Effective trapping of random walkers in complex networks

Exploring the World Wide Web has become one of the key issues in information science, specifically in view of its application to the PageRank-like algorithms used in search engines. The random walk approach has been employed to study such a problem. The probability of return to the origin (RTO) of random walks is inversely related to how information can be accessed during random surfing. We find analytically that the RTO probability for a given starting node shows a crossover from a slow to a fast decay behavior with time and the crossover time increases with the degree of the starting node. We remark that the RTO probability becomes almost constant in the early-time regime as the degree exponent approaches two. This result indicates that a random surfer can be effectively trapped at the hub and supports the necessity of the random jump strategy empirically used in the Google's search engine.

P2-08-02: Magnetic Resonance Imaging as a Predictor of Pathologic Response in Patients Treated with Neoadjuvant Systemic Treatment for Operable Breast Cancer (TBCRC 017)

Background: Increased pathologic complete response (pCR) rates observed with neoadjuvant chemotherapy for invasive breast cancer has prompted interest in whether patients with pCR can be identified preoperatively and potentially spared the morbidity of surgery. This multicenter retrospective study was performed to determine the accuracy of preoperative MRI in predicting pCR in the breast and whether MRI performance differs by molecular subtype, histology, and treatment regimen.

Methods: 770 women from 8 institutions were retrospectively identified as having received neoadjuvant systemic therapy with MRI obtained at baseline and after completion of systemic treatment. Tumor phenotypes were defined on the basis of estrogen and progesterone receptor (ER/PR or HR) and HER2 receptor status. Univariate and multivariate analyses of factors influencing radiographic complete response (rCR) and pCR were recorded, with rCR defined as resolution of any abnormal enhancement, mass, or distortion on MRI, and pCR defined as resolution of both invasive disease and DCIS.

Results: rCR and pCR for the total group were 182/746 (24%) and 179/746 (24%), respectively, with the highest rate of pCR seen among the triple-negative (TN; 57/155; 37%) and HR-/HER2+ (38/101; 38%) subtypes. Covariates significantly associated with rCR included T stage (p=0.0002), tumor grade (p=0.005), IHC phenotype (p=0.005), and chemotherapy regimen (p<0.0001). On multivariate analysis, only tumor phenotype was independently associated with likelihood of rCR, with both TN (OR = 2.00, 95% CI 1.20−3.33) and HR-HER2+ (OR=2.30, 95% CI 1.09–4.83) more likely to achieve rCR than HR+HER- (reference group). Overall accuracy of MRI for prediction of pCR was 74%. Sensitivity, NPV, PPV, and accuracy differed significantly among tumor subtypes, with the greatest NPV in the HR-/HER2+ and TN subtypes (table1). Among patients with rCR, ER- status (OR=6.4, 95% CI 1.1 to 35.6), PR- status (OR=3.8, 95% CI 1.2 to 11.4), and tumor grade of 3 vs 1 or 2 (OR=2.49, 95% CI 1.22−5.07) were independently associated with likelihood of pCR. Discussion: MRI performance for predicting pCR in patients with invasive breast cancer receiving neoadjuvant systemic therapy differed significantly among breast cancer subtypes; however this difference is likely due to subtype differences in frequency of pCR and not to intrinsically better or worse MRI detection. The relatively low NPV of MRI following neoadjuvant systemic therapy does not support using MRI rCR alone to accurately identify those patients that can safely avoid surgery.

P5-01-04: FOXP3 Positive Regulatory T Lymphocytes and Epithelial FOXP3 Expression in Synchronous Normal, Ductal Carcinoma In Situ and Invasive Cancer of the Breast

Background: FOXP3 expressing regulatory T cells (Tregs) have been associated with worse outcome in a number of malignancies, including breast cancer. In this study we evaluate the number of FOXP3 positive T lymphocytes as well as quantitating FOXP3 expression of epithelium in synchronous normal, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) in order to determine whether FOXP3 expression increases with cancer progression.

Materials and Methods: 32 cases containing concurrent normal, DCIS and IDC lesions of the breast were stained for FOXP3 (e-Bioscience) and CD3 (DAKO) using the Envision G/2 Double stain System (DAKO). Multiplex stains were separated by imaging using the CRi's Nuance imager. The ratio of colocalized FOXP3 and CD3 pixels (Treg lymphocytes)/CD3 pixels (all lymphocytes) in adjacent stroma was used as a measure of FOXP3 positive Tregs. Epithelial FOXP3 expression was quantitated by Image J analysis. A subset of the cases (n= 13) were also stained by standard immunohistochemistry for FOXP3. The number of FOXP3 positive lymphocytes/total lymphocytes and the epithelial intensity were scored.

Results: The mean patient age was 52 years. ER, PR and HER2 positivity in the invasive component was 94%, 84% and 16% respectively. One case was triple negative.

The median fraction of FOXP3 lymphocytes increased from normal to DCIS to IDC (0.005, 0.019 and 0.030 respectively). Significant differences were seen for normal vs. IDC (p=<0.0001) and DCIS vs. IDC (p=0.0039). FOXP3 lymphocyte fraction was significantly higher in grade 3 compared to grade 1 tumors (p=0.0140). Standard immunohistochemistry showed similar results (median value for fraction of FOXP3 positive lymphocytes = 0.03, 0.14 and 0.16 in normal, DCIS and IDC respectively). This was significantly different in the normal stroma vs. invasive cancer stroma comparison (p=0.017).

For epithelial FOXP3 staining intensity, the median increased significantly from normal to DCIS (0.130 to 0.175, p=<0.0001) and decreased significantly from DCIS to IDC (0.175 to 0.150, p=0.0181). However, FOXP3 epithelial intensity was higher in grade 3 compared to grade 1 tumors (p=0.0381). Epithelial FOXP3 expression by standard IHC also showed a similar trend (median H score 100, 150 and 120, respectively) with a significant increase in the normal vs. DCIS comparison (p=0.0090).

FOXP3 lymphocyte count had a positive correlation with FOXP3 epithelial intensity in the normal and invasive components (Spearman r=0.4343, p=0.0130 for normal and Spearman r=0.5456, p=0.0012 for IDC).

FOXP3 lymphocyte fraction and FOXP3 epithelial intensity did not vary significantly with size of invasive tumor, nodal status, or stage of disease.

Discussion: FOXP3 is expressed both by tumor infiltrating T lymphocytes as well as tumor epithelium. The significant increase in FOXP3 T regulatory lymphocytes and FOXP3 epithelial expression from normal to invasive cancer suggests a role of FOXP3 in breast carcinogenesis and progression. The significant correlation of FOXP3-T regulatory lymphocytes and FOXP3 epithelial expression in the normal and invasive components suggests expression of one may influence the other early in the breast cancer progression pathway.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-01-04.

P1-03-01: ECM Stiffness and Breast Tumor Histology and Treatment Phenotype

Currently, the extent of local surgery and radiation for breast cancer is not guided by biological or anatomical principles, and the optimal volume of treatment is not defined. Local tumor progression is strongly influenced by a dynamic interplay between the genetically-modified epithelium and the associated cellular and non-cellular stroma (Butcher, 2009; Levental, 2009). The extracellular matrix (ECM) is modified in breast tumors and data indicate that the ECM stiffens progressively as mammary tumors evolve and enhancing ECM stiffness promotes mammary tumorigenesis while inhibiting ECM stiffening reduces tumor progression. However, the degree and extent of local stromal changes, and their clinical impact in breast cancer evolution and treatment remain unclear. This has led us to predict that the desmoplastic stroma surrounding breast tumors reflects tumor phenotype and behavior and can be characterized by biophysical metrics of the ECM stroma and molecular signatures of the breast epithelium. Accordingly, we hypothesize that these features may be integrated into a stromal phenotype that can be developed as a predictive tool. To test this concept we used a rigorous biomechanical and biochemical analysis of mastectomy specimens from women with various stages and histology phenotypes of treated and non-treated breast cancer to explore the relationship between ECM stiffness, mechanotransduction and tumor behavior. The goal of the study was to characterize stromal changes as a function of tumor stage and histology phenotype as well as before and after chemotherapy by measuring biophysical and topological features of the ECM and biochemical and molecular signatures of the mammary epithelium. The objective was to determine if there is a significant association with tumor histology phenotype that could be integrated to generate a stromal phenotype. Egan sections of were acquired from breast tissue containing benign and invasive ER positive and negative carcinoma and from treated and non-treated patients. All tissues were subjected to IHC histological and mechanosignaling analysis (H&E; 397FAK; Lysyl Oxidase; phosphomyosin) and biomechanical assessment (Atomic Force Microscopy; Structured Illumination Polarized Imaging; Two Photon Imaging). Preliminary data were consistent with prior in vitro and in vivo studies and showed that there was a significant increase in ECM stiffness as the tissues transitioned from normal to an invasive lesion with the highest stiffness being located at the tumor edge (∼2-4 folds greater). Intriguingly, we observed that ER negative tumors were substantially stiffer than ER positive tumors (50% increase in upper 10-percentile) and that there were tracks of ECM stiffness that correlated with orientated parallel collagen fibers and ECM birefringence. Moreover, we quantified a significant decrease in ECM stiffness following treatment (40% lower) with the most striking reduction in ECM tension being noted in ER negative patient tissues who demonstrated the most robust response. This study should lead to a deeper understanding of the nature of breast cancer stroma and its role in tumor phenotype and response to therapy.

Supported by: NCI SPORE P50 CA058207 to VMW, CP, & SH; U01 ES019458-02 to ZW; NCI R01 CA138818-01A1 to VMW; & U54 CA143836-01 to VMW & JL.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-03-01.

Effect of splenic artery embolization for splenic artery steal syndrome in liver transplant recipients: estimation at computed tomography based on changes in caliber of related arteries

PURPOSE

To estimate the effect of splenic artery embolization (SAE) on blood flow in orthotopic liver transplantation (OLT) recipients with splenic artery steal syndrome (SASS) based on changes in caliber of related arteries upon serial computed tomography (CT) scans.

METHODS

Between 2004 and 2007, nine OLT recipients with SASS underwent SAE. They had CT scans before and after SAE: short-, mid-, and long-term, ie, approximately 1 week, 1 month, and 1 year, respectively. The diameters of the celiac axis (CA), common hepatic artery (CHA), and splenic artery (SA) were measured with arterial phase of each CT scan and the ratios of SA to CHA diameter (SA/CHA) calculated to analyze their changes during the follow-up period.

RESULTS

The diameters of celiac axis, CHA, and SA and SA/CHA changed most rapidly during the short-term period. The CHA diameter significantly increased short-term post-SAE by CT and slightly decreased thereafter. However, the mid-term and long-term post-SAE CT values were still significantly greater than those on the pre-SAE CT. The SA diameter steadily decreased throughout the follow-up. The SA/CHA decreased until the mid-term. The SA diameter and SA/CHA were significantly smaller upon mid-term and long-term post-SAE CT compared with those at pre-SAE CT.

CONCLUSIONS

The effect of SAE to improve hepatic arterial flow in OLT recipients with SASS might be expected for at least approximately one year. The effect maximally occurred during the short-term after SAE on the basis of changes in the caliber of related arteries upon CT.

Association of filamin A and vimentin with hepatitis C virus proteins in infected human hepatocytes

Chronic hepatitis C (CHC) infection caused by hepatitis C virus (HCV) is a major cause of liver disease and remains a major therapeutic challenge. A variety of host proteins interact with HCV proteins. The definitive role of cytoskeletal (CS) proteins in HCV infection remains to be determined. In this study, our aim was to determine the expression profile of differentially regulated and expressed selected CS proteins and their association with HCV proteins in infected hepatocytes as possible therapeutic targets. Using proteomics, qRT-PCR, Western blot and immunofluorescence techniques, we revealed that filamin A (fila) and vimentin (vim) were prominently increased proteins in HCV-expressing human hepatoma cells compared with parental cells and in liver biopsies from patients with CHC vs controls. HCV nonstructural (NS) 3 and NS5A proteins were associated with fila, while core protein partially with fila and vim. Immunoprecipitation showed interactions among fila and NS3 and NS5A proteins. Cells treated with interferon-α showed a dose- and time-dependent decrease in CS and HCV proteins. NS proteins clustered at the perinuclear region following cytochalasin b treatment, whereas disperse cytoplasmic and perinuclear distribution was observed in the no-treatment group. This study demonstrates and signifies that changes occur in the expression of CS proteins in HCV-infected hepatocytes and, for the first time, shows the up-regulation and interaction of fila with HCV proteins. Association between CS and HCV proteins may have implications in future design of CS protein-targeted therapy for the treatment for HCV infection.

Incidence and risk factors for the development of prolonged severe intrahepatic cholestasis after pediatric living-donor liver transplantation

The aim of this study is to evaluate the incidence, etiology, and risk facrors for prolonged severe intrahepatic cholestasis (PSIC) after 129 pediatric living-donor liver transplantations (LDLT). The incidence of PSIC was 25.6% (n = 33). Twenty-eight (84.8%) versus 5 (15.2%) children experienced early versus late PSIC, respectively. Among these 33 children with PSIC, 8 (24.2%) received a donor liver with mild to moderate fatty change, 4 (12.1%) with low graft-body weight ratios, and 4 (12.1%) with ABO incompatibility. The predominant etiologies were acute rejection (n = 15; 45.5%), chronic rejection (n = 6; 18.2%), virus (n = 3; 9.1%), vascular complications (n = 4; 12.1%), and initial graft dysfunction (n = 10; 30.3%). ABO incompatibility (P = .032; odds ratio [OR] 3.25), chronic rejection (P = .012; OR 4.76), and vascular complications (P = .046; OR 1.82) were significant variables associated with PSIC. Donor selection with ABO compatibility as well as early detection and management of chronic rejection and vascular complications may be important to prevet PSIC in LDLT.

Substitutionally Doped II–VI Semiconductor Films and Layered Structures

Photoassisted molecular beam epitaxy (PAMBE), in which the substrate is illuminated during film growth, is being employed in a new approach to controlled substitutional doping of II–VI compound semiconductors. Substitutional doping of these materials has been a long standing problem which has severely limited their applications potential. The PAMBE technique gives rise to dramatic changes in the electrical properties of as-grown epilayers. In particular, highly conducting n-type and p-type CdTe films have been grown using indium and antimony as n-type and p-type dopants, respectively. Double-crystal x-ray rocking curve data indicate that the doped epilayers are of high structural quality. Successful n-type doping of CdMnTe, a dilute magnetic semiconductor, with indium has also been achieved. Most recently, the photoassisted growth technique has been employed to prepare doped CdMnTe-CdTe quantum well structures and superlattices. In addition, HgCdTe films which exhibit excellent optical and electrical properties as well as exceptional structural perfection have been grown by the PAMBE technique.

Peritransplant monitoring of immune cell function in adult living donor liver transplantation

PURPOSE

We evaluated the clinical utility of peritransplant in vitro assays of immune cell function in adult living donor liver transplant (LDLT) recipients.

METHODS

In particular, we measured immune cell function, using the ImmuKnow assay, in 107 adult LDLT recipients and 200 potential living liver donors (control group) admitted to our center between July 2008 and January 2009.

RESULTS

In the control group, the mean proportion of T-helper/inducer cells was 36.8% ± 8.2%. The degree of immune response was strong in 12%, moderate in 77%, and low in 11%. In the study group, the degree of immune response within the first month was strong in 4.6%, moderate in 38.2%, and low in 57.2%, thus significantly lower than in the control group (P < .001). ImmuKnow results and tacrolimus levels did not show a significant correlation (r(2) = .002, P = .392). Although six patients showed biopsy-proven acute cellular rejection, none showed a strong immune response. Patients with overt infection showed a lower immune response.

CONCLUSIONS

These results indicate that peritransplant assessment of immune response using the ImmuKnow assay does not reliably predict the occurrence of acute rejection. Additional studies are necessary to accurately assess the clinical utility of immune response monitoring.

Comparison of the molecular adsorbent recirculating system and plasmapheresis for patients with graft dysfunction after liver transplantation

BACKGROUND

Graft dysfunction after liver transplantation (OLT) is a life- threatening condition. Molecular adsorbent recirculating system (MARS) or plasmapheresis (PLP) may be effective supportive therapy of graft dysfunction for patients who cannot undergo retransplantation. The aim of this study was to compare the effects of MARS and PLP in patients with graft dysfunction after OLT.

METHODS

Between January 2002 and July 2007, 31 OLT recipients who experienced graft dysfunction, defined as hyperbilirubinemia (>10 mg/dL) without bile duct obstruction and/or presence of hepatic encephalopathy, were treated with MARS or PLP. Biochemical and hemodynamic data and survival were compared in MARS and PLP groups.

RESULTS

Fifteen patients were treated with 41 MARS sessions and 16 with 105 PLP sessions. After a single MARS session, patients showed significant reductions in creatinine, urea nitrogen, bilirubin, and ammonia. After a single PLP session, patients showed significant improvements in prothrombin time, bilirubin, alanine aminotransferase, alkaline phosphatase, and albumin. After the completion of treatment, Both MARS and PLP significantly improved bilirubin values. at 90 days there were no differences in overall survival rates; 53% in MARS versus 56% in PLP.

CONCLUSION

Both MARS and PLP are alternative supportive treatments for graft dysfunction after OLT.

102 PROTEOMIC ANALYSIS OF CONDITIONED MEDIUM SUPPLEMENTED WITH PORCINE FOLLICULAR FLUID

Follicular fluid (FF) contains growth factors, electrolytes, hormones, amino acids, and unknown factors. Supplementation of porcine FF (pFF) to in vitro maturation (IVM) medium was reported to improve the oocyte maturation, monospermic fertilization and embryonic development. This study aimed at investigating whether pFF supplementation affects the characteristics of donor cells for somatic cell nuclear transfer and the proteomic composition of the culture medium. Ear fibroblast cells from an NIH major histocompatibility complex (MHC) inbred miniature pig were cultured with different culture methods: 1) DMEM + 10% FBS (FBS); 2) DMEM + 10% FBS + 10% pFF (pFF). The conditioned medium was collected at 72 h. After isoelectric focusing (IEF), the equilibrated strips were submitted to SDS-PAGE. Normalized protein spots were considered significantly different between the two groups if expression levels varied by two standard deviations. To identify the protein spots, an Ettan MALDI-TOF method was used. Upon submission of the amino acid sequences, proteins were identified by a homology search using ProteinInfo or BLAST search using the ExPASy Molecular Biology Server. The proportion of G0/G1 stage cells in the pFF group was significantly higher than the proportions in the other groups (P < 0.05). Among 42 differentially expressed spots, 36 proteins were identified in the pFF group. Some molecular functions of the spots were: catalytic or methytransferase activity, eukaryotic cell surface binding, or ferric iron binding. It can be concluded that pFF supplementation of culture medium positively affects cell-cycle synchronization and cell metabolism. Further studies are needed to analyse the function of these important cellular proteins. This work received grant support from the Agenda Program (No. PJ006688) and (No. PJ007189), Rural Development Administration, Republic of Korea.

202 KNOCK-DOWN AND DEVELOPMENTAL EFFICIENCY OF Arhgap15 GENE KNOCK-DOWN EMBRYOS

The technique of RNA interference (RNAi) knock-down is a powerful tool for the analysis of gene function in mammalian cells and eggs. Rho GTPase-activating protein 15 (Arhgap15) is closely related to anaemia and immunity, especially as caused by trypanosome. This study was performed to investigate the effect of Arhgap15 gene knock-down on the developmental competence of bovine embryos in vitro. Bovine fibroblast cells were treated with 50 and 100 nM concentrations of Arhgap15 RNAi, respectively. After 24 h of transfection, the control group showed no change in Arhgap15 mRNA level, whereas mRNA expression in the RNAi-treated donor cells was obviously decreased in a dose-dependent manner. These RNAi-treated cells were then transferred into enucleated bovine oocytes to analyse the consequence of RNAi-mediated Arhgap15 gene knock-down. In the control group, cleavage and blastocyst development rates were 75% (102/136) and 14.7% (20/136), whereas those in the knock-down embryos were 81.6% (120/147) and 24.5% (36/147), respectively. The occurrence of cell death by apoptosis was examined in Day 7 blastocysts. Apoptotic cells numbered 12 ± 3.2 in control embryos and 8.9 ± 4.8 in knock-down embryos. Therefore, it can be concluded that RNAi-mediated Arhgap15 gene knock-down in somatic cells did not affect the developmental competence of bovine cloned embryos. This work was supported by grant 120080401034062 from the BioGreen 21 Program, Rural Development Administration, Republic of Korea.

Spectral dimensions of hierarchical scale-free networks with weighted shortcuts

Spectral dimensions have been widely used to understand transport properties on regular and fractal lattices. However, they have received little attention with regard to complex networks such as scale-free and small-world networks. Here, we study the spectral dimension and the return-to-origin probability of random walks on hierarchical scale-free networks, which can be either fractal or nonfractal depending on the weight of the shortcuts. Applying the renormalization-group (RG) approach to a Gaussian model, we obtain the exact spectral dimension. While the spectral dimension varies between 1 and 2 for the fractal case, it remains at 2, independent of the variation in the network structure, for the nonfractal case. The crossover behavior between the two cases is studied by carrying out the RG flow analysis. The analytical results are confirmed by simulation results and their implications for the architecture of complex systems are discussed.

Living-donor liver transplantation in patients with concurrent active tuberculosis at transplantation

SETTING

Although active tuberculosis (TB) is a contraindication for liver transplantation (LT), LT may be the only possible treatment option in patients with irreversible liver failure and concurrent TB.

OBJECTIVES

To assess the outcome of LT in patients with concurrent TB and liver failure.

METHODS

We retrospectively evaluated the clinical outcomes of nine LT recipients with concurrent TB in Korea, an intermediate TB burden country.

RESULTS

The primary causes of living-donor LT (LDLT) in nine patients were anti-tuberculosis drug-induced fulminant hepatic failure (n = 4) and end-stage liver disease (n = 5). The sites of active TB were the lungs (n = 5), lymph nodes (n = 3) and pleura (n = 1). After LDLT, most patients were treated with less hepatotoxic drugs, including fluoroquinolones, ethambutol and cycloserine; none was treated with pyrazinamide. One patient experienced acute rejection, probably attributable to an interaction between rifampicin and cyclosporine. All nine patients, including one taking rifabutin, successfully completed anti-tuberculosis treatment and have been followed up for a median of 926 days after LDLT, without relapse of TB.

CONCLUSION

When properly managed, the prognosis of LDLT recipients with concurrently active TB at transplantation is very favourable. The current protocol, which considers active TB an absolute contraindication for LT, should be modified or relaxed, particularly for patients with LDLT.

Increase of modified retrograde to antegrade flow ratio on doppler ultrasounds of the hepatic vein indicating tricuspid regurgitation during follow-up of liver transplantation: correlation with echocardiographic results

The purpose of this study was to explore the best parameter of hepatic vein (HV) Doppler ultrasounds (DUS) that correlated with echocardiographic findings of and particularly the optimal cutoff value for tricuspid regurgitation (TR) following liver transplantation (LT). Thirty-six patients underwent echocardiography and DUS after LT from January 2006 to July 2007. Echocardiographic records were searched for TR grade and peak velocity of TR flow. The HV DUS parameters included peak velocity of retrograde flow (R), peak velocity of antegrade flow (A), the difference between R and A (R-A), the ratio of R to A (R/A ratio), and a modified R/A ratio, namely, the product of the R/A ratio and the R/A duration ratio. Correlation tests and receiver-operator characteristic analyses explored their interrelations and to obtained cutoff values to diagnose moderate and severe TR. TR grade best correlated with the modified R/A ratio (rho = 0.585), followed by the R/A ratio (rho = 0.503) and R (rho = 0.455). The modified R/A ratio was the most accurate parameter for the diagnosis of moderate and severe TR (Az = 0.825 and 0.895, respectively); its cutoff value was > or =0.11 for moderate TR (sensitivity and specificity both 77.78%) and 0.13 for severe TR (sensitivity, 100%; specificity, 81.2%). The modified R/A ratio best correlated with echocardiographic results of TR, although the strength of correlation was only moderate. Additionally, the modified R/A ratio was an accurate DUS parameter to diagnose moderate and severe TR among patients following LT.

Oncoplastic Approach for Reconstruction of Large Partial Mastectomy Defects Using Reduction Mammoplasty in Large Breasted Women

Background: Women with large breast tumors are often treated with mastectomy as their definitive operation. However, women with large breasts can have a significant resection and still achieve an excellent aesthetic outcome if the partial mastectomy is combined with a reduction mammoplasty. It is not clear if the limitation for breast conservation should be made based on tumor size, or on the basis of the volume of tissue that needs to be resected relative to the total volume of breast tissue. Our study aims to assess the oncologic safety and cosmetic outcome of large partial mastectomies in large breasted women combined with reduction mammoplasty.Materials and Methods: All patients undergoing partial mastectomy and reduction mammoplasty performed at the University of California San Francisco were included. Medical records were reviewed for demographics, breast cancer data, oncologic and reconstructive operations, postoperative recurrences, complications, and need for additional operations.Results: Sixty-five patients undergoing partial mastectomy and reduction mammoplasty reconstruction were identified. Average tumor size was 2.8 cm (range 0.6 cm to 8.9 cm). The stage distribution for 63 patients was stage 0 (n=11), I (n=15), II (n=24), III (n=10), and IV (n=3), and 2 patients had Phylloides tumor. Twenty-five patients had neoadjuvant therapy, followed by breast reduction as their primary resection once chemotherapy was completed. Twenty patients (30.8%) required re-excision, four of whom required multiple re-excisions. Fifty nine patients (90.8%) were successfully treated with our approach, while 6 patients (9.2%) required completion mastectomy for their definitive resection, based on margin status after initial resection. There were a total of two recurrences, one in a patient who had a local DCIS recurrence after initial presentation with stage 0 disease and one in a patient who presented with metastatic disease. The patient with stage 0 disease and subsequent recurrence did not have radiation; the other patient presented initially with synchronous metastatic disease, had a poor response to chemotherapy, and her local recurrence occurred simultaneously with progression of distant disease. Of the patients with stage 0-III disease, the recurrence rate was 1.6% with a mean follow-up of 13 months. Eleven patients (15.9%) developed postoperative complications, including fat necrosis (n=1), hematoma (n=1), cellulitis (n=2), seroma (n=3), and wound healing complications (n=4). Despite complications and radiation therapy, all patients were exceptionally pleased with their reconstruction.Conclusion: Partial mastectomy with reduction mammoplasty breast reconstruction is a viable option that combines a safe oncologic procedure with immediate breast reconstruction. While further follow-up is needed, it is a viable alternative to mastectomy, enabling breast conservation and correction of significant breast redundancy and ptosis, which can impair the efficacy of radiation therapy. Prospective data collection should continue for these cases to establish the long term outcomes of large-breasted patients undergoing partial mastectomy and reduction mammoplasty.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4125.