Abstract P5-15-04: Clinical benefits of using nomogram for predicting positive resection margins in breast conserving surgery

Achieving a clear resection margin in breast conserving surgery (BCS) is an important factor in tumor recurrence in breast cancer. To obtain clear resection margins and reduce re-excision rates, some surgeons obtain intraoperative assessments of the margins of excised specimens, using intraoperative frozen biopsy. But intraoperative frozen biopsy has several problems such as low sensitivity or longer operation time. We have previously reported a nomogram for prediction of positive resection margin by integrating preoperatively available clinical and pathologic information. The factors were the presence of microcalcification, mammographic density, tumor size discrepancy between magnetic resonance imaging and ultrasonography, and the presence of ductal carcinoma in situ or lobular carcinoma in needle biopsy specimens.

We conducted a prospective trial to examine the accuracy and clinical benefits of the nomogram in 442 breast cancer patients (nomogram group) who underwent BCS between Dec 2011 and March 2013, and compared the clinical outcome with that of the 253 patients (control group) who underwent BCS between Jan 2011 and Oct 2011. For nomogram group, the intraoperative frozen section biopsy was omitted in patients with low nomogram scores.

Applying our nomogram did not increase the rate of reoperation due to resection margin positivity when compared to the control group (6.56% vs. 4.25%, respectively, p = 0.22). In the nomogram group, the reoperation rate in patients with low nomogram score who did not undergo intraoperative frozen biopsy was 3.2%, and this is lower than the reoperation rate in the control group. Additionally, we experienced a significant reduction in operation time by 15 minutes when compared to the control group (p<0.001).

In conclusion, our results show that out nomogram for predicting positive resection margin for patients who receive BCS can significantly reduce the operation time without increasing reoperation rate.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-15-04.

Endothelial cells on the proliferation and expression of intercellular adhesion molecule 1 and interleukin 8 of vascular smooth muscle cells

The aim of this study was to investigate the influence of activated endothelial cells on the proliferation and secretion of vascular smooth muscle cells (VSMCs). Cultured lung microvascular endothelial cells were treated with or without tumor necrosis factor alpha (TNF-α; 10 ng/mL) for 6 h, and the supernatant was collected and filtered. The supernatant with TNF-α was called fluid A, and that without TNF-α was called fluid B. VSMCs were cultured and divided into 3 groups with different media as follows: activated medium [fluid A and Dulbecco's modified Eagle medium (DMEM); activated group], inactivated medium (fluid B and DMEM; inactivated group), and DMEM only (control group) for 24 h. Intercellular adhesion molecule 1 (ICAM-1), interleukin (IL)-8, and IL-6 levels in the supernatant of VSMCs were measured with enzyme-linked immunosorbent assay 0 and 24 h after grouping. The proliferation of VSMCs was detected with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. ICAM-1 and IL-8 increased above baseline values in the 3 groups; the maximum increase occurred in activated medium. The optical densities in MTT assay of the activated, inactivated, and control groups was 1.35 ± 0.11, 1.01 ± 0.09, and 0.29 ± 0.01, respectively, which correlated positively with the initial IL-6 level in the supernatant of the VSMCs (r = 0.63, P < 0.05). TNF-α-activated endothelial cells promote VSMC proliferation and secretion of ICAM-1 and IL-8 by elevating IL-6 release.

Autophagy and chemotherapy resistance: a promising therapeutic target for cancer treatment

Induction of cell death and inhibition of cell survival are the main principles of cancer therapy. Resistance to chemotherapeutic agents is a major problem in oncology, which limits the effectiveness of anticancer drugs. A variety of factors contribute to drug resistance, including host factors, specific genetic or epigenetic alterations in the cancer cells and so on. Although various mechanisms by which cancer cells become resistant to anticancer drugs in the microenvironment have been well elucidated, how to circumvent this resistance to improve anticancer efficacy remains to be defined. Autophagy, an important homeostatic cellular recycling mechanism, is now emerging as a crucial player in response to metabolic and therapeutic stresses, which attempts to maintain/restore metabolic homeostasis through the catabolic lysis of excessive or unnecessary proteins and injured or aged organelles. Recently, several studies have shown that autophagy constitutes a potential target for cancer therapy and the induction of autophagy in response to therapeutics can be viewed as having a prodeath or a prosurvival role, which contributes to the anticancer efficacy of these drugs as well as drug resistance. Thus, understanding the novel function of autophagy may allow us to develop a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes in the treatment of cancer patients.

Effects of microencapsulated Enterococcus fecalis CG1.0007 on growth performance, antioxidation activity, and intestinal microbiota in broiler chickens

We performed a series of trials to assess the effect of dietary supplementation with microencapsulated Enterococcus fecalis CG1.0007 on growth performance, antioxidation activity, and intestinal microbiota in Arbor Acres broiler chickens ("broilers"). A total of 150 1-d-old broilers were assigned randomly to 5 feeding treatments (a control group fed the basal diet, 3 groups fed the basal diet plus various concentrations of microencapsulated CG1.0007, and 1 group fed the basal diet plus an antibiotic). Changes in important genera of intestinal bacteria were studied using 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis (DGGE) profiling and real-time quantitative PCR analysis of fecal samples. During the course of the 42-d experimental period, ADG of the birds fed the high and intermediate concentrations of microcapsules were significantly greater (9.90 and 9.50%, respectively) and the ratios of feed to gain fed were significantly lower (4.40 and 4.00%, respectively) compared with the control group. The total antioxidant capacity and the content of malondialdehyde and superoxide dismutase in the microcapsule-treated groups showed significant changes in terms of antioxidation. The numbers of Lactobacillus and Bifidobacterium were significantly greater in the microcapsule-treated groups than in the control group. Cluster analysis indicated that the DGGE bacterial profiles were related to the feeding treatments and revealing the diversity and richness of the intestinal microbiota associated with supplementation of microcapsules. In summary, our results indicate that dietary addition of microencapsulated E. fecalis CG1.0007 enhanced the growth performance of the broilers and improved their health.

Effect of multiple invasive foci on breast cancer outcomes according to the molecular subtypes: a report from the Korean Breast Cancer Society

BACKGROUND

In this study, the prognostic impact of the presence of the multifocal or multicentric tumor (MMT) and its association with molecular subtypes were investigated.

PATIENTS AND METHODS

We investigated the breast cancer metastasis and survival in patients with multifocal or multicentric invasive foci in the same breast. The study population includes 2882 patients in the Seoul National University Hospital Breast Care Center (SNUHBCC) dataset and 41 179 patients in Korean Breast Cancer Registry (KBCR) dataset.

RESULTS

From SNUHBCC dataset, we observed a significant role of MMT in developing distant metastasis and death when the tumors were triple-negative subtype. This subtype-specific prognostic importance of MMT in overall survival was also seen in KBCR dataset (HR, 1.32; 95% CI, 1.02-1.69). In tumors <2 cm, the hazard ratios (HRs) for node metastasis and death were similar along the tumor size change in triple-negative subtype, while other subtypes showed a stepwise increment, suggesting the biologic importance of small invasive foci in this subtype.

CONCLUSIONS

Our results demonstrate the prognostic importance of MMT in patients with triple-negative breast cancers. Small additional invasive foci in triple-negative breast cancer patients should be considered as clinically relevant tumor deposits.

Nuclear factor κB (NF-κB) suppresses food intake and energy expenditure in mice by directly activating the Pomc promoter

AIMS/HYPOTHESIS

While chronic low-grade inflammation is associated with obesity, acute inflammation reduces food intake and leads to negative energy balance. Although both types of inflammation activate nuclear factor κB (NF-κB) signalling, it remains unclear how NF-κB activation results in opposite physiological responses in the two types of inflammation. The goal of this study was to address this question, and to understand the link between inflammation and leptin signalling.

METHODS

We studied the ability of NF-κB to modulate Pomc transcription, and how it impinges on signal transducer and activator of transcription 3 (STAT3)-mediated leptin signalling by using a combination of animal models, biochemical assays and molecular biology.

RESULTS

We report that suppression of food intake and physical movement with acute inflammation is not dependent on STAT3 activation in pro-opiomelanocortin (POMC) neurons. Under these conditions, activated NF-κB independently leads to increased Pomc transcription. Electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) experiments reveal that NF-κB v-rel reticuloendotheliosis viral oncogene homologue A (avian) (RELA [also known as p65]) binds to the Pomc promoter region between -138 and -88 bp, which also harbours the trans-acting transcription factor 1 (SP1) binding site. We found significant changes in the methylation pattern at this region and reduced Pomc activation under chronic inflammation induced by a high-fat diet. Furthermore, RELA is unable to bind and activate transcription when the Pomc promoter is methylated. Finally, RELA binds to STAT3 and inhibits STAT3-mediated promoter activity, suggesting that RELA, possibly together with forkhead box-containing protein 1 (FOXO1), may prevent STAT3-mediated leptin activation of the Pomc promoter.

CONCLUSIONS/INTERPRETATION

Our study provides a mechanism for the involvement of RELA in the divergent regulation of energy homeostasis in acute and chronic inflammation.

Motor neuron degeneration in a mouse model of seipinopathy

Heterozygosity for missense mutations (N88S/S90L) in BSCL2 (Berardinelli–Seip congenital lipodystrophy type 2)/Seipin is associated with a broad spectrum of motoneuron diseases. To understand the underlying mechanisms how the mutations lead to motor neuropathy, we generated transgenic mice with neuron-specific expression of wild-type (tgWT) or N88S/S90L mutant (tgMT) human Seipin. Transgenes led to the broad expression of WT or mutant Seipin in the brain and spinal cord. TgMT, but not tgWT, mice exhibited late-onset altered locomotor activities and gait abnormalities that recapitulate symptoms of seipinopathy patients. We found loss of alpha motor neurons in tgMT spinal cord. Mild endoreticular stress was present in both tgMT and tgWT neurons; however, only tgMT mice exhibited protein aggregates and disrupted Golgi apparatus. Furthermore, autophagosomes were significantly increased, along with elevated light chain 3 (LC3)-II level in tgMT spinal cord, consistent with the activation of autophagy pathway in response to mutant Seipin expression and protein aggregation. These results suggest that induction of autophagy pathway is involved in the cellular response to mutant Seipin in seipinopathy and that motoneuron loss is a key pathogenic process underlying the development of locomotor abnormalities.

Parallel manipulator robot assisted femoral fracture reduction on traction table

The principle of femoral shaft fracture reduction is to restore its pre-fractured limb length and mechanical axis. The current documented treatment method with traction table reduction does not conform to the quantitative alignment and reduction. There is also a great amount of X-Ray radiation exposure to both surgeon and patient during the procedure. For this reason, we introduced an innovated Parallel Manipulator Robot (PMR) application: A Femoral Shaft Fracture Reduction with Parallel Manipulator Robot on Traction Table. With this application, the quantitative control on fracture reduction and alignment can be achieved and the radiation exposure to both surgeons and patients can be greatly reduced.

Clinical significance of pituitary tumor transforming gene 1 and transgelin-2 in pancreatic cancer

Human pituitary tumor transforming gene 1 (PTTG1) is an oncogenic transcription factor that is overexpressed in many malignancies, especially cancers with metastatic potential, while transgelin-2 (TAGLN2) is an actin-binding protein shown to be a tumor suppressor. However, the expression and clinical significance of PTTG1 and TAGLN2 in pancreatic cancer remain unclear. The present study aimed to investigate the expression and clinical significance of PTTG1 and TAGLN2 in human primary pancreatic cancer. Seventy-five cases of human pancreatic cancer tissues were collected. The expression of PTTG1 and TAGLN2 protein was assessed using immunohistochemistry (IHC) through tissue microarray procedure. The clinicopathologic characteristics of all patients were analyzed. As a result, the expression of PTTG1 and TAGLN2 in cancerous tissues showed the positive staining mainly in the cytoplasm, and they were found in cancerous tissues with higher strong reactivity rate compared with the adjacent non-cancer tissues (ANCT) (56.0 percent vs 22.7 percent, P less than 0.001; 100 percent vs 84 percent, P=0.002), elevating with the ascending order of tumor malignancy. Furthermore, the positive expression of PTTG1 was associated with the gender of pancreatic cancer patients, but did not correlate with their age, pathological styles, tumor size, tumor sites, TNM staging, perineural infiltration and distant metastasis (each P greater than 0.05). In addition, Spearman rank correlation analysis showed the positive correlation of PTTG1 with TAGLN2 (r=0.624, P less than 0.001). Taken together, PTTG1 and TAGLN2 are highly expressed in human pancreatic cancer, and the positive expression of PTTG1 is associated with the gender of cancer patients, suggesting that it may represent a potential therapeutic target for the treatment of pancreatic cancer.

Abstract P5-18-23: The prognosis of T1a, T1b N0 M0, HER2+ patients in Korea

Backgrounds: Increased expression of HER-2 or amplification of the HER-2/neu gene has been associated with a worse prognosis than with other breast cancer phenotypes. Especially in cases of size of 0.5∼1cm and node-negative status, adjuvant chemotherapy with or without Trastuzumab treatment is suggested by recent National Comprehensive Cancer Network(NCCN) guidelines. In Korea, the breast cancer patient pool is more younger than western data, and there could be some ethnic differences.

Methods: The Korean Breast Cancer Society (KBCS) has been collaborating with the Korean Central Cancer Registry (KCCR) to improve the completeness and validity of the breast cancer registry and the mortality data. Data of T1a, bN0M0 breast cancer patients from 1999 to 2006 from KBCS on-line registry was obtained, and a total of 2,962 patients were included for survival analysis.

Results: 711 patients (24.0%) was HER-2 positive. Hormone receptor and HER2 status was used to classify 4 molecular subtypes; Hormone receptor(HR)+/HER2−, HR+/HER2+, HR−/HER2+, HR−/HER2−. The median follow-up was for 55.82 month (±24.196). Breast cancer specific survival rate was lowest at HR−/HER2+ subtype(97.9%). It's 1.0∼1.8% lower than other subtypes. Between all T1N0M0 cases, especially T1b HR−/HER2+ cases showed lowest survival of 96.4%.

Conclusion: This study calculated the nationwide survival rates of Korean breast cancer patients with T1a, bN0M0 disease for the first time. HER2 gene positivity was associated with worse prognosis and it's concordant with western studies. But prognosis of T1N0M0 lesion is much better than that of other nations. So, the usage of chemotherapy and Trastuzumab treatment should be considered more carefully in Korea. Further analysis of the long-term survival and a nationwide collaborative study should be performed to estimate the survival trend of Korean breast cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-18-23.

Abstract P3-06-16: Predictive biomarker of pathologic complete response to neoadjuvant chemotherapy in triple negative breast cancer

Neoadjuvant chemotherapy has been considered valuable beyond its role in facilitating conservative surgery and improving prognosis associated with pathologic complete response. Predictive factors of response would help to assess the expected individual benefit of this treatment. Bcl-2 and p53 have been mostly investigated predictive biomarker for the efficacy of chemotherapy in breast cancer, however, studies documenting predictive significance of biomarkers in triple negative breast cancer(TNBC) are limited by low n values of patients. Furthermore, studies did not provide consistent result to conclude about predictive value of biomarkers. There is no unique explanation to date to account for such inconsistencies across studies. In the present study, the two most studied inhibitors of apoptosis, the bcl-2 and p53, have been evaluated to assess whether they may play a role in modulating response to triple negative breast cancer to neoadjuvant chemotherapy. From January 2003 to December 2011, 187 patients presenting T1-4 N0-3 M0 primary TNBC were submitted to two different chemotherapeutic regimens before surgery. The first 154 received the doxetaxel/doxorubicin regimen, the remaining 33 were submitted to doxorubicin and cyclophosphamide followed by doxetaxel. The expression of p53, bcl-2 was evaluated in TNBC specimens obtained at diagnosis by core needle biopsy and at postchemotherapy surgery. Overall pathologic complete response(pCR) occurred in 43 of the 187 cases(23%). The pCR rate was superimposable in the patient subgroups with bcl-2-positive or –negative primary tumors. Conversely, p53 expression was significantly associated with higher pCR rate(19.5 vs 73.2%; p = 0.026; in patients with p53- and p53+ breast cancer). In a multivariate regression analysis, after adjusting for tumor and node status, treatment administered, p53 status maintained an independent predictive role for pCR.[relative risk(RR)=6.247, 95% confidence interval (CI)=0.9–39.1] In our homogeneous patient population, pCR was not associated with initial clinical stage, nodal status as well as other clinicopathologic factors. The status of the p53, which is mutated in a high percentage of breast tumors, is a predictive factor for cytotoxic drug activity. By contrast, bcl-2 failed to be related to chemotherapy activity.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-16.

Abstract P1-01-08:

BACKGROUND: Completion axillary lymph node dissection (ALND) is currently the standard of care in the event of a positive sentinel lymph node biopsy (SLNB). However, result from Z0011 indicate that women with a one or two involved axillary nodes and clinical T1-T2 tumors undergoing lumpectomy with radiation therapy followed by systemic therapy do not benefit from completion of ALND in terms of survival. As a result, the use of intraoperative frozen section during SLNB will be declined.

OBJECTIVE: To define possible predictors of having two or less involved axillary node using preoperative image study to provide information for surgeons making decision about sparing intraoperative frozen section analysis of sentinel lymph node.

METHODS: We reviewed the records of 1214 patients with clinical T1-T2 and clinical node negative invasive breast cancer. None of these patients were in situ cancer on initial gun biopsy nor received neoadjuvant chemotherapy. Factors associated with having three or more involved axillary nodes were evaluated by univariate and multivariate logistic regression analysis.

RESULTS: Among 1214 patients, 203 patients (16.7%) had three or more positive nodes. On a multivariate analysis, having three or more positive nodes was associated with primary tumor size by breast US, axillary LN grade according to cortical thickness by US and presence of axillary LN enlargement on chest CT. The area under ROC curve corresponding to the multivariate logistic regression model applied to dataset of 1214 patients was 0.827 (95% CI: 0.793–0.860). When applied to a validation dataset of 378 patients, it was 0.899 (95% CI: 0.841–0.957). A nomogram to predict the probability of having two or less axillary nodes involvement based on patients' age and preoperative image findings was developed from the multivariate logistic regression model.

CONCLUSION: Patients with a low probability of having three or more positive nodes can be identified from preoperative image finding. The nomogram developed will be helpful to surgeons making decision about sparing intraoperative frozen section analysis of sentinel lymph.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-01-08.

Abstract P2-05-20: Validation and comparison of CS-IHC4 score with a nomogram based on Ki67 index, Adjuvant! Online, and St. Gallen risk stratification to predict recurrence in early Hormone Receptor (HR)-positive breast cancers

Background: Recently, the information in the IHC score was reported to be similar to that in the 21-gene Genomic Health recurrence score (GHI-RS). The aim of this study is to develop a nomogram based on Ki67 index to predict recurrence and to validate the nomogram by comparison with CS-IHC4 as well as Adjuvant! Online and St. Galen risk stratification. In addition, we validated our nomogram with external cohort.

Methods: We retrospectively analyzed the clinicopathologic characteristics and outcomes of 1,070 postoperative HR-positive breast cancer patients between 2004 and 2007 at the Samsung Medical Center to determine recurrence-free survival (RFS). We constructed nomogram using Cox proportional hazard model and validated externally in a cohort of 1,028 at Seoul National University Hospital. A prognostic model that used classical variables, Adjuvant! Online, St. Gallen risk stratification, and the four IHC markers (IHC4 score) were created and assessed in our cohort by LR-χ2 test using the bootstrapping method.

Results: Nomogram showed an area under the receiver operating characteristic curve (AUC) of 0.70 (95% CI, 0.62–0.75) in the training set. The validation set showed a good discrimination with an AUC of 0.65 (95% CI, 0.58–0.72). In LR-χ2 test, the nomogram score was found to be more informative than the IHC4 with CS (LR-χ2 4.0539 [df1], 95% CI; 0.1038–8.004 for CS-IHC4 + nomogram score vs. CS-IHC4).

Abstract P1-14-16: Young age: predicts poor response rate after neoadjuvant chemotherapy in endocrine-responsive breast cancer

Background: Breast cancer rarely occurs in very young women(age&lt;35years), its diagnosis and management could sometimes be difficult. Especially, the patients with positive hormone receptors have significantly lower overall and disease-free survival rates in very young age group than in the older age group. In the previous study, adjuvant tamoxifen therapy might provide less survival benefit when added to chemotherapy in very young breast cancer patients. This study was to compare the response to neoadjuvant chemotherapy for HR-positive breast cancer patients according to the age.

Patients and Methods: A total of 551 consecutive patients were evaluated, received preoperative chemotherapy and referred to surgery at the Seoul National University Hospital from January 2001 to December 2010. The clinicopathologic factors and the response to neoadjuvant chemotherapy between the very young age group and the older age group were retrospectively compared. A pCR was defined as the absence of residual invasive carcinoma in the breast.

Results: Among the 551 patients who received neoadjuvant chemotherapy, 297 patients revealed HR-positive. The median age of all patients was 42 (range, 24∼67)years and very young age group accounted for 17.2%(51/297). Of 297 patients, 262 (88.2%) received taxane-containing regimen pre-operatively, and there's no difference of chemotherapeutic regimen between two age groups. There were no differences noted between two age groups about clinicopathologic characteristics. The univariate and multivariate analysis of variables related to ORR(CR+PR vs SD+PD) to neoadjuvant chemotherapy showed that very young age at diagnosis was independent predictive factor for poor neoadjuvant chemotherapeutic response.(p = 0.043, OR = 0.528) And this tendency was observed more significantly in age under 30.(p = 0.001, OR = 0.147) Only thirteen patients(4.4%) achieved pCR, which is relatively lower rate, reflective poor chemotherapeutic response in HR-positive group, and there was no relations between pCR rate and the two age groups(p = 0.861) in this study. Taxane-containing regimen(p = 0.004) and Ki67 level(p = 0.005) were related to pCR statistically significantly. Breast conservation rate is not significantly different between two age groups.(age&lt;35: age&gt;35= 51.2% vs 41.3%, p = 0.150)

Conclusions: The very young age group showed lower ORR(CR+PR) to neoadjuvant chemotherapy, although there was no significant difference in pCR rate between the two age groups in HR-positive breast cancer patients. We might have to consider and revalue the chemotherapeutic role as neoadjuvant therapy in very young age, HR-positive group, since they had lower survival rate than others.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-16.

Abstract PD05-07: Detection of fusion transcripts among 100 breast cancer samples by next generation sequencing

Introduction Fusions genes and it's products are widely applied as biomarker and therapeutic target in hematopoietic cancers. It's role as a “driver” of oncogenic pathway have also been proved in several epithelial solid cancers including prostate, lung and breast cancer. We performed high throughput next generation sequencing technique (RNA-Seq) to identify the novel fusion transcript(FT) in a large set of primary breast cancer samples.

Materials and Method Total RNA was prepared using the Illumina® TrueSeq™ RNA sample Preparation Kit and TrueSeq mRNA library was constructed. Clustering was done with HiSeq 2000 and Solexa's sequencing was performed. We used tissues extracted from previously collected 100 fresh-frozen primary breast cancer samples obtained after surgical resection. Among 100 samples, 1 failed to pass the process of RNA sequencing and no expression of fusion transcripts were observed in 7 samples resulting in 92 samples with mRNA-Seq data of fusion transcripts. Fourteen(15.2%) samples were cases with distant metastasis during follow up. Estrogen receptor(ER) was positive in 40(43.5%) samples and 23(25%) were triple negative breast cancer.

Results and discussion We detected 958 fusion transcripts among 92 tumors and 58 were chosen for tumor-specific fusion transcript candidate (Fragments per kilo-base of exon per million fragments mapped, FPKM&gt;500 and 3 times higher than average, probability&gt;0.6). Most of the fusion transcripts were “private”, expressed only in one sample. Estrogen receptor(ER) positive breast cancer samples had 29 fusion transcripts and ER negative had 25 fusion transcripts among the 58 tumor-specific candidates. HER2 negative samples exhibited 29 fusion transcripts while 15 were identified in HER2 negative samples. Triple negative sample showed 4 TF candidates. Among the 17 recurrence samples 190 fusion transcripts were identified. Of the 190 fusion transcripts in recurred samples, 24 candidates of recurrence-specific FTs were chosen by it's high expression level (FPKM&gt;300 and 2 times higher than average, probability&gt;0.5). Eight were expressed both in recurred, non-recurred samples and 16 were exclusively expressed in recurred samples. No fusion transcript matched directly with the currently known actionable gene-list owing to the limited number while majority is unexploited. Further validation and functional pathway analysis is under progress to ascertain the role of highly suspected fusion transcripts with oncogenic property. Considering the high incidence of breast cancer world-wide, identification of TF expressed even in only a minor percentage among the whole breast cancer population, if druggable, it can be applicable to large number of patients.

Conclusion We performed a whole-transcriptome sequencing with a large set of primary breast cancer samples and detected abundant fusion transcripts. The majority of breast cancer(92.9%, 92/99) had at least one fusion transcript suggesting it's role during the tumorigenesis and progression process. With scarce evidence and confirmed data of actionable fusion gene and it's product, data interpretation for it's clinical utility is rather complicated. Accumulation of these large set data of fusion transcript must serve as a groundwork for future work.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD05-07.

Microenvironment-dependent homeostasis and differentiation of epidermal basal undifferentiated keratinocytes and their clinical applications in skin repair

Skin homeostasis is maintained by controlling the balance between proliferation and differentiation of epidermal stem cells. The microenvironment, including extrinsic stresses, growth factors, soluble molecules, cell-ECM and cell-cell communications, plays an important role in cell fate determination in vivo and in vitro. In response to external signals, keratinocytes cooperate with other cell types to modulate and facilitate the wound microenvironment during wound healing; however, the aberrant signals or conjunctions in the environment will lead to pathologic abnormalities. In addition, despite some drawbacks, the epidermal stem-cellbased bioengineered skin substitutes have greatly improved the quality of cutaneous repair. Thus, exploring the characteristics and regulation mechanisms of microenvironment-dependent homeostasis and differentiation of epidermal basal undifferentiated keratinocytes is necessary to understand skin development and wound repair and to design novel therapeutic strategies for skin wound healing.