Abstract P1-05-11: Comprehensive comparison of breast cancer molecular portraits by African and European ancestry in the cancer genome atlas

Background: African American breast cancer patients have worse survival rates than European American patients. Although racial differences in the distribution of breast cancer intrinsic subtype are known, it is unclear if there are other inherent genomic differences contributing to this racial outcome disparity.

Methods: We defined patient race based on genomic ancestry and compared multiple molecular features of breast cancer between 154 black and 776 white patients in The Cancer Genome Atlas (TCGA). We examined the contribution of these molecular features to survival outcomes using Cox proportional hazards models. We also estimated the heritability of breast cancer subtypes using a mixed effect model.

Results: Compared to whites, black patients had higher odds of basal-like (odds ratio=3.80, p<0.001) and HER2-enriched (odds ratio=2.22, p=0.027) breast cancers in reference to luminal A subtype. Beyond differences in relative frequency of intrinsic subtypes, black and white patients had distinct gene expression, protein expression, and somatic mutation landscapes. However, the majority of these molecular differences were eliminated after adjusting for subtype; in the subtype-adjusted models, we found 142 genes, 16 methylation probes, 4 copy number segments, 1 protein, and no somatic mutation were differentially expressed or present between black and white patients. Using the top 40 differentially expressed genes, we built a race-enriched gene signature, which had excellent capacity of distinguishing breast tumors from black versus white patients (c-index=0.852 in the validation dataset). We also estimated the heritability of breast cancer subtype (basal vs. non-basal) to be 0.436 (p=1.5x10-14) and showed that two genetic variants (rs1078806 in FGFR2, rs34084277 in BABAM1) were associated with intrinsic subtype and can partially explain racial differences in subtype frequencies.

Conclusion: On the molecular level, once intrinsic subtype frequency differences are accounted for, there are few genomic or proteomic differences observed between blacks and whites. More than 40% of breast cancer subtype frequency differences may be due to genetic ancestry. These results suggest that future studies are warranted to investigate genetic and non-genetic factors that contribute to the development and progression of breast cancer subtypes in order to reduce racial disparity.

Citation Format: Huo D, Hu H, Rhie SK, Gamazon ER, Cherniack AD, Liu J, Yoshimatsu TF, Pitt JJ, Hoadley KA, Troester M, Ru Y, Lichtenberg T, Sturtz LA, Shelley CS, Mills GB, Laird PW, Shriver CD, Perou CM, Olopade OI. Comprehensive comparison of breast cancer molecular portraits by African and European ancestry in the cancer genome atlas [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-11.

Abstract P5-09-02: Breast cancer risk prediction using a polygenic risk score in women of African ancestry: Findings from GWAS in breast cancer in the African diaspora

Background: Multiple common susceptibility loci for breast cancer (BC) have been identified/confirmed in Caucasian women. Combination of these SNPs into a polygenic risk score (PRS) could improve risk stratification and provide guidance for preventive and screening strategies. However, due to differences in allele frequencies of genetic variants, tumor characteristics between women of African and European ancestries, we sought to evaluate the association of PRS with BC in a large consortium of African women.

Methods: The GWAS in BC in the African Diaspora (ROOT consortium) included 3686 participants of African ancestry from Nigeria, USA, and Barbados (1657 cases, 2029 controls). PRS was constructed from the published odds ratios (ORs) from 90 susceptibility loci for BC. Logistic regression was used to examine its association with overall BC risk as well as associations by hormone receptor status, family history and other clinical features.

Results: One unit change in the PRS was associated with an OR of 1.13 (95% CI: 1.01-1.28, P=0.042) for overall BC risk, 1.15 (95%CI: 0.95-1.41, P=0.160) for ER+ BC risk, and 1.17 (95%CI: 0.95-1.44, P=0.133) for ER- BC risk. The ORs for developing BC by percentiles of the PRS, relative to women in the middle quintile, showed weak linear trend. The discriminative accuracy of the PRS, as measured by the C-statistic, was 0.524 (95% CI: 0.505-0.542) for overall BC, 0.511(95% CI: 0.479-0.543) for ER+ BC, and 0.513 (95% CI: 0.481-0.545) for ER- BC. There was a statistically significant interaction between PRS and age, the association between PRS and overall BC risk were stronger in two age groups (aged <40 years and ≥60 years). The PRS was also more strongly associated with PR+ (OR=1.26, 95%CI: 1.01-1.58) compared to PR- (OR=1.08, 95%CI: 0.95-1.44) BC. Association between PRS and BC were similarly non-significant across different strata of family history of BC, BMI, alcohol consumption, oral contraceptive use, menopausal, ER and HER2 status.

Table 1. Performance of the 90-SNP polygenic risk score (PRS) in the GWAS in Breast Cancer in the African DiasporaPercentile of PRS (%) OR (95%CI)  Overall BC (n=1657) vs Ctrl (n=2029)ER+ BC (n=403) vs Ctrl (n=2029)ER- BC (n=374) vs Ctrl (n=2029)<51.01 (0.73-1.41)1.32 (0.28-2.13)0.89 (0.51-1.55)5-100.83 (0.59-1.15)0.71 (0.40-1.26)0.63 (0.34-1.17)10-200.74 (0.57-0.95)0.69 (0.44-1.07)0.72 (0.46-1.12)20-400.97 (0.79-1.19)0.80 (0.56-1.14)0.98 (0.69-1.39)40-601.00 (ref)1.00(ref)1.00(ref)60-800.89 (0.73-1.10)0.94 (0.66-1.33)0.90 (0.63-1.28)80-901.14 (0.89-1.47)0.87 (0.56-1.34)0.90 (0.63-1.28)90-951.14 (0.82-1.58)1.54 (0.92-2.58)0.88 (0.48-1.61)>951.10 (0.79-1.52)1.15 (0.67-1.99)1.34 (0.79-2.25)Note: Odds ratios are for different percentiles of the PRS relative to the middle quintile (40% to 60%). Odds ratios were adjusted for study site and the first ten eigenvectors from principal components analysis.

Conclusion: BC PRS obtained from prior GWASs conducted in Caucasian women didn't provide a comparable degree of risk stratification for African Americans. Additional studies are needed to identify SNPs specific to women of African ancestry that could provide improved risk prediction. Further studies can also combine the PRS with lifestyle/environmental factors.

Citation Format: Wang S, Qian F, Zheng Y, Ogundiran T, Ojengbede O, Zheng W, Blot W, Nathanson KL, Hennis A, Nemesure B, Ambs S, Olopade OI, Huo D. Breast cancer risk prediction using a polygenic risk score in women of African ancestry: Findings from GWAS in breast cancer in the African diaspora [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-02.

An electrochemical DNA biosensor based on nitrogen-doped graphene/Au nanoparticles for human multidrug resistance gene detection

Multidrug resistance (MDR) has become a major obstacle to the adequate treatment of cancer patients; thus, there is an urgent need for exploring new strategies for early diagnosis of MDR in clinic. Here, we report a novel electrochemical biosensor based on nitrogen-doped graphene nanosheets functionalized with Au nanoparticles (N-G/Au) for sensitive and selective DNA detection. The highly conductive nanocomposite layer was characterized by using scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry. DNA with thiol groups at the 5' end was immobilized on the N-G/Au surface via the strong Au-S bond. Differential pulse voltammetry was applied to monitor the target DNA hybridization event using methylene blue as an electrochemical indicator. Under optimal conditions, the biosensor could detect target DNA down to 3.12×10(-15)M with a linear range from 1.0×10(-14) to 1.0×10(-7)M, showing high sensitivity. Further, the sensing strategy was successfully used for detecting MDR1 DNA in real clinical samples. These results will aid in developing a new portable detection system for MDR that will allow effective diagnosis in the early stages of related cancer.

Abstract P6-04-05: Genotype-phenotype classification of triple negative breast cancers (TNBC) in women of African descent using the PAM50 NanoString platform and genomic data

Introduction: TNBC has the highest mortality rate amongst all other breast cancer types due to its complex tumor heterogeneity and lack of well-defined molecular targets. It is known that women of African descent are two to three times more likely to develop TNBC compared to women of European ancestry, yet wide-scale genomic studies of African and African American breast tumors are limited. To elucidate genotypes and molecular subtypes associated with the most aggressive forms of breast cancer, we used the PAM50 NanoString platform to reclassify Nigerian (NG), African American (AA) and Caucasian (CA) tumors previously annotated by Immunohistochemistry (IHC), and correlated our findings to their germline genotype data obtained using high-throughput technologies.

Methods: RNAs were isolated from formalin-fixed, paraffin embedded (FFPE) tumor tissues using the High Pure Paraffin Kit (Roche) following manufacturer's protocol, and assayed on NanoString nCounter Analysis System using a custom Nano110 (PAM50 + claudin-low & VEGF signatures) probe set. Intrinsic subtyping and gene-expression data were evaluated using R statistical software. All study samples were previously annotated and subtyped by the ER/PR/HER2 IHC classifier. Genotypes were obtained from next generation sequencing or Illumina Human2.5M BeadChip platform using germline DNA from more than 2000 breast cancer cases and 2000 controls were studied.

Results: To date, Intrinsic molecular subtyping by Nano110 has been completed on 69 NG, 81 AA and 74 CA tumors. Concordance between IHC and PAM50 was 59%, which is adequate and comparable to previous studies. Basal-like subtype was overrepresented and accounted for nearly 30% of NG and AA cases, compared to 17% in CA cases. HER2-enriched subtype was overrepresented only in NG cases (9%). The proportion with Luminal A tumors were 44% NG, 56% AA and 68% CA, respectively.

Conclusions: PAM50 NanoString assay is reliable and high-throughput for molecular subtyping breast cancer using RNA extracted from FFPE tumors. Ongoing work will correlate PAM50 intrinsic subtypes to genotype data.

Citation Format: Olayiwola OA, Ogundiran TO, Hardeman A, Yoshimatsu TF, Clayton W, Adeoye A, Ademola A, Ajani MA, Khramtsova G, Grushko TA, Huo D, Zheng Y, Parker J, Perou C, Olopade OI. Genotype-phenotype classification of triple negative breast cancers (TNBC) in women of African descent using the PAM50 NanoString platform and genomic data. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-04-05.

Abstract P6-03-17: Genomic landscape of breast cancers from women of African ancestry across the diaspora

Objectives: Of all ethnic/racial groups, age-standardized mortality rate from breast cancer is highest for African American women in the US for reasons that remain understudied. The paucity of genomic studies of breast tumors across the African Diaspora further restricts our understanding of the biology of breast cancer in underserved populations. To gain a better understanding of the genomic landscape of breast cancer in women of African Ancestry, we have developed a cross continent translational research infrastructure to examine the spectrum of genetic alterations in breast tumors from West Africa compared to the spectrum of alterations observed in tumors from African-American and other women who are predominantly white in The Cancer Genome Atlas (TCGA) dataset.

Methods: Peripheral blood and breast cancer biopsy tissues were collected from 214 patients enrolled in the West Africa Breast Cancer Study (WABCS) at the University of Ibadan/University College Hospital (UI/UCH) and at Lagos State University Teaching Hospital (LASUTH). Blood DNA as well as breast cancer tissue DNA and RNA were extracted at the Novartis Institutes for Biomedical Research (NIBR), UI/UCH, and LASUTH using a modified protocol of PAXgene Tissue DNA and RNA extraction method. Whole-exome (WES) and transcriptome (RNA-seq) sequencing were performed on the Illumina HiSeq2000 platform at NIBR. Single Nucleotide Variants (SNVs) and insertions/deletions (indels) were called using MuTect and Pindel, while Copy Number Alterations (CNAs) were called using an in-house implementation of the ABSOLUTE method. Observed mutations were compared against those reported in the TCGA dataset. ER, PR and HER2 status were determined by immunohistochemistry (IHC) at UI/UCH, LASUTH and UChicago.

Results: WES data for 95 tumors have been analyzed thus far. Genes commonly mutated in breast cancer in TCGA are also mutated in WABCS but the mutational spectrum is vastly different. TP53 (64%), MYC (31%), and GATA3 (26%), showed significantly higher alteration frequencies in WABCS and African Americans. In contrast, PIK3CA (20%), CDH1 (2%), and MAP3K1 (2%) were less frequently mutated in women of African ancestry. In addition to the high proportion with TP53 mutations, the proportion with HER2 positive subtype of 42.1% and triple-negative subtype of 37.9% suggest that tumors with the most aggressive features are overrepresented in breast cancer patients in West Africa.

Conclusions: In the first study of its kind, high throughput genomic analysis of the largest cohort of women of African ancestry has uncovered alterations in cancer genes, some of which may be amenable to treatment with targeted therapies. Furthermore, we provide evidence that population differences in frequency and spectrum of mutations should drive the design and deployment of precision medicine initiatives. Only then can we develop innovative interventions to reduce the unacceptably high rates of mortality from breast cancer in underserved and under resourced populations.

Citation Format: Olopade OI, Odetunde A, Riester M, Yoshimatsu T, Labrot E, Ademola A, Sanni A, Okedere B, Mahan S, Nwosu I, Leary R, Ajani M, Johnson RS, Sveen E, Zheng Y, Clayton W, Khramtsova G, Oludara M, Omodele F, Benson O, Adeoye A, Morhason-Bello O, Ogundiran T, Babalola C, Popoola A, Morrissey M, Huo D, Falusi A, Winckler W, Obafunwa J, Papoutsakis D, Ojengbede O, Ibrahim N, Oluwasola O, Barretina J. Genomic landscape of breast cancers from women of African ancestry across the diaspora. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-03-17.

A randomized trial comparing standard outcomes in two treatment models for substance users with tuberculosis

SETTING

Chicago Department of Public Health (CDPH), TB Control Program.

OBJECTIVES

To compare anti-tuberculosis treatment outcomes using two different types of directly observed therapy (DOT) outreach workers.

METHODS

Substance users diagnosed with TB from October 1996 to July 2000 were randomized to DOT administered by either 1) CDPH personnel (standard arm) or 2) previous substance-using human immunodeficiency virus/acquired immune-deficiency syndrome outreach workers (enhanced arm). Treatment completion was physician-determined, and adherence was estimated based on risk of missed DOT appointments.

RESULTS

Of 94 patients, 46 were randomized to the standard and 48 to the enhanced arm. The standard arm had a significantly higher risk of non-completion of treatment (39% vs. 15%, RR 2.7, 95%CI 1.2-5.8), and a significantly higher risk of missing DOT appointments (RR 2.6, 95%CI 1.4-4.8). For both outcomes, housing instability was a significant predictor in multivariate analyses.

CONCLUSIONS

TB treatment completion and adherence among substance users was improved by the enhanced intervention; the familiarity of enhanced-arm DOT workers with the patients' social norms due to their own previous substance use may have made them more effective. Successful DOT in hard-to-reach populations may require strategies that directly address the population's circumstances and utilize DOT workers who are intimately familiar with patients' life situations.

Plant Esterase-Chitosan/Gold Nanoparticles-Graphene Nanosheet Composite-Based Biosensor for the Ultrasensitive Detection of Organophosphate Pesticides

As broad-spectrum pesticides, organophosphates (OPs) are widely used in agriculture all over the world. However, due to their neurotoxicity in humans and their increasing occurrence in the environment, there is growing interest in their sensitive and selective detection. This paper reports a new cost-effective plant esterase-chitosan/gold nanoparticles-graphene nanosheet (PLaE-CS/AuNPs-GNs) biosensor for the sensitive detection of methyl parathion and malathion. Highly pure plant esterase is produced from plants at low cost and shares the same inhibition mechanism with OPs as acetylcholinesterase, and then it was used to prepare PLaE-CS/AuNPs-GNs nanocomposites, which were systematically characterized using SEM, TEM, and UV-vis. The PLaE-CS/AuNPs-GNs composite-based biosensor measured as low as 50 ppt (0.19 nM) of methyl parathion and 0.5 ppb (1.51 nM) of malathion (S/N = 3) with a calibration curve up to 200 ppb (760 nM) and 500 ppb (1513.5 nM) for methyl parathion and malathion, respectively. There is also no interference observed from most of common species such as metal ions, inorganic ions, glucose, and citric acid. In addition, its applicability to OPs-contaminated real samples (carrot and apple) was also demonstrated with excellent response recovery. The developed simple, sensitive, and reliable PLaE-CS/AuNPs-GNs composite-based biosensor holds great potential in OPs detection for food and environmental safety.

Reduction of Lactobacillus in the milks of cows with subclinical mastitis

Clinical and subclinical bovine mastitis are the most frequent diseases encountered on dairy farms worldwide, which cause significant economic loss and veterinary cost. The mastitic disease status is associated with increases in both milk bacterial pathogens and somatic cell count (SCC). Although it is well established that the mastitic pathogens generally correlate with the milk SCC, to our knowledge, the correlation between the probiotic genus, Lactobacillus, and the mastitic causative bacteria and SCC have not been determined previously. Thus, in this study, milk samples from 12 mild and 28 severe subclinical mastitic dairy cows were collected from the same farm. The overall milk bacterial load was quantified with the total plate count method. The Lactobacillus genus and 4 common clinical and subclinical mastitic pathogens (Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, and Trueperella pyogenes) in the sampled milk were enumerated by quantitative PCR. Mild and severe subclinical mastitic samples were distinctly separated on the principal component analysis score plot generated based on the quantities of these 5 target bacteria, suggesting that clear differences existed in the microbiological composition between the two sample groups. Based on comparison with the pairwise Mann-Whitney test, the mild subclinical mastitic dairy cows had a significantly higher amounts of lactobacilli (P=0.0175), but lower E. coli (P=0.0002), S. aureus (P<0.0001), S. agalactiae (P=0.0001) and T. pyogenes (P=0.0044) quantities, while an opposite trend occurred in the severe subclinical mastitic group. The negative correlation between Lactobacillus and the pathogenic bacteria, as well as the SCC, was confirmed with Spearman correlation analysis. Data generated from the current study may hint to a close relationship between Lactobacillus and the health of bovine udder.

Abstract P5-14-09: Brachytherapy, 3-dimentional conformal radiotherapy, and intensity modulated radiotherapy for breast cancer patients undergoing breast conservation: Effectiveness and guideline concordance

Background: There has been a rapid increase in the use of new radiation techniques for postlumpectomy radiation, including partial breast irradiation via brachytherapy (APBI-b), 3-dimentional conformal radiotherapy (3D-CRT), and intensity modulated radiotherapy (IMRT) techniques. However, it is unknown if these new radiation techniques provide survival benefit equivalent to external beam whole-breast irradiation (WBI) in patients undergoing breast conservation. Additionally, compliance with the 2009 ASTRO guidelines for partial breast radiation has not been examined in a contemporary cohort of patients.

Method: From the National Cancer Database, we identified 718,392 women diagnosed with AJCC stage 0-III breast cancer between 2003 and 2010, who underwent breast conserving surgery. Patients were classified into suitable, cautionary, or unsuitable for APBI-b according to ASTRO guidelines. Cox proportional hazard models were used to examine the effectiveness of the new irradiation modalities on overall survival in all eligible patients and within each ASTRO category.

Results: Overall, 37,363 patients (6.4%) underwent APBI-b, 40,767 (5.7%) underwent IMRT, 45,721 (6.4%) underwent 3D-CRT, 421,497 (58.7%) underwent conventional WBI. The utilization of the three new radiation techniques increased over the study period, and 31.3% of all patients treated with radiotherapy after lumpectomy actually used one of the three new methods in 2010. Overall, 35% of patients receiving APBI-b fell in the suitable category, 47% in the cautionary category, and 18% in the unsuitable category. After publication of the ASTRO guideline, the proportion of patients receiving APBI-b in the suitable category has increased from 34% in 2008 to 40% in 2010. After a median follow up of 46 months, 52,099 patients died. In invasive breast cancer patients, we found patients undergoing APBI-b had a 38% reduction in the risk of death, compared to patients without radiotherapy (hazard ratio, HR = 0.62, 95% CI: 0.57-0.66, p&lt;0.001) after adjusting for age, tumor stage, tumor grade, hormone receptor status, race/ethnicity, insurance, and other clinical, pathologic, and facility factors. The adjusted HR was 0.63 (95% CI: 0.59-0.67, p&lt;0.001) for IMRT, 0.60 (95% CI: 0.57-0.64, p&lt;0.001) for 3D-CRT, and 0.62 (95% CI: 0.60-0.64, p&lt;0.001) for conventional WBI. The effectiveness of the four radiation modalities was similar (p = 0.84). In the ASTRO suitable category, the HR of APBI-b was 0.70 (95% CI: 0.63-0.79), which is similar to the effect of APBI-b in the cautionary category (HR = 0.64, 95% CI: 0.56-0.73).

Conclusions: In a large cohort of women with early stage breast cancer, radiotherapy using three new techniques (APBI-b, IMRT, and 3D-CRT) was found to be as effective in reducing mortality as conventional whole breast irradiation. Although this is promising, long-term follow-up studies and randomized clinical trials are warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-09.

Abstract P3-06-13: Transient increase in breast cancer risk after a full term pregnancy among African women

Background

African women affected by breast cancer (BC) have high parity with five children or more, are relatively young at first full term pregnancy (FFTP), are diagnosed at a young age and are often premenopausal at diagnosis. While several studies have assessed the role of reproductive factors for BC risk among African women, none of them have assessed whether there is dual effect of age at full term pregnancy (FTP). In this communications, using a large dataset from an on-going hospital-based case-control study, we examine the role of age at full term pregnancy on breast cancer risk among African women.

Methods

The study includes sites in Nigeria (University College Hospital, Ibadan), Cameroon (Yaoundé General Hospital) and Uganda (Breast Clinic of Mulago Hospital of Kampala). It was initiated in 1998 in Nigeria and extended to Cameroon and Uganda in 2011. Cases were consecutive females diagnosed with invasive BC. Controls were recruited from the community or within the hospital and have never being diagnosed with any cancer. Cases and controls were aged 18 years or more and gave informed consent. Full term pregnancy was defined as a pregnancy that lasted at least 7 months and included both live birth and stillbirth. Logistic regression models were used to assess the effects of age at first and second FTP, and their interaction with current age on BC risk. Age at menarche, parity, body mass index and hormone contraception use were included in the models.

Results

The study includes 1668 cases and 2399 controls recruited between 1998 and May 2013. Mean duration of live birth was 9 months (SD±0.52) and 8.8 months (SD±0.66) for a stillbirth. Overall, the mean age at FFTP was 23 years (SD±4.91) for both cases and controls. Compared to nulliparous women, parous women who had FFTP at 20 years have increased risk (OR = 1.59, CI 95%, 1.16-2.21) to develop BC in the year following the pregnancy. Up to 5 years following the FFTP, this OR is 1.38 (CI 95%, 1.06-1.80) while it is 0.77 (CI 95%, 0.62-0.95) 25 years later. This observation was also true for parous women who have had their FFTP at 25, 30, or 35 years. Moreover, a similar pattern was observed when comparing uniparous women to women with 2 or more children.

Conclusion

Our results show a transient increase in risk of BC after a full term pregnancy which declined and became protective over time. This observation is consistent with the effect of pregnancy on BC that has been described in other populations and may partially explain the current profile of breast cancer among African women.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-13.

Abstract P3-06-14: Increase in the proportion of stage IV breast cancer amongst young women with newly diagnosed breast cancer, report from the National cancer data base, 1998-2009

Background: A recent SEER study showed a significant increase in the incidence of advanced breast cancer in women 25 to 39 years old. We hypothesized a similar trend amongst newly diagnosed breast cancer patients treated at Commission on Cancer Accredited Cancer Centers in the United States and that such increase is greatest among minority young women.

Methods: We utilized data from the National Cancer Data Base to determine the proportion of patients &lt;40 years old who were diagnosed with Stage IV disease from 1998-2009. Patient demographics (insurance, race, income) and tumor characteristics (size, node status, grade, estrogen receptor (ER), histology) were included to compare the risk factors associated with advanced disease between younger and older women. Statistical analyses were performed using both univariate and multivariable logistic regressions in SAS 9.3 (SAS Inc., Cary, NC).

Results: A total of 1,955,190 women with newly diagnosed breast cancer were included. The proportion of young women (&lt;40 years old) diagnosed with stage IV breast cancer has increased by 58% between 1998 and 2009 (Table 1). This increase in young women was significantly greater than other age groups with Stage IV disease: 40-54 years old (Δ = 9%), 55-69 (Δ = 13%) and &gt;70 years old (Δ = 17%) (all p&lt;0.001). Amongst women with stage IV disease, women &lt;40 years old compared to women ≥40 years old were more likely to be nonwhite (29% vs. 19%, p&lt;.0001), have grade III tumors (70% vs. 57%, p&lt;.0001), have an estrogen receptor (ER) negative tumor (34% vs. 28%, p&lt;.0001), and have a ductal carcinoma (85% vs. 78%, p&lt;.0001). In the multivariable analysis, young women (&lt;40 yr) remained at significantly greater risk of being diagnosed with stage IV disease (OR = 1.19, 95% CI 1.14-1.24, p&lt;.0001) compared to women ≥40 years old after adjusting for income, race/ethnicity and tumor characteristics. While the proportion of women with stage IV disease has increased between 1998 and 2009, the increasing odds was significantly greater among young women (OR = 1.54) as compared to old women (OR = 1.17) in the risk adjusted multivariable models.

Table 1. Trend in proportion of women diagnosed with Stage IV disease according to patient age, 1998 and 2009.Age19982009Age &lt;401.973.12Age 40-541.471.61Age 55-691.591.81Age 70+1.802.11

Conclusions: The proportion of women with stage IV disease under 40 years old has increased significantly over the past decade and this trend was not seen in older age groups. Young minority women with ER negative tumors are at greatest risk to be diagnosed at a later stage.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-14.

The diversity of intestinal microbiota of Mongolians living in Inner Mongolia, China

The Mongolian nationality has developed their unique lifestyle and dietary habit for thousands of years. However, by now, little research has been focused on Mongolian gut microbiota and how it is related to different dietary habits. In this study, denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction (qPCR) methods were applied to reveal the diversity of predominant gut bacteria of 48 healthy Mongolians recruited from Hohhot city and the Xilin Gol pasturing area in Inner Mongolia. Compared to similar studies of other nationalities, results from the present study have confirmed that the composition of Mongolian gut microbiota is highly similar at the phylum level (Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria) but variable at the genus level. Especially, the numbers of Phascolarctobacterium, Lactobacillus and Bifidobacterium are rather high. DGGE profiles of Lactobacillus and Bifidobacterium revealed that Lactobacillus casei, Bifidobacterium longum and Bifidobacterium animalis subsp. lactis were predominant in the gut of the Mongolian subjects studied. On the contrary, Lactobacillus helveticus was detected in every pasturing area Mongolian, but not in any of the Hohhot city Mongolians. qPCR results revealed that the numbers of Lactobacillus and Bifidobacterium of Xilin Gol Mongolians were significantly higher (P<0.05) than that of Hohhot Mongolians, whereas the numbers of Enterobacterium were significantly lower (P<0.05). In addition, by partial least squares discriminate analysis and cluster analysis of data generated from DGGE and qPCR experiments, a striking difference in the composition of intestinal microbiota of Mongolians living in Hohhot city and the Xilin Gol pasturing area has been found. This study clearly shows that diet affects the microbiota composition of Mongolians living in different circumstances, i.e. urban versus rural.

Discrimination of Chinese green tea according to varieties and grade levels using artificial nose and tongue based on colorimetric sensor arrays

Colorimetric artificial tongue and nose were used to discriminate nine Chinese green teas from different geographical origins and grade levels. Printing nanoporous porphyrin, dimeric metalloporphyrins, metallosalophen complexes and chemically responsive dyes on a hydrophobic membrane, the developed sensor array of artificial tongue and nose showed a unique pattern of colorimetric change upon exposure to green tea liquids or gases. All green tea samples, both in liquid and gas analysis, gave distinct patterns according to geographical origin and grade level, thus resulting in their facile identification. The good reproducibility of colorimetric artificial tongue and nose was proved. Data analysis was performed by chemometric techniques: hierarchical cluster analysis (HCA), and principal component analysis (PCA). Chinese green tea from the same geographical origin could cluster together in PCA score plot. No errors in classification by HCA were observed in 90 trials. The colorimetric artificial tongue and nose can be used to discriminate Chinese green tea according to geographical origin and grade level.

Allergy sensitization and asthma among 13-14 year old school children in Nigeria

BACKGROUND

The prevalence of asthma and role of atopy in asthma among children has not been clearly defined in Nigeria.

OBJECTIVE

To determine the prevalence of asthma and investigate risk factors related to allergy sensitization among urban and rural school children in southwest Nigeria.

METHODS

Validated ISAAC questionnaire was administered to 1736 high school children in randomly selected schools in rural and urban communities. Identified asthma cases were matched to controls. Allergy skin tests, blood eosinophil count, serum IgE and stool examination for parasites were performed. Dust samples from homes were also collected and analyzed for allergens.

RESULTS

The prevalence of asthma was 7.5% (95% CI 6.0 to 9.2%) and 8% (95% CI 6.0-10.4%) in the rural and urban communities respectively . Risk factors for asthma included cigarette-smoking, cats in the home and family size. Eosinophil count (109/L) was elevated in asthmatics [0.70 (95% CI 0.48-1.11) vs. 0.32 (95% CI 0.19-0.69); p<0.01], but IgE levels were similar between the two groups (298±229 IU/mL vs. 288±257; p=0.97). Positive skin tests to cat hair, cockroach, mango blossom and mouse epithelium were more frequent in asthmatics than in healthy controls, especially in the rural communities. There was no correlation between allergens in dust collected from homes and skin test reactivity.

CONCLUSION

Asthma prevalence is similar in rural and urban children in Southwest Nigeria and atopy with elevated IgE was not observed to be a major factor for asthma in our cohort of children in both communities.

Abstract P2-10-21: Prognostic value of estrogen receptor status in women with synchronous or metachronous breast cancers

Background: Estrogen receptor (ER) is an important prognostic and predictive factor for breast cancer (BC) patients. For women with two primary breast cancers, however, estrogen receptor status measured at the two tumors is not always the same, either due to tumor heterogeneity, or because of limited reproducibility of receptor assays. For women with metachronous breast cancers, it is unclear if estrogen receptor status of previous cancer has prognostic value. For women with synchronous breast cancers, it is important to know if inconsistent receptor status predicts worse clinical outcome.

Methods: Data on ER status of two primary breast cancers were obtained from the Surveillance, Epidemiology, and End Results program 1990–2009. We used piecewise proportional hazard Cox models to examine the joint effect of ER statuses of two tumors on overall survival or disease-free survival. Hazard ratio (HR) and 95% confidence interval (CI) were calculated, after adjusting for age, stage, race/ethnicity, histology, grade, and treatments in Cox models. Synchronous and metachronous cases were analyzed separately.

Results: There are 12,285 patients with synchronous breast cancers; 81.2% had both tumors being ER positive, 10.2% had one tumor being ER positive but the other being ER negative, and 5.6% had both tumors being ER negative. As shown in the Table, patients with inconsistent ER status (heterogeneity) had worse short-term survival rate than patients with double ER positive tumors. Among the 14,470 patients with metachronous breast cancers, 60.2% had two ER+ tumors, 13.8% had two ER− tumors, 11.8% had ER status changing from negative to positive, and 14.1% had ER status changing from positive to negative. In addition to ER status of the index cancer, ER status of the first cancer has independent prognostic value in predicting both short-term and long-term outcome (p = 0.0002).

Molecular interactions of dimethyl methylphosphonate (DMMP) with metalloporphyrins: determination of the binding mechanism by spectroscopic methods

The molecular interactions of 5,10,15,20-tetraphenylporphine zinc (ZnTPP) and 5,10,15,20-tetraphenyl-21H,23H-porphine cobalt(II) (CoTPP) with dimethyl methylphosphonate (DMMP) have been investigated by absorption/absorption difference spectroscopy. The interactions between the metalloporphyrins and DMMP change the absorbance characteristics of the porphyrins resulted from the formation of the metalloporphyrin-DMMP complexes. According to the Benesi-Hildebrand (B-H) equation, the equilibrium constants and stoichiometries of the binding systems at four different temperatures (288, 293, 298 and 303 K) were obtained. Experimental results showed that both ZnTPP and CoTPP bind to DMMP via axial coordination, resulting in the formation of 1:1 metalloporphyrin-DMMP complexes. However, it was found that ZnTPP showed stronger binding capacity with the equilibrium constant (K) of 83.864 M(-1) at room temperature, while CoTPP exhibited weaker binding with K of 24.904 M(-1). The thermodynamic parameters, enthalpy change (Δ(r)H(m)(θ)), entropy change (Δ(r)S(m)(θ)) and free energy changes (Δ(r)G(m)(θ)) were also studied for the interactions, indicating that the formation of the metalloporphyrins-DMMP complex was an exothermic reaction.

Atopy is associated with asthma in adults living in rural and urban southwestern Nigeria

RATIONALE

Factors affecting the course of asthma are not clearly understood in rural and urban communities within low-resource countries. Furthermore, the interactions between atopy, environmental exposure, and helminthic infections in modulating asthma have not been well investigated.

OBJECTIVES

To conduct a feasibility study to examine the relationship between atopy and asthma in adults at two rural Health Centers and urban university college hospital in southwestern Nigeria.

METHODS

A convenient sample of 55 consecutive patients with stable physician-diagnosed asthma and 55 age-matched nonasthmatic controls seen at the outpatient clinics in two rural Health Centers and an urban university hospital were enrolled. All subjects underwent blood test, allergy skin test, and stool examination for ova and parasites. Wilcoxon sign-rank tests were used to compare serum eosinophilia and allergy skin test between the two groups.

RESULTS

Asthmatics in both urban and rural settings had significantly more positive skin reactions to house dust mite, cockroach, mold, and mouse epithelium than nonasthmatic controls (p < .05). Mean total serum IgE was also significantly higher in asthmatics than in nonasthmatic controls (360 vs. 90 IU/L, p <.001). Stool parasitemia was infrequent in both groups and not statistically significant.

CONCLUSION

Atopy is associated with adult asthma in southwest Nigeria. Larger studies to confirm the nature of this association and to examine the role of helminthic infection and other environmental factors on the expression of asthma are needed.

Interaction of monosulfonate tetraphenyl porphyrin (H2TPPS1) with plant-esterase: determination of the binding mechanism by spectroscopic methods

The interaction of monosulfonate tetraphenyl porphyrin (H(2)TPPS(1)) with plant-esterase was investigated using fluorescence and UV-vis absorption spectroscopy. Fluorescence quenching, from which the binding parameters were evaluated, revealed that the quenching of the esterase by H(2)TPPS(1) resulted from the formation of a dye-esterase complex. According to the modified Stern-Volmer equation, the effective quenching constants (K(a)) between H(2)TPPS(1) and plant-esterase at four different temperatures (297 K, 300 K, 303 K, and 306 K) were obtained to be 14.132×10(5), 5.734×10(5), 2.907×10(5), and 2.291×10(5) M(-1), respectively. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) for the reaction were calculated to be -181.67 kJ M(-1) and -0.49 kJ M(-1)K(-1), indicating that van der Waals force and hydrogen bonds were the dominant intermolecular force in stabilizing the complex. Site marker competitive experiments showed that the binding of H(2)TPPS(1) to plant-esterase primarily took place in the active site. The binding distance (r) was obtained to be 5.99 nm according to Förster theory of non-radioactive energy transfer. The conformation of plant-esterase was investigated by synchronous fluorescence and UV-vis absorption spectroscopy, and the results confirmed some micro-environmental and conformational changes of plant-esterase molecules.

SNP discovery, expression and cis-regulatory variation in the UGT2B genes

UGT2B enzymes metabolize multiple endogenous and exogenous molecules, including steroid hormones and clinical drugs. However, little is known about the inter-individual variation in gene expression and its determinants. We re-sequenced candidate regulatory regions and the partial coding regions (41.1 kb) of UGT2B genes and identified 332 genetic variants. We measured gene expression in normal breast and liver samples and observed different patterns. The expression levels varied greatly across individuals in both tissues and were significantly correlated with each other in liver. Genotyping of tagging single-nucleotide polymorphisms (SNPs) in the same samples and association tests between genotype and transcript levels identified 62 variants that were associated with at least one UGT2B mRNA levels in either tissue. Most of these cis-regulatory SNPs were not shared between tissues, suggesting that this gene family is regulated in a tissue-specific manner. Our results provide insight into studying the role of UGT2B variation in hormone-dependent cancers and drug response.

Abstract P3-12-07: Polymorphisms in the UDP-Glucuronosyltransferase 2B Gene Family and Risk of Breast Cancer in Women of African Descent

Background: The UDP-glucuronosyltransferase 2B (UGT2B) enzymes catalyze glucuronidation, which is an important clearance pathway of steroid hormones, and medications, and potential carcinogens. As steroid hormones play a central role in breast cancer development, genetic polymorphisms in the UGT2B gene family may affect breast cancer susceptibility.

Methods: We evaluate two missense mutations in UGT2B15 (rs1902023, D85Y and rs4148269, K523T), one missense mutation in UGT2B7 (rs7439366, H268Y), and one single nucleotide polymorphism (SNP) 497 bp upstream to UGT2B4 (rs13129471) using pooled case-control studies of breast cancer, which included 1,287 cases and 851 controls. Cases and controls were enrolled in Nigeria, Barbados, and the US, and all are women of African ancestry.

Results: All four SNPs followed Hardy-Weinberg equilibrium in each ethnicity group. We found the rs13129471 SNP was significantly associated with breast cancer risk after adjusting for ethnicity (P=0.003). Compared with homozygous genotype for the A-rs13129471 allele, the odds ratio for heterozygous genotype and homozygous genotype for the G-rs13129471 allele was 1.02 (95% CI: 0.81-1.28) and 1.50 (1.15-1.95), respectively. The association was stronger in Nigerian women (P=4x10- 5) and the corresponding odds ratio was 1.13 (95% CI: 0.85-1.49) and 2.39 (1.61-3.55). No significant association was found for the other three non-synonymous SNPs.

Conclusion: Our results suggest that polymorphism in the UGT2B4 gene may be associated with breast cancer risk in women of African ancestry and the association may follow a recessive model. The finding needs to be confirmed in other populations.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-12-07.

Abstract P6-01-06: Identification of Molecular Subtypes of DCIS and Invasive Breast Cancer Using Computerized Image Analysis for Data Integration

Background: Breast cancer is a heterogeneous disease with different putative therapeutic targets based upon the particular subtype. The particular subtype can have profound implications for therapy, as in the case of basal-like carcinomas which tend to be more aggressive with less therapeutic options. Although many studies have examined the transition from Ductal Carcinoma in-situ (DCIS) to Invasive Breast Cancer (IBC), the mechanisms involving the transformation are poorly understood. DCIS cases that are more likely to progress to IBC can be treated more aggressively. This study used image analysis to examine the association between predictive molecular biomarkers between pure DCIS, DCIS associated with IBC and IBC.

Methods: With approval by the Institutional Review Board, we evaluated tissue microarrays comprising 453 tissue cores from 149 patients. Five immunohistochemical biomarkers were utilized: estrogen (ER), progesterone (PR), human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), and cytokeratin 5/6 (CK-5/6). We then employed the Automated Cellular Image Analysis (ACIS) to score the biomarker status. We compared regional scoring (rated 0, 1, 2, or 3) between an experienced pathologist's subjective assessment and an automated score derived from ACIS. An image library was generated and integrated to our Translational Data Mart (TraM: http://tram.uchicago. edu). Statistical analyses included a comparison of histological grade, race, age, tumor size, and lymph node status associated with the prevalence of subtypes between pure DCIS tumors and those that advanced to IBCs. Results: The concordance between ACIS-based and pathologist-based scoring was moderate (kappa = 0.38). There was more variability in the pathologist's scoring with a standard deviation of 1.14 as compared to 0.85 for ACIS. Subtypes associated with IBC were also present in DCIS. In the pure DCIS cases, there was a higher proportion of the luminal A subtype (74.1%, n = 54) as compared to DCIS adjacent to IBC (54.2%, n=24) or pure IBC cases (57.4%, n = 115) (p=0.05). In contrast, there was more basal-like subtypes in DCIS juxtaposed with IBC (20.8%) and IBC (27.8%) than in pure DCIS tumors (9.3%).

Discussion: Molecular subtype analysis of DCIS could be useful in predicting DCIS with high risk of progressing to invasive cancer. The resemblance between subtypes bolsters the hypothesis that IBCs and DCIS originate from the same precursor lesion. Although the automated scoring featured by ACIS would be useful in expediting readings, it must be validated by a pathologist's assessment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-01-06.

Abstract P6-09-02: Risk of Breast Cancer Associated with Hormone Replacement Therapy Use Differs by Age, Race, and Breast Density

Background: Observational studies and randomized trials have demonstrated an association between hormone replacement therapy (HRT) use and increased risk for breast cancer. However, this risk may vary by age and other factors, including breast density and race/ethnicity. Using data from the Breast Cancer Surveillance Consortium (BCSC), we investigate whether self-reported HRT use in the peri-menopausal and immediate post-menopausal age groups is associated with breast cancer, and also whether risk associated with HRT use differs by breast density and race. Subjects and Methods: The BCSC is a longitudinal registry of mammography screening in seven U.S. centers. In the breast cancer risk prediction model developed by Barlow et al (J Natl Cancer Inst 2006 98:1204-14), HRT use and ten other features were identified as risk factorsfor breast cancer. Data for our study consists of 1,642,824 screens and 9,300 breast cancers among the post-menopausal women aged &gt; 44 in this cohort. Logistic regression models were used to estimate odds ratios for breast cancer associated with HRT use within race, age, and density strata, adjusting for other variables from the Barlow model. Multiple imputation methods were used to accommodate missing data for HRT (14%) and other predictors.

Results: Breast cancer risk for HRT use varied by age, with no risk excess among women aged 45-49 and risk excess of 20% or greater for women aged 50-64 (Table 1). Women &gt;64 had a smaller excess risk with HRT use. There was no significant excess risk at any age for Black women, while White women age 50-64 had &gt; 20% excess risk for HRT use. White women with higher breast density had increased risk with HRT use, while Black women did not.

Table 1: Odds ratios (95% confidence interval) for HRT use (yes/no)

Conclusions: In this large cohort of mammography-screened women, HRT use did not increase breast cancer risk in the peri-menopausal period (age 45-49). Women with low breast density had smaller risk increments associated with HRT than those with high density. For Black women, increased breast cancer risk due to HRT was not apparent at any age or breast density category.

Data collection for the BCSC was supported by a NCI-funded Breast Cancer Surveillance Consortium co-operative agreement (U01CA63740, U01CA86076, U01CA86082, U01CA63736, U01CA70013, U01CA69976, U01CA63731, U01CA70040).

Abstract P3-11-10: Risk Factors for Pregnancy-Associated Breast Cancer: A Report from the Nigerian Breast Cancer Study

Background: It is known that pregnancy has a dual effect on breast cancer risk, with increased risk of breast cancer in short term and decreased risk in the long run. Pregnancy-associated breast cancer (PABC), occurring during pregnancy and several years postpartum, has poor prognosis and is challenging in clinical management. However, risk factors for PABC, except for pregnancy per se, are less understood. Other reproductive factors including age at menarche and age at first live birth may play important roles in the development of PABC.

Methods: The study is based on the Nigerian Breast Cancer Study, a case-control study of breast cancer conducted in Ibadan, Nigeria, between 1998 and 2009. In-person interviews were conducted using structured questionnaires to collect detailed epidemiologic data. Pre-menopausal women who were 50 years old or younger were eligible to this analysis. The breast cancer cases were divided in two groups: PABC (diagnosed during pregnancy or within 5 years postpartum) and non-PABC. Polytomous logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI), contrasting each group of cases versus controls. Age in 3-year category, ethnicity, education, family history of breast cancer, history of benign breast disease, hormonal contraceptive use, alcohol drinking, height, and body mass index were adjusted in the multivariate models.

Results: In total, 1440 women were eligible to this study, including 311 PABC cases, 357 non-PABC cases, and 772 healthy controls. In the multivariate analysis adjusting aforementioned potential confounders, age at menarche was inversely associated with non-PABC (p=0.002, Table 1) but only trend towards significance for PABC (p=0.12). Age at first live birth was associated with lower risk of non-PABC but was associated with elevated risk of PABC.

Table 1. Odds ratios and 95% confidence intervals for PABC and non-PABC

Conclusions: We found menarche at older age may be protective against all premenopausal breast cancer, but age at first live birth has different role in the development of pregnancy-associated breast cancer and other premenopausal breast cancer in Nigerian women. The findings suggest that the trend towards delayed child-bearing may increase in the occurrence of breast cancer complicated by pregnancy.

Concordance in Hormone Receptor Status between First and Second Breast Cancers

Background: Women with breast cancer are more likely to have second breast cancer. It is uncertain on the biologic relationship between the two tumor lesions. Whether the second cancer represents an independent second primary versus recurrent or metastatic disease has implications in both cancer treatment and understanding of carcinogenesis. This study was conducted to evaluate the concordance of estrogen receptor (ER) and progesterone receptor (PR) status, and examine factors that influence the concordance. This study also examined whether there is a difference in the proportion of hormone receptor positivity between two breast cancers.Methods: 37,362 patients with diagnoses of two breast cancers between 1990 and 2006 were identified through 17 cancer registries of the Surveillance, Epidemiology, and End Results program. Logistic regressions were used to assess the association in hormone receptor status between two cancers. Odds ratios (OR) and 95% confidence interval (CI) were used to indicate the strength of association. Conditional logistic regressions were used to examine the change in proportion of hormone receptor positivity.Results: The two breast cancers were contralateral in 79% of patients and ipsilateral in 21% of patients. There was a strong association in ER status between two tumors, with OR of 17.8 (CI: 14.2-22.3) for ipsilateral pairs and 8.85 (CI: 8.08-9.69) for bilateral pairs. The strength of association in ER status depended on lag interval between first and second tumor. In patients with ipsilateral cancers, the OR was 170 for synchronous tumors (&lt;1 month) and 6.6 for metachronous cases separated by 5 years or longer. In patients with contralateral cancers, the corresponding OR was 31.5 and 4.12. The strength of association also depended on age at diagnosis. In patients with contralateral cancers, the OR was 11.7 and 7.03 for patients with first breast cancer diagnosed before and after 50 years old, respectively. There was also a strong association in PR status between two tumors, with OR of 8.39 (CI: 6.95-10.1) for ipsilateral pairs and 4.84 (CI: 4.48-5.24) for bilateral pairs. The ER positive proportion in second tumors occurred within 1 year was similar to that of first tumors. However, compared with the first tumors, the odds of ER positivity was decreased by 47% and 21%, respectively, in second ipsilateral and contralateral breast cancers occurred 1-5 years after first tumors.Conclusions: Hormone receptor status of the primary breast cancer is strongly predictive of that of the second breast cancer, occurred either in the same or in contralateral breast, and the predictive value was very good even after 5 years. These findings suggest that two breast cancers of the same patient arise in a common predisposing milieu, which is probably predetermined by genetic makeup and/or environmental exposures in early life. The second cancer occurred after 1-5 years was more likely to be hormone receptor negative compared with the first cancer, suggesting that treatment for the first cancer, possibly tamoxifen, can modify the expression of subsequent breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4144.

Association of Proliferating Macrophages with High Grade, Hormone Receptor Negative Breast Cancer

Macrophages, a key cell in the inflammatory cascade, have been associated with poor prognosis in cancers, including breast cancer. Tumor associated macrophages (TAM) have also been shown to play a role in invasion and metastases. In this study, we investigated the role of a subset of macrophages known as proliferating macrophages (promacs) in breast cancer. We examined the relationship between promacs and clinico-pathologic characteristics such as tumor size, grade, lymph node metastasis, hormone receptor status, molecular subtype, and survival. This study was conducted at two independent institutions (University of California, San Francisco and University of Chicago) using two independent cohorts of patients with breast cancer. Formalin-fixed, paraffin-embedded sections and/or tissue microarrays were double-stained with anti-CD68 (a macrophage marker) and anti-PCNA (a proliferation marker) antibodies. The number of total macrophages as well as promacs per high power field were counted. Molecular subtypes were determined from gene expression array analyses. Outcomes were available for a subset of the cases and Kaplan Meier survival curves were generated.Tumor tissue from two different cohorts of patients with breast cancer were stained and analyzed at two independent institutions. In both studies, promac density was significantly correlated with higher grade, hormone-receptor negative tumors, and a basal-like subtype. In contrast there was no correlation between numbers of promacs and tumor size, stage, or number of involved lymph nodes. The presence of increased promacs was a significant predictor of survival in these treated patients. Proliferating macrophages are more abundant in high grade tumors, and predict a worse outcome, independent of stage and grade. These findings, corroborated at two independent institutions, suggest that the presence of promacs is associated with tumor progression and increased promac density may serve as a prognostic indicator for poor outcomes. Novel therapies that are able to target and halt the activity of promacs may be a promising strategy for the treatment of promac rich tumors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3042.

Genetic Risks for Breast Cancer in African American Women: Analysis of Candidate Single Nucleotide Polymorphisms from Association Studies

Background: African American breast cancer patients present with more aggressive disease than Caucasian women. They are also more likely to experience earlier onset of illness and tumors that are resistant to current treatment options due to their high grade and negative hormone receptor status. These attributes are correlated with greater mortality. The different frequencies of these indicators in African American and Caucasian patients have been associated with genetic susceptibility and genetically driven progression of breast cancer. However, these studies have focused on well-known breast cancer genes, not the low-penetrance mutations identified by genome-wide association studies (GWAS).Aims: This pilot case-control replication study investigated both the overall and attribute-based breast cancer risk of African American women associated with three single nucleotide polymorphisms (SNPs) selected through previously published association studies, including a genome-wide association study by Gold et al. (2008), and predicted high odds ratios and high minor allele frequencies in the African American population compared to the original study populations. We hypothesized that rs2180341 and rs7776136, located in 6q22.33 and associated with risk in a GWAS of Ashkenazi Jewish familial breast cancer cases, would contribute to overall risk in a case-control cohort of African American women. We also hypothesized that rs3741378, a SNP in SIPA1 previously associated with hormone-receptor negative tumors, would contribute to this outcome in the same cohort. These SNPs were additionally studied for relevance to other clinical outcomes.Methods: Two hundred and eighteen cases and 105 controls from the University of Chicago Cancer Risk Clinic were genotyped for these three SNPs using SNaPshot multiplex. Clinical information, including age of diagnosis, family history, hormone receptor status, survival, and tumor grade and stage, was also collected. Statistical analysis was performed using Pearson's χ2 test, Fisher's exact test, logistic regression and supplementary tests in Stata.Results: Unlike other populations, the African American population showed allelic odds ratios of approximately 1.0 for all SNPs tested, indicating no statistically significant association between these SNPs and breast cancer risk. We also found no association with age of diagnosis, hormone receptor status, tumor stage and grade. However, the minor allele of rs2180341 was associated with decreased survival in patients with a hazard ratio of 3.991 (p=0.044, 95% CI: 1.038-15.337) for the homozygous minor allele genotype.Conclusion: This pilot study represents one of the first forays into the translation of breast cancer GWAS results to populations of African ancestry. Based on our preliminary findings, future studies on a larger cohort of breast cancer cases of African ancestry will be needed to identify risk factors that may be particular to this patient population.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3068.

Molecular interactions of monosulfonate tetraphenylporphyrin (TPPS1) and meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) with dimethyl methylphosphonate (DMMP)

The molecular interactions of monosulfonate tetraphenylporphyrin (TPPS(1)) and meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) with dimethyl methylphosphonate (DMMP) have been investigated by UV-vis and fluorescence spectroscopies. The association constants and interaction stoichiometries of the bindings were obtained through Benesi-Hildebrand (B-H) method. Particularly, both linear and nonlinear fitting procedures were performed to evaluate the possible 1:2 interactions. Experimental results showed that hydrogen-bonding interactions existed in both of the two systems, resulting in regular changes in the absorbance and fluorescence characteristics of the porphyrins. The association constants and stoichiometries determined from absorbance and fluorescence studies were in excellent agreement. Using a nonlinear fitting method, we demonstrated that the one-step 1:2 interaction took place in the TPPS(1)-DMMP system, and the association constants were determined to be 71.4 M(-1) by absorbance measurements and 70.92 M(-1) by fluorescence measurements. The interaction stoichiometry of the TPPS-DMMP system was 1:1, and the association constants were determined to be 16.06 M(-1) by absorbance measurements and 16.03 M(-1) by fluorescence measurements. It was concluded that the interaction between TPPS(1) and DMMP was stronger than that between TPPS and DMMP.

Lack of association of the TP53 Arg72Pro SNP and the MDM2 SNP309 with systemic lupus erythematosus in Caucasian, African American, and Asian children and adults

The p53 tumour suppressor is the central regulator of apoptosis. Previously, the functional TP53 Arg72Pro polymorphism was found to be associated with systemic lupus erythematosus (SLE) in Koreans but not Spaniards. MDM2 is the major negative regulator of p53. An intronic polymorphism in MDM2, the SNP309, attenuates p53 activity and is associated with accelerated tumour development in premenopausal women. Polymorphic variation in MDM2 has never been studied in SLE. The aim of this study is to further assess the contribution of p53-pathway genetic variation to SLE by testing the association of the TP53 Arg72Pro polymorphism and the MDM2 SNP309 with SLE in a well-characterised and ethnically diverse cohort of patients with both childhood- and adult-onset SLE (n = 314). No association was found between the TP53 Arg72Pro polymorphism and SLE in patients of European descent, Asian descent or in African Americans, nor was an association found between the MDM2 SNP309 and SLE in patients of European descent or in African Americans. In addition, there was no correlation between either variant and early-onset disease or nephritis, an index of severe disease. It is concluded that neither the TP53 Arg72Pro polymorphism nor the MDM2 SNP309 contributes significantly to either susceptibility or disease severity in SLE.

Validation of breast cancer biomarkers between a field immunohistochemistry laboratory in Nigeria and its US-based counterpart

Abstract #4039

Introduction: The importance of hormone receptor status in assigning treatment and the potential use of HER2 targeted therapy have made it imperative for laboratories to improve detection techniques. As inter-laboratory variability in immunohistochemical (IHC) tests may also affect epidemiologic studies of breast cancer subtypes in different countries, we conducted a validation study of breast cancer biomarkers between a well-established laboratory in the US and a field laboratory at the Institute for Medical Research and Training at the University College Hospital in Ibadan Nigeria.&#x2028; Method: 232 breast tumor blocks were evaluated for ER, PR, and HER2 at both laboratories using tissue micro arrays (TMA) technique. Web-based conferences were held periodically to discuss IHC staining protocols, standardize scoring systems and to resolve discrepant cases. Pathologists used whole slide imaging for joint review and kappa statistic (κ) was used to indicate concordance between the two laboratories. Fluorescence in situ hybridization was carried out to confirm HER2 status in all cases.&#x2028; Results: Initially, concordance analysis revealed an agreement of 91% (κ=0.52) for ER, 85% (κ=0.49) for PR, and 80% (κ=0.39) for HER2 between the two labs. Antigen retrieval techniques and scoring methods were identified as important reasons for discrepancy. After quality assurance and training, the agreement improved to 92% (κ=0.53) for ER, 88% (κ=0.64) for PR, and 94% (κ=0.75) for HER2. To date, florescence in situ hybridization (FISH) has been completed for 67 cases to confirm HER2 status, out of which 16 (24%) were shown to amplify the HER2 gene, 6 out of the 12 discordant HER2 results were resolved by FISH.&#x2028; Conclusion: We found web-based conference with TMA and digital microscopy a useful and cost-effective tool for quality assurance of IHC, consultation and collaboration between distant laboratories. Quality improvement exercises in testing of tumor biomarkers will reduce misclassification in epidemiologic study of breast cancer subtypes and provide much needed capacity building in resource poor field sites.&#x2028; Acknowledgement&#x2028; This study was carried out with the support of Breast SPORE NCI P50 CA125183, Breast Cancer Research Foundation and the Lee Jeans Entertainment Industry Fund.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4039.

The role of VEGFR-2 genetic variation in breast cancer progression

Abstract #904

Background: Substantial laboratory and clinical data have demonstrated the critical role of angiogenesis in breast tumor progression. A significant correlation between vascular endothelial growth factor receptor-2 (VEGFR-2) expression and cell proliferation has been described in invasive breast carcinomas, suggesting that VEGF stimulates mammary cell growth through VEGFR-2. We sought to examine whether variability in VEGFR-2 expression and activation in tumors might be due to individual genetic variations, which may also play a role in response to anti-angiogenic therapy. To our knowledge, no study has correlated genetic variation in VEGFR-2 to expression and activity in primary breast tumors.&#x2028; Methods: DNA from 42 primary breast tumors was extracted from fresh frozen tissue. The core promoter, 5'-untranslated region (UTR), 3'-UTR, exons and intron-exon boundary regions of VEGFR-2 were sequenced for all tumors. Tissue microarrays were constructed, and tumor and paired normal breast tissue were stained with anti-VEGFR-2 antibody (Calbiochem). Microvessel density (MVD) was determined by immunohistochemical staining using a primary antibody against platelet endothelial cell adhesion molecule (anti-CD34, Novocastra). Semiquantitative analysis was performed independently by two pathologists. VEGFR-2 expression was correlated with genotype and MVD using the Mann-Whitney test. VEGFR-2 expression in normal and tumor tissue was compared using the Wilcoxon signed-rank test.&#x2028; Results: Two-thirds of tumors were from self-reported African Americans (AA), and the majority were ER positive. Twenty-three different single nucleotide polymorphisms (SNPs) were identified; ten were previously reported in dbSNP. Three of these SNPs were common (minor allele frequency &gt;10%): one was located in the core promoter region and the other two were located in exons 7 and 11 (both non-synonymous SNPs). Using PolyPhen prediction software (http://genetics.bwh.harvard.edu/pph/), the two non-synonymous SNPs were predicted to affect protein function. Of the 23 different SNPs identified, 11 were only seen in tumors from AA and 3 were only observed in tumors from Caucasians. Thirty-six of the 42 tumors (86%) had at least one SNP. VEGFR-2 expression in tumor was significantly higher than in paired normal tissue (p=0.0002). VEGFR-2 expression was significantly lower in tumors with the AA genotype of the 4032 A/G core promoter SNP as compared to those with the AG and GG genotypes combined (p=0.02). VEGFR-2 expression was significantly associated with MVD in tumor tissues (p=0.04).&#x2028; Discussion: Our preliminary study suggests an association between genetic variations in the VEGFR-2 gene and protein expression in tumor tissue. Future work will examine the spectrum of these genetic variations in diverse populations and their potential role in predicting response to anti-angiogenic therapy.&#x2028; This study was funded by the University of Chicago Breast SPORE NCI P50 CA125183.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 904.