Kruppel-like factor 4 (KLF4) is required for maintenance of breast cancer stem cells and for cell migration and invasion

Kruppel-like factor 4 (KLF4) is highly expressed in more than 70% of breast cancers and functions as an oncogene. However, an exact mechanism by which KLF4 enhances tumorigenesis of breast cancer remains unknown. In this study, we show that KLF4 was highly expressed in cancer stem cell (CSC)-enriched populations in mouse primary mammary tumor and breast cancer cell lines. Knockdown of KLF4 in breast cancer cells (MCF-7 and MDA-MB-231) decreased the proportion of stem/progenitor cells as demonstrated by expression of stem cell surface markers such as aldehyde dehydrogenase 1 (ALDH1), side-population (SP), and by in vitro mammosphere assay. Consistently KLF4 overexpression led to an increase of the cancer stem cell population. KLF4 knockdown also suppressed cell migration and invasion in MCF-7 and MDA-MB-231 cells. Furthermore, knockdown of KLF4 reduced colony formation in vitro and inhibited tumorigenesis in immunocompromised NOD/SCID mice, supporting an oncogenic role for KLF4 in breast cancer development. Further mechanistic studies revealed that the Notch signaling pathway was required for KLF4-mediated cell migration and invasion, but not for CSC maintenance. Taken together, our study provides evidence that KLF4 plays a potent oncogenic role in mammary tumorigenesis likely by maintaining stem cell-like features and by promoting cell migration and invasion. Thus, targeting KLF4 may provide an effective therapeutic approach to suppress tumorigenicity in breast cancer.

Detection of type III secretion gene as an indicator for pathogenic Edwardsiella tarda

AIMS

To differentiate pathogenic and nonpathogenic Edwardsiella tarda strains based on the detection of type III secretion system (T3SS) gene using polymerase chain reaction (PCR).

METHODS AND RESULTS

Primers were designed to amplify Edw. tarda T3SS component gene esaV, catalase gene katB, haemolysin gene hlyA and 16S rRNA gene as an internal positive control. Genomic DNAs were extracted using a commercial isolation kit from 36 Edw. tarda strains consisting of 18 pathogenic and 18 nonpathogenic strains, and 50 ng of each DNA was used as the template for PCR amplification. PCR was performed with a thermocycler (TaKaRa TP600) in a 25-μl volume. Products of esaV were detected in all pathogenic strains, but not in nonpathogenic strains; katB was detected in all pathogenic strains and one of nonpathogenic strains; hlyA was not detected in any strains.

CONCLUSIONS

The detection of esaV gene can be used for the assessment of pathogenic Edw. tarda strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

The strategy using T3SS gene as the virulence indicator provides a useful tool for the clinical assessment of pathogenic Edw. tarda strains and prediction of edwardsiellosis risk in fish culture environments.

Unfocused extracorporeal shock waves induce anabolic effects in rat bone

BACKGROUND

Extracorporeal shock waves are known to stimulate the differentiation of mesenchymal stem cells toward osteoprogenitors and induce the expression of osteogenic-related growth hormones. The aim of this study was to investigate if and how extracorporeal shock waves affected new bone formation, bone microarchitecture, and the mechanical properties of bone in a healthy rat model, in order to evaluate whether extracorporeal shock wave therapy might be a potential treatment for osteoporosis.

METHODS

Thirteen rats received 1000 electrohydraulically generated unfocused extracorporeal shock waves to the right tibia. The contralateral, left tibia was not treated and served as a control. At two, seven, twenty-one, and forty-nine days after administration of the shock waves, in vivo single-photon-emission computed tomography (SPECT) scanning was performed to measure new bone formation on the basis of uptake of technetium-labeled methylene diphosphonate ((99m)Tc-MDP) (n = 6). Prior to and forty-nine days after the extracorporeal shock wave therapy, micro-computed tomography (micro-CT) scans were made to examine the architectural bone changes. In addition, mechanical testing, microcrack, and histological analyses were performed.

RESULTS

Extracorporeal shock waves induced a strong increase in (99m)Tc-MDP uptake in the treated tibia compared with the uptake in the untreated, control tibia. Micro-CT analysis showed that extracorporeal shock waves stimulated increases in both trabecular and cortical volume, which resulted in higher bone stiffness compared with that of the control tibiae. Histological analysis showed intramedullary soft-tissue damage and de novo bone with active osteoblasts and osteoid in the bone marrow of the legs treated with extracorporeal shock waves. Microcrack analysis showed no differences between the treated and control legs.

CONCLUSIONS

This study shows that a single treatment with extracorporeal shock waves induces anabolic effects in both cancellous and cortical bone, leading to improved biomechanical properties. Furthermore, treatment with extracorporeal shock waves results in transient damage to the bone marrow, which might be related to the anabolic effects. After further examination and optimization, unfocused extracorporeal shock waves might enable local treatment of skeletal sites susceptible to fracture.

Impact of HIV on liver fibrosis in men with hepatitis C infection and haemophilia

Hepatitis C virus (HCV) is the major cause of liver disease in haemophilia. Few data exist on the proportion with liver fibrosis in this group after long-term HCV and HIV co-infection. We conducted a cross-sectional multi-centre study to determine the impact of HIV on the prevalence and risk factors for fibrosis in haemophilic men with chronic hepatitis C. Biopsies were independently scored by Ishak, Metavir and Knodell systems. Variables were tested for associations with fibrosis using logistic regression and receiver operating curves (ROC). Of 220 biopsied HCV(+) men, 23.6% had Metavir ≥ F3 fibrosis, with higher mean Metavir fibrosis scores among HIV/HCV co-infected than HCV mono-infected, 1.6 vs. 1.3 (P = 0.044). Variables significantly associated with fibrosis included AST, ALT, APRI score (AST/ULN × 100/platelet × 10(9) /L), alpha-fetoprotein (all P < 0.0001), platelets (P = 0.0003) and ferritin (P = 0.0008). In multiple logistic regression of serum markers, alpha-fetoprotein, APRI and ALT were significantly associated with ≥ F3 fibrosis [AUROC = 0.77 (95% CI 0.69, 0.86)]. Alpha-fetoprotein, APRI and ferritin were significant in HIV(-) [AUROC = 0.82 (95% CI 0.72, 0.92)], and alpha-fetoprotein and platelets in HIV(+) [AUROC = 0.77 (95% CI 0.65, 0.88]. In a multivariable model of demographic and clinical variables, transformed (natural logarithm) of alpha-fetoprotein (P = 0.0003), age (P = 0.006) and HCV treatment (P = 0.027) were significantly associated with fibrosis. Nearly one-fourth of haemophilic men have Metavir ≥ 3 fibrosis. The odds for developing fibrosis are increased in those with elevated alpha-fetoprotein, increasing age and past HCV treatment.

38 DNA METHYLATION IN PORCINE PREIMPLANTATION EMBRYOS DEVELOPED IN VIVO AND PRODUCED BY IN VITRO FERTILIZATION, PARTHENOGENETIC ACTIVATION, AND SOMATIC CELL NUCLEAR TRANSFER

DNA de- and re-methylation are crucial for reprogramming of the differentiated parental/somatic genome in the ooplasm. The presented research was aimed at analysis of the DNA methylation dynamics in porcine preimplantation embryos developed in vivo (IV) and produced in vitro by IVF, somatic cell nuclear transfer (SCNT), and parthenogenetic activation (PA). Embryos of early and late 1-cell, 2-, 4-, and 8-cell, and early and late blastocysts stages obtained by the mentioned methods were fixed in 4% paraformaldehyde and subjected to immunocytochemistry using anti-5MetC (Mouse monoclonal, Abcam, Cambridge, MA, USA) antibody. DNA was labelled using Hoechst 33258 (Sigma, Copenhagen, Denmark). Epifluorescence microscopy (Leica Microsystems, Wetzlar, Germany) images were subjected to NIH imageJ software to measure the DNA methylation/DNA content signal by manually outlining the nuclei (n = 2003) of the embryos. The data were analysed using PROC-GLM statistical procedure in SAS 9.1 (SAS Institute Inc., Cary, NC, USA), least square means were compared and P-values were used to decide the significant differences within and between different groups of embryos. The 1-cell stages lacked active demethylation of paternal genome in IV and IVF embryos. Embryos produced under in vitro conditions presented higher levels of DNA methylation than IV. A lineage specific DNA methylation (hypermethylation of inner cell mass and hypomethylation of trophectoderm) observed in porcine IV late blastocysts was absent in PA and SCNT blastocysts despite the occurrence of de novo methylation in early blastocysts. SCNT early (50%) and late (14%) blastocysts presented DNA methylation pattern similar to IV early and late blastocysts, respectively. Concluding, DNA methylation patterns are strongly impaired under in vitro conditions in porcine preimplantation embryos.

49 IMPROVED PORCINE CLONING EFFICIENCY WITH CELLS CULTURED FOR SEVERAL GENERATIONS AFTER A SINGLE TREATMENT WITH XENOPUS EGG EXTRACT

Extracts from eggs of Xenopus laevis frogs can induce nuclear remodelling or increase transcriptional reprogramming in somatic cells. However, it is not known if this effect is passed on from one cell generation to another, or how it affects somatic cell nuclear transfer in porcine cells. This study aimed to investigate the effect of extract-treated cells over several generations on porcine cloning. Extracts were prepared from 2 frogs (B1 and B2) by the same protocol (Higa et al. 2006 Methods 39, 284–290). Fetal fibroblasts grown on poly-L-lysine coated coverslips were permeabilized by digitonin (7 μg mL–1, 2 min, 4°C) and incubated with 1 extract batch at 37°C for 30 min. After resealing the membrane in DMEM supplemented with 2 mM CaCl2 at 37°C for 2 h, the remaining cells were cultured in ES medium (Vejlsted et al. 2005 Mol. Reprod. Dev. 70, 445–454) for 7 to 8 days when they formed colonies. The colonies were trypsinized and divided onto 2 coverslips for subculture, defined as Experimental Passage 1 (XP1). New subcultures were made every 7 to 8 days when 70 to 80% clusters become colonies until XP15. Colonies from XP3, 8 and 15 were isolated and trypsinized before being used in handmade cloning. Nontreated cells grown in DMEM were used as controls (no colony formation was observed). On each cloning day, cells from different XP number and controls were used. Rates of cleavage (Day 2) and blastocyst development (Day 6) were analysed with chi-square test (SAS version 9.2, SAS Institute Inc., Cary, NC, USA). Results are summarised in Table 1. No difference was observed in cleavage rate between groups. Blastocyst rates of all XP colony cells were significantly higher than their controls. For the same XP number and their controls, blastocyst rates were similar between the colony cells from the 2 extract batches, and there was no difference between their controls, either. In conclusion, the cloning efficiency in porcine cells could be increased with extract-treated cells used for several generations, and this effect was present at XP3, 8, and 15. Table 1.Developmental competence of cloned porcine embryos with extract-treated cells from different batches of extract (B1 and B2) and Experimental Passage (XP) numbers

48 DEVELOPMENTAL COMPETENCE OF CLONED OR PARTHENOGENETICALLY ACTIVATED PORCINE EMBRYOS: EFFECT OF DIAMETER OF PREPUBERTAL GILT OOCYTES

One of the primary factors influencing the developmental ability of cloned embryos is the oocyte′s diameter (Hirao et al. 1994 J. Reprod. Fertil. 100, 333–339). However, the oocyte donor's age (i.e. its sexual maturity) is also important to consider, because a high proportion of immature oocytes can be expected (Ikeda and Takahashi 2003 Reprod. Fertil. Dev. 15, 215–221). The present study was to investigate the effect of diameter of oocytes collected from prepubertal gilts weighing 100 to 120 kg on the developmental ability of cloned and parthenogenetically activated (PA) embryos. Cumulus–oocyte complexes collected from ovaries of prepubertal gilts were in vitro matured for 42 to 44 h as described for sow oocytes (Li et al. 2008 Theriog 70, 800–808). After removal of the cumulus cells, the matured oocytes were sorted into 2 groups based on visual inspection: large (L) and small (S) oocytes, whereas non-sorted oocytes were used as control (C). In addition, 1 batch from each of the 3 groups of oocytes had their mean size measured. Subsequently, all 3 groups were used for handmade cloning (HMC; Li et al. 2009 Reprod. Domest. Anim. 44, 122–127) or parthenogenetic activation (PA; Kragh et al. 2005 Theriogenology 64, 1536–1545). Then a chemical activation with 5 μg mL–1 cytochalasin B and 10 μg mL–1 cycloheximide in PZM-3 medium was applied for 4 h on both HMC and PA embryos. Finally, the activated embryos were washed and cultured in PZM-3 medium using the WOW system. The embryo development was evaluated by cleavage rate (Day 2), blastocyst rate (Day 6), and total cell number in blastocysts. Data were analysed by ANOVA with single factor in Excel (Microsoft Excel 2007, Redmond, WA, USA). The results showed (Table 1) that by simple visual observation, oocytes could be easily sorted into the following groups: L group (mean diameter 110 μm, from 105 to 116 μm), S group (mean diameter 101 μm, from 93 to 106 μm) and C group (mean diameter 107 μm, from 93 to 116 μm). Cleavage rates and total cell number were similar in the 3 groups. However, the blastocyst rate in L group either for HMC or PA was higher than S group. The data confirm that prepubertal gilt oocytes are useful for cloning and PA, but developmental rates can be increased by selection of large oocytes by simple visual observation. Table 1.Data analysis results

Dips and rims in dried colloidal films

We describe a spatial pattern arising from the nonuniform evaporation of a colloidal film. Immediately after the film deposition, an obstacle is positioned above its free surface, minimizing evaporation at this location. In a first stage, the film dries everywhere but under the obstacle, where a liquid region remains. Subsequently, this liquid region evaporates near its boundaries with the dry film. This loss of water causes a flow of liquid and particles from the center of the obstructed region to its periphery. The final film has a dip surrounded by a rim whose diameter is set by the obstacle. This turns out to be a simple technique for structuring films of nanometric thickness.

Abstract P2-07-03: Tumors Resistant to Iressa Treatment Show Increased Aberrant Expression of CREB (Ser133)

Background: Activation of tyrosine kinase receptors, including EGFR, HER2, HER3 and HER4, plays a key role in the prognosis of mammary cancer. EGFR is a validated therapeutic target; but unfortunately, only a small percentage of patients with EGFR-overexpressing tumors respond to therapy, and resistance develops even in responsive patients. Iressa is a small molecule tyrosine kinase inhibitor that suppresses the activation of EGFR. Completely understanding the molecular mechanisms and protein targets involved in the effects of Iressa can help determine why efficacy varies. This requires the simultaneous identification of specific molecular markers in the complex network of signaling pathways that are secondarily modulated by Iressa in mammary cancer.

Methods and Materials: In this study, female Sprague-Dawley rats (50 days old) were given methylnitrosourea (MNU) by IV injection through the jugular vein (75 mg/kg BW). The rats were palpated for mammary cancers 2 times per week. When a palpable mammary cancer of approximately 200-250 mm2 was present, the rat was administered Iressa (6 mg/kg BW/day) by gavage for 2 days. The tumor was then biopsied. The rats were treated with Iressa at the same dose for an additional 40 days and tumors were harvested. At sacrifice, the mammary cancer was rapidly removed and frozen for protein array analysis. The tumors were sorted into two groups based on sensitivity to treatment with Iressa and analyzed by a phospho-protein Proteome Profiler™ Array (R&D, Minneapolis, MN). Three tumors that regressed 27, 39, and 59% were compared to 4 tumors that continued to grow, increasing in size by 56, 106, 210, and 236%. Results and Discussion: Most notably, tumors that continued to grow in spite of Iressa treatment consistently showed a marked increased phosphorylation of CREB (Ser133) and Src (Tyr419) compared to tumors that regressed. CREB phosphorylation at Ser133 enhances its transactivation and transcriptional activities, resulting in increased expression of many downstream target genes involved in cell proliferation and cancer development. In addition, tumors that continued to grow also showed increased phosphorylation of p27 (Thr157) compared to regressed tumors. Phosphorylation of p27 at Thr157 is known to impair its nuclear localization, suggesting an acceleration of the G1/S cell cycle transition, resulting in enhanced cell proliferation. In contrast, tumors that regressed showed marked increased phosphorylation of Hck (Tyr411) compared to tumors that continued to grow. The hck gene is located at 20q11-q12, which is a region affect by interstitial deletions in some acute myeloid leukemias and myeloproliferative disorders and damage to hck might contribute to the pathogenesis of these conditions, suggesting that autophosphorylation of Hck (Tyr411) might be involved in tumor suppression. Conclusions: These results indicated that Iressa resistance in mammary cancer induced by MNU is closely related with activation of the signaling axis of the cytosolic tyrosine kinase, CREB, and that increased p27 phosphorylation could contribute to continuous proliferation. Supported by NCI Contract Number HHSN-261200433009C - NO1-CN-55006-72.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-07-03.

Abstract P6-04-04: Hypoxia Is Associated with Somatic Loss of BRCA1 Protein and Pathway Activity in Triple Negative Breast Cancer

Background: Triple negative breast cancer (TNBC) has loss of BRCA1 activity either through germline mutation, epigenetic modification or negative transcriptional regulators. Yale investigators have demonstrated that tumor hypoxia leads to loss of critical DNA repair activities, including BRCA1, RAD-51 and γ-H2AX (Bindra RS, et al. Cancer Res 2005;65(24): 11597-604). This study was designed to explore the relationship of BRCA1 loss and hypoxia using Carbonic Anhydrase IX (CA-IX), a downstream target of hypoxia-induced factor 1a (HIF-1a), an accepted surrogate biomarker for tumor hypoxia, in TNBC. Methods: Two cohorts of breast tumors from Yale archival materials were studied. The first consisted of 660, unselected breast tumors, the second a cohort of 130 TNBC, both with long term clinical followup. Automated Quantitative Analysis (AQUA) was used to detect the intensity of BRCA1 and CAIX within specific subcellular compartments. CA-IX antibody M75 was provided by the J Zavada lab (1:10000), BRCA1 monoclonal antibody M110 (Ab-1) was purchased from Calbiochem (1:1000). The 130 TNBC cohort was also subjected to whole genome expression analysis. In brief, tissue core biopsies from tumor blocks were subjected to nucleic acid extraction using RecoverAll Total Nucleic Acid Isolation kit (Applied Biosystems) and 600ng total RNA were processed by the Keck Microarray Facility for the Illumina DASL platform. Statistical analysis of gene expression data was carried out in Bioconductor/R software. A set of relevant signatures was selected by enrichment analysis of modules identified by principal component analysis. Signature scores were computed as Pearson correlation between the signature vector of gene contributions and each sample's expression profile for these genes. Results: In the cohort of 660 specimens, 22 were found to have high CA-IX expression score (above cut-off value of 10). Cut-off was based on known positive cell lines and corresponding AQUA scores, as well as visual confirmation of positivity. A negative correlation (Rho=-0.6, p=0.0165) of BRCA1 nuclear protein with CA-IX level was found and this data was reproducible on a duplicate array. Of note, 14 out of 22 hypoxic breast tumors were from triple negative breast cancers (TNBC) (p=0.0034). In the triple negative cohort, CAIX staining was positive in 20 % of cases (n=15/75) and in these samples it was associated with the 2002 van ‘t Veer BRCA1 mutant signature (Rho=0.51). Positive CAIX staining was also associated with worse outcome (p=0.046) as was CAIX mRNA expression (p=0.02).

Conclusions: In human breast tumors BRCA1 nuclear expression is negatively correlated with tumor hypoxia, measured by CAIX. A subset of TNBC has higher levels of hypoxia and BRCA1 signatures. This data suggests that CAIX may be a useful biomarker for BRCA1 loss, and possibly for response to PARP inhibitor therapy. This will be evaluated in our recently completed trial of BSI-201+Irinotecan.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-04-04.

Abstract P1-01-27: Level III and Interpectoral Lymph Nodes Involvement in Breast Cancer with Positive Axillary Lymph Nodes after Neoadjuvant Chemotherapy

Background: In the era of sentinel node biopsy (SNB), mainly aimed at local control, the axillary dissection (AD) was performed for breast cancer with positive node. It was argued that only level I/II lymph nodes dissection might be inadequate because nodes involvement was found in level III and interpectoral region when axillary node was positive. It is necessary to assess the extent of AD after modern preoperative axillary staging. The aim of this study was to investigate the incidence and associated factors of node involvement in level III/interpectoral region. Methods: A consecutive series of 338 core needle biopsy confirmed T0-2 invasive breast cancer cases were included in this study. Axillary node metastases were proved by ultrasound guided needle biopsy (NB) if ultrasonographic abnormal node was detected prior to SNB or by SNB if no abnormal node was detected. Cases of negative NB but positive SNB with image abnormal node were excluded. Prior to AD included level III and interpectoral lymph nodes, 4 to 8 cycles of neoadjuvant chemotherapy with anthrocyclin and/or taxane regimen were completed for each case. The chi-square test was used to determine the relation between level III/interpectoral lymph nodes metastases and clinicopathological factors. Multivariate logistic regression was analyzed for covariate selection. Results: A median of 19 axillary nodes was harvested per case (range: 5-46, average: 19.2). The pathologic complete response rate of axillary nodes was 35.3% (70/198) in NB positive subgroup. Level III and interpectoral lymph nodes were harvested in 76.9% (260/338) of cases (range: 1-8, average: 1.9, median: 1) and 49.7% (168/338) of cases (range: 1-10, average: 1.6, median: 1), respectively. The incidence of positive level III and interpectoral lymph nodes were 8.9% (30/338) and 8.9% (30/338), respectively. Node involvement of level III/interpectoral region was found in 13.3% (45/338) of these cases. The incidence of node involvement in level III/interpectoral region of NB positive subgroup (14.6%, 29/198) was not significantly higher compared with SNB positive subgroup (11.4%, 16/140, P=0.391). Increasing tumor size was significantly correlated with increasing likelihood of node involvement in level III/interpectoral region (T0-1: 6.3% vs T2: 16.7%, P=0.008). In SNB positive T0-1 subgroup, there was no positive node found in level III/interpectoral region. Multivariate analysis showed that tumor size was the only independent factors predicting node involvement in level III/interpectoral region (OR=3.488, 95%CI:1.427-8.528, P=0.006).

Conclusions: The incidence of node involvement in level III/interpectoral region was 13.3% of nodes positive T0-2 breast cancer treated with neoadjuvant chemotherapy. Tumor size may be the predictor of node involvement in this region.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-01-27.

Abstract P1-17-02: Outcome after Locoregional Recurrence in Patients with Inflammatory Breast Cancer

Purpose: High rates of locoregional recurrence (LRR) have been reported in spite of comprehensive tri-modality therapy for patients with inflammatory breast cancer (IBC). The aim of this study was to examine the prognosis of patients who have experienced LRR after treated primary IBC. Methods:

We retrospectively reviewed information for 124 IBC patients who experienced a LRR seen in our institution from 1990-2008. 63 patients had simultaneous distant disease (DM) +/−3 months of LRR (simLRR),

5 patients had LRR &gt; 3 months subsequent to DM, while 56 patients had isolated LRR &gt;3 months prior to DM (isLRR). Overall survival (OS) was calculated from date of recurrence using the Kaplan-Meier method. Results:

Median time to LRR from diagnosis was 13 months (interquartile range 8-21 months). Median survival after LRR was 15 months. 2-yr OS was 46%. Regarding the primary tumors, 23% were estrogen receptor positive (ER+), 33% were HER2-neu positive (H2N+), 81% had lymph vascular space invasion (LVSI), and 83% were grade 3. Comparing isLRR and simLRR cohorts, median survival was 18 months vs. 10 months and 2 yr-OS was 66% vs. 28%, respectively. ER+ and H2N+ primary status predicted for longer 2 yr OS among patients with simLRR but not among isLRR patients. (simLRR, ER+ 57% vs. ER-19% p = 0.02, H2N+ 45% vs. H2N-17% p = 0.01; IsLRR ER+ vs. ER-92% vs. 55% p = 0.15, H2N+ 86% vs. H2N-57% p = 0.11). LVSI was not prognostic in either group and Grade 3 primary trended towards worse outcome among isLRR cohort only, Grade 2 83% vs. Grade 3 64% P = 0.08. Molecular subtyping using ER and H2N status to group tumors demonstrates basal subtype in the primary tumor compared to H2N, luminal B and luminal A is associated with significantly worse 2 yr OS after isLRR (43% vs. 88%, 82%, and 83%, P = 0.04) and simLRR (13% vs. 34%, 80%, 32% P = 0.005) respectively. Conclusions:

Forty-five% of LRR occurred as isolated first events. LRRs generally occur within 2 years after primary IBC treatment and are associated with poor outcomes even as first events. Basal subtype predicts for worse overall survival regardless of distant disease.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-17-02.