bluuebunny/crossref_metadata_2025 huggingface dataset:
Initial radiation experience evaluating early tolerance and toxicities in patients undergoing accelerated partial breast irradiation using the Contura™ multi-lumen balloon (MLB) breast brachytherapy catheter.
Authors: Brown S , McLaughlin M , Pope K , Haile K , Whitaker TJ , Hughes L , Israel P
Published: December 2010

Abstract #5138

Purpose: We reviewed our institution's experience treating patients with the Contura™ Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) to determine short-term treatment efficacy, cosmesis, toxicity and additional dosimetric capabilities of the new APBI device.  Materials and Methods: From 05/07 to 05/08, 41 patients, from a single surgeon (PI), were treated with breast conserving therapy (BCT) received adjuvant radiation using the Contura™ catheter (34 Gy in 3.4 Gy fractions). 13/41 patients (31.7%) had stage 0 disease, 21 (51.2%) had stage I and 7 (17.1%) had stage II breast cancer.  For each patient, the dosimetric plan was customized using the 5 high dose rate brachytherapy channels of the Contura™ catheter by selecting from 45 different dwell positions (9 per catheter).  Results: Median, minimum skin spacing was 10 mm (range 2 to 17). The median maximum skin dose (% of prescribed dose [PD]) was 99.7 (57.1 to 124.1). Eight patients were able to be treated with a skin spacing of 5 mm or less, 2 had spacing of 2 mm. The median maximum rib dose was 102.6 % of PD (10.0 to 187.7), median percentage of the planning target volume (PTV) receiving 95% of the PD was 98.8 (79.4 to 107.4) and the median volume receiving 200% of the PD was 5.7 cc (range 1.3 to 9.9).  The percentage of patients with excellent/good cosmetic results at 3 and 6 months was 94% (16 evaluable patients) and 89% (9 evaluable patients), respectively. One patient developed skin ulceration after receiving chemotherapy. Patient tolerance was assessed on a scale 0-10 (0=no pain, 10 = requiring narcotic analgesics). In 37/38 (97.3%) patients, pain was graded ≤ 3 at the time of catheter insertion. Four transient breast infections (11%) developed and one transient symptomatic seroma developed (3%).  Conclusion: Adjuvant APBI using the Contura™ MLB catheter exhibited similar toxicities to standard single-lumen balloon brachytherapy with absolute improvements in dosimetric capabilities (i.e., reduced skin dose, improved PTV coverage and normal tissue avoidance). With multiple lumen planning, more conformal dosimtery was achieved as compared to single-lumen balloon treatment. This allowed the treatment of 8 patients with skin spacing of 5 mm or less, normally not achievable with single-lumen balloon treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5138.
Long term disease control outcomes for partial breast irradiation using MammoSite brachytherapy.
Authors: Harper JL , Watkins JM , Baker MK , Cole DJ , Dragun AE , Garrett-Mayer E , Wahlquist AE , Jenrette JM
Published: December 2010

Abstract #5145

Purpose: To describe 4-year local and ipsilateral breast recurrence-free intervals, overall freedom from disease failure, and disease-specific and overall survivals in a cohort of MammoSite Brachytherapy (MBT) patients with mature follow-up, treated at a single institution over a 6-year period.  Methods and Materials: An analysis of MBT cases was performed using prospectively collected quality assurance database, departmental chart review, and electronic medical records. Patient-, tumor-, treatment-, and outcome-specific data were extracted and recorded into a research database. Eligible patients were required to have >6 months post-MBT follow-up. Local tumor failure was defined as pathologically-proven recurrence within 2 cm of the resected tumor bed, with all other ipsilateral breast recurrences (excluding axilla or internal mammary nodal failures) defined as ipsilateral breast failures. Any local, ipsilateral breast, nodal, or distant failure was censored for overall freedom from failure.  Results: From 2004 through 2008, 115 MBT patients have been treated, of which 104 were eligible for the present analysis. Median patient age was 62 years (range 25–86). Primary tumors included ductal carcinoma in situ (DCIS) for 20 patients, T1a (12), T1b (31), T1c (34), and T2 (7). Lymph nodes were assessed in 94 patients (including all patients with invasive carcinomas), and revealed pN0 disease in 85 patients, pN1(mic) (3), and pN1a (6). Histologies of invasive carcinomas were ductal in 68 patients, lobular (3), mixed ductal/lobular (3), mucinous/colloid (7), medullary (2), and tubular (1). At a median follow up of 45.7 months (range 7.3-71.4), 6 patients have experienced disease recurrence, including 4 within the ipsilateral breast. Three patients with ipsilateral breast recurrence underwent salvage mastectomy, two of whom remain without evidence of disease recurrence at 56 and 14 months, respectively. Seven patients have died, 3 of or with recurrent breast cancer. Estimated 4-year outcomes for the entire cohort were: local tumor control 100%, ipsilateral breast control 97.0% (95% CI, 93.6%-100%), overall freedom from failure 93.8% (88.5%-99.5%), disease specific survival 97.8% (94.8%-100%) and overall survival 92.7% (87.2%-98.6%).  Conclusions: The present study demonstrates low rates of local and ipsilateral breast disease failure in a well-defined cohort of MBT patients with mature follow-up.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5145.
Do conventional radiotherapy fields irradiate the regional lymphatics correctly in patients with breast cancer?.
Authors: Haydaroglu A , Karakoyun-Celik O , Hoca S , Bolukbasi Y , Olacak N
Published: December 2010

Abstract #5147

Purpose: In this study, we compared the 3-Dimentional Conformal Radiotherapy (Method I) and conventional radiotherapy (Method II) plans of patients who receive loco-regional irradiation for breast cancer. Two methods were analyzed statistically with DVH's.  Material and Methods: Twenty-five patients underwent computed tomography (CT) scanning in the supine treatment position and axial images with slice thickness of 5 mm were obtained. The patients were virtually treated and a total dose of 50 Gy with 2 Gy/fraction was prescribed to the PTV using 6 MV photon beams. In Method I, breast or chest wall volumes, axillary levels (AL) I, II and III and supraclavicular lymph node (SC) volumes delineated and then radiotherapy fields, tangents, SC and posterior axillary boost (PAB) were developed according to each patients own anatomy. The depth for SC lymph nodes was measured from the isocenter of SC field, for AL's II and III lymph nodes from the isocenter of PAB field in each patient. In Method II, conventional radiotherapy fields which include standard tangents, SC and PAB fields were developed on DRR images for each patient. Dose prescribed to a tissue depth of 3 cm for SC, to the midaxillary depth for PAB field. Analyses were done using composite plans of tangents, SC and PAB fields of each method. The volumes of AL's II and III out of PAB field were identified, and the dose distributions were assessed from the DVH's of the contoured volumes.  Results: The mean depth of midaxillary level was 7.75 cm (6.5-8.5). In Method I, the maximum mean depths for AL II and III were 6.5 and 5.3 respectively; both two levels were anterior to the midaxillary level. The mean depth of SC lymph nodes was 4.6 cm (3.3-8.6) that is more that 3 cm. In Method II, the mean volume percentage received 50 Gy was lower than Method I. This was due to SC depth, majority of the patients had more that 3 cm SC depth. Mean 50 Gy volume was 98 % in Method I, where as 65% in Method II (p=0.00001). In Method II, a part of AL II lymph nodes were out of PAB field in 9 (36%) patients and a part of AL III lymph nodes were out of PAB field in 18 (72%) patients.  Conclusion: Both SC and AL's II and III lymph node depths were presented a wide variety. Additionally, AL II and III lymph nodes were out of PAB fields in a significant number of patient's Method II plans. According to this study, the mean depth of SC lymph nodes was deeper than 3 cm and AL II and III lymph nodes were anterior to the midaxillary depth. For this reasons, SC lymph nodes received less than prescribed 50 Gy. Three-Dimensional Conformal Radiotherapy, delineating regional lymph nodes is more effective in achieving better dose and nodal volume coverage than that of the conventional radiotherapy in patients with breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5147.
Breast conservation in the treatment of T2 breast tumors – analysis of 1988-2003 SEER data.
Authors: Rouzier R , Lesieur B , Gligorov J , Huguet F , Uzan S
Published: December 2010

Abstract #5151

Background: Breast-conserving therapy (BCT) has been shown to be as effective as mastectomy in the treatment of tumors 5 cm or smaller. However, few patients with tumors larger than 2 cm have been included in the randomized trials. We sought to investigate the prognosis of patients with tumors measuring 2.1 to 5 cm according to local treatment in the SEER database.  Methods: The SEER registry provided data from 17 registries. Survival was studied according to surgical treatment of tumor with stratifications on tumor size, nodal status, pathological characteristics and adjuvant radiation therapy. Cause specific survival was measured by SEER as the time from diagnosis to date of death and date of last follow-up, respectively. We used the Kaplan-Meier product limit method to describe cause specific survival and the log-rank test to assess differences between patient groups. All tests were two tailed, and p values < 0.05 were considered to denote significant differences. All analyses were performed using the R package with the Design, Hmisc, and Survival libraries.  Results: The study population comprised 128,454 patients. The median follow-up for patients alive at the last follow-up visit was 47 months. Survivals according to tumor size are reported in the table below. For patients with T2 tumors measuring 4.1-5cm, a better survival at 5 years (74%) was observed for patients treated by mastectomy compared to patients treated by BCT (67.5%) (P=1.22e-15) (Figure A). Subgroup analysis revealed that absence of radiation after BCT was the only reason for a higher survival in patients treated with mastectomy (Figure B). No clear deleterious effect of BCT was observed according to nodal status, grade or ER status.  Conclusion: Our study demonstrates that T2 tumor patients should not be treated with BCT if adjuvant radiation therapy cannot be administered.    Survival according to local treatment in patients with 4.1-5 cm tumors.[figure1]

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5151.
Breast conservation: factors predictive of residual disease following reoperation for narrow surgical margins.
Authors: Forouhi P , Brahmbhatt DH , Benson JR , Wishart GC
Published: December 2010

Abstract #5152

Introduction:  Ensuring pathologically tumor free surgical margins reduces local recurrence rates following breast conserving surgery for breast cancer or DCIS. There is no general agreement regarding the definition of a clear margin but units with an agreed policy report reduced local recurrence rates. In our unit all patients with a surgical clearance of <5mm are offered further surgery either by mastectomy or by re-excision. We have examined factors that may predict residual disease in re-excised tissues.  Method:  All attempted breast conserving operations between 01/01/2004 to 31/09/2007 were identified from a dedicated database. Patient age, presentation (symptomatic or screening), surgeon (any of 4 surgeons), weight of tissue removed, tumour size, grade, presence of lymphovascular invasion (LVI) and the closest radial margin (categorised as involved, <2mm, 2-5mm) were examined.  Results:  Breast conservation was attempted in 605 women (mean age 60; 297 symptomatic, 308 screening). Further surgery was performed in 166 (27.4%) women, including 89 (14.7%) mastectomies. Median tumour size was 20mm (range 0-109). Residual disease was found in 83(50%) of re excisions (66/111 with involved margins, 16/40 for non involved margins up to 2mm, and 1/15 for margins over 2mm). On univariate analysis excision margin (OR=0.33, p=0.000) and total tumor size (OR=4.0 p=0.045 for the smallest size quartile versus the largest) were associated with residual disease. On multivariate analysis only tumor margin remained predictive (OR for <2mm vs involved: 0.46, p=0.043; OR for 2-5mm vs involved: 0.05, p=0.004).  Conclusion:  In a unit with an aggressive re-excision policy, involved or close surgical margins predict the presence of residual disease in re-excision specimens. A margin of greater than 2mm reduces the risk of residual disease to 1/20 of that seen with microscopically involved margins. This study supports a 2mm minimum radial margin policy when attempting breast conservation for breast malignancy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5152.
Radiofrequency ablation therapy: results in 100 patients with breast cancer.
Authors: Oura S , Tamaki T , Yoshimasu T , Ohta F , Hirai Y , Naito K , Miyasaka M
Published: December 2010

Abstract #5153

Background: Radiofrequency ablation therapy (RFA) is one of the most minimally invasive approaches for the treatment of hepatic cancers and other solid malignancies. The aim of this study is to assess the safety and local controllability of RFA against breast cancer.  Patients and Methods: A total of 100 pts with localized early breast cancer were enrolled. Ductal spreading and/or daughter nodules were preoperatively checked with mammography, ultrasound and MRI. Tumor size was 0.5-2.0cm (median 1.5cm). LeVeen system and Cool-tip RF system was used in 5 pts and 95 pts respectively. One session of RFA was applied to 96 pts, 2 sessions to 4 pts. To avoid skin burn, 5% glucose was injected subcutaneously just above the tumor and the skin was cooled during RFA. After completing RFA, temperatures along the needle tract were measured at 1 cm intervals in 89 pts. All pts underwent cytological and MR-imaging study 3-4 weeks after operation, and received adjuvant radiotherapy (50Gy) to the breast.  Results: RFA heated the tumors up to over 60° in 1 pt, 70° in 4 pts, 80° in 21 pts, 90° in 51 pts, and 100° in 13 pts. Skin burn was found in 2 pts over the tumor, and 1 pt at the grounding pads. No major side effects except for skin burn were found. Postoperative cytological and imaging study showed complete ablation of all the target tumors. No pts developed local and distant recurrence for 16-54 months (median 31 months).  Discussion: Our RFA procedures can offer good local control without serious adverse events to breast cancer patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5153.
Immediate breast reconstruction with contralateral pectoralis major myomammary flap for breast conserving surgery.
Authors: Lee S , Bae Y , Lee J , Kang T
Published: December 2010

Abstract #5157

Purpose: The breast reconstruction techniques are mandatory in case of the indication permits for there has been lots of data showing no less survival as far as surgery keeps the principle of cancer surgery. It could be selected by many factors but mainly by breast size, site of tumor. The latissimus dorsi musculocutaneous flap (LDMCF) is one of the most commonly used techniques in early breast cancer patient who has small breast. But, it has difficulties to supply enough tissues to the widely excised tumor site. And especially in case of ptosis patient, reduction mammoplasty only is not enough to get the symmetry of the breast. We suggest a pectoralis major myomammary flap(PMMF) as a useful technique for the patients with ptosis.  Methods: Seventeen patients with ptosis were treated with breast conserving using PMMF surgery. A quadrantectomy rather than lumpectomy was performed through a planned skin incision, and axillary lymph node dissection was performed according to the sentinel lymph node result. PMMF is harvested carefully without perforating branch injury of internal thoracic artery. And reconstruction was done by the PMMF through the medial tunnel between both breasts.  Results: Among those of seventeen patients, seroma occurred in two patients and no necrosis was occurred. The cosmetic result showed good in fifteen and excellent in two patients based on four-point scoring system of breast cosmetics.  Conclusions: After enough quadrantectomy to keep the cancer surgery principles, PMMF was quite useful to supply proper tissues for breast reconstructions, especially for the ptosis patient.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5157.
Oncoplasty for lateral breast cancers.
Authors: Salmon RJ , Reyal F , Berry M , Ballester M , Couturaud B , Fitoussi A
Published: December 2010

Abstract #5158

Introduction: 65% of breast cancers develop in the lateral pole, particularly superiorly. Following conservative treatment, , tumourectomy may produce a typical deformity of superolateral nipple-areolar complex (NAC) deviation. This unaesthetic deformity, is exaggerated by the post-operative irradiation mandated by contemporary breast conserving therapy. Primary utilisation of the oncoplastic technique, 'lateral mammaplasty', allows both the avoidance of such deformities and wider excision margins.  Patients and methods: The principle behind the technique is the combination of a wide, wedge-shaped tumourectomy combined with NAC repositioning on a de-epithelialised dermoglandular pedicle. Sentinel lymph node biopsy or formal axillary dissection may be performed simultaneously either via a separate or combined incision for inferior and superior lateral mammaplasties respectively. Aesthetic outcomes were assessed on a five-point scale with 1 being excellent and 5 poor.  Results: eighty-six patients, with a mean age of 53 years (range 29 – 75) underwent lateral mammaplasty. Fifty-five (64%) were palpable and 73 (86%) had simultaneous axillary surgery. Mean tumour size pre- and post-operatively were 29.8 mm (8 – 81) and 33.6 mm (0 – 140) respectively. Mean excision weight was 150g (24 – 484). Eleven (12.8%) required revisional surgery due to involved or close margins and the aesthetic outcome was graded highly satisfying or satisfying in 68 (79%).  Discussion: lateral mammaplasty has been found to be simple to perform with a short learning-curve. With clear excision margins in 87.8%, it is oncologically sound and compares favourably with simple tumourectomy. It should be considered when the tumour-to-breast volume ratio anticipates an aesthetic deformity. We have found it to be particularly satisfactory after neo-adjuvant chemotherapy for large volume tumours when a positive clinical response allows conservative surgery. It is also useful for revisional surgery in cases of involved or close margins following initial tumourectomy.  Conclusion: lateral mammaplasty became routine in our institution as it allows, with the assistance of a simple oncoplastic procedure, highly satisfying aesthetic outcomes and the added security of wide excision margins.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5158.
Metastasis-associated microtentacles are induced in detached and circulating breast tumor cells by expression of the microtubule-binding protein, Tau.
Authors: Matrone M , Whipple R , Balzer E , Cho E , Yoon J , Martin S
Published: December 2010

Abstract #55

Detached human breast tumor cell lines produce microtentacles composed of a unique kinesin-dependent coordination of vimentin filaments and detyrosinated microtubules. Compelling in vivo studies show that a mechanism consistent with microtentacles is responsible for the attachment of circulating tumor cells to blood vessel walls. However, the molecular regulators of microtentacle extension have only begun to be defined. Increased expression of the microtubule-binding protein, Tau, is associated with poor patient outcome in breast cancer, but the mechanism by which Tau protein affects prognosis remains unclear. We report here that expression of Tau directly regulates the formation of metastasis-associated microtentacles in detached and circulating breast tumor cells. First, increased expression of Tau correlates with increased microtentacle frequency in a panel of human breast tumor cell lines. Endogenous Tau protein colocalizes with tubulin microtentacles in cells detached from extracellular matrix. Exogenous expression of Tau significantly increases microtentacle frequency in weakly invasive breast tumor cell lines. Tau-induced microtentacles are longer, thicker and more rigid than those in cell lines without Tau expression. Although there is increasing interest in targeting the actin cytoskeleton to reduce tumor cell motility and division, our results indicate that breast tumor cells with high Tau expression have particularly dramatic increases in microtentacles when treated with inhibitors of actin polymerization. Likewise, tubulin-stabilizing compounds, like paclitaxel, increase microtentacles and may be ill-advised in patients with high Tau expression. Indeed, clinical studies show that high Tau expression increases the likelihood of recurrence following paclitaxel treatment. We observed an enrichment of Tau in metastatic tumors compared to matched primary tumors. So while stabilizing microtubules and disrupting actin filaments can each decrease tumor cell growth, it is important to consider the effects of these treatments on Tau-expressing cells to avoid accidentally enhancing the metastatic potential of circulating tumor cells while targeting cell division.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 55.
c-MYC amplification and correlation with patient outcome in early stage HER2+ breast cancer from the NCCTG adjuvant intergroup trial N9831.
Authors: Perez EA , Reinholz MM , Dueck AC , Wiktor AE , Lingle WL , Davidson NE , Martino S , Kaufman PA , Kutteh LA , Jenkins RB
Published: December 2010

Abstract #56

Background: Recent findings from NSABP B-31 suggested that breast cancer (BC) patients (pts) with c-MYC (MYC)/HER2 co-amplification in their primary tumors may benefit more in terms of disease-free survival (DFS) from adjuvant trastuzumab (n=471; p<0.0001, HR 0.24; 13 vs. 51 events) than those pts with only HER2 amplification in their primary tumors (n=1078, p=0.007, HR 0.63; 55 vs. 82 events).  Purpose: The overall objective of this analysis is to determine the association between MYC/HER2 co-amplification and outcome of pts randomized to receive chemotherapy alone (Arm A) or chemotherapy with concurrent trastuzumab (Arm C) on N9831.  Patients/Methods: This analysis included 868 pts from the HER2+ NCCTG N9831 Intergroup adjuvant trastuzumab phase III clinical trial on Arms A or C. Fluorescent in situ hybridization (FISH) was performed at a central laboratory, Mayo Clinic Clinical Cytogenetics Laboratory, using dual probe mixtures for HER2 (17q11.2-12/centromere 17) and for MYC (8q24/centromere 8). The HER2 amplification status in whole tissue sections was evaluated to determine eligibility of pts for N9831. Tissue microarrays containing three cores from each patient's tumor were analyzed for MYC amplification status. The gene and centromere copy number as well as the distribution of the signals for each marker were determined in sixty non-overlapping interphase nuclei.  Results: Of 273 pts with completed FISH analyses, 34 (12%) pts had MYC amplification. The rate of MYC amplification was similar across arms (18/135 [13%] vs. 16/138 [12%]; ChiS p=0.66). Co-amplification of MYC/HER2 was observed in 32 (12%) pts with similar co-amplification rates across arms (17/135 [13%] vs. 15/138 [11%]; ChiS p=0.66). Based on preliminary analyses, MYC amplification and MYC/HER2 co-amplification do not appear to be associated with race, menopausal status, hormone receptor status, nodal status, tumor histology, tumor grade, or tumor size (all ChiS p>0.05); however, MYC amplified pts were significantly younger than MYC non-amplified pts (mean 46.4 vs. 51.0, t-test p=0.02) and MYC/HER2 co-amplified pts were significantly younger than MYC/HER2 non-co-amplified pts (mean 45.9 vs. 51.0, t-test p=0.01).  Conclusions: In our initial analyses of 239 pts, we observed a lower frequency of MYC/HER2 co-amplification than the previously reported 30% for NSABP B-31. Complete FISH analyses of 868 pts in N9831 and association with DFS will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 56.
A 6 gene molecular predictor of lapatinib related benefit: from cell line models to clinical trials.
Authors: Gray J , Das D , Spellman P , Wang N , Kuo W , Wyrobek A , Bhattacharya S , Press M , Di Leo A , Ellis C , Arbushites M , Casey M , Gagnon R , Koehler M
Published: December 2010

Abstract #58

Background: Identification of molecular predictors of response is an important aspect of individualized cancer treatment. Responses to lapatinib (L), an oral inhibitor of HER2 and EGFR, approved in combination with capecitabine for HER2+ metastatic breast cancer (MBC), were evaluated in a panel of BC cell lines. Computational approaches were used to identify transcripts that quantitatively associate with response to L in the cell line panel that were then tested in 2 clinical trials.  Methods: The clinical utility of a 6-gene predictor was tested retrospectively using a branched-chain DNA assay in paraffin-embedded archival tumor tissue from patients (pts) with HER2 negative or untested MBC tumors enrolled in a phase III trial of paclitaxel (P) vs. P+L, and from pts with HER2 positive MBC enrolled in a L monotherapy trial. Expression of HER2 transcript using the branched-chain assay was compared with HER2 fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) status; discordant cases were analyzed. Response patterns for pts with HER2+ tumors and a computational model that predicts L sensitivity or resistance is described.  Results: Ingenuity analysis of the mRNA predictors of response to L identified in the BC cell line panel revealed saturated gene networks with HER2 as a major node. The 6-gene predictor of response was comprised of 2 genes associated with sensitivity to L: HER2 and GRB7; 4 genes associated with resistance to L: CRK, ACOT9, FLJ31079, and DDX5. Expression results for the 6 genes and progression-free survival (PFS) data were available for 159 pts on L+P. Median PFS in the branched-chain HER2+ group was 32.9 wks vs. 22.4 wks in the HER2-negative group. The 6-gene predictor was used to predict response to L in the HER2+ pts. Comparison of PFS in the 24 “L sensitive” tumors vs. 25 “L resistant” tumors indicated that the predictor, derived from cell-line analyses, had the potential to predict clinical response to L in pts treated with L+P (HR=0.58; 95% CI=0.30-1.11; p=0.07). The 6-gene predictor was further tested in an independent L monotherapy study in pts with HER2 FISH+ MBC. Comparison of PFS in the 24 “L sensitive” tumors vs. 28 “ L resistant” tumors reconfirmed the potential of the 6-gene predictor to enrich for HER2+ pts most likely to experience clinical benefit from L (HR=0.40; 95% CI=0.19-0.84; p=0.015). Further testing is ongoing.  Conclusions: This study suggests that molecular predictors of clinical response can be developed through an analysis of response from a collection of 50 BC cell lines. The identification of a L specific 6-gene assay is promising as a clinical predictor of benefit from L in pts with HER2+ BC.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 58.
Comparative breast tumor imaging to identify the expression of type I IGF receptor (IGF1R) by anti-IGF1R antibody-conjugated small molecule fluorophore or quantum dots in vivo.
Authors: Zhang H , Zeng X , Yee D
Published: December 2010

Abstract #6001

The type I insulin-like growth factor (IGF) receptor (IGF1R) is a transmembrane receptor tyrosine kinase involved in breast cancer proliferation, survival, and metastasis. Several antibodies against IGF1R, including some in clinical trials, downregulate the level of IGF1R both in cell line studies and in in vivo animal experiments. Thus, this downregulation is a biodynamic marker of antibody delivery to the tumor. To date, identification of IGF1R expression and its downregulation in vivo in a non-invasive way is still challenging. In this study, we sort to use two different fluorescent technologies, small molecule fluorophores, or quantum dots (QDs), to detect receptor expression and its downregulation by antibodies in vivo. Alexa 680 is a small molecule fluorophore that can be excited with a peak emission at 705 nm. QDs are nanocrystals that emit fluorescence upon excitation, and QDs with a peak emission at 705 nm was used in this study. Both Alexa 680 and QDs were conjugated with AVE-1642, a humanized anti-IGF1R antibody developed by sanofi-aventis. After conjugation, they both were able to detect the expression of IGF1R and its downregulation in in vitro cell line studies. We used mouse xenograft tumor models to examine their efficacies in vivo. AVE-1642 conjugated Alexa 680 or QDs (705 nm) was intravenously delivered to mice bearing mammary xenograft tumors that express IGF1R. After 24 hours of circulation, Alexa 680 fluorescence was shown to solely localize to the xenograft tumor, with little non-specific targeting to other tissue or organs in mice. In addition, Alexa 680 fluorescence was diminished in tumors that had downregulated IGF1R by antibody pretreatment. In contrast, conjugated QDs fluorescence was mainly localized to liver, spleen, bone marrow and lymph nodes, with very small amount of QDs in the xenograft tumors. The QDs fluorescence in xenograft tumors remained unchanged even when IGF1R was downregulated by antibody pretreatment. Furthermore, we identified that QDs were mainly localized to the hepatic sinusoids, and subsequently engulfed by Kupffer cells. Taken together, our data suggest that small molecule fluorophores, such as Alexa 680, are useful agents to detect the expression and downregulation of IGF1R in vivo. Our data provide valuable insight not only into the clinical development of anti-IGF1R antibodies, but also to other targeted therapy as well.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6001.
Metabolism-perfusion mismatch as assessed by PET varies with breast cancer phenotype and predicts response to neoadjuvant chemotherapy.
Authors: Specht JM , Kurland BF , Dunnwald LK , Doot RK , Gralow JR , Ellis GK , Linden HM , Livingston RB , Schubert EK , Mankoff DA
Published: December 2010

Abstract #6005

Background: Kinetic analysis of FDG and water PET can identify patterns of breast cancer metabolism and perfusion in patients receiving neoadjuvant chemotherapy (NC). Previously, we found that high pre-therapy glucose tumor metabolism relative to perfusion was associated with poor tumor pathologic response, early relapse, and death in patients with locally advanced breast cancer (LABC) treated with NC. This analysis examines tumor metabolism and perfusion as a function of tumor phenotype. Material and Methods: Tumor phenotype, defined by immunohistochemistry (IHC), was determined in 51 patients undergoing NC between 1995 and 2005. Luminal tumors were defined as those expressing either estrogen receptor (ER) or progesterone receptor (PR). The triple-negative (TN) phenotype was defined as ER and PR negative without HER2 overexpression by IHC or amplification by FISH. HER2 phenotype showed HER2 overexpression or amplification but were ER/PR negative. Women with LABC underwent dynamic [18F]-FDG and [15O]-water PET scans prior to NC. The FDG metabolic rate (MRFDG) and transport (FDG K1) parameters were calculated; blood flow (BF) was estimated from the water PET scan. Response to NC was determined from surgical specimens with pathologic complete response (pCR) defined as eradication of invasive tumor in the breast vs. other. Results: Of the tumors studied, 16 (31%) were TN, 30 (59%) were luminal, and 5 (10%) were HER2. pCR was observed in 4/16 (25%) TN tumors (95% CI: 0.10-0.50) compared to only 4/30 (13%) of luminal tumors (95% CI: 0.05-0.30) and 3/5 HER2 tumors. Linear regression of the association between PET parameters and phenotype (TN vs. luminal) found that TN was associated with higher MRFDG (p=0.007) and MRFDG/BF ratio (p=0.02), but not with BF (p=0.27). Only patients with low pre-therapy MRFDG/BF ratio (<35 umol/mL) achieved a pCR. Using this value as an ad-hoc cutoff, 4/7 (57%) of TN patients with low ratios had a pCR, while 0/9 with higher ratios had pCR. In contrast, only 4/21 (19%) of the luminal patients with low ratios had a pCR (one-sided mid-p=0.04 for TN vs. luminal pCR rate for patients with MRFDG/BF < 35 umol/mL). Discussion: These results demonstrate heterogeneity in breast tumor metabolism and perfusion as assessed by PET, and suggest a clinically relevant association between PET parameters and tumor phenotypes. The high MRFDG/BF ratio that predicts poor response to NC is more common in TN tumors; whereas in luminal or HER2 tumors, high MRFDG is generally matched with higher BF. Measurement of tumor metabolism and perfusion may identify a subset of tumors which are unlikely to respond to NC. Identification of such tumors may direct therapy toward those biologic targets most likely to overcome resistance.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6005.
DCE-MRI and dynamic FDG PET to monitor breast cancer response to neoadjuvant sunitinib in patients with locally-advanced breast cancer.
Authors: Specht JM , Partridge S , Dunnwald L , Doot R , Schubert E , Kurland B , Gralow J , Linden H , Gadi V , Ellis G , Mankoff D
Published: December 2010

Abstract #6006

Background: We are enrolling patients with locally-advanced (LABC) or inflammatory breast cancer on a phase II trial of neoadjuvant sunitinib and metronomic chemotherapy. The addition of sunitinib is hypothesized to increase rate of pathologic complete response (pCR) via its effect on tumor vasculature. Measurement of FDG PET and MRI parameters of metabolism and blood flow (BF) after a one week run-in of sunitinib alone provides an opportunity to evaluate in vivo pharmacodynamics of sunitinib which may be predictive of response and provide insight into mechanism of sunitinib activity. Materials and Methods: Patients with HER2 negative LABC participated in an imaging trial with pre-therapy [18F]-FDG PET and DCE-MRI (T0) followed by a one-week run-in of sunitinib 37.5 mg orally daily with a second PET and MRI on day 7 (T1). FDG metabolic rate (MRFDG), transport (FDG K1) and MR indices of tumor perfusion (peak enhancement (PE), signal enhancement ratio (SER), and washout volume(WV)) were assessed. Results: Metabolism and perfusion parameters are available for the first 3 patients treated on this trial. All patients presented with grade 3, HER2 negative LABC. DCI-MRI (left) and PET images (right) pre-therapy (T0, top) and after one week sunitinib (T1, bottom) are illustrated in Figure 1. DCE-MRI studies show gray-scale images with color-coded regional perfusion (SER) superimposed; red indicates high levels of perfusion and blue lower levels. Three different responses were observed and expressed as percent change T0 to T1: patient 1 had no significant change in metabolism (MRFDG) or perfusion (K1,SER, PE); patient 2 showed a decline in perfusion with decreases in K1 (-55%), SER (-19%), PE (-10%), and WV (-56%), but minimal change in MRFDG (+ 5.9%); while patient 3 had marked declines in perfusion K1 (-41%), SER (-25%), WV (-78%) and MRFDG (-59%). Discussion: These early data demonstrate the ability to measure changes in tumor metabolism and blood flow by PET and MRI and illustrate heterogeneity in tumor response to sunitinib. As patients complete neoadjuvant chemotherapy (NC), metabolism and perfusion parameters from mid-therapy (T2) and end-therapy (T3) imaging will be evaluated in the context of pCR versus other with the goal of exploiting functional imaging parameters to predict response to NC and elucidate mechanism of response to sunitinib and metronomic chemotherapy. Supported by grant from NCCN, SI11.   

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6006.
Novel mouse model for studying role of ER-nongenomic actions in breast cancer.
Authors: Rajhans R , Cortez V , Nair SS , Tekmal RR , Kumar R , Vadlamudi RK
Published: December 2010

Abstract #601

Back ground: Estradiol (E2) and estrogen receptor (ER) signaling play a key role in development and progression of breast cancer. ER signaling is complex, involves coregulatory proteins and the status of ER coregulators in tumor cells plays an important role in hormonal responsiveness and tumor progression. In addition, ER also participates in non-genomic signaling events in the cytoplasm, however the significance of non-genomic signaling in mammary tumorigenesis remain unknown. PELP1/MNAR is novel ER coregulator that participates in ER genomic and non-genomic actions. PELP1 expression is deregulated in breast tumors and in a subset of tumors PELP1 is predominantly localized in the cytoplasm. Since PELP1 cytoplamsic localization promotes excessive activation of Src and AKT pathways, we hypothesized that PELP1 mediated excessive activation of ER-nongenomic functions may play a role tumorigenesis. To test this, we have generated MMTV-PELP1cyto TG model that uniquely express PELP1 in the cytoplasm of mammary glands that mimics the pathological situation of PELP1 localization seen breast cancer.  Methods: As a means of targeting the expression of the PELP1 transgene to the mammary gland, we placed the PELP1cyto cDNA under the control of the MMTV promoter. PELP1 transgene integration was verified by PCR and expression levels by Western and IHC in each founder line. Whole-mount preparations and IHC analysis was performed using Tg and age controlled wild type littermates from different developmental stages. Total protein extracts of mammary gland were used for western blot analysis of nongenomic signaling components.  Results: Preliminary analysis of mammary gland from PELP-cyto mice showed hyperplasia, increased proliferation as analyzed by PCNA staining. Mammary tumors were observed as early as 32 weeks. No spontaneous mammary tumors were found in the wild type cohort. Pathological analysis revealed that these tumor masses represent full blown mammary adenocarcinomas. Mammary tumors showed excessive activation of nongenomic signaling including activation of Src and AKT pathways. A clear induction of aromatase expression was found in PELP1 tumors compared with the wild-type that showed no aromatase expression in the mammary gland.  Discussion: We have established and characterized a transgenic mouse model that mimics deregulated ER-nongenomic signaling. Our results suggest that PELP1 is a proto-oncogene and demonstrates its in vivo tumorigenic potential. PELP1 driven tumors are ER+ve, express aromatase, thus provide an interesting in vivo model for studying ER-mediated tumorigenesis and to study effect of local E2 on ER-mediated tumorigenesis.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 601.
In vivo magnetic resonance imaging of the progression of murine ductal carcinoma in situ: finding timescales and predictors of future invasion.
Authors: Jansen SA , Conzen SD , Newstead GM , Markiewicz EJ , Karczmar GS
Published: December 2010

Abstract #6011

Background: Understanding the natural history of breast cancer is important for effective patient management and treatment. For example, some evidence suggests that preinvasive ductal carcinoma in situ (DCIS) may be over-treated, since not all will progress to invasive cancer. Unfortunately, due to obligate surgical excision of newly diagnosed breast cancers, the natural history of disease is difficult to study in women. However, mouse models of breast cancer can serve as an alternative; the purpose of this study was to use magnetic resonance imaging (MRI) to investigate the progression of DCIS into invasive cancer in a transgenic model.  Methods:12 SV40 Tag mice were imaged every 2-3 weeks (wks) starting at 10 wks of age. SV40 mice develop mammary cancer similar to DCIS and IDC, and usually live to 22 wks when they succumb to breast cancer. T1-weighted gradient echo images of inguinal mammary glands were obtained. DCIS lesions and invasive tumors were identified and volumes were measured over time. For each lesion we measured: the time at initial development (TDCIS and Ttumor), the growth rate of DCIS and invasive tumors (calculated from 'V=V0exp(αt)'), and for DCIS lesions that progressed to invasive tumors the progression time Tprog was measured.  Results:DCIS (n=21) and invasive (n=16) tumors developed, at an average initial age of TDCIS =12.7±2.6 wks and Ttumor =16.3±3.1 wks, and at an initial volume of 0.3±0.2 mm3 and 1.7 mm3, respectively. The average growth rate for DCIS lesions was αDCIS= 0.08±0.23 wk-1, significantly smaller than that of invasive tumors (αtumor= 0.55±0.35 wk-1, p =0.001). 9/21 DCIS lesions progressed to invasive cancers in an average time of Tprog=4.56 ± 1.9 wks(Figure 1a). 11/21 DCIS did not progress within the study window and 5/21 were stable for over 8 wks (Figure 1b).    The volume of DCIS was not a predictor of progression, but there was a trend for DCIS growth rate to be related to eventual development of invasiveness.  Discussion:To our knowledge, the results reported here are the first direct measurements of the timescales and characteristics of progression from in situ to invasive carcinoma. Surprisingly, even in transgenic mice that are strongly pre-disposed to develop cancer, some DCIS lesions did not progress to invasive cancer. Interestingly, DCIS volume did not predict future progression to invasive tumors, but growth rate may have been a predictor. The methods and data here provide a foundation for using MRI in pre-clinical studies of early cancer progression, prevention and targeted treatment. Extensions of this pilot study may yield image-based biomarkers of progressing vs. indolent DCIS.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6011.
Novel roles of a transcription elongation regulator in mammary gland development and tumorigenesis.
Authors: Sreejith Janardhanan N , Sun J , Amleh A , Sun L , Wang L , Li R
Published: December 2010

Abstract #6013

Historically, transcriptional regulation in mammary gland development and breast cancer development is thought to primarily occur at the stage of transcription initiation. However, recent studies of genome-wide transcription suggest that the majority of “inactive” genes in human cells experience transcription initiation and many of them have binding of RNA polymerase at the promoter-proximal region. Thus, transcription elongation may represent a widespread, yet vastly under-appreciated step for mammalian gene regulation. Cofactor of BRCA1 (COBRA1), which was first identified as a BRCA1-binding protein, acts as an integral subunit of the negative elongation factor (NELF) complex to stall RNA polymerase II (RNAPII) during estrogen-stimulated transcription elongation. COBRA1 also shares a number of target genes for transcriptional regulation with BRCA1 in breast cancer cells. In support of its potential role in tumor suppression, COBRA1 is preferentially expressed in luminal epithelial cells in normal mammary ducts; and its reduced expression is strongly correlated with metastatic breast cancer. Knockdown of COBRA1 leads to elevated hormone-dependent transcription and accelerated cell proliferation in vitro. To further investigate the biological function of COBRA1, we compared tumor growth of control and COBRA1 knockdown human breast cancer cells in a xenograft mouse model. In contrast to tumors from the control cells whose growth was strictly estrogen-dependent, tumors from COBRA1-depleted cells achieved sustained growth even in the absence of exogenously added estrogen. This result suggests that depletion of COBRA1 either allows hormone-independent cell proliferation or sensitizes cells to grow under extremely low levels of estrogen. In a complementary approach, a Cre-lox system was used to delete mouse Cobra1 in whole body or in mammary gland. Mouse embryos deficient in Cobra1 do not develop beyond E5.5; and mammary gland-specific Cobra1 knockout mice exhibit severe defects in alveologenesis and lactogenesis. The molecular basis for the Cobra1-associated developmental defects and the possible impact of Cobra1 deletion on mammary tumorigenesis will be discussed. By linking regulation of transcription elongation with mammary gland-specific functions, our work establishes a novel paradigm for gene regulation in mammary gland biology and breast cancer research.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6013.
Inhibition of E-cadherin is associated with down-regulation of members of the miR-200 family but not with promoter methylation in human breast cancer cell lines.
Authors: Tryndyak VP , Beland FA , Pogribny IP
Published: December 2010

Abstract #6017

Background: Increasing evidence indicates the fundamental role of epithelial to mesenchymal transition (EMT) in breast cancer progression and this is viewed as an essential early step in tumor cell invasion and metastasis. One of the pivotal events of EMT is down-regulation of E-cadherin. Recent findings have demonstrated the importance of the miR-200 microRNA family in the regulation of E-cadherin and EMT. In view of these findings, we examined the relationship between expression of members of the miR-200 family and status of E-cadherin levels in various human breast cancer cell lines.  Materials and Methods: Using quantitative real-time PCR analysis, we analyzed the expression of miR-200b, miR-200c, and miR-141 in 15 human breast cancer cell lines. Additionally, we measured the level of ZEB1, ZEB2, and E-cadherin proteins using Western blot analysis and E-cadherin promoter methylation by methylation-specific PCR.  Results: We found a substantial down-regulation of miR-200b, miR-200c, and miR-141 in the breast cancer cell lines. The extent of down-regulation was correlated with metastatic potential of cells. The down-regulation of members of the miR-200 family was associated with up-regulation of ZEB1 and ZEB2, transcriptional repressors of E-cadherin, and a subsequent decrease in the E-cadherin levels. More importantly, inhibition of E-cadherin expression was not due to its promoter hypermethylation. Treatment of breast cancer cells with demethylating agent 5-aza-2'-deoxycytidine resulted in over-expression of miR-200b and miR-200c, increase of the level of E-cadherin, and diminished metastatic properties of cancer cells.Discussion: Previous studies have revealed the important role of promoter methylation-related inhibition of E-cadherin in EMT in human breast cancer. However, the transcriptional silencing of E-cadherin is not always related to promoter hypermethylation, which indicates the existence of other mechanisms in E-cadherin down-regulation. In the present study, we demonstrated the crucial role of members of the miR-200 family in up-regulation of ZEB1 and ZEB2 proteins leading to subsequent E-cadherin down-regulation in human breast cancer cell lines. The extent of down-regulation of the miR-200 family was dependent of cancer stage and was associated with metastatic potential of cancer cell lines. This suggests that expression of miR-200 may be a powerful diagnostic marker determining breast cancer stage and cancer invasive phenotype. More importantly, the results indicate the great potential for reversing the invasive phenotype of cancer cells by up-regulation of miR-200 microRNAs.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6017.