bluuebunny/crossref_metadata_2025 huggingface dataset:
Cancer Survivorship Care: How Primary Care Providers Perceive Their Role.
Authors: Robinson P. , Rychlik K. , Mumby P. , Lo S. , Albain K. , Friend P.
Published: December 2010

Background: The majority of cancer survivors are breast cancer patients since about 80% live five years beyond diagnosis. It is projected that by 2020, demand for medical oncologists will exceed supply, in large part due to this increased number of cancer survivors. One proposed solution to address the disparity of resources is to enlist primary care physicians (PCP) in the care of cancer survivors. This pilot study aims to describe the perceptions of primary care physicians relative to cancer survivorship care.Materials and Methods: We conducted a prospective, cross sectional survey of PCPs including internists, family practitioners and gynecologists in the outpatient setting. The primary outcome measure was a 45 item measure of knowledge and perceived role of the PCP in the care of cancer survivors.Results: A total of 84 PCPs of 200 surveyed (42%) responded. Overall, 66 PCPs stated they are interested in participating in the care of cancer survivors (79%); however, only a minority of the PCPs commonly discuss the survivorship phase of the cancer control continuum (n=8, 10%). The majority of PCPs believe that the medical oncologist should remain active in the follow up care in association with the PCP (n=28, 36%) or as a single provider (n=17, 20%). Only 20 PCPs (25%) agreed or strongly agreed that survival outcomes are similar for PCPs and medical oncologists. Most PCPs felt that cancer survivors are more compliant with survivorship care recommendations when proposed by the medical oncologist versus PCP (n=42, 55%). The majority of PCPs felt that survivorship follow up care guidelines would be extremely helpful or very helpful (n=61, 81%), a treatment summary of care document would be extremely helpful or very helpful (n=60, 80%), and a treatment summary care plan would change current practice (n=67, 90%). PCPs treat co-morbidities such as diabetes mellitus, obesity and hypertension; however only a minority of PCPs are aware of the relationship between co-morbidities and cancer survivorship. A little over a third of the PCPs strongly agreed that co-morbidities impacted upon the incidence of cancer, incidence of cancer recurrence and overall cancer mortality; n=30, (39%), n=27 (35%), and n=41 (42%) respectively.Discussion: Although PCPs recognize the opportunity to favorably impact on cancer survivorship issues, there appears to be a level of uncertainty regarding their role. PCPs are receptive to participating in the care of cancer survivors provided that they are given the necessary educational resources to do so. Interventions need to be developed and validated to improve the role of the PCP cancer survivorship care.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1061.
Bone Mineral Density (BMD) Changes at 1 Year in Postmenopausal Women Who Are Not Receiving Adjuvant Endocrine Therapy for Breast Cancer (BCA).
Authors: Van Poznak C. , Morris P. , D'Andrea G. , Schott A. , Griggs J. , Fornier M. , Smerage J. , Henry N. , Hurria A. , Drullinsky P. , Mills N. , Hayes D. , Hudis C.
Published: December 2010

Background: Adjuvant therapy for breast cancer (BCA) may be associated with an increased risk for osteoporosis. This prospective, observational study evaluates BMD changes in postmenopausal women undergoing adjuvant chemotherapy (CTX) for early stage BCA, in the absence of endocrine therapy.Methods: Women who have been postmenopausal for at least 5 years, and who were recently diagnosed with Stage 0-III BCA were eligible to undergo serial BMD if adjuvant endocrine therapy was not recommended. Study BMDs were performed at baseline, 1 and 2 years. All patients (pts) were counseled on calcium, vitamin D and weight bearing exercise. This study was designed to assess serial changes in BMD in the individual and to compare changes in those treated with CTX to those who received no systemic therapy (observation). The study was closed prior to reaching target sample size due to slow accrual.Results: Sixteen pts enrolled. Eleven pts received CTX with a dose dense anthracycline and taxane containing regimen and 5 pts received no systemic adjuvant therapy. Twelve pts, median age 63 (range 52-80), have completed the 1 year assessment and are reported here. Two pts treated with CTX and 1 pt on observation were on bisphosphonates at study entry. Baseline BMD mean in gm/cm2 at the lumbar spine (LS) was 1.112 (range 0.807-1.389) and total hip (TH) was 0.989 (range 0.760-1.213). At 1 year, mean BMD at LS was 1.078 (range 0.767-1.347) and TH was 0.956 (range 0.753-1.210). For all 12 pts at 1 year, the individual BMD changes in LS & TH BMD ranged from 10% loss to 2% gain, with 8 of the 9 CTX treated pts losing 1-10% of BMD and the 3 pts on observation staying within 2% of baseline. The mean dosage of dexamethasone used during CTX by the 9 CTX pts was 230 mg (range 156-288mg). The 3 observation pts had no exposure to steroids during the parallel time period.Conclusions: This prospective, observational study supports the hypothesis that adjuvant CTX, and/or its supportive medications, may be associated with acute changes in BMD in postmenopausal women. Patient follow up continues.Funded by Susan G. Komen for the Cure POP0402593

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1066.
Evaluation of Important Contact Persons and Their Helpfulness in Coping with Metastatic Breast Cancer Induced Psycho-Social Distress. A Prospective Study at a Community-Based Oncology Group Practice in Germany.
Authors: Weide R. , Mergenthaler U. , Köppler H. , Thomalla J. , van Roye C. , Heymanns J.
Published: December 2010

Introduction: Since psycho-social distress is a prevalent condition in metastatic breast cancer patients, it is important to find out which contact persons are called on most frequently to find help in dealing with this situation. In addition to the significance of these contact persons we wanted to find out to what extend they were actually helpful for the patients when contacted.Methods: 57 patients with metastatic breast cancer visiting the practice in April and May 2009 were administered the Distress Thermometer (DT) and Problem List (PL). Thereafter a standardized personal interview was held concerning their important contact persons where patients were asked to name their important contact persons freely. After this additionally a list of possible contact persons was read to the patients to complete the set of persons the patient has contacted. For each contact person the patient was asked to indicate if this contact was helpful or not.Results: The mean distress level observed in this population of 57 metastatic breast cancer patients was 4.9. 36% showed a distress level > 5. Physical problems as a source of distress were stated by 93%, emotional, familial, practical or spiritual problems were causing distress in 72%, 26%, 21% and 4% respectively. 88% of patients named their oncologist as an important person to help them with their distress. Children, partner, friends and general practitioner were important persons for 70%, 65%, 60% and 54% respectively. Regarding only the free answers the order of the most important persons was partner (60%), children (54%), friends (42%), other family members (35%), oncologist (28%), general practitioner (14%). All patients (100%) who sought help from their oncologist described this as helpful. Children, partner, friends and general practitioner were helpful in 90%, 86%, 94% and 94% of cases. 10 patients (18%) had contacted a psychiatrist. This was helpful for 8 (80%) of these patients.There is a positive and statistically significant correlation between distress level and number of persons contacted. (r=.283; p=0.033).Conclusions: Psycho-social distress in patients with metastatic breast cancer is mostly caused by physical and emotional problems. Patients treated in an oncology practice reported a network of care-giving persons as helpful in the coping process. Persons described as being most helpful were oncologists, partner, children, friends an general practitioner. Patients with higher distress levels tend to contact more different persons in trying to find help.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1072.
The Relationship between Breast Cancer and Research; a Bibliometric Study.
Authors: Glynn R. , Chin J. , Kerin M. , Sweeney K.
Published: December 2010

Background: Thousands of articles are published every year in the medical literature relating to the diagnosis and treatment of cancer patients. An area of contention of late has been the amount of research time and money being devoted to breast cancer, to what some believe is to the detriment of research into other forms of malignancy. The aims of this study were to further investigate the relationship between malignancy and research, in order to better quantify the degree to which breast cancer is being over- or under-represented in the research world.Methods: Bibliometrics is the science of studying written communication by systematic measurement and analysis of research publications. In this study, we examined research output over a one-year period for the 26 most commonly diagnosed cancers in the UK. Our strategy was based on that employed by a group in Edinburgh in 2001, and involved correlating research output with incidence and mortality statistics. In addition, we sought to elucidate changes in research output over time and then to correlate these changes with improvements in survival. The survival data used was that published by Coleman et al in 2004, and represents changes in survival over 5 year periods between 1986 and 1999 in England and Wales.Results: A total of 73,798 publications were included in this study. Breast cancer received more research attention than any other malignancy in the time period of this study. Proportional to its incidence and associated mortality, however, breast cancer was markedly underrepresented. This relationship was consistent across publication and study types, and in the higher impact journals. There was a strong positive correlation between improvement in 5-year survival and research output (p = 0.003). Those malignancies enjoying the greatest increases in output included those involving the prostate, non-hodgkins lymphoma, breast and vaginal cancer.Conclusions: This study was intended to provide a snapshot-in-time of research output in malignancy. It has shown that, on the basis of both incidence and mortality, breast cancer is not receiving disproportionate attention by the research community, contrary to popular opinion. Whilst the absolute figures clearly reflect the success of the breast cancer advocacy community in raising and maintaining the profile of the disease, the evidence suggests that, if anything, breast cancer is not receiving the interest it deserves, based on its burden to society.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1080.
A Multi-Center Study To Determine the Optimum Duration of Neoadjuvant Letrozole on Tumour Regression To Permit Breast Conserving Surgery – An Interim Analysis.
Authors: Carpenter R. , Doughty J. , Cordiner C. , Moss N. , Gandhi A. , Wilson C. , Andrews C. , Gui G.
Published: December 2010

Background: Neoadjuvant letrozole is an attractive alternative to chemotherapy for post menopausal women with large, ER positive breast cancer, who are destined for mastectomy but would prefer breast conservation. Prospective studies have not investigated treatment duration beyond 6 months and retrospective studies suggest useful responses can occur after this period.Materials and Methods: This trial is a prospective, UK centrally quality assured, multi-centre, longitudinal study to assess the optimal duration of neoadjuvant letrozole treatment to allow breast conserving surgery for a period of up to12 months. Post menopausal women with large (≥T2), ER and/or PgR positive primary tumours, not considered eligible for breast conservation, were commenced on neoadjuvant letrozole and response was assessed every 2 months with clinical and ultrasound examination until sufficient shrinkage for breast conservation, progression or 12 months had been reached. Ultrasound and Mammography were undertaken at baseline and end-point. We present the initial analysis for time to response and breast conservation.Results: By January 2009, 103 women were available for analysis. 23 (22.3%) had undergone a mastectomy, 60 (58.3%) had achieved breast conservation and 20 (19.4%) remained under evaluation within the trial. The mean age of the group was 74.1 years (52-92). 25 (24.3%) had invasive lobular cancer and 13 (12.6%) had grade 3 tumours. 22 (21.4%) were node positive.Figure 1. Kaplan-Meier plot for time (days) to response sufficient for breast conservation.25% had breast conservation by 5.8 months, 50% by 8.2 months and 75% by 12 months. Median time to breast conservation was 8.2 months (95% CI 6.4-9.3)Figure 2. Median change in tumour volume from baselineAfter an initial rapid response in the first 4 months, the rate of response was slower and constant for a further 6 months. Tumour volume reduction to permit breast conservation varied between 65 and 80% .Discussion: This interim analysis indicates that the conventional treatment period of 4 to 6 months of neoadjuvant letrozole should be revised. For most women longer duration will increase the likelihood of achieving sufficient volume reduction to allow breast conserving surgery.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1082.
Impact of Progression during Neoadjuvant Chemotherapy on Operative Management of Breast Cancer.
Authors: Caudle A. , Gonzalez-Angulo A. , Hunt K. , Kuerer H. , Pusztai L. , Kau S. , Mittendorf E. , Hortobagyi G. , Meric-Bernstam F.
Published: December 2010

Background: Neoadjuvant chemotherapy (NCT) is the standard of care for locally advanced breast cancer, but remains controversial in early stage disease. Some have raised concerns that disease progression may make breast-conserving therapy (BCT) or even mastectomy impossible. The goal of this study was to determine the impact of disease progression during NCT on operative management. Methods: We reviewed clinicopathologic data on patients receiving NCT for Stage I-III breast cancer at a cancer center between 1994 and 2007. Chemotherapy regimens were anthracycline and/or taxane-based as determined by the medical oncologist. Results: 1928 patients received NCT, of which 1762 (91%) had a response (minor, partial, or complete), 107 (6%) had stable disease (SD), and 59 (3%) progressed (PD) on at least one regimen. Of the 59 patients with progression, 13 (22%) had tumor response and 7 (12%) had SD with their first regimen, but progressed on their second regimen. Thirty-nine (66%) had progression on their first regimen of which 4 (10%) proceeded to surgery, 1 (3%) developed metastasis, and 1 (3%) refused further therapy. Thirty-three (85%) received a second chemotherapy regimen after progression on the first regimen; 18 (55%) had response to the second regimen, 5 (15%) had SD, and 10 (30%) had further progression. Eight (14%) had XRT to control local progression. In the 59 patients with progression at any point during NCT, 40 (68%) underwent mastectomy, 12 BCT (20%), and 7 (12%) had no surgery. In patients who had mastectomies, 3 (8%) were BCT candidates before progression, one (3%) was converted to mastectomy for technical reasons, and 2 (5%) were not evaluable from available data. Overall, disease progression changed the operative plan in 11 (0.5%): 2 developed distant metastasis, 2 developed clinical lymphadenopathy, 3 required mastectomy instead of BCT, 3 became inoperable, and 1 required flap closure. Conclusion: Patients treated with NCT should be evaluated by multi-disciplinary team members for response to therapy. Progression on NCT is infrequent (3%), but the optimal management in these patients needs further study. Overall, progression on NCT changes the operative management in only a small proportion of patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1090.
Prognostic Factors for Locoregional Recurrence in Operable Breast Cancer Patients Treated with Preoperative Systemic Chemotherapy.
Authors: Jung S. , Min S. , Lee S. , Park C. , Kwon Y. , Kim E. , Ko K. , Lee K. , Park I. , Jeong J. , Shin K. , Lee S. , Kim S. , Kang H. , Ro J.
Published: December 2010

Background: We aimed to evaluate the clinicopathologic factors affecting locoregional recurrence (LRR) in potentially operable breast cancer patients receiving preoperative systemic chemotherapy (PST).Methods: We reviewed the records of 316 breast cancer patients treated with PST (doxorubicin/cyclophosphamide, 101; docetaxel /capecitabine, 103; paclitaxel/gemcitabine, 43; doxorubicin/docetaxel, 69) followed by surgery and adjuvant radiotherapy between 2002 and 2006. The majority of patients had clinical positive axillary lymph nodes. To define the prognostic factors for LRR, age, clinical stage, hormone receptor (HR) and HER2 status, clinical and pathologic response, type of operation, pathological characteristics including tumor size, tumor grade, nodal status, number of positive axillary nodes, size of metastatic lymph node and status of resection margin and tumor multiplicity before and after PST were analyzed.Results: Overall 52 patients (16.5%) in the primary tumor and 87 patients (27.5%) in the axillary nodes achieved a pathologic complete response (pCR), and 206 patients (65.2%) underwent breast conserving surgery (BCS). With a median follow-up of 52.4 month (range: 4.7 - 89.4), total 18 (5.7%) patients developed LRR; 2 of 110 (1.8%) patients with mastectomy vs. 16 of 206 (7.7%) patients with BCS (p=0.04). Other significant factors in the univariate analysis were clinical T stage, HR status, clinical response and tumor multiplicity. A pCR in the primary tumor or node was not a prognostic factor for LRR in this study. In multivariate analysis, clinical T stage (T3/4, HR 7.8; 95% CI, 2.33-26.24; P=0.001), hormone receptor status (negative, HR 6.2; 95% CI, 1.91-20.22; P=0.002) and type of surgery (BCS, HR 9.5; 95% CI, 1.97-46.37; P=0.005) were independent prognostic factors. Among patients with BCS, advanced clinical T stage (HR 12.4; 95% CI, 3.45-44.56; P<0.001), negative hormone receptor (HR 4.74; 95% CI, 1.33-16.96; P=0.02), non-responding disease (HR 6.54; 95% CI, 1.07-40.12; P=0.04) and multiple tumors (HR 4.36; 95% CI, 1.06-17.90; P=0.04) developed more frequent LRR.Conclusions: Significantly more patients with advanced clinical T stage, negative HR status and BCS developed LRR in operable breast cancer treated with PST. Moreover, in patients with BCS after PST, clinically non-responding disease and multiple tumors showed unfavorable prognosis besides the larger tumors and negative hormone receptor.Partly supported by NCC Grant No 0610240

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1095.
Ibandronate Shows Marked Pain Relief and a Favorable Renal Safety Profile – Updated Results of a Non Interventional Study in Breast Cancer Patients with Metastatic Bone Disease.
Authors: Schmidt M. , Hesse T. , Kuehnle H. , Lerchenmueller C. , Schlag R.
Published: December 2010

Background: Bisphosphonates (BP), the current standard of care for patients with metastatic bone disease (MBD) due to breast cancer (BC), effectively reduce the incidence of skeletal related events (SRE) and the severity of bone pain. However, BP treatment may adversely affect kidney function and thus renal safety is a key determinant of BP risk/benefit assessment. In randomized clinical trials (RCT), Ibandronate (IBA), a third generation amino-BP available in IV and oral formulations, has demonstrated sustained effects on SRE and bone pain with a low incidence of renal adverse events. To verify those results under real life conditions, a large-scale non interventional study (NIS) is currently being conducted in Germany.Patients and methods: In accordance with the terms of the marketing authorization, BC patients with MBD receive 6 mg IBA IV every 3–4 weeks or 50 mg of oral IBA once daily (at the physician's discretion) for up to 24 weeks. Pain severity (VAS), analgesic use (WHO analgesic ladder), SRE, and renal function (serum creatinine levels and estimated creatinine clearance, eCrCl; Cockcroft-Gault formula) are recorded in 4-week-intervals.Results: For this interim analysis, data for 2676 patients, mean age 63.6 ±11.8 years, were evaluated. 1735 (65%) were BP-naïve; 317 (12%) had received prior treatment with IBA, 614 (23%) with other BPs, including zoledronic acid (ZOL) (393; 15%) and pamidronate (PAM) (210; 8%). At baseline, mean pain severity (VAS) was lower for patients pretreated with IBA (2.7 ± 2.2) compared to BP-naïve patients (3.3 ± 2.4; p < 0.0001) or patients pretreated with other BPs (3.2 ± 2.4; p= 0.0041) and analgesic use was less frequent (38% vs 49% and 47%, respectively).In patients reporting pain at baseline, mean pain severity decreased on IBA treatment throughout the observation period (VAS: 3.2 ± 2.4 to 2.4 ± 2; p < 0.0001). In parallel, there was an overall reduction of analgesic use with 57% of patients not requiring analgesics at the end of the observation period. SRE were rare (7%), irrespective of prior treatment. For patients evaluable for renal function throughout the observation period, mean eCrCl at baseline was significantly lower in patients pretreated with ZOL (70.7 ml/min) than in BP-naïve (78.9 ± 30.9 ml/min; p < 0.0001) or IBA-pretreated patients (78 ± 29.1 ml/min; p=0.00386). Changes in renal function during IBA treatment were small and balanced across all subgroups. Overall tolerability of IBA treatment was rated as very good or good by 96% of physicians and patients alike.Conclusion: In this interim analysis of a large scale NIS in BC patients with MBD, IV and oral IBA showed marked and sustained pain relief with an overall reduction of analgesic use and a renal safety profile comparable to results of RCTs.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1108.
Aprepitant for the Prevention of Chemotherapy-Induced Nausea and Vomiting (CINV) Associated with Moderately Emetogenic (MEC) Chemotherapy in Patients with Breast Cancer.
Authors: Webb T. , Hardwick J. , Carides A. , Street J.
Published: December 2010

Purpose: Aprepitant was shown previously to be effective for prevention of CINV associated with MEC in breast cancer patients. A recent study (PN130) assessed aprepitant in patients with a variety of tumor types receiving a broad range of MEC regimens. A post-hoc subgroup analysis of patients with breast cancer was performed and results (nominal p-values) are reported.Methods: This randomized, gender-stratified, double-blind trial enrolled patients with confirmed malignancies, naïve to HEC or MEC agents, who received at least one MEC agent. Patients received an aprepitant triple-therapy regimen (aprepitant 125 mg PO day 1 and 80 mg PO days 2-3, ondansetron 8 mg PO bid day 1, and dexamethasone 12 mg PO day 1) or an active control regimen (ondansetron 8 mg PO bid days 1-3 and dexamethasone 20 mg PO day 1). Primary and key secondary efficacy endpoints were proportions of patients with No Vomiting and Complete Response (no vomiting/no rescue medication use) respectively, during the overall phase (120 hours post-chemotherapy). Treatment group comparisons were based on a logistic regression model with terms for treatment, region, and gender.Results: Of 832 patients in the modified intent to treat population analyzed, 53% (n=439) had breast cancer. In the overall phase, significantly more patients in the aprepitant group achieved No Vomiting and Complete Response both overall and in the subgroup of patients with breast cancer (Table 1). The magnitude of the treatment group differences were similar to the differences observed in the entire study population. Similar trends were seen in the acute and delayed phase in both the overall population and the subgroup of patients with breast cancer. Results for additional endpoints are consistent with the data presented here. Adverse events were generally similar in the aprepitant and control groups.  Aprepitant, n/m (%)Active control, n/m (%)No vomitingAll tumors324/425 (76.2)*252/406 (62.1) Breast cancer152/219 (69.4)*116/220 (52.7)Complete responseAll tumors292/425 (68.7)*229/407 (56.3) Breast cancer139/219 (63.5)*102/220 (46.4)n/m = patients with favorable response/patients included in subgroup; * p-value < 0.001Conclusions: The aprepitant regimen provided superior efficacy over the control regimen for prevention of CINV for all patients receiving MEC. The benefit of aprepitant triple therapy in patients with breast cancer in this trial is in agreement with the results of a previous large-scale trial of aprepitant in this population. Control of CINV in breast cancer patients in this trial was consistently lower than in the overall population for all endpoints, demonstrating the importance of CINV prophylaxis in women with breast cancer undergoing MEC.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1116.
Survivin Protects Breast Cancer Cells from DNA Damage during Mitosis.
Authors: Desplanques G. , Hulin P. , Juin P. , Barillé-Nion S.
Published: December 2010

Survivin has attracted considerable attention as a therapeutic target for anticancer strategies because of its dual role in regulating cell division and apoptosis, which are both involved in tumor development. Survivin associates with Aurora B kinase and inner centromere protein to form chromosomal passenger complex, dictating the localization of the complex and the activation of Aurora B kinase. Therefore, survivin plays an important role in mitotic spindle checkpoint. Survivin has been consistently identified as a risk-associated gene in various malignancies, carrying unfavorable implications for cancer prognosis, disease recurrence and abbreviated survival. Of note, together with other gene signatures, this information is now being used in the clinic for the risk assessment of breast cancer patients. Of particular interest, high Survivin levels have been consistently linked to inhibition of apoptosis induced by DNA damaging agents. We first confirmed in breast cancer cells that Survivin protected cells from cytotoxicity induced by the genotoxic agents cisplatin or doxorubicin. We further analyzed how Survivin might regulate DNA damage in these cells. We pointed out that Survivin knockdown by RNA interference led to mitotic arrest in breast cancer cells associated to DNA damage accumulation. Indeed phosphorylation on serine c-4 of the protein H2AX (gH2AX) and formation of (gH2AX) chromatin-associated foci were evidenced in Survivin-depleted cells in the absence of exogenous DNA damage. Moreover increase in comet parameters in single cell gel electrophoresis (alkaline comet assay) was also detected in these cells compared to control cells. Of note, this process was independent of apoptosis triggering since the pan-caspase inhibitor z-VAD-fmk did not abolish the DNA damage marks. Interestingly, Survivin knockdown had no impact on cell response to DNA damage, since (1) the increase in gH2AX foci was also associated with significant colocalization with both actors of DNA damage repair response Mre11 and Nbs1 and (2) the resolution of ionizing radiation-induced foci was similar in Survivin-depleted cells compared to control cells. These results demonstrate that Survivin depletion is indeed genotoxic in breast cancer cells but not involved in DNA repair pathways. Finally,we evidenced that taxol, that stabilizes microtubules in mitotic spindle and blocks cells cancer cells in mitosis, also induced DNA damage in breast cancer cells. Thus we conclude that prolonged mitosis induced by Survivin depletion contributes to DNA damage accumulation in breast cancer cells. We speculate that Survivin depletion in combination with genotoxic agents or inhibitors of DNA repair pathways may contribute to trigger apoptosis in these cells. Altogether, our results highlight the interest to use Survivin inhibitors in breast cancer therapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1124.
Mechanisms of SLUG-Induced Drug Resistance Development in Breast Cancer Cells.
Authors: Mittal M. , Singh K. , Chaudhuri G.
Published: December 2010

Down regulation of vitamin D receptor and over-expression of cyclin D1 are often associated with breast cancers. Depending upon the genetic context of the breast cancer cells, these alterations also often lead to development of resistance of the breast cancer cells against drugs like vitamin D3, all-trans retinoic acid and tamoxifen. We report here that the metastasis promoter protein SLUG indirectly induces the elevation of cyclin D1 levels in human breast cancer cells by repressing vitamin D3 receptor (VDR) and ubiquitin conjugating enzyme UbE2D3 genes. SLUG over-expression repressed the mRNA and protein levels of VDR and UbE2D3 in SLUG-negative human breast cells whereas knockdown of SLUG in the SLUG-expressing human breast cells had the reverse effect. SLUG also E2-box-dependently inhibited the activity of VDR and UbE2D3 gene promoters. CtBP1 and HDAC1 are co-recruited at the VDR and UbE2D3 gene promoters with SLUG, further indicating that SLUG represses this gene through chromatin remodeling. Knockdown of UbE2D3 or VDR in the SLUG-negative human breast cells elevated the levels of cyclin D1 as well as the rates of proliferation/invasiveness of these cells. While SLUG over expression has no effect on tamoxifen-resistance of ER-negative breast cancer cells, it significantly decreases tamoxifen-sensitivity of ER-positive breast cancer cells. On the other hand, knockdown of VDR gene expression by SLUG increased the resistance of both ER-positive and ER-negative breast cancer cells to 1, 25(OH)2D3 and all-trans retinoic acid. Our data thus suggest that SLUG not only promotes metastatic development of breast cancer cells, but also conspire to the development of resistance of these cells against several anti-cancer compounds. Supported by the DOD-CDMRP IDEA Grant# W81XWH-06-1-0466 and the Susan G. Komen Breast Cancer Foundation grant# BCTR0707627 to GC.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1128.
CYR61 Expression Promotes Taxol Resistance: A Molecular Link with the p53 in Breast.
Authors: Espinoza I. , Lupu R.
Published: December 2010

CYR61 render human breast cancer cells highly resistance to the microtubule-interfering agent Taxol, a drug of choice for the treatment of metastatic breast cancer. The angiogenic factor CYR61 and its receptor avβ3 are markedly up-regulated in very aggressive breast carcinomas. Integrin signaling has been shown to modulate cancer cell responses to chemotherapy agents. Thus, the signal transduction pathways initiated by integrin may be a potential target for inhibiting cell survival during cytotoxic drug exposure. However, the molecular mechanism for CYR61-induces cytoprotection still unknown. Our data demonstrates that functional blockade of avβ3 with a synthetic chemical peptidomimetic based upon the αvβ3 the RGD (Arg-Gly-Asp) motif, is specifically cytotoxic towards CYR61-overexpressing breast cancer cells and that pharmacological interference of the CYR61/αvβ3 interaction restores Taxol efficacy. This data suggests that a previously unrecognized CYR61/αvβ3-driven cellular signaling actively modulates cell growth, apoptosis and chemosensitivity. To better understand the mechanism by which CYR61 induces Taxol resistance, we studied a series of molecular events and reveal that CYR61 prevents Taxol induction of p53 accumulation, blocks p21WAF1/CIP1 overexpression, and furthermore we demonstrated that CYR61 induces JNK activation. These observations suggest that increased expression of CYR61 could promote a chemoresistance by suppressing a specific pro-apoptotic signaling while still given chemotherapeutic treatments to induce cell damage.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1139.
The Response of Breast Cancer Initiating Cells to Fractionated Radiation.
Authors: Lagadec C. , Vlashi E. , Della Donna L. , Pajonk F.
Published: December 2010

Recent experimental data provide evidence for a hierarchical structure of many solid cancers including breast cancer. Using surface markers, a small population of highly tumorigenic breast cancer initiating cells (CICs) has been prospectively identified, which exhibited a cancer stem cell phenotype, thus being able to self-renew and to give rise progeny of multiple different lineages of differentiated cells. We previously demonstrated that this population of cells was relatively resistant against ionizing radiation if compared to their non-tumorigenic counterparts. Furthermore, we reported that this population of CICs increased during the course of fractionated irradiation. The extent of the remaining self-renewing capacity and multi-lineage potency of these CICs after fractions of radiation is currently unknown. However, this information is crucial for evaluating the significance of radiation resistance of CICs.In the present study, we hypothesized that CICs not only survive fractions of ionizing more likely than their non-tumorigenic counterparts but also retain the CSC phenotype as defined by operational means and may even become more aggressive than populations of non-irradiated control CICs.Using CD24, CD44, ESA, and lack of proteasome function to identify breast cancer CICs we investigated their response to fractionated radiation and showed that CICs cells are more resistant to radiation (from 2Gy to 8x2Gy) than non-tumorigenic cells. At 2Gy, the stem cells population CD44high/CD24-/low in monolayer increased 3 times (from 0.25% at 0Gy to 0.74% at 2Gy). The analysis of CICs population after 8x2Gy demonstrated than the CICs containing population was not affected at higher total doses (0.25% at 0Gy and 0.28% at 8x2Gy). A sphere forming capacity assay demonstrated self-renewal capacity of the survivig CICs after irradiation (2Gy: +93% or 8x2Gy: +105%).Using low proteasome to identify stem cells and membrane labeling (PKH26) we analyzed the effect of fractionated irradiation treatment (0, 3Gy, 2x3Gy, 3x3Gy 4x3Gy and 5x3Gy) on CIC and non-tumorigenic cell proliferation. We demonstrated that CSCs irradiated with 3Gy or 2x3Gy lost the PHK26 dye faster than the control indicating recruitment of these cells into the pool of cycling cells (mean division of CSCs; 0Gy: 2.6, 3Gy or 2x3Gy: 3), while an treatment with 5x3Gy still enriched for CSCs but the reduction of proliferation rate of CSCs indicated that this enrichment is essentially due to their radioresistant phenotype (mean division; 5x3Gy: 1.9). Tumorigenicity of double positive and double negative cell was tested in limiting dilution assay using a mouse model (Rag2-/-IL2Rγc-/-).We conclude that radiation resistant CICs not only survive fractionated radiation but retain their CSC phenotype. This indicates that radiosensitizing CICs could be a reasonable approach to improve treatment outcome.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1153.
Blockade of Notch Signaling with Gamma-Secretase Inhibitors Induces Apoptosis in the Stem-Like Population of Breast Cancer Cells.
Authors: Foreman K. , Grudzien P. , Lo S. , Robinson P. , Albain K. , Strack P. , Miele L.
Published: December 2010

BACKGROUND: Numerous studies have identified stem-like cells, termed cancer stem cells (CSCs), in breast tumors and established cell lines. These self-renewing CSCs are believed to be responsible for breast cancer formation, progression and recurrence; therefore, a deeper understanding of the signaling pathways regulating their survival will benefit development of novel therapeutic strategies. Notch signaling, which is known to be dysregulated in breast cancer and has been implicated in mammary stem cell self-renewal, can be effectively blocked by gamma-secretase inhibitors (GSIs). While GSIs are currently in clinical trials for breast cancer, it is unclear how these compounds will affect CSCs or if CSCs from different breast cancer phenotypes (estrogen receptor-alpha (ER)-positive, ER negative, Her2/neu overexpressing) will be differentially affected. We previously reported that stem-like cells derived from the T47D breast cancer cell line showed elevated levels of Notch activity and Notch inhibition using GSIs or Notch decoy proteins abolished secondary mammosphere formation.METHODS: We have expanded our studies to breast cancer cell lines of different phenotypes (T47D-A18, T47D-C42, MCF7, SKBR3, BT474, MBA-MD231) and five primary clinical specimens. We studied expression of a panel of Notch pathway genes including Notch receptors, ligands and immediate downstream targets of Notch activation in CSCs and non-CSCs. We also determined the effect of Notch inhibition on secondary mammosphere formation (a measure of self-renewal) and clonogenicity. We evaluated cell death using TUNEL assays.RESULTS: We report that CSCs possess elevated levels of Notch activation compared to non-CSCs regardless of breast cancer phenotype or sample origin (cell culture or primary tumor). However, the specific Notch target genes most abundantly expressed vary depending on the cell line, and may suggest that CSC from different subtypes of breast cancer have different “Notch signatures”. Blockade of Notch signaling with a GSI abolished secondary mammosphere formation, eventually resulting in apoptosis, a finding that was consistent for ER-positive, ER-negative, and Her2/neu overexpressing cancer cells and primary tumor samples from heavily pre-treated, late-stage patients. Furthermore, GSIs blocked colony formation in soft agar.CONCLUSIONS: These novel findings support a role for Notch signaling in CSC self-renewal and proliferation, and they suggest Notch inhibition with agents currently in clinical development may prove beneficial in targeting CSCs in a wide variety of breast cancers.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1154.
Presence of Intratumoral Stem Cells in Breast Cancer Patients with or without BRCA Germline Mutations.
Authors: Singer C. , Zabkova P. , Pfeiler G. , Gschwantler-kaulich D. , Fink-Retter A. , Staudigl C. , Walter I. , Hudelist G. , Spiess A. , Kubista E.
Published: December 2010

Background:BRCA-1/2 germline mutations are responsible for early onset breast cancer with poor outcome. The underlying causes of the particularly malignant phenotype are not completely understood, but mammary stem cells appear to have a key role in this process.Materials and Methods: We have investigated the presence of mammary stem/progenitor cells in normal tissues and in tumor tissues obtained from women with and without BRCA1/2 germline mutations by utilizing ALDH-1 immunohistochemistry.Results: Isolated ALDH-1 positive cells were found in 15/18 (64%) of breast cancer samples from women with BRCA 1 or 2 mutations and in 33 /51 (65%) of matched sporadic breast cancer cases (p=0.5949, Chi Square test). While mammary stem cells were also detected in non-malignant breast lesions, only 41% of the tissues contained ALDH-1 positive cells (p=0.0371, Chi Square test). In patients with BRCA germline mutations ALDH-1 positive cells were more common in p53 positive (p=0.0028, Chi Square test) tumors, in high grade (p=0.0796), and in larger tumors (p=0.0604), while no such association was seen in sporadic cancer cases. In our patients, the expression of ALDH-1 positive cells in breast cancer was neither associated with disease-free and overall survival, nor time to metastasis.Conclusion: Breast cancers from BRCA mutation carriers do not harbour more ALHD-1 positive cells than sporadic tumors, and their more aggressive phenotype can thus not be explained by an increased stem cell pool. The presence of ALDH-1 in normal breast tissue suggests that additional factors determine the biological behaviour of mammary stem cells.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1156.
Novel Stably Transplantable Xenograft Models of Human Breast Cancer for Evaluation of Experimental Therapeutics.
Authors: Dobrolecki L. , Landis M. , Zhang X. , Huang J. , Lai Q. , Wong H. , Contreras A. , Chang J. , Lewis M.
Published: December 2010

In translational breast cancer research, our ability to evaluate clinical responses of human tumors to new therapeutic agents is severely limited experimentally. For example, it is not possible to evaluate the response of a single tumor to multiple candidate therapeutic agents. Conversely, the limited number of well-characterized in vivo preclinical human tumor models currently available precludes evaluation of multiple clinically relevant tumors with candidate therapeutic agents. These limitations severely impinge on our ability to develop and test novel therapeutic agents, particularly those that may target tumor-initiating “cancer stem cells”, which are relatively resistant to chemotherapy and radiation and may be responsible for disease recurrence and metastases.Historically, in vivo experimental therapeutic research has relied on either genetically engineered animal models, or “xenograft” transplantation models in which established human cancer cell lines are transplanted into immunocompromised host mice. However, each type of model has significant limitations. We sought to circumvent some of these limitations by propagating a cohort of human tumors as stably transplantable xenograft tissue lines grown in the absence of engineered or immortalized fibroblasts by transplanting clinical biopsies directly into the mammary fat pad of SCID/Beige immunocompromised mice (lacking B-cell, T-cell, and NK cell function) without intervening culture in vitro.Thus far, we have established 13 independent stably transplantable xenograft lines representing nine “triple-negative” (ER-PR-HER2-), two HER2+, and two ER+ breast cancers. Established xenograft lines show phenotypic similarity to the primary tumor with respect to histology and gene expression. Xenografts are being characterized genetically by whole genome sequencing as well as for the diversity of tumor-initiating cell types present. These models are proving useful for the evaluation of experimental therapeutics for their ability to inhibit tumor growth, and for their ability to target the subset cancer cells capable of regenerating tumors upon transplantation, with the goals of overcoming chemoresistance, preventing disease recurrence, and eliminating metastases.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1159.
The Impact of CD44+CD24- Cells on Non-Sentinel Axillary Lymph Node Metastases in Sentinel Node-Positive Breast Cancer.
Authors: Nogi H. , Kawase K. , Toriumi Y. , Fukushima H. , Suzuki M. , Uchida K.
Published: December 2010

Background: Although completion axillary lymph node dissection (CALND) is the standard for evaluating axillary status after identification of a positive sentinel lymph node (SLN) in breast cancer, approximately 30-60% of SLN-positive patients have negative non-SLN. It has been recently demonstrated that the putative breast cancer stem cells with CD44+CD24low/- phenotype are associated with self-renewal and tumorigenic potential. In this study, in order to explore such putative breast cancer stem cells in the SLN, we intended to retrospectively analyze expression of CD44+CD24low/- on metastatic tumor cells within SLN as a predictive factor for positive non-SLN (NSLN).Methods: We tested 271 patients for the SLNs by using serial sectioning and cytokeratin immunohistochemistry (IHC) and hematoxylin-eosin, and identified 67 patients who had a positive SLN biopsy and CALND. CD44 and CD24 expression was detected using IHC. Immunostaining for CD44 and CD24 interpreted as positive if at least 1% of tumor cells show distinct membranous staining. Univariate logistic regression techniques were used to assess significant associations.Results: Twenty-seven patients out of 67 patients (40%) had positive NSLN metastases. Six positive SLNs with micrometastases were not available for evaluation of CD24 and CD44 expression. Out of the 61 patients, 22 (36%), 47 (77%) and 28 (62%) patients had CD24-positive, CD44-positive and CD44+/CD24low/- metastatic tumor cells in SLN, respectively. Positive NSLN metastase was significantly associated with primary tumor size (P=0.004), negative CD24 expression (P=0.04), positive CD44 expression (P=0.04) and CD44+/CD24low/- (P=0.03).Conclusion: This is the first evidence for the existence of the putative stem-like phenotype within the SLN, which is significantly associated with positive NSLN, in early breast cancer patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1160.
Hedgehog Signaling Pathway Is a New Target of Cancer Stem Cell Therapy for Breast Cancer Patients.
Authors: Tanaka H. , Nakamura M. , Sohzaki M. , Kai M. , Kubo M. , Ohnishi H. , Tanaka M. , Katano M.
Published: December 2010

Introduction: Hedgehog (Hh) signaling pathway is crucial for growth and patterning during embryonic development. We have shown that Hh pathway is constitutively reactivated in human breast cancer (Kubo M et al. Cancer Res 2004). Recently, it has been proposed that only a small subset, termed cancer stem cells (CSCs), posseses tumorigenicity. And, several investigations suggest contributions of morphogenesis pathways including Hh pathway in the maintenance of CSCs. Purpose of this study is to reveal an essential role of Hh pathway in the maintenance of CSCs, and also to reveal a possibility of Hh pathway as a target of CSCs therapy for breast cancer patients.Materials and Methods: A human breast cancer cell line MCF-7 was used. In the present study, we estimated CD44+CD24-/low cells or side population (SP) cells as CSCs. Flow cytometric analysis and sorting were performed to detect and collect CSCs, respectively. To confirm the high tumorigenicity of CSCs, we used a MCF-7 cell xenograft mouse model in NOD/SCID mice. To assess the expression of Hh pathway-related molecules, real-time RT-PCR and fluorescent immunostaining were performed. For blockade of Hh pathway, a Hh inhibitor, cyclopamine, and small interference RNA (si-RNA) against Gli1, a trans-activator of the Hh pathway, were used. We also synthesized peptides with specific affinity for a transmembrane receptor Patched1 (Ptch1).Results: CD44+CD24-/low cells and SP cells in total MCF-7 cells were 10-25% and 1-4%, respectively and these two populations were overlapped with each other. These CSCs were highly tumorigenic, and resistant to anticancer drugs including taxanes.Hh pathway-related molecules such as Shh, a ligand of Hh pathway, and Gli1 were predominantly expressed in CSCs. Cyclopamine and Ptch1 affinitive peptides could suppress the tumorigenicity of CSCs in NOD/SCID mice xenograft transplantation model.Conclusions: Hh pathway at least partly contributes to the maintenance of CSCs in MCF-7 cells. Thus, Hh pathway may be a valuable therapeutic target for CSCs therapy for breast cancer patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1161.