Citations

Abstract Purpose: Obesity is associated with an increased risk of colon cancer. However, the influence of body mass index (BMI) upon the prognosis of colon cancer survivors and its relationship to gender remains unknown. Experimental Design: BMI (kg/m2) was categorized in patients with TNM stage II and III colon carcinomas (n= 4,381) enrolled in 7 randomized trials of 5-fluorouracil-based adjuvant chemotherapy. Cox proportional hazards models were used to determine the association of BMI with disease-free (DFS) and overall survival (OS). Results: Among colon cancer patients, 868 (20%) were obese (BMI >30 kg/m2) of which 606 were class 1 (BMI 30-34 kg/m2) and 262 were class 2,3 (BMI >35 kg/m2). Obese versus normal-weight patients were more likely to be younger (p=0.038), have distal tumors (0.058), show intact DNA mismatch repair (MMR) (p=0.035), and have more lymph node metastases (p=0.017). In a multivariate analysis, BMI was significantly associated with both DFS (p=0.030) and OS (p=0.0017). Men with class 2,3 obesity showed reduced OS compared to normal weight men [HR 1.35 (1.02, 1.79); p=0.039]. Women with class I obesity had reduced OS [HR 1.24 (1.01, 1.53), p=0.045] compared to normal weight women. Overweight status was associated with improved OS in men (p= 0.006) and underweight women had significantly worse OS (p= 0.019). BMI was not predictive of therapeutic benefit. Conclusions: Obesity is an independent prognostic variable in colon cancer survivors and shows gender-related differences. These data suggest that obesity-related biological factors can influence clinical outcome. 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 904.

Abstract Introduction: Mammographic breast density is one of the strongest risk factors for breast cancer and appears to be modifiable. However, whether longitudinal changes in density are associated with breast cancer risk is unknown. We hypothesize that decreases in breast density are associated with reduced breast cancer risk. Methods: The Mayo Mammography Health Study cohort enrolled 19,924 women having a screening mammogram (mgm) at the Mayo Clinic, Rochester, between 2003 and 2006. Participants were 35 years and older, had no prior breast cancer and lived in the tri-state area (MN, IA and WI). Risk factor data were collected through self-administered questionnaire and clinic databases. Incident breast cancers were identified through tumor registries (Mayo Clinic, MN, IA, WI). The BI-RADS, 4-category clinical density measure (fatty, scattered density, heterogeneous density and extreme density) was available on all mgms performed after 1996. A case-cohort design consisting of incident cases (n=241) and a random selection of the cohort (n=2300, 28 developed cancer) was used to examine the association between change in BI-RADS density and breast cancer. BI-RADS densities measured from the earliest available, and enrollment mgms (average 6 years apart) were used to assess density change. Proportional hazards regression was performed to estimate the hazard ratio (HR) associated with a change in one or more BI-RADS density categories over time, relative to staying within the same category. Age was used as the time scale, and the subcohort was weighted by the inverse of the sampling proportion. Analyses were adjusted for age, years between mgms, BI-RADS density at earliest mgm, and changes in BMI, postmenopausal hormone use, and menopausal status. Results: Longitudinal analyses were conducted on the 219 cases and 1900 non-cases in the subcohort with at least one mgm available prior to enrollment mgm. Compared to the subcohort, cases were older (56.8 vs. 52.9 years), more likely postmenopausal (73.4% vs. 61.6%), had higher BMI (29.0 vs 28.1) and were more frequently screened (8.0 vs. 6.9 pre-enrollment mgms). As expected, cases were more likely to have extreme density (BI-RADS=4) at earliest mgm than non-cases (16.2% vs 14.3%). Cases were less likely than non-cases to experience a reduction of one density category or more (37.0% vs 38.6%) following earliest mgm. Adjusting for potential confounders, women who decreased one BI-RADS category or more over an average 6 years were at reduced risk of breast cancer (HR=0.72, 95%CI: 0.50-0.99) compared to those whose density was unchanged. However, women who increased one or more BI-RADS categories had suggestion of increased risk (HR=1.52, 95%CI: 0.97-2.4). Conclusion: Women with a decrease in BI-RADS density category over 6 years may have decreased breast cancer risk relative to women whose breast density category remains stable. Two measures of breast density may inform women's risk beyond a measure at one point in time. 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 4828.

Abstract The plasma cell malignancy Multiple Myeloma (MM) is a rare but deadly form of cancer with 5 year survival rates of ∼30%. The disease exacts an especially heavy burden on African American (AA) patients. In fact, African Americans are twice a likely to be diagnosed with and die from MM as compared to Caucasian Americans. Although socio-economic factors likely influence this disparity, the role of biology has not been ruled out. We have profiled ∼250 MM tumors for somatic copy number alterations using array-based Comparative Genomic Hybridization (aCGH) and Gene Expression Profiling as part of the Multiple Myeloma Genomics Initiative. To determine if somatic alterations may play a role in the disparity in incidence and/or severity of MM in AA, we compared the frequency of specific chromosomal aberrations in genes and genomic regions previously found to be involved in progression and poor outcome in MM among a cohort of one hundred ninety-six (196) patients including 16 African Americans and 180 Caucasians. The frequency of occurrence (expressed as a percentage) was determined for each of the following aberrations: 1p deletion, homozygous deletion of p18, chromosome 13 deletion, and chromosome 13 monosomy. No significant difference was detected in the frequency of chromosome 13 deletion and chromosome 13 monosomy between the two groups. However, significant differences were observed for chromosome 1p alterations. Homozygous deletion at the p18 locus at 1p occurred in 12.5% (2/16) of tumors from AA patients and 2.8% (5/180) of CA patient tumors (p = 0.045). We further stratified tumors by hyperdiploid or non-hyperdiploid status using a-CGH profiles to determine ploidy status. Most significantly, p18 homozygous deletion was found in 25% (2/8) of AA patients with non-hyperdiploid tumors and in only 1.2% (1/83) of CA patients with non-hyperdiploid tumors (p=3.2 × 10-4). A nominally significant difference among non-hyperdiploid patients was also present for overall 1p deletion, which was observed in 2/8 (25%) of AA non-hyperdiploid tumors and 33/83 (40%) of CA with non-hyperdiploid tumors (p=0.05). No differences were observed for 1p deletion or p18 homozygous deletion among hyperdiploid tumors between AA and CA patients. These results suggest that deletions at 1p are more common among African American MM patients. Furthermore, homozygous deletion encompassing the p18 locus is more significantly common among AA MM patients, especially AA patients with non-hyperdiploid tumors. As 1p deletion and p18 homozygous deletion have been linked to poor outcome, our results suggest that the increased frequency of these alterations in tumors from AA patients may in part explain the disparity in unfavorable outcomes seen among AA MM patients 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 4822.

Abstract In July, 2009 the United States’ Food and Drug Agency (FDA) approved the use of a new biologically-targeted drug called ‘cetuximab’ (Erbitux) for the treatment of patients with advanced colorectal cancer (CRC). Cetuximab is a chimeric antibody directed against the extracellular domain of the epidermal growth factor receptor (EGFR). Paradoxically, EGFR expression, as it is currently measured by commercially available assays, has not been useful for predicting who will respond to cetuximab. We propose that one problem with these assays is their inability to measure EGFR and soluble EGFR (sEGFR) isoforms independently. We previously have documented the expression of an sEGFR isoform in human tissues (1), and have generated antibodies directed against a 31-mer peptide (residues 604-634) located within the unique 78 amino acid carboxy-terminal sequence of sEGFR (2). Interestingly, this anti-sEGFR antibody recognizes a second protein of ∼140-kDa (p140), which we have identified as human α5-integrin. Biochemical and mass spectrometry analyses show that a short region in the calf domain of α5-integrin shares sequence identity with the 31-mer sEGFR peptide. We have used this 31-mer antibody with an antibody directed against the intracellular domain of full-length EGFR to develop a novel EGFR vs. sEGFR/α5-integrin expression assay. This assay demonstrates that sEGFR/α5-integrin is co-expressed with EGFR in normal as well as malignant tissues, including in a number of carcinoma-derived cell lines. We also observe that high expression of EGFR and sEGFR/α5-integrin in a large cohort of ovarian cancer patients defines a strong adverse prognostic determinant of survival. These results implicate EGFR, sEGFR, and integrins as cancer biomarkers and demonstrate the critical importance of independently assessing both full-length and soluble EGFR isoforms in prognostic EGFR expression assays. *–JAW and ATB contributed equally to this study (1). Reiter et al. (2001) Genomics. 71(1):1-20 (2). Christensen et al. (2002) Hybrid Hybridomics. 21(3):183-9 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 4649.

ABSTRACT Introduction Erectile dysfunction (ED) may be the most commonly observed adverse event (AE) associated with the combination of radiation therapy (RT) and androgen deprivation therapy (ADT). A significant number of men are trying phosphodiesterase type 5 inhibitors (PDE5s) such as sildenafil to treat ED, yet sildenafil studies to date shed little light on the response to ED after ADT. Aim The purpose of this trial was to evaluate sildenafil in the treatment of ED in prostate cancer patients previously treated with external beam RT and neoadjuvant and concurrent ADT. Methods In this randomized, double-blinded crossover trial, eligible patients received RT/ADT for intermediate risk prostate cancer and currently had ED as defined by the International Index of Erectile Function (IIEF). Patients were randomized to 12 weeks of sildenafil or placebo followed by 1 week of no treatment then 12 weeks of the alternative. Treatment differences were evaluated using a marginal model for binary crossover data. Main Outcome Measures The primary end point was improved erectile function, as measured by the IIEF. Results The study accrued 115 patients and 61 (55%) completed all three IIEF assessments. Sildenafil effect was significant (P = 0.009) with a difference in probabilities of erectile response of 0.17 (95% confidence interval: 0.06, 0.29), and 0.21 (0.06, 0.38) for patients receiving ≤120 days of ADT. However, as few as 21% of patients had a treatment-specific response, only improving during sildenafil but not during the placebo phase. Conclusions This is the first controlled trial to suggest a positive sildenafil response for ED treatment in patients previously treated with RT/ADT, however, only a minority of patients responded to treatment. ADT duration may be associated with response and requires further study. The overall low response rate suggests the need for study of additional or preventative strategies for ED after RT/ADT for prostate cancer.

AbstractGenome‐wide association studies (GWAS) are being conducted at an unprecedented rate in population‐based cohorts and have increased our understanding of the pathophysiology of complex disease. Regardless of context, the practical utility of this information will ultimately depend upon the quality of the original data. Quality control (QC) procedures for GWAS are computationally intensive, operationally challenging, and constantly evolving. Here we enumerate some of the challenges in QC of GWAS data and describe the approaches that the electronic MEdical Records and Genomics (eMERGE) network is using for quality assurance in GWAS data, thereby minimizing potential bias and error in GWAS results. We discuss common issues associated with QC of GWAS data, including data file formats, software packages for data manipulation and analysis, sex chromosome anomalies, sample identity, sample relatedness, population substructure, batch effects, and marker quality. We propose best practices and discuss areas of ongoing and future research. Curr. Protoc. Hum. Genet. 68:1.19.1‐1.19.18 © 2011 by John Wiley & Sons, Inc.

Abstract It is now widely accepted that a spectrum of somatic alterations occur in human cancer and that particular alterations are associated with response or lack of response to anti-cancer therapies. Here, we undertook a systematic correlation analysis of somatic mutations, copy number aberrations and drug response across 300+ human cancer cell lines. We studied the RAF and VEGFR inhibitor, sorafenib, evaluating associations between sorafenib response and somatic mutations in 35 common cancer genes and high-level amplifications and homozygous deletions in more than 100 minimal common regions of gain and loss, which include many known oncogenes and tumor suppressor genes. Notably, we found that NRAS mutations, among other alterations, were significantly associated with sensitivity to sorafenib (odds ratio = 7, p-value = 0.003), whereas activating BRAF mutations were strongly associated with a lack of response (odds ratio = 4.9, p-value = 0.012). Specifically, 64% (7 of 11) of NRAS mutant cell lines were sensitive to sorafenib, while only 20% (34 of 170) of NRAS wild-type lines were sensitive. On the contrary, just 6.7% (2 of 30) of BRAF mutant lines were sensitive to sorafenib. Because NRAS mutations occur frequently in leukemia and no leukemia cell lines were included in the original analysis, we selected 5 NRAS mutant and 5 NRAS wild-type leukemia cell lines for further evaluation. Consistent with our previous observation, the four most sensitive leukemia cell lines were all NRAS mutant, each line exhibiting greater than 50% growth inhibition after 72 hours of exposure to 4μM sorafenib. These results confirm the original association and suggest that across both solid tumors and hematologic malignancies, NRAS mutations may identify a subset of cancers that are likely to respond sorafenib. In addition, this work demonstrates that systematic analysis of somatic alterations and drug response across a large collection of cancer cell lines is capable of discovering novel predictive biomarkers. Citation Information: Clin Cancer Res 2010;16(7 Suppl):A41

Abstract Purpose: SR13668, an orally active AKT pathway inhibitor, has demonstrated cancer chemopreventive potential in preclinical studies. To accelerate the clinical development of this promising agent, we designed and conducted the first-ever phase 0 chemoprevention trial to evaluate and compare the effects of food and formulation on SR13668 bioavailability. Patients and Methods: Healthy adult volunteers were randomly assigned to receive a single 38-mg oral dose of SR13668 in one of five different formulations, with or without food. Based on existing animal data, SR13668 in a PEG400/Labrasol@ oral solution (formulation 1) was defined as the reference formulation. Four self-emulsifying solid dispersion test formulations in capsules were also investigated: Solutol@ HS 15 (formulation 2), Solutol@ HS 15/Vitamin E TGPS (50/50 w/w %) (formulation 3), Vitamin E TGPS (formulation 4), and Myrj 53 (formulation 5). SR163668 bioavailability was compared using a two-stage study design. In stage I, participants were randomized to receive the formulation 1 with or without a high-fat meal after an overnight fast. In Stage II, participants were randomly assigned to receive the test formulations, using the preferred dietary condition identified in stage I. Blood samples were obtained pre- and post-agent administration for pharmacokinetic analyses. Area under the plasma concentration-time curve (AUC) was defined as the primary endpoint. Data were analyzed and compared using established statistical methods for phase 0 trials with a limited sample size. Results: Participants (N=20) were rapidly accrued over a 5-month period. Complete pharmacokinetic data were available for 18 randomized participants. The time to peak plasma concentration and half-life values for SR13668 were 3 hours (range, 2 — 6 hours) and 11.2 ± 3.1 hours, respectively, and were not dependent on the formulation. In stage I, the oral bioavailability of SR13668 in formulation 1 was greater under the fed versus fasting dietary state (p = 0.05, Wilcoxon rank-sum test). Therefore, the fed state was selected as the preferred dietary condition for stage II. In stage II, the bioavailability of SR13668 for each of the test formulations were compared with the bioavailability of formulation 1 in the fed state. While not significantly different from formulation 1, formulation 2 AUC0-24h was significantly different (p = 0.004, ANOVA) from formulation 3, 4, and 5 (AUC0-24h, formulation 1- 222 ± 53 ng/ml·hr; AUC0-24h, formulation 2 — 302 ± 78 ng/ml·hr; AUC-177±39ng/ml·hr; AUC-144±29 0-24h, formulation30-24h, formulation 4 ng/ml·hr; AUC0-24h, formulation 5- 98 ± 21 ng/ml·hr). Formulation 1 AUC0-24h was almost 40% lower than the value achieved with formulation 2, and not significantly different from formulation 3, 4, and 5. Thus, formulation 2 provided the highest bioavailability of SR13668. Conclusions: Using a novel, highly efficient study design, we rapidly identified a lead formulation (Solutol@ HS 15) of SR13668 for further clinical testing. Our findings support application of the phase 0 trial paradigm to accelerate chemoprevention agent development. Supported by NIH grants N01-CN-35000, CA15083-34C3 and UL1 RR024150. Citation Information: Cancer Prev Res 2010;3(12 Suppl):CN02-03.

Abstract Background: Epithelial proliferation in benign breast disease (BBD) is a well-established biomarker of breast cancer risk, and BBD tissues can be used as a platform to assess other biomarkers for breast cancer risk. Lobular involution (the degree of age-related atrophy in lobules) is a new biomarker, with greater degrees of involution associated with lower breast cancer risk. Successful application of tissue biomarkers of risk to breast tissues from normal women would be valuable for risk prediction in the general population. We hypothesized that normal breast tissue samples would differ from BBD tissues in these histologic features of breast cancer risk, with less epithelial proliferation but a similar degree of involution compared to BBD tissues. Methods: Core biopsy samples from the Mayo Benign Breast Disease Cohort Study were compared to core biopsy samples of normal breast tissue obtained from the Susan G. Komen for the Cure Tissue Bank at IU Simon Cancer Center (KTB), a unique resource of breast tissue from donor women without any known breast abnormalities. All core biopsies were assessed histologically by a single breast pathologist for degree of epithelial proliferation (classified as non-proliferative, proliferative without atypia, or atypical hyperplasia) and extent of lobular involution (classified as none, 1-24%, 25-74%, or >75% of lobules). Data were analyzed using chi-square tests and logistic regression. Results: Overall, 318 Mayo BBD and 303 normal (KTB) core breast biopsy samples were evaluated. As anticipated, significantly less epithelial proliferation was present in normal samples compared to BBD samples. Proliferative disease occurred in 9/303 (3%) of normals versus 79/318 (25%) of BBD, and atypical hyperplasia was seen in 2/303 (0.7%) of normal samples versus 24/318 (8%) of BBD core biopsies, p < 0.0001. This difference remained significant after adjusting for age (which was greater overall in the BBD samples). Complete involution was more frequent in normal compared to BBD tissues, although the difference did not reach statistical significance. The age-adjusted odds ratio of complete involution in normal versus BBD tissues was 1.46 (95% CI 0.98-2.17, p = 0.06), suggesting a possible delay or failure of involution in women with BBD. Conclusions: Histologic features of normal breast tissues are different from those of BBD tissues, with less epithelial proliferation and more lobular involution, consistent with a lower risk of breast cancer expected for women with normal breast tissue compared to those with benign breast disease. Normal breast tissues are a valuable and distinct resource that should be considered for biomarker validation studies. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B23.