marker Ki67. RESULTS: Of the patients with detectable DTCs by DIF, 27% had ≥ 50% NR2F1high DTCs, chosen a priori as the cut-off for "dormant profile" classification. All patients with systemic relapse within 12 months after BM aspiration carried ≤ 1% NR2F1high DTCs, including patients who transitioned from having NR2F1high-expressing DTCs in previous BM samples. Of the patients with serial samples, half of those with no relapse at follow-up had ≥ 50% NR2F1high DTCs in the last BM aspiration analyzed. Among the 18 relapse-free patients at the time of the last DTC-positive BM aspiration with no subsequent BM analysis performed, distant disease-free intervals were favorable for patients carrying ≥ 50% NR2F1high DTCs compared with those with predominantly NR2F1low DTCs (p = 0.007, log-rank). No survival difference was observed by classification according to Ki67-expressing DTCs (p = 0.520). CONCLUSIONS: Our study translates findings from basic biological analysis of DTC dormancy to the clinical situation and supports further clinical studies of NR2F1 as a marker of dormancy.

Prognostic significance of S100A4-expression and subcellular localization in early-stage breast cancer.

PURPOSE: Prognostic factors are useful in order to identify early-stage breast cancer patients who might benefit from adjuvant treatment. The metastasis-promoting protein S100A4 has previously been associated with poor prognosis in breast cancer patients. The protein is expressed in diverse subcellular compartments, including the cytoplasm, extracellular space, and nucleus. Nuclear expression is an independent predictor of poor outcome in several cancer types, but the significance of subcellular expression has not yet been assessed in breast cancer. METHODS: Nuclear and cytoplasmic expression of S100A4 was assessed by immunohistochemistry in prospectively collected tumor samples from early-stage breast cancer patients using tissue microarrays. RESULTS: In patients not receiving adjuvant systemic therapy, nuclear or cytoplasmic expression was found in 44/291 tumors (15%). Expression of either nuclear or cytoplasmic S100A4 was associated with histological grade III, triple-negative subtype, and Ki-67-expression. Patients with S100A4-positive tumors had inferior metastasis-free and overall survival compared to S100A4-negative. When expression was analyzed separately, nuclear S100A4 was a significant predictor of outcome, while cytoplasmic was not. In patients who received adjuvant treatment 23/300 tumors (8%) were S100A4-positive, but no tumors displayed nuclear staining alone. S100A4-expression was strongly associated with histological grade III and triple-negative subtype. Although not significant, metastasis-free and overall survival was numerically reduced in patients with S100A4-positive tumors. CONCLUSION: S100A4-expression was associated with poor outcome in early-stage breast cancer, but the low percentage of positive tumors and the modest survival differences imply that the clinical utility in selection of patients for adjuvant treatment is limited.

Comparison of molecular and immunocytochemical methods for detection of disseminated tumor cells in bone marrow from early breast cancer patients.

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.

Combined analysis of vascular invasion, grade, HER2 and Ki67 expression identifies early breast cancer patients with questionable benefit of systemic adjuvant therapy.

INTRODUCTION: Over-treatment of low-risk early breast cancer patients with adjuvant systemic therapies is an important clinical challenge. Better techniques are required which can be used to distinguish between the large group of patients with no residual disease after surgery and consequently no benefit of adjuvant treatment, from the smaller group with high relapse risk. A better integration of available prognostic factors might contribute to improved prediction of clinical outcome. MATERIAL AND METHODS: The current study included 346 unselected pT1pN0 patients who did not receive adjuvant systemic treatment. In Norway, no patients with this stage were recommended systemic treatment at the time of the study (1995-1998). Histological type, tumour size, grade, vascular invasion (VI), hormone receptor (HR) status, HER2 and Ki67 (cut-off 10%) were analysed. Median follow-up was 86 months for relapse and 101 months for death. RESULTS: Thirty-eight patients experienced relapse, 31 with distant metastasis. Twenty-one patients died of breast cancer. In univariate analysis grade, HER2, HR, VI and Ki67 had impact on clinical outcome (p < 0.005, log rank). In multivariate analysis, only grade 1-2 vs. grade 3, HER2, VI, and Ki67 status were significant for disease free survival, distant disease free survival, and/or breast cancer specific survival. These factors were used in combination, to separate patients into groups based on the number of unfavourable factors present [combined prognostic score (CPS) 0-4]. Close to 2/3 of the patients (61.4%) had no unfavourable factor (CPS0), whilst 18.4% had CPS ≥ 2. Only 3.6% of those with CPS0 developed metastasis (p < 0.001). The outcome was clearly worse for patients with CPS ≥ 2 (p < 0.001), systemic relapse was detected in approximately 40%. CONCLUSIONS: This study indicates that the combined use of grade, VI, HER2 and Ki67 identifies a subgroup of breast cancer patients with a relapse risk that may question the benefit of adjuvant systemic therapy.

Expression of vascular endothelial growth factor and vascular endothelial growth factor receptors 1 and 2 in invasive breast carcinoma: prognostic significance and relationship with markers for aggressiveness.

AIMS: Vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGFR-1) and VEGF receptor 2 (VEGFR-2) play a role in breast cancer growth and angiogenesis. We examined the expression and relationship with clinical outcome and other prognostic factors. METHODS AND RESULTS: Tumour sections from 468 breast cancer patients were immunostained for VEGF, VEGFR-1, and VEGFR-2, and their relationships with tumour vascularity, disseminated tumour cells (DTCs) in bone marrow and other clinicopathological parameters were evaluated. VEGF, VEGFR-1 and VEGFR-2 immunoreactivities were observed in invasive breast carcinoma cells. VEGF expression was significantly associated with VEGFR-1 and VEGFR-2 expression (P < 0.001). High-level cytoplasmic expression of VEGFR-1 was associated with significantly reduced distant disease-free survival (DDFS) (P = 0.017, log-rank) and breast cancer-specific survival (BCSS) (P = 0.005, log-rank) for all patients, and for node-negative patients without systemic treatment (DDFS, P = 0.03, log-rank; BCSS, P = 0.009, log-rank). VEGFR-1 expression was significantly associated with histopathological markers of aggressiveness (P < 0.05). Significantly reduced survival was observed in DTC-positive patients as compared with DTC-negative patients in the combined moderate/high VEGFR-1 group (P < 0.001 for DDFS and BCSS), and the same was true for DDFS in the moderate VEGFR-2 group (P = 0.006). CONCLUSIONS: High-level expression of VEGFR-1 indicates reduced survival. Higher-level expression of VEGFR-1 or VEGFR-2 in primary breast carcinomas combined with the presence of DTC selects a prognostically unfavourable patient group.

Disseminated tumor cells as selection marker and monitoring tool for secondary adjuvant treatment in early breast cancer. Descriptive results from an intervention study.

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.

The prognostic significance of tumour cell detection in the peripheral blood versus the bone marrow in 733 early-stage breast cancer patients.

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.

Detection and clinical relevance of early disseminated breast cancer cells depend on their cytokeratin expression pattern.

The factors determining the clinical relevance of disseminated tumor cells (DTC) in breast cancer patients are largely unknown. Here we compared the specificity and clinical performance of two antibodies frequently used for DTC detection. Reactivities of antibodies A45-B/B3 (A45) and AE1/AE3 (AE) for selected cytokeratins (CK) were assessed by 2-DE Western Blot analysis. Using these antibodies bone marrow aspirates from 391 breast cancer patients (M(0), pT1-3, pN0-3) were screened for the presence of DTC. To obtain prognostic information, patients were followed up over a median of 83 months for time to relapse and 99 months for time to death. Among the analyzed CK, AE detected CK5, CK7, CK8, and CK19, whereas A45 recognized CK7 and CK18. In total, 24 of 391 patients (6.1%) were DTC-positive for A45, and 41 (10.5%) for AE. Although concordance between the two antibodies was 84.4%, overlap among positive cases was only 3.2%. DTC-positivity with AE and A45 was more frequent in patients of higher nodal status (P=0.019 and P=0.036, respectively). Nearly all patients with A45-positive DTC had hormone receptor-positive tumors (23/24), while detection of AE-positive DTC was more frequent among hormone receptor negative patients (P=0.006). Survival analyses of all patients revealed shorter distant disease-free survival (P=0.039) for patients with A45-positive DTC, whereas the prognostic relevance of AE-positive DTC was restricted to node-positive patients. The clinical utility of immunocytochemical (ICC) DTC detection depends on the anti-CK antibody used, which may reflect the complex CK composition of DTC.

Low Z-4OHtam concentrations are associated with adverse clinical outcome among early stage premenopausal breast cancer patients treated with adjuvant tamoxifen.

Low steady-state levels of active tamoxifen metabolites have been associated with inferior treatment outcomes. In this retrospective analysis of 406 estrogen receptor-positive breast cancer (BC) patients receiving adjuvant tamoxifen as initial treatment, we have associated our previously reported thresholds for the two active metabolites, Z-endoxifen and Z-4-hydroxy-tamoxifen (Z-4OHtam), with treatment outcomes in an independent cohort of BC patients. Among all patients, metabolite levels did not affect survival. However, in the premenopausal subgroup receiving tamoxifen alone (n = 191) we confirmed an inferior BC -specific survival in patients with the previously described serum concentration threshold of Z-4OHtam ≤ 3.26 nm (HR = 2.37, 95% CI = 1.02-5.48, P = 0.039). The 'dose-response' survival trend in patients categorized to ordinal concentration cut-points of Z-4OHtamoxifen (≤ 3.26, 3.27-8.13, > 8.13 nm) was also replicated (P-trend log-rank = 0.048). Z-endoxifen was not associated with outcome. This is the first study to confirm the association between a published active tamoxifen metabolite threshold and BC outcome in an independent patient cohort. Premenopausal patients receiving 5-year of tamoxifen alone may benefit from therapeutic drug monitoring to ensure tamoxifen effectiveness.

The prognostic impact of occult nodal metastasis in early breast carcinoma.

The clinical relevance of isolated tumor cell (ITC: 0.2-2.0 mm) in axillary lymph nodes (ALNs) remains unknown. The aim of this study was to determine their prognostic significance. A total of 295 patients considered as pN0 after routine histological assessment, were reevaluated with ten-level cytokeratin immunohistochemistry (IHC) and two-level hematoxylin-eosin sections. Survival rates, i.e. disease-free survival (DFS), distant disease-free survival (DDFS) and breast cancer specific survival (BCSS) were compared with those of reevaluated node-negative patients. A total of 84 patients (28%) had ITC/MM identified on IHC sections. ITC had no impact on survival at a median 8.2 years of follow-up, whereas MM showed a trend toward poorer DFS (P = 0.091, log rank) and DDFS (P = 0.066) and significantly reduced BCSS (P = 0.016). In multivariate analyses, detection of MM was an independent prognostic factor for DDFS (P = 0.025) and BCSS (P = 0.01) in adjuvant un-treated patients. Micrometastases (MMs) in axillary lymph nodes have prognostic impact. This was not found for ITC. This finding supports the use of systemic adjuvant therapy in patients with MM.