Magnetic resonance imaging system for intraoperative margin assessment for DCIS and invasive breast cancer using the ClearSight™ system in breast-conserving surgery-Results from a postmarketing study.

BACKGROUND AND OBJECTIVES: Breast-conserving surgery (BCS) is followed by reoperations in approximately 25%. Reoperations lead to an increased risk of infection and wound healing problems as well as a worse cosmetic outcome. Several technical approaches for an intraoperative margin assessment to decrease the reoperation rate are under evaluation, some of them are still experimental. METHODS: A prospective single-arm post-marketing study with 60 patients undergoing BCS for ductal carcinoma in situ (DCIS) and invasive breast cancer was conducted. The specimen was intraoperatively examined by the ClearSight™ system, a mobile magnetic resonance imaging system that is based on a diffusion-weighted imaging protocol. However, the results were blinded to the surgeon. RESULTS: The ClearSight™ system was performed for both ductal and lobular breast cancer and DCIS, with a sensitivity of 0.80 (95% confidence interval [CI]: 0.44-0.96) and a specificity of 0.84 (95% CI 0.72-0.92), with an overall diagnostic accuracy of 80%. CONCLUSION: Had the ClearSight™ been known to the surgeon intraoperatively, the reoperation rate would have been reduced by 83% for invasive carcinoma, from 10% to 2%, and 50% for DCIS, from 30% to 15% reoperations. A trial designed to examine the impact on reoperation rates is currently ongoing.

Neo-adjuvant doxorubicin and cyclophosphamide followed by paclitaxel in triple-negative breast cancer among BRCA1 mutation carriers and non-carriers.

The purpose of this study was to assess pathological complete response and whether it serves a surrogate for survival among patients receiving neo-adjuvant doxorubicin-cyclophosphamide followed by paclitaxel for triple-negative breast cancer with respect to BRCA1 mutation status. From a neo-adjuvant systemic therapy database of 588 breast cancer cases, 80 triple-negative cases who had undergone BRCA genotyping were identified. Logistic regression model was fitted to examine the association between BRCA1 status and pathological complete response. Survival outcomes were evaluated using Kaplan-Meier method, differences between study groups calculated by log-rank test. Thirty-four BRCA1 carriers and 43 non-carriers were identified. The BRCA1 carriers had pathological complete response rate of 68 % compared with 37 % among non-carriers, p = 0.01. Yet this did not translate into superior survival for BRCA1 carriers compared with non-carriers. No difference in relapse-free survival were noted among those with or without pathological complete response in BRCA1 carriers regardless of pathological complete response status (Log-rank p = 0.25), whereas in the non-carrier cohort, relapse-free survival was superior for those achieving pathological complete response (Log-rank p < 0.0001). Response to neo-adjuvant systemic therapy differed in BRCA1-associated triple-negative breast cancer compared with triple-negative non-carriers, with a higher rate of pathological complete response. However, compared with non-carrier triple-negative breast cancer, pathological complete response was not a surrogate for superior relapse-free survival in BRCA1 patients. Future studies using specific chemotherapy regimens may provide further improvements in outcomes.

An intraoperative MRI system for margin assessment in breast conserving surgery: Initial results from a novel technique.

BACKGROUND AND OBJECTIVES: One of the major unmet needs in Breast Conserving Surgery (BCS) is a rapid and accurate margin assessment of the lumpectomy specimen. This study evaluates the ability of a novel MRI system (prototype of the ClearSight™ system; Clear-Cut Medical Ltd., Rehovot, Israel) to distinguish malignant and non-malignant tissues in freshly excised breast specimen by comparing MR measurements to histopathology results. METHODS: Seventy-seven samples were obtained from 22 patients undergoing BCS enrolled in the study. A T2* (T2 Star) value in milliseconds (ms) was calculated for each sample and correlated with histopathology results. RESULTS: Of the 77 samples, 35 samples were classified by histopathology as malignant and 42 as non-malignant. T2* values were significantly higher in malignant samples compared to non-malignant samples (15.3 ± 2.72 ms and 10.6 ± 1.47 ms, respectively [P < 0.00001]). Analysis for a determined cutoff of 11.7 ms revealed 91% sensitivity, 93% specificity, and 92% accuracy. ROC curve analysis yielded AUC of 0.97. CONCLUSIONS: This study demonstrates that the system is sensitive and specific in differentiating malignant and non-malignant tissues in freshly excised breast specimen. The system has the potential to be used for breast specimen margin assessment during BCS, with the goal of decreasing the need for re-operation. J. Surg. Oncol. 2016;114:22-26. © 2016 Wiley Periodicals, Inc.

[Clean margins in breast surgery, mission impossible?].

BACKGROUND: Surgical margin involvement is a major cause for local recurrence of breast cancer. In many cases, surgical margin involvement entails re-operation in order to achieve clean margins. The "MarginProbe" device uses radiowave spectroscopy to identify malignant tissue in excised tumor specimens. The current paper describes our experience with "MarginProbe" to evaluate the margin status during surgery. METHODS: MarginProbe was used consecutively to evaluate margin involvement of histology-proven breast cancer patients. The excised tumor specimen was assessed visually as well as by palpation and specimen radiography. RESULTS: Forty-five patients who underwent breast preserving surgery were assessed with "MarginProbe" during surgery. Ten patients (22%) underwent re-excisions during the operation as indicated by the probe, which led to clear margins as the end result of surgery. In 2 patients (4.4%) additional surgery was performed at a later date to clear the margins. No adverse effects were noted due to the use of the probe. SUMMARY AND CONCLUSIONS: Use of the "MarginProbe" during breast preserving surgery helps identify involved margins and assists in reaching clear margins following tumor excision. Probe use was effective for infiltrating as well as in situ cancers. Routine use of the probe may contribute to a decreased re-operation rate for involved margins.

Laparoscopic sleeve gastrectomy as a revisional option after gastric band failure.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) is an effective bariatric procedure with low morbidity and mortality. Unfortunately, it is fraught with high failure rates in long-term follow-up. Laparoscopic sleeve gastrectomy (LSG) is an emerging procedure, quickly gaining momentum in the arsenal of bariatric practice as a first step toward gastric bypass/biliopancreatic diversion or as a stand-alone operation. Recently, it has been described as a revisional option for previous bariatric surgery failures. We report our early experience with LSG as a revisional procedure for failed LAGB. METHODS: From January 2007 to April 2010, 46 patients, who had undergone LAGB, underwent LSG. Patient demographics, reason for band removal, interval between removal and LSG, operative times, estimated blood loss, complications, length of hospital stay, and percent of excess weight loss were collected. RESULTS: Of the 46 patients, 20 (43%) had their bands removed before LSG (median time interval, 2 years; range, 2 months to 9 years); the rest had concomitant band removal and LSG. Twelve patients were men (26%). Mean age and BMI were 40 (range, 20-60) years and 43.1 kg/m(2) (range, 33-57), respectively. In two cases, surgery was converted to an open procedure due to extensive adhesions related to previous surgeries. Median operative time, estimated blood loss, and length of hospital stay were 118 (range, 70-250) minutes, 41 (range, 5-600) ml, and 3 (range, 1-100) days, respectively. Major morbidity was encountered in three patients (6%; leak in 2 and bleeding in 1). There were no mortalities. Mean follow-up time for our cohort is 17 (range, 1-39) months. Percent of excess weight loss at 2, 6, 12, 24, and 36 months was 24, 37, 53, 51, and 48%, respectively. CONCLUSIONS: Our results suggest that LSG is safe, feasible, and effective as a revisional procedure for failed LAGB and can be considered as an appealing option in these cases. Larger series and longer follow-up are needed to confirm this.

Single-nucleotide polymorphisms in the p53 pathway genes modify cancer risk in BRCA1 and BRCA2 carriers of Jewish-Ashkenazi descent.

Germline mutations in the BRCA1 and BRCA2 genes are associated with a significantly increased lifetime risk for developing breast and/or ovarian cancer. However, incomplete penetrance and substantial variability in age of disease onset among carriers of the same mutation suggests the involvement of additional modifier genes and/or environmental factors. Somatic inactivating mutations in the p53 gene and genes of the p53 pathway often accompany BRCA1/2-associated tumors. Therefore, we assessed whether these genes are modifiers of penetrance. We genotyped Jewish-Ashkenazi women for functional single-nucleotide polymorphisms (SNPs) in the AKT1 (C>T rs3730358) and the PERP (C>T rs2484067) genes that affect p53-mediated apoptosis, as well as two tag-SNPs in the CHEK2 (C>T rs743184) and the ZBRK1/ZNF350 (G>A rs2278414) genes that encode for proteins involved in growth arrest following DNA damage. The study population included 138 healthy women, 148 breast/ovarian cancer BRCA1/2 mutation carriers, 121 asymptomatic BRCA1/2 mutation carriers, and 210 sporadic noncarrier breast cancer patients. Utilizing lambda(2) and Kaplan-Meier analysis revealed a hazard ratio (HR) of 3.23 (95% CI: 1.44-54, P = 0.0184) for the TT genotype of AKT (rs3730358), HR = 2.105 (95% CI: 1.049-7.434, P = 0.039) for CHEK2 CC genotype (rs743184), and HR = 2.4743 (95% CI: 1.205-11.53, P = 0.022) for the AG genotype of ZBRK1/ZNF350 (rs2278414). No significant association between PERP variants and cancer was identified HR = 0.662 (95% CI: 0.289-1.324, P = 0.261). Our results suggest that genes that act upstream of p53, or participate in the DNA damage response, may modify the risk of cancer in women with mutant BRCA1/2 alleles.

The significance of occult carcinoids in the era of laparoscopic appendectomies.

BACKGROUND: We present data acquired in our institution about the incidence of incidental appendiceal carcinoids over a period of 16 years. The possibility of occult carcinoids raises the question of appendectomy of a noninflamed appendix during diagnostic laparoscopy for suspected appendicitis. METHODS: We performed a retrospective chart analysis of the surgical registry of a university-affiliated tertiary care center of a major population area for the past 16 years. Data were collected on all patients (n = 7592) who underwent appendectomy for the presumed diagnosis of acute appendicitis. Outcome measures were the incidence of incidental carcinoids of the appendix found during appendectomies and whether the introduction of laparoscopic appendectomy should alter the surgical management of a normal-appearing appendix. RESULTS: A total of 20 carcinoid appendices were resected by open surgery and 17 by laparoscopy. The diagnosis of a carcinoid tumor was not suspected in any patient before the operation, nor was a tumor identified at the time of the operation. In 6 (16%) patients the appendix appeared normal at the time of the operation. CONCLUSIONS: It has long been the standard of care to remove any appendix found in laparotomy for suspected appendicitis, but it is not clear what should be done during laparoscopy for suspected appendicitis when the appendix appears normal. Our data confirm the presence of occult carcinoids in normal-appearing appendices. Further studies are needed to determine the clinical significance of this finding.

Sleeve gastrectomy: radiologic patterns after surgery.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is gaining popularity as an additional bariatric procedure, either as a first step for biliopancreatic diversion or gastric bypass or as a stand-alone option for selected patients. Early postoperative fluid tolerance varies between patients and influences the length of hospital stay. Swallow studies after LSG are not uniform and display different patterns with regard to contrast passage through the gastric sleeve. METHODS: The 55 patients (40 women) in this study underwent LSG during 18 months. These patients had a mean age of 38.2 years (range: 17-61 years) and a mean body mass index (BMI) of 44.8 kg/m(2) (range: 39-75 kg/m(2)). The LSG procedure was performed using a four-port technique to resect the greater curvature of the stomach around a bougie. The mean operative time was 120 min (range: 45-240 min). A routine swallow study was performed on postoperative day 1, and clear fluids were initiated if no leak was detected. Patients were discharged when they could tolerate a daily fluid intake of 2 l. RESULTS: No mortalities, obstructions, or leaks occurred in the study cohort. Two main patterns of contrast passage were identified: type 1 (immediate unhindered flow through the sleeve to the antrum with a slight delay before continuation of the contrast to the duodenum) and type 2 (contrast filling of the proximal sleeve with delay of flow distally toward the duodenum). Patients with rapid contrast passage (group 1, n = 24) tolerated clear fluids better than those with delayed flow (group 2, n = 31) and were discharged earlier than their counterparts (mean length of hospital stay, 2.5 vs. 3.4 days; p < 0.001). CONCLUSIONS: Tolerance of fluid intake after LSG is crucial for patient recovery and discharge. A distinct radiologic appearance on postoperative day 1 helps to predict this behavior. The different patterns could be related to gastric sleeve construction or to possible postoperative sleeve spasm, hindering fluid passage. The influence of immediate fluid tolerance on weight loss after LSG is currently under investigation.

Outcome of thick (> 4 mm) node-negative melanomas.

BACKGROUND: Patients with thick melanomas > 4 mm deep are at great risk for regional and distant metastatic disease. Historically, the appropriate management of thick melanomas has remained unclear and there is no consensus in the literature. Many have taken the nihilistic view that surgical intervention to excise regional nodal basins is not justified in light of the poor overall prognosis and risk of occult distant disease. OBJECTIVES: To review the outcome of patients with thick node negative melanoma treated at a multidisciplinary academic center METHODS: We retrospectively reviewed a database of melanoma patients to identify patients with thick melanomas, > 4 mm, who were either clinically or sentinel node biopsy negative, staged T4N0, stage IIb or IIc. The charts of these patients were reviewed and updated, with a median follow-up of 4 years. RESULTS: We identified 23 patients who fit these criteria. Of these, 18 (78%) remain alive with a median follow-up of 4 years. Five patients died of metastatic disease. Of the 18 surviving patients, 14 remained with no evidence of disease after initial resection of their primary lesions. The majority of the recurrences were non-nodal. CONCLUSIONS: The overall survival of patients in our study remains above 75% at median follow-up of 4 years, even with thick initial index tumor depths. Most of the failures were due to hematogenous spread with lymphatic sparing. Tumor biology that may inhibit lymphatic spread could be a target of future investigation.

The posterior intrahepatic approach to the left portal pedicle using the ligamentum venosum: anatomical basis.

PURPOSE: Prevention of blood loss in liver resections is essential for reducing postoperative morbidity. The main method to control bleeding during surgery of the left hemiliver is occlusion of the left portal pedicle. This may be accomplished by hilar, fissural or posterior intrahepatic techniques. However, these techniques may injure transposed vessels or bile ducts from the right portal pedicle to the left. The purpose of this study was to describe the anatomical aspects of the posterior intrahepatic ligamentum venosum approach to the left portal pedicle. METHODS: Anatomical study was carried out on 215 isolated adult livers. In 57 specimens, sections of the extra- and intrahepatic portions of the left portal pedicle were prepared under stereoscopic microscopy. RESULTS: The ligamentum venosum is the anatomical landmark between the medial and lateral portions of the left portal vein. The convergence of the ligamentum venosum along the left portal pedicle is where the left portal sheath reaches its maximal thickness and these connections are tight. In 8-12%, the medial portion of the left portal pedicle includes a transposed right paramedian vein or right-sided bile ducts. CONCLUSIONS: According to our anatomical study, we believe that it is possible to use the ligamentum venosum as an anatomical guide to achieve a controlled approach of the left portal pedicle during left-sided hepatectomies. Moreover, ligation of the left portal pedicle at its convergence with the ligamentum venosum may prevent erroneous injury of transposed right paramedian vessels or bile ducts.

Timing of sentinel lymph node biopsy in patients receiving neoadjuvant chemotherapy for breast cancer.

OBJECTIVE: To address optimal timing of sentinel lymph node biopsy (SLNB) in breast cancer patients undergoing neoadjuvant treatment. METHODS: The study population included 117 patients with locally advanced cancer with clinically negative nodes treated with primary chemotherapy. Group 1 underwent SLNB and completion axillary lymph node dissection (ALND) in conjunction with lumpectomy/mastectomy, after neoadjuvant treatment (n = 31). Group 2 underwent SLNB followed by neoadjuvant therapy and subsequently surgery and completion of ALNDs (n = 58). Group 3 was treated using the same sequence as group 2, however, completion ALND was performed only for patients with positive sentinel lymph nodes (SLNs) (n = 28). RESULTS: SLN identification was lowest in group 1 compared to groups 2 and 3 (87% and 98.8% respectively; P = <0.05). The highest false negative rate was in group 1 (15.8% compared with 0% in group 2). CONCLUSION: Neoadjuvant treatment lowers the SLN identification rate, possibly due to fibrosis within the axilla, and increases the false negative rate due to downstaging. SLN biopsy prior to chemotherapy could give a more accurate evaluation of axillary status, unaffected by any previous therapeutic intervention.

High efficacy of pre-operative trastuzumab combined with paclitaxel following doxorubicin & cyclophosphamide in operable breast cancer.

BACKGROUND: Trastuzumab in combination with adjuvant chemotherapy improves disease free survival and overall survival in HER2 over-expressing breast cancer patients. Data concerning the use of trastuzumab in the neo-adjuvant setting is limited. We aimed to compare outcome of HER2 over-expressing breast cancer patients treated with either standard chemotherapy, consisting of doxorubicin, cyclophosphamide and a taxane to outcome of patients treated with the same chemotherapy regimen with the addition of trastuzumab in concurrence with paclitaxel. METHODS: We conducted a retrospective review of all consecutive HER2 over-expressing breast cancer patients treated at the participating institutions during the study period and received neo-adjuvant therapy. Allocation to trastuzumab was not based on clinical parameters and was approved only by part of the insurers. Clinical and pathological characteristics, as well as response rate and type of surgery were analyzed. RESULTS: Thirty seven patients received chemotherapy alone and 24 patients received chemotherapy and trastuzumab. A similar distribution of age, clinical stage and histology was noted in both groups. The rate of pathological complete response (pCR) was significantly higher among the trastuzumab-treated group compared to chemotherapy-alone group (75 vs. 24% respectively, p=0.0002). pCR in the breast was noted in 18 of 24 (75%) compared to 10 of 36 (28%, p=0.0005) and pCR in the axillary lymph nodes was noted in 19 of 20 (95%) compared to 8 of 28 (29%, p=0.0001), in the trastuzumab group compared to the chemotherapy-alone group respectively. The safety profile was similar between both groups and no clinical cardiotoxicity were noted. CONCLUSIONS: The addition of trastuzumab to standard chemotherapy in the neo-adjuvant setting improves pathological complete response rates in HER2 over-expressing breast cancer patients.

Elevated insulin-like growth factor-I receptor (IGF-IR) levels in primary breast tumors associated with BRCA1 mutations.

The insulin-like growth factors (IGFs) play a pivotal role in breast cancer. Inherited predisposition to breast and ovarian cancer is associated with germline BRCA1/BRCA2 mutations. To evaluate the impact of BRCA1 mutations on IGF-IR gene expression, we performed an immunohistochemical analysis of IGF-IR in primary breast tumors from BRCA1 mutation carriers and non-carriers. Results obtained revealed a significant elevation in IGF-IR levels in tumors from BRCA1 mutation carriers compared with non-carriers. To assess the potential inhibitory role of BRCA1 on IGF-IR levels, we infected the BRCA1-deficient HCC1937 cell line with a BRCA1-encoding adenoviral vector. Results of Western blots showed that BRCA1 induced a large reduction in endogenous IGF-IR levels. Furthermore, results of chromatin immunoprecipitation assays indicated that the mechanism of action of BRCA1 involves interaction with Sp1, a potent transactivator of the IGF-IR gene. In conclusion, our data suggests that the IGF-IR gene is a physiologically relevant downstream target for BRCA1 action.

Germline CHEK2 mutations in Jewish Ashkenazi women at high risk for breast cancer.

BACKGROUND: Germline mutations in BRCA1 and BRCA2 genes account for only 20-40% of familial breast cancer cases. The CHEK2 gene encodes a checkpoint kinase, involved in response to DNA damage, and hence is a candidate gene for breast cancer susceptibility. Indeed, the CHEK2*1100delC truncating mutation was reported in a subset of mostly North European breast cancer families. The rate of the CHEK2*1100delC variant in the Ashkenazi Jewish population was reported to be 0.3%. OBJECTIVES: To evaluate whether CHEK2 germline mutations contribute to a breast cancer predisposition in Ashkenazi** Jewish high risk families. METHODS: High risk Ashkenazi Jewish women, none of whom was a carrier of the predominant Jewish mutations in BRCA1/BRCA2, were genotyped for germline mutations in the CHEK2 gene by exon-specific polymerase chain reaction followed by denaturing gradient gel electrophoresis and sequencing of abnormally migrating fragments. RESULTS: Overall, 172 high risk women were genotyped: 75 (43.6%) with breast cancer (average age at diagnosis 49.6 +/- 9.6 years, mean +/- SD) and 97 asymptomatic individuals (age at counseling 48.3 +/- 8.2 years). No truncating mutations were noted and four previously described missense mutations were detected (R3W 1.2%, 1157T 1.2%, R180C 0.6% and S428F 5%), one silent polymorphism (E84E 20.5%) and one novel missense mutation (Y424H 1.2%). Segregation analysis of the 1157T and S428F mutations (shown to affect protein function) with the cancer phenotype showed concordance for the CHK2*1157T mutation, as did two of three families with the CHK2*S428F mutation. CONCLUSIONS: CHEK2 missense mutations may contribute to breast cancer susceptibility in Ashkenazi Jews.

BRCA1 at the crossroad of multiple cellular pathways: approaches for therapeutic interventions.

Approximately 10% of the cases of breast cancer and invasive ovarian cancer are hereditary, occurring predominantly in women with germ-line mutations in the BRCA1 or BRCA2 genes. Low expression of these genes in sporadic tumors extends their significance to sporadic breast and ovarian cancers as well. For over a decade since its identification, extensive research has been directed toward understanding the function of the breast and ovarian tumor suppressor gene BRCA1. The long-term goal has been to identify the biochemical pathways reliant on BRCA1 that can be exploited for developing targeted therapies and benefit mutation carriers. To date, no one specific role has been identified, but rather it is clear that BRCA1 has significant roles in multiple fundamental cellular processes, including control of gene expression, chromatin remodeling, DNA repair, cell cycle checkpoint control, and ubiquitination, and overall is important for maintenance of genomic stability. Major findings and potential BRCA1-dependent therapies will be discussed.

Association between diabetes mellitus and adverse characteristics of breast cancer at presentation.

Type 2 diabetes mellitus is associated with increased incidence and inferior outcome of various malignancies. The aim of this study was to explore the impact of type 2 diabetes on breast cancer characteristics at presentation. The study population included 79 diabetic and 158 age-matched non-diabetic patients. Parity, country of birth, co-morbidity other than diabetes, and mode of diagnosis were similar in both groups. Mean body mass index (BMI) was higher among diabetic patients. Tumour stage and size were higher among diabetic patients and the differences remained significant after adjustment for BMI. Moreover, after adjustment for BMI, breast cancer among diabetic patients was more often hormone receptor negative. Our results show that diabetes mellitus is associated with negative prognostic factors at breast cancer presentation.

Hormone replacement therapy is more prevalent among Jewish BRCA1/2 mutation carriers.

The aim of this study was to compare reproductive factors, use of oral contraceptives (OC) and hormone replacement therapy (HRT) in consecutive Jewish Ashkenazi breast cancer patients, with and without BRCA1/BRCA2 mutations. Jewish Israeli women with breast cancer (n=385) were genotyped for the three predominant Jewish mutations in BRCA1 and BRCA2, and data on reproductive factors, OC and HRT use, were analyzed using logistic regression analyses. Overall, 28/385 (7.3%) of participants were mutation carriers, the majority of whom were Ashkenazi (n=22; 78.6%) and were diagnosed with breast cancer at or under age 49 years (n=18; 64.3%). Mutation carriers were more likely than non-carriers to ever use OC (39.3% vs. 20.2%; P=0.053), HRT (35.7% vs. 13.7%; P=0.007), and have first menarche at or below 12 years of age (71.4% vs. 40.6%; P=0.03). Multivariate analysis showed that Ashkenazi women diagnosed with breast cancer under 40 years of age, with a family history of breast/ovarian cancer, who ever used HRT were more likely to be mutation carriers. This study has shown that HRT use is more prevalent among Jewish Ashkenazi mutation carriers, but its role in modifying breast cancer risk in mutation carriers remains unknown.

A specific RAD51 haplotype increases breast cancer risk in Jewish non-Ashkenazi high-risk women.

While the precise genes involved in determining familial breast cancer risk in addition to BRCA1/2 are mostly unknown, one strong candidate is RAD51. Jewish non-Ashkenazi women at high-risk for breast/ovarian cancer and ethnically matched controls were genotyped using four single nucleotide polymorphisms spanning the RAD51 genomic region, and the resulting haplotypes were constructed using the GERBIL algorithm. A total of 314 individuals were genotyped: 184 non-Ashkenazi high-risk women (119 with breast cancer), and 130 unaffected, average-risk ethnically matched controls. Using GEBRIL, three frequent haplotypes were constructed. One of the haplotypes (TGTA - coined haplotype 3) was present in 7.3% (19/260 haplotypes) of controls (n=130) and in 16.8% (40/238 haplotypes) of high-risk breast cancer patients (n=119, P=0.001). A specific RAD51 haplotype is more prevalent among non-Ashkenazi Jewish high-risk women than in average-risk population.

Estrogen receptor regulates insulin-like growth factor-I receptor gene expression in breast tumor cells: involvement of transcription factor Sp1.

The insulin-like growth factors, IGF-I and IGF-II are a family of mitogenic polypeptides with important roles in growth and differentiation. The biological actions of the IGFs are mediated by the IGF-I receptor (IGF-IR), a cell-surface tyrosine kinase, whose activation by serum IGF-I seems to be a key step in breast cancer initiation. Evidence accumulated indicates that estrogens stimulate the expression and activity of IGF axis components. The aim of our study was to examine the transcriptional mechanisms involved in regulation of IGF-IR gene expression by the estrogen receptor (ER). For this purpose, transient transfections using an IGF-IR promoter-luciferase reporter plasmid were performed in breast cancer-c derived ER-positive MCF-7 cells and isogenic ER-negative C4 cells. To examine the potential involvement of zinc-finger nuclear proteins in the transactivating effect of estrogens, chromatin immunoprecipitation (ChIP) experiments were performed using an Sp1 antibody, along with the Sp1-family-binding inhibitor Mithramycin A. The results obtained indicate that basal IGF-IR promoter activity was 5.8-fold higher in MCF-7 than in C4 cells. Estradiol treatment significantly activated the IGF-IR promoter in MCF-7, but not in C4 cells. Furthermore, the estrogen responsive region in the IGF-IR promoter was mapped to a GC-rich sequence located between nucleotides -40 and -188 in the 5' flanking region. ChIP experiments revealed that at least part of the estrogen effect on IGF-IR expression was mediated through activation of the Sp1 transcription factor. In summary, our studies demonstrate that IGF-IR gene transcription in breast cancer cells is controlled by interactions between ERalpha and Sp1. Dysregulated expression of the IGF-IR gene may have pathologic consequences with relevance in breast cancer etiology.