Wang, Alice H.

Abstract Background: Despite recent advances in prevention and therapy, colorectal cancer (CRC) continues to account for nearly 50,000 deaths per year in the US. TNM stage is the current CRC prognostic standard, yet within-stage prognostic heterogeneity is well documented. Microsatellite instability (MSI), CpG island methylation phenotype (CIMP), and BRAF- and KRAS-mutation status represent candidate prognostic markers. However, associations between these markers and CRC survival have not been described in a population-based setting. Methods: Data and tissue resources were obtained from the Iowa Women's Health Study (IWHS), which recruited 41,836 women, ages 55-69 years, at study entry (1986). Incident CRC cases were ascertained by annual linkage with the Iowa Cancer Registry. Archived, paraffin-embedded tissue specimens were collected from 732 representative CRC cases diagnosed through 12/31/2002. Established laboratory methods were used to characterize CRC cases: MSI-H or MSS/MSI-L (by instability in β3 vs. <3 out of 10 markers, respectively); CIMP+ or CIMP− (by promoter hypermethylation in β3 vs. 0-2 out of 5 genes, respectively); BRAFwt or BRAFmut (by fluorescent allele specific PCR to detect the V600E point mutation in exon 15); and KRASwt or KRASmut (by direct sequence analysis of codons 12 and 13 in exon 2). Cox regression models were fit to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for time to death of any cause adjusted for age, stage, grade, and treatment status. Results: CRC cases with informative molecular marker data ranged from 515/732 (70%) for KRAS to 548/732 (75%) for MSI status. Mean follow-up was 4.4 years for deceased individuals and 11.2 years for women alive at last contact. After multivariable adjustment, both MSS/MSI-L (p=0.004) and KRASmut (p=0.048) tumors were associated with poorer survival. Survival did not significantly differ across levels of CIMP and BRAF status. Conclusions: MSI and KRAS status may influence CRC survival among older women. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4492. doi:1538-7445.AM2012-4492

Abstract Background. Several recent studies have reported an inverse relationship between sun exposure and non-Hodgkin (NHL) risk. One hypothesis is that vitamin D mediates this effect. We evaluated the association of sun exposure at various ages and common variants in vitamin D related genes with risk of NHL and its major subtypes. Methods. Newly diagnosed NHL cases (N=1023) and frequency matched controls (N=1254) were enrolled in a clinic-based case-control study conducted at the Mayo Clinic. Thirty-eight single nucleotide polymorphisms (SNPs) from 5 candidate genes relevant to vitamin D metabolism and sun sensitivity (IRF4, RXR, VDR, CYP24A1, CYP27B1) were genotyped. Participants also completed a detailed questionnaire, including self-reported sun exposure at ages 13-21, 22-40, and 41+ years. Odds ratios (OR), 95% confidence intervals (CI), and tests for trend and effect modification were estimated using unconditional logistic regression adjusted for age and gender. ORs are reported for the highest vs. lowest exposure category or as the ordinal OR for SNPs. Results. The mean age of diagnosis/enrollment was 61 years for cases and 60 years for controls. The most common subtypes were chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; 34%), follicular (FL; 24%), and diffuse large B-cell (DLBCL; 18%) lymphomas. There was a significant decrease in NHL risk with increased sun exposure at ages 13-21 years (OR=0.66, 95% CI 0.44-1.00; ptrend=0.04), which attenuated with increasing age at exposure. Exploratory analysis by NHL subtype indicated a trend toward a protective effect of sun exposure at ages 13-21 years for each of the major subtypes, though these estimates did not reach statistical significance. Of the 38 SNPs evaluated, there was a significant association for 3 SNPs in VDR and 1 SNP in CYP24A1: rs3819545 (OR=1.24, 95% CI 1.10-1.40, p=0.0004), rs2239186 (OR=1.22, 95% CI 1.05-1.41, p=0.009), and rs886441 (OR=0.82, 95% CI 0.70-0.96, p=0.02) for VDR and rs2762939 (OR=0.85, 95% CI 0.75-0.98, p=0.02) for CYP24A1. Both the VDR and CYP24A1 associations were observed for CLL/SLL, FL, but were attenuated for DLBCL. There was no evidence of any significant effect modification of sun exposure at ages 13-21 years by genotype in these four SNPs for NHL overall, or for NHL subtypes. Conclusions. We observed an inverse association between the frequency of sun exposure at ages 13-21 years and NHL risk, which attenuated for sun exposure at older ages, suggesting that early life exposure may be more relevant. While genetic variation in VDR and CYP24A1 were associated with NHL risk, there was no evidence for an interaction of sun exposure with these genes, suggesting that a sun association may not act through the vitamin D metabolism pathway. This would be consistent with a lack of association of circulating vitamin D with NHL risk recently published from the Cohort Consortium pooling project. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1894. doi:10.1158/1538-7445.AM2011-1894

Abstract Background: Folate intake (FI) appears to affect colorectal cancer (CRC) risk, but the molecular mechanism(s) involved are incompletely defined. In this study, we analyzed associations between FI and incident CRC, overall and by KRAS mutation status, in the population-based Iowa Women's Health Study (IWHS). Methods: The IWHS recruited 41,836 randomly selected Iowa women, ages 55-69 years, with a valid driver's license at study entry (1986). FI and other exposure variables were assessed at baseline, by self-report. Incident CRC cases were ascertained by annual linkage with the Iowa Cancer Registry. Archived, paraffin-embedded tissue specimens were recently collected from 732 representative CRC cases diagnosed through 12/31/2002. FI (including supplements) was categorized by quartiles. KRAS mutation status (wildtype [wt] vs. mutated [mut]) was determined by direct sequence analysis of codons 12 and 13 (exon 2). Multivariate Cox regression models were fit to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Of the 732 available CRC cases, 470 (64%) had complete FI and KRAS data. FI was not associated with incident CRC overall (for quartile 4 vs. quartile 1, RR = 1.03; 95% CI = 0.82-1.28; p trend = 0.90), or with the KRAS-wt or KRAS-mut subtypes (see Table). Conclusions: These data do not support an association between FI and incident CRC, overall or by KRAS-defined subtypes, among older, predominately white, non-Hispanic women. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1892. doi:10.1158/1538-7445.AM2011-1892

Abstract Background: NHL is a malignancy of lymphocytes, and there is growing evidence for a role of immune dysfunction in the etiology of this malignancy. We conducted a 2-stage analysis of single nucleotide polymorphisms (SNPs) from 1,253 genes using the ParAllele (now Affymetrix) Immune and Inflammation Panel with risk of NHL. Methods: In Stage 1, we successfully genotyped 7,670 SNPs in a clinic-based study of 425 NHL cases and 465 frequency matched controls seen at the Mayo Clinic. Genes were tagged with SNPs from HapMap to provide coverage at r2 = 0.8 and minor allele frequency (MAF) >0.05. In Stage 2, we genotyped the top 768 SNPs on an additional 584 cases and 768 controls from the Mayo Clinic Study, and then conducted a pooled analysis of all 1009 cases and 1233 controls. The association of individual SNPs with NHL risk was assessed using the Odds Ratios (ORs) and 95% confidence intervals, adjusted for age and gender. The most prevalent homozygous genotype was used as the reference group, and each SNP was modeled individually as having a log-additive effect. Results: Overall, the mean age at diagnosis was 62.0 years for cases and the mean age at enrollment for controls was 61.1 years. The most common subtypes were chronic lymphocytic leukemia (CLL, N=343), follicular lymphoma (FL, N=245), and diffuse large B-cell lymphoma (DLBCL, N=178). In the pooled analysis, there were 3 SNPs at p<0.0004. The top SNP was rs241447 (MAF=0.26) from TAP2 at 6p21.3 (OR=1.34, 95% CI 1.17-1.53, p=0.00003). This SNP is a cSNP that leads to a missense change (Ala→Thr). The second SNP was rs2857597 (MAF=0.26) from AIF1, also at 6p21.3 (OR=0.77, 95% CI 0.67-0.88, p=0.0002). The region spanning these two SNPs had multiple risk SNPs with p<0.01, including SNPs in BAT2 (rs3132453), BAT3 (rs2242656), C2 (rs7746553), HLA-DRA (rs8084, rs7192), and TAP2 (rs1894408). Of these SNPs, only rs241447 (TAP2) and rs7192 (HLA-DRA) displayed any substantial LD (r2=0.84, all other r2<0.25). The third SNP was rs754505 (MAF=0.07) from NFATC1 at 18q23 (OR=0.63, 95% CI 0.49-0.81, p=0.0003). There were 4 additional SNPs in this gene with a p<0.05 (rs7240932, rs396127, rs177820, rs183374). In subtype analysis, the SNPs from 6p21.3 showed the strongest associations with FL (including the TAP2 SNP rs241447, p=6.9 × 10−8), although there were also associations with CLL (except for the TAP2 and C2 SNPs) and DLBCL (except for the HLA-DRA SNPs). For NFATC1 the associations were similar across the main NHL subtypes. Conclusions: We identified strong associations with NHL risk in the 6p21.3 region, which includes the MHC locus. Our results were particularly striking for FL and supports recent GWAS and candidate gene studies that implicate this region. We also identified NFATC1 as a susceptibility gene. NFATC1 is known to regulate the expression of growth and survival genes including MYC, TNF, CD40L, and BAFF, all of which have also been linked to lymphomagenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2761. doi:10.1158/1538-7445.AM2011-2761

Abstract INTRODUCTION: Mammographic breast density is a strong risk factor for breast cancer (BC). We established the Mayo Mammography Health Study (MMHS) cohort study at the Mayo Clinic in Rochester, Minnesota (MN) to examine the association of breast density with BC. We evaluated the influence of the image acquisition technique on the density and BC association. METHODS: From October 2003 to September 2006, all women scheduled for screening mammography at the Mayo Clinic were invited to participate. Eligible women were residents of MN, Iowa (IA) or Wisconsin (WI); age 35+; and had no personal history of BC. A risk factor questionnaire, consent form and permission to link to tumor registries were obtained. Incident BC was identified through 2009 by linkage to the Mayo and state cancer registries. A case-cohort of all incident BCs and 2300 randomly selected women (the subcohort) were used to examine the association of breast density and BC using digitized film mammograms at the time of enrollment while controlling for the influence of the acquisition parameters (peak kilovoltage, milliampere-second, and compressed breast thickness). Two density measures were considered: a quantitative percent density (PD) measure estimated using the computer-assisted thresholding program, Cumulus (University of Toronto), and the 4-category clinical BI-RADS measure. Proportional hazards regression was used to calculate hazards ratios (HR) and 95% confidence intervals (CI) for BC associated with quartiles of PD (0-6.2%,6.3-14.9%, 15.0-25.7% and 25.8%+) and BI-RADS categories 1-4 (almost entirely fatty to extremely dense). All models included age, postmenopausal hormone use (PMH), BMI, and menopausal status. The influence of acquisition parameters was evaluated by examining models with and without their inclusion. RESULTS: A total of 20,982 (50%) women participated in MMHS; 1058 (5%) with a prior history of BC were excluded, for a total cohort of 19,924. Compared to nonresponders, responders were younger (57.5 vs. 58.4 yrs), more likely to have ever used PMH (45% vs. 33%), and more likely to have a BC family history (19% vs 16%). The case-cohort consisted of 317 incident cases and 2300 women in the subcohort. Women were excluded from the current analysis if PD could not be estimated or if acquisition parameters were not available, leaving 249 cases and 1937 in the subcohort. As expected, PD was associated with BC [HR (95% CI): 1.0 (REF), 2.1 (1.4-3.1), 3.0 (2.0-4.5), and 4.6 (3.0-7.0) for quartiles; p-trend<0.001]. Controlling for acquisition parameters attenuated the association [HR (95% CI): 1.0 (REF), 2.3 (1.5-3.4), 2.4 (1.6-3.7), and 3.0 (1.8-5.0) for quartiles; p-trend<0.001]. Results for BI-RADS density were similar to those for PD. CONCLUSION: This study confirms that breast density is a significant risk factor for BC and demonstrates that the acquisition technique confounds the density and BC risk association. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3716. doi:10.1158/1538-7445.AM2011-3716

Abstract Background: Colorectal cancer (CRC) is the third most common incident cancer among women in the United States. Alcohol use has been proposed as a CRC risk factor, but existing observational data remain inconsistent. To date, relatively few studies have examined associations between alcohol use and CRC risk based on molecularly-defined subtypes. Aim: To evaluate associations between alcohol use and incident CRC overall, as well as by molecularly-defined subtypes including microsatellite instability (MSI), CpG island methylator phenotype (CIMP) and BRAF mutation status in the prospective, population-based, Iowa Women's Health Study (IWHS). Methods: The IWHS recruited 41,836 randomly selected Iowa women, ages 55–69 years at enrollment, in 1986. Women with prevalent cancers or no follow-up were excluded, leaving 38,001 eligible for this study. Alcohol use was obtained from a self-administered food frequency questionnaire at study baseline. Incident CRCs were identified through annual linkage with the State Health Registry of Iowa. Archived, paraffin-embedded tissue specimens were recently requested for incident CRC cases diagnosed through December 31, 2002. In the present study, useable tissue specimens were obtained and molecularly characterized for 563/1,255 cases (45%), whose baseline age, body mass index, physical activity level, total energy intake and alcohol use were similar to non-retrieved cases (p > 0.05 for each comparison). Alcohol use was categorized as never (n=21,464), < 3.4 g/day (n=8,313) and > 3.4 g/day (n=8,224), based on the median split among users. Molecularly-defined CRC subtypes were categorized as MSI-high (MSIH; n=148), MSI-low or microsatellite stable (MSI-L/MSS; n=400); CIMP-positive (n=167) or CIMP-negative (n=368); and BRAF-mutation (n=154) or BRAF-wildtype (n=391). Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated for alcohol use compared to never drinkers, using multivariable Cox regression models adjusted for body mass index, waist-to-hip ratio, smoking status, physical activity level, exogenous estrogen use, and daily intakes of total energy, total fat, red meat, sucrose, calcium, folate, methionine and vitamin E. Results: There was no statistically significant association between alcohol use and overall CRC risk (RR=1.00; 95% CI = 0.86–1.15 for < 3.4 g/day versus none; RR=1.06; 95% CI=0.91–1.24 for >3.4 g/day versus none). Further, there were no associations with alcohol use for specific, molecularly-defined CRC subtypes (RRs shown for > 3.4 g/day versus none): MSI-H (RR=1.07; 95% CI=0.70–1.64); MSI-L or MSS (RR=1.12; 95% CI=0.85–1.47); CIMP-positive (RR=0.97; 95% CI=0.64–1.47); CIMP-negative (RR=1.13; 95% CI=0.85–1.50); BRAF-mutation (RR=0.94; 95% CI=0.61–1.45); and BRAF-wildtype (RR=1.20; 95% CI=0.91–1.57). Conclusion: In this cohort of older women, alcohol use did not appear to be a risk factor for incident CRC, overall or by the defined molecular subtypes. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A115.

Abstract Background: Postmenopausal hormone (PMH) therapy represents a controversial colorectal cancer (CRC) preventive intervention. Because colorectal carcinogenesis is a heterogeneous process, we evaluated associations between PMH therapy and incident CRC in relation to KRAS mutation status in a population-based cohort of older women [Iowa Women's Health Study (IWHS)]. Methods: The IWHS enrolled 41,836 randomly selected women, ages 55 to 69 years, in 1986. PMH therapy and other exposure data were recorded at baseline. Tissue samples from prospectively identified CRC cases (n = 507) were analyzed for somatic KRAS mutations (exon 2, codons 12 and 13). Multivariable Cox regression models were fit to estimate relative risks (RR) and 95% confidence intervals (CI). Results: PMH therapy (ever vs. never) was inversely associated with KRAS mutation–negative (RR = 0.83; 95% CI, 0.66–1.06; P = 0.14) and KRAS mutation–positive (RR = 0.82; 95% CI, 0.58–1.16; P = 0.27) tumors, although the observed risk estimates were not statistically significant. When anatomic subsite was additionally considered, the strongest association was found for KRAS mutation–negative, distal colorectal tumors (RR = 0.64; 95% CI, 0.43–0.96; P = 0.03). Conclusions: To our knowledge, we provide the first report of KRAS-defined CRC risks associated with PMH therapy. These data suggest that PMH therapy may reduce CRC risk through mechanisms beyond KRAS mutation status but might provide greater benefits for KRAS mutation–negative than mutation-positive tumors (at least in the distal colorectum). Impact: Findings from this prospective cohort study provide novel insights about the molecular biology of PMH therapy–related CRC risk reduction. Cancer Epidemiol Biomarkers Prev; 21(4); 681–4. ©2012 AACR.

Background Postmenopausal hormone (PMH) therapy may reduce colorectal cancer (CRC) risk, but existing data are inconclusive. Objectives To evaluate associations between PMH therapy and incident CRC, overall and by molecularly defined subtypes, in the population-based Iowa Women's Health Study of older women. Methods Exposure data were collected from Iowa Women's Health Study participants (55–69 years) at baseline (1986). Archived, paraffin-embedded tissue specimens for 553 CRC cases were collected and analysed to determine microsatellite instability (MSI-L/MSS or MSI-H), CpG island methylator phenotype (CIMP-negative or CIMP-positive) and BRAF mutation ( BRAF -wildtype or BRAF -mutated) status. Multivariable Cox regression models were fit to estimate RRs and 95% CIs. Results PMH therapy (ever vs never use) was inversely associated with incident CRC overall (RR=0.82; 95% CI 0.72 to 0.93), with a significantly lower risk for MSI-L/MSS tumours (RR=0.75; 95% CI 0.60 to 0.94), and borderline significantly lower risks for CIMP-negative (RR=0.79; 95% CI 0.63 to 1.01) and BRAF -wildtype (RR=0.83; 95% CI 0.66 to 1.04) tumours. For PMH therapy >5 years, the subtype-specific risk estimates for MSI-L/MSS, CIMP-negative and BRAF -wildtype tumours were: RR=0.60, 95% CI 0.40 to 0.91; RR=0.68, 95% CI 0.45 to 1.03; and RR=0.70, 95% CI 0.47 to 1.05, respectively. PMH therapy was not significantly associated with the MSI-H, CIMP-positive or BRAF -mutated CRC subtypes. Conclusions In this prospective cohort study, PMH therapy was inversely associated with distinct molecularly defined CRC subtypes, which may be related to differential effects from oestrogen and/or progestin on heterogeneous pathways of colorectal carcinogenesis.

Abstract Increased alcohol consumption is a putative colorectal cancer (CRC) risk factor. However, existing data are less conclusive for women than men. Also, to date, relatively few studies have reported alcohol-related CRC risks based on molecularly defined tumor subtypes. We evaluated associations between alcohol intake and incident CRC, overall and by microsatellite instability [MSI high (MSI-H) or MSI low/microsatellite stable (MSI-L/MSS)], CpG island methylator phenotype (CIMP positive or CIMP negative), and BRAF mutation (mutated or wild-type) status in the prospective, population-based Iowa Women's Health Study (IWHS; n = 41,836). Subjects were 55 to 69 years at baseline (1986), and exposure data were obtained by self-report. Incident CRCs were prospectively identified and archived, paraffin-embedded tissue specimens were collected from 732 representative cases, diagnosed through December 31, 2002. Multivariate Cox regression models were fit to estimate relative risks (RR) and 95% confidence intervals (CI). Among alcohol consumers, the median intake (range) was 3.4 (0.9–292.8) g/d. Compared with nonconsumers, alcohol intake levels of 3.4 g/d or less (RR = 1.00; 95% CI, 0.86–1.15) and more than 3.4 g/d (RR = 1.06; 95% CI, 0.91–1.24) were not significantly associated with overall CRC risk. Analyses based on alcohol intake levels of 30 g/d or less and more than 30 g/d or quartile distributions yielded similar risk estimates. Null associations were also observed between each alcohol intake level and the MSI-, CIMP- or, BRAF-defined CRC subtypes (P > 0.05 for each comparison). These data do not support an adverse effect from alcohol intake on CRC risk, overall or by specific molecularly defined subtypes, among older women. Cancer Prev Res; 4(12); 2035–43. ©2011 AACR.

Abstract Background. Vitamin K1 (phylloquinone) is a fat soluble vitamin found mainly in green leafy vegetables, with smaller amounts found in other vegetables, vegetable oils, and some fruits. Vitamin K-dependent gamma-carboxylation of specific glumatic acid residues is critical to the functioning of several key proteins in the coagulation cascade. Vitamin K compounds also inhibit IL-6 and other inflammatory cytokines and serve as transcription factors that foster cell-cycle arrest and apoptosis, pathways relevant to lymphomagenesis. We tested the hypothesis that dietary and supplemental intake of Vitamin K was inversely associated with risk of NHL and the common subtypes of diffuse large B cell, follicular, and chronic lymphocytic leukemia/small lymphocytic lymphomas. Methods. We evaluated dietary and supplemental intake of vitamin K and NHL risk in a clinic-based study of 603 newly diagnosed NHL cases and 1007 frequency-matched controls enrolled at the Mayo Clinic from 2002-2008. Usual diet two years before case diagnosis or control enrollment was assessed using a self-administered, 128-item food frequency questionnaire. Dietary intake of vitamin K was estimated using the Food Processor SQL system. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI), adjusted for age, sex, residence, and total energy. NHL subtypes were centrally reviewed, and subtype-specific risks were estimated using polychotomous logistic regression. Results. The mean age at diagnosis was 60.8 years for cases and 57% were male; for controls, the mean age at enrollment was 60.1 years and 53% were male. Median intake of vitamin K from diet among controls was 63.5 ug/day; 16% used a multivitamin supplement that included vitamin K. NHL risk was inversely associated with intake of dietary vitamin K (p-trend=0.001); compared to intake <39.3 ug/d, risk was decreased for intakes of 39.3-63.4 ug/d (OR=0.76; 95% CI 0.57-1.02), 63.5-107.7 ug/d (OR=0.74; 95% CI 0.55-1.00), and >107.7 (OR=0.56; 95% CI 0.40-0.77). There was an U-shaped association for supplemental intake of Vitamin K and NHL risk; compared to no use, supplemental intake of <5.9 ug/d (OR=0.63; 95% CI 0.37-1.08) and 5.9-17.6 ug/d (OR=0.53; 95% CI 0.30-0.93) were inversely associated with NHL risk, while intake of >17.6 ug/d (OR=1.13; 95% CI 0.73-1.74) showed no association. There was no evidence of heterogeneity by NHL subtype (p=0.4). Further adjustment for education, family history of NHL, pack-years of smoking, body mass index, and alcohol consumption did not alter these results, nor did adjustment for a food-frequency questionnaire-based estimate of total antioxidant intake. Conclusion: Higher intake of vitamin K from the diet was inversely associated with risk of NHL overall and for the major subtypes. These first results, which require replication, suggest that the coagulation pathway or other biologic effects of vitamin K may play a role in lymphomagenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2811.