A west African ancestry-associated SNP on 8q24 predicts a positive biopsy in African American men with suspected prostate cancer following PSA screening

BACKGROUND

African American (AA) men have the highest incidence and mortality rates of prostate cancer (PCa) among all racial groups in the United States. While race is a social construct, for AA men, this overlaps with west African ancestry. Many of the PCa susceptibility variants exhibit distinct allele frequencies and risk estimates across different races and contribute substantially to the large disparities of PCa incidence among races. We previously reported that a single-nucleotide polymorphism (SNP) in 8q24, rs7824364, was strongly associated with west African ancestry and increased risks of PCa in both AA and Puerto Rican men. In this study, we determined whether this SNP can predict biopsy positivity and detection of clinically significant disease (Gleason score [GS] ≥ 7) in a cohort of AA men with suspected PCa.

METHODS

SNP rs7824364 was genotyped in 199 AA men with elevated total prostate-specific antigen (PSA) (>2.5 ng/mL) or abnormal digital rectal exam (DRE) and the associations of different genotypes with biopsy positivity and clinically significant disease were analyzed.

RESULTS

The variant allele carriers were significantly over-represented in the biopsy-positive group compared to the biopsy-negative group (44% vs. 25.7%, p = 0.011). In the multivariate logistic regression analyses, variant allele carriers were at a more than a twofold increased risk of a positive biopsy (odds ratio [OR] = 2.14, 95% confidence interval [CI] = 1.06-4.32). Moreover, the variant allele was a predictor (OR = 2.26, 95% CI = 1.06-4.84) of a positive biopsy in the subgroup of patients with PSA < 10 ng/mL and normal DRE. The variant allele carriers were also more prevalent in cases with GS ≥ 7 compared to cases with GS < 7 and benign biopsy.

CONCLUSIONS

This study demonstrated that the west African ancestry-specific SNP rs7824364 on 8q24 independently predicted a positive prostate biopsy in AA men who were candidates for prostate biopsy subsequent to PCa screening.

A genome-wide association study of prostate cancer in Latinos

Latinos represent <1% of samples analyzed to date in genome‐wide association studies of cancer. The clinical value of genetic information in guiding personalized medicine in populations of non‐European ancestry will require additional discovery and risk locus characterization efforts across populations. In the present study, we performed a GWAS of prostate cancer (PrCa) in 2,820 Latino PrCa cases and 5,293 controls to search for novel PrCa risk loci and to examine the generalizability of known PrCa risk loci in Latino men. We also conducted a genetic admixture‐mapping scan to identify PrCa risk alleles associated with local ancestry. Genome‐wide significant associations were observed with 84 variants all located at the known PrCa risk regions at 8q24 (128.484–128.548) and 10q11.22 (MSMB gene). In admixture mapping, we observed genome‐wide significant associations with local African ancestry at 8q24. Of the 162 established PrCa risk variants that are common in Latino men, 135 (83.3%) had effects that were directionally consistent as previously reported, among which 55 (34.0%) were statistically significant with p < 0.05. A polygenic risk model of the known PrCa risk variants showed that, compared to men with average risk (25th–75th percentile of the polygenic risk score distribution), men in the top 10% had a 3.19‐fold (95% CI: 2.65, 3.84) increased PrCa risk. In conclusion, we found that the known PrCa risk variants can effectively stratify PrCa risk in Latino men. Larger studies in Latino populations will be required to discover and characterize genetic risk variants for PrCa and improve risk stratification for this population.

What's new?

There is strong evidence for a genetic predisposition to prostate cancer (PrCa). Most of this information has come from European ancestry populations, with Latinos representing less than 1% of samples in cancer genome‐wide association studies (GWAS). In this study, the majority of established PrCa risk variants (83.3%) were consistently associated with PrCa risk in Latinos. A polygenic risk score comprised of GWAS‐identified risk variants could identify 10% of Latino men with a ~three‐fold increase in PrCa risk. These findings suggest that common germline variants for PrCa can stratify risk in Latino men, which has implications for targeted screening and prevention.

Abstract 227: Germline variation at 8q24 and prostate cancer risk in men of European ancestry

We performed an in-depth and well-powered investigation of genetic variation across the cancer susceptibility region at chromosome 8q24 (127.6-129.0 Mb) to search for novel risk variants associated with prostate cancer (PCa) risk in the European ancestry population. We combined genotyped and imputed data from the PRACTICAL/ELLIPSE OncoArray and iCOGS consortia consisting of 71,535 PrCa cases and 52,935 controls of European ancestry. Variants with high imputation quality score (&gt;0.8) were retained for a total of 5,600 overlapping variants between the two datasets. Associations of genetic variants with PCa risk were evaluated using unconditional logistic regression with adjustment for country and ten principal components. The marginal risk estimates for the 5,600 variants that passed quality control were combined by a fixed effects meta-analysis. A meta-stepwise selection was performed on variants marginally associated with PCa risk from the meta results (P&lt;0.05). A polygenic risk score and the contribution to the familial relative risk of PCa were estimated for variants from the final model. Of the 5,600 variants at 8q24 retained for analysis, 1,268 (23%) were associated with PCa risk at P&lt;5x10-8 while 2,772 (49%) were marginally associated at P&lt;0.05. In the stepwise model, 12 variants remained statistically significantly associated with PCa risk with conditional meta p-values between 2.93x10-137 and 4.28x10-15. The independent stepwise signals were confirmed by Joint Analysis of Marginal (JAM) summary statistics, which defined the credible sets of variants driving those signals. Three of the variants (rs1914295, rs190257175, rs12549761) were weakly correlated (r2≤0.17) with any known PCa risk marker, and may define novel association signals. Men in the top 1% of the polygenic risk score distribution had a 3.97-fold relative risk (95%CI=3.87-4.07) compared to men with "average risk" (25th-75th percentiles). The 12 independent signals at 8q24 capture 11.54% (95%CI=9.86-13.65) of the familial relative risk of PCa, which is approximately one quarter of the total PCa familial relative risk explained by known genetic risk factors. Most of the independently associated signals have good evidence for biologic functionality; in particular, many reside within putative transcriptional enhancers and/or binding sites for AR and FOXA1 transcription factors in prostate cell lines. In summary, we defined 12 independent association signals among men of European ancestry, with three of the risk variants representing putative novel association signals. Whereas the individual associations of these variants with PCa risk are relatively modest (ORs&lt;2.0), their cumulative effects are substantial, and their contribution to the overall familial relative risk of PCa is substantially greater than any other known prostate cancer risk locus.

Citation Format: Marco Matejcic, Edward J. Saunders, Tokhir Dadaev, Mark Brook, Ali Amin Al Olama, Fredrick R. Schumacher, Sonja I. Berndt, Sara Benlloch, Kenneth Muir, Koveela Govindasami, Victoria L. Stevens, Susan M. Gapstur, Catherine M. Tangen, Jyotsna Batra, Judith Clements, APCB (Australian Prostate Cancer Bio Resource), Henrik Gronberg, Nora Pashayan, Johanna Schleutker, Demetrius Albanes, Alicja Wolk, Catharine West, Lorelei Mucci, Peter Kraft, Géraldine Cancel-Tassin, Stella Koutros, Karina Dalsgaard Sorensen, Lovise Maehle, Eli Marie Grindedal, Sara Strom, David E. Neal, Freddie C. Hamdy, Jenny L. Donovan, Ruth C. Travis, Robert J. Hamilton, Sue Ann Ingles, Barry Rosenstein, Yong-Jie Lu, Graham G. Giles, Adam S. Kibel, Ana Vega, Jeanette Bensen, Manolis Kogevinas, Fredrik Wiklund, Stephen Chanock, Douglas F. Easton, Rosalind A. Eeles, Zsofia Kote-Jarai, David V. Conti, Christopher A. Haiman. Germline variation at 8q24 and prostate cancer risk in men of European ancestry [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 227.

Prostate-specific antigen velocity in a prospective prostate cancer screening study of men with genetic predisposition

This corrects the article DOI: 10.1038/bjc.2017.429.

Prostate-specific antigen velocity in a prospective prostate cancer screening study of men with genetic predisposition

BACKGROUND

Prostate-specific antigen (PSA) and PSA-velocity (PSAV) have been used to identify men at risk of prostate cancer (PrCa). The IMPACT study is evaluating PSA screening in men with a known genetic predisposition to PrCa due to BRCA1/2 mutations. This analysis evaluates the utility of PSA and PSAV for identifying PrCa and high-grade disease in this cohort.

METHODS

PSAV was calculated using logistic regression to determine if PSA or PSAV predicted the result of prostate biopsy (PB) in men with elevated PSA values. Cox regression was used to determine whether PSA or PSAV predicted PSA elevation in men with low PSAs. Interaction terms were included in the models to determine whether BRCA status influenced the predictiveness of PSA or PSAV.

RESULTS

1634 participants had ⩾3 PSA readings of whom 174 underwent PB and 45 PrCas diagnosed. In men with PSA >3.0 ng ml-l, PSAV was not significantly associated with presence of cancer or high-grade disease. PSAV did not add to PSA for predicting time to an elevated PSA. When comparing BRCA1/2 carriers to non-carriers, we found a significant interaction between BRCA status and last PSA before biopsy (P=0.031) and BRCA2 status and PSAV (P=0.024). However, PSAV was not predictive of biopsy outcome in BRCA2 carriers.

CONCLUSIONS

PSA is more strongly predictive of PrCa in BRCA carriers than non-carriers. We did not find evidence that PSAV aids decision-making for BRCA carriers over absolute PSA value alone.

Abstract 1303: A genome-wide association study of prostate cancer in Latinos

Recent studies estimate that individuals of African or Latin American ancestry represent less than 4% of samples analyzed to date in genome-wide association studies. The clinical value of genetic information in guiding personalized medicine in populations of non-European ancestry will require additional discovery and risk locus characterization efforts in these populations. Here, we performed a genome-wide association study (GWAS) meta-analysis of prostate cancer in Latino men to search for risk loci that may be important in this population. We combined GWAS data for 1034 cases and 1046 controls genotyped with the Illumina 660 Beadarray with GWAS data for 1235 cases and 1053 controls genotyped with the Illumina Oncoarray as part of the ELLIPSE U19 GAME-ON Consortium. A total of ~11 million genotyped and imputed SNPs of ≥1% frequency were tested for association with prostate cancer risk in logistic regression models controlling for age, study and genetic ancestry. Genome-wide significant associations were observed with 24 variants all located at 8q24 (128.484-128.548), and which capture the first reported prostate cancer susceptibility locus in ‘region 1’ of 8q24. The most significant association genome-wide was with SNP rs7824776 (risk allele frequency, 0.35; OR=1.69, p=3.4x10-11). No novel genome-wide significant associations were noted outside of 8q24. We observed a high degree of generalizability of known prostate cancer risk loci, with 78 (76%) of the 103 known risk variants having effects that were directionally consistent in their association with prostate cancer risk as previously reported, of which 31 (30%) were statistically significant with p &lt; 0.05. In addition to these findings from the largest GWAS of prostate cancer in Latinos conducted to date, we will also present the results investigating effect heterogeneity by local ancestry (i.e. proportion Native American vs. European). In addition, we will present a comparison of polygenic risk models between Latinos, African Africans and men of European ancestry that incorporate the known risk loci to better understand how genetic risk tracks with population differences in prostate cancer incidence.

Citation Format: Hannah Hopp, Sue Ingles, Chad Huff, Xin Sheng, Brandi Weaver, Mariana Stern, Sara Strom, Ian Thompson, David Conti, Christopher A. Haiman. A genome-wide association study of prostate cancer in Latinos [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1303. doi:10.1158/1538-7445.AM2017-1303

Cohort Profile: The Mexican American Mano a Mano Cohort

Hispanic Americans comprise the largest and fastest-growing ethnic minority in the USA. In Houston, Texas, 44% of the population is of Hispanic descent, with the majority being Mexican Americans (78%). This population is under-represented in health-related research despite their high prevalence of obesity and diabetes, which may predispose them to cancer and other chronic conditions. Recognizing the need for a greater research effort into the health risks of Hispanic Americans, the population-based Mexican American (Mano a Mano) Cohort study was launched in 2001. This is an open cohort with enrolment ongoing to 2019, and as of 30 June 2014, 23 606 adult participants from over 16 600 households were enrolled. Bilingual interviewers elicit information in person on demographics, acculturation, lifestyle, occupation, medical history, family cancer history, self-reported and measured height and weight, and other exposures. Urine, blood and saliva samples have been collected at baseline from 43%, 56% and 63% of participants, respectively. DNA samples are available for about 90% of participants. Incident cancers and other chronic diseases are ascertained through annual telephone re-contact and linkage to the Texas Cancer Registry and/or medical records. Molecular data such as genetic ancestry markers, blood telomere length and HbA1c, a marker of impaired glucose tolerance, are available for a substantial proportion of the participants. Data access is provided on request [manoamano@mdanderson.org]. For further information please visit [www.mano-mano.us].

Low serum testosterone is associated with tumor aggressiveness and poor prognosis in prostate cancer

Serum testosterone is a potential marker to distinguish between indolent and aggressive prostate cancer (PCa). The present study aimed to investigate whether low levels of total serum testosterone at diagnosis were associated with aggressive PCa and poor clinical outcomes. In total, 762 non-Hispanic Caucasian men with previously untreated PCa were recruited from The University of Texas MD Anderson Cancer Center (Houston, TX, USA). Patients were categorized into three groups based on their total serum testosterone levels according to clinical guidelines [low (<230 ng/dl), intermediate (230-350 ng/dl) and normal (>350 ng/dl)]. PCa aggressiveness (low-, intermediate- or high-risk, or metastatic) was compared using multinomial logistic regression. Rates of disease progression, mortality from any cause and PCa-specific mortality were compared using the multivariate Cox proportional hazards model. Testosterone levels significantly decreased as PCa aggressiveness increased (P<0.001). Compared with the normal testosterone group, the low testosterone group had 2.9-fold (OR, 2.92; 95% CI, 1.74-4.90; P<0.001), 5.6-fold (OR, 5.63; 95% CI, 3.14-10.12; P<0.001) and 72.4-fold (OR, 72.40; 95% CI, 20.89-250.89; P<0.001) increased risks of having intermediate-risk, high-risk and metastatic PCa, respectively. Furthermore, low levels of testosterone were significantly associated with a 10.7-fold (HR, 10.68; 95% CI, 1.35-84.44; P=0.03) increased risk of PCa-specific mortality. The results of the present study indicate that low levels of total serum testosterone at diagnosis are associated with aggressive PCa and predict poor PCa-specific survival.

De Novo Donor-Specific HLA Antibody Formation in Two Patients With Crigler-Najjar Syndrome Type I Following Human Hepatocyte Transplantation With Partial Hepatectomy Preconditioning

Clinical hepatocyte transplantation is hampered by low engraftment rates and gradual loss of function resulting in incomplete correction of the underlying disease. Preconditioning with partial hepatectomy improves engraftment in animal studies. Our aim was to study safety and efficacy of partial hepatectomy preconditioning in clinical hepatocyte transplantation. Two patients with Crigler-Najjar syndrome type I underwent liver resection followed by hepatocyte transplantation. A transient increase of hepatocyte growth factor was seen, suggesting that this procedure provides a regenerative stimulus. Serum bilirubin was decreased by 50%, and presence of bilirubin glucuronides in bile confirmed graft function in both cases; however, graft function was lost due to discontinuation of immunosuppressive therapy in one patient. In the other patient, serum bilirubin gradually increased to pretransplant concentrations after ≈600 days. In both cases, loss of graft function was temporally associated with emergence of human leukocyte antigen donor-specific antibodies (DSAs). In conclusion, partial hepatectomy in combination with hepatocyte transplantation was safe and induced a robust release of hepatocyte growth factor, but its efficacy on hepatocyte engraftment needs to be evaluated with additional studies. To our knowledge, this study provides the first description of de novo DSAs after hepatocyte transplantation associated with graft loss.

Incidence and prognostic impact of other cancers in a population of long-term survivors of chronic lymphocytic leukemia

BACKGROUND

Information on the impact of other cancers (OCs) in long-term survivors (LTSs) of chronic lymphocytic leukemia (CLL) is limited.

PATIENTS AND METHODS

Patients with CLL who survived >10 years were defined as LTSs of CLL. We calculated standardized incidence ratios (SIRs) to compare the incidence of OC in LTS of CLL versus the general population. A multivariable model was used to identify independent predictors of OC. Overall survival was analyzed as a function of the presence of OC.

RESULTS

Among 797 LTSs of CLL, the cumulative frequency of OC was 36%, similar between 570 patients (72%) who required treatment for CLL (TRT) and 227 (28%) who remained untreated (UT). The most common OC in both groups was non-melanoma skin cancer, followed by prostate cancer, breast cancer, melanoma, lung cancer, and leukemia in TRT patients, and by prostate cancer, breast cancer, melanoma, lung cancer, and gastrointestinal tumors in the UT group. The SIR for all OC was 1.2 (P = 0.034). It was higher in males (SIR 1.31; P = 0.013) and patients <60 years (SIR 1.27; P = 0.027). A higher SIR was shown for secondary leukemia, melanoma, and head-and-neck cancers, whereas a lower SIR was found for gastrointestinal and bladder cancers. Independent predictors of OC development were advanced age, male gender, and lower platelets. The survival of patients with OC was 16.2 months and that of patients without OC 22.9 years.

CONCLUSIONS

LTSs of CLL have an increased incidence of OC compared with the general population. CLL therapy is not a risk factor for OC in LTSs of CLL. The presence of an OC in these patients may be associated with shorter survival.

Abstract B14: Dietary patterns in Puerto Rican and Mexican-American breast cancer survivors: A pilot study

Breast cancer survivors comprise the largest group of cancer survivors in the US, with an estimated 2.8 million survivors. Breast cancer is the leading cause of cancer death among Hispanics, with greater mortality rates compared to non-Hispanic whites. Certain dietary factors have been associated with a decreased or increased risk of breast cancer recurrence; therefore, it is important to characterize the dietary patterns of the target population to develop effective dietary intervention prevention strategies.

Objective: to examine the dietary patterns in two groups of Hispanic breast cancer survivors.

Methods: Participants included Mexican American (MA) and Puerto Rican (PR) female breast cancer survivors, who participated in Project VIVA!, a randomized controlled trial to pilot test the effectiveness and feasibility of a 16-week culturally tailored exercise intervention. At the end of the trial, participants completed a culturally adapted and validated food frequency questionnaire. Daily dietary intake values were standardized for total energy (per 1,000 kcal) and compared to US Dietary Guidelines (1 cup/d fruits, 1 cup/d vegetables, ½ cup/wk beans, 2 cups/wk starchy vegetables, 2 cups/d dairy products, 50% of grains as whole grains, 12 g/d of added fat).

Results: A total of 23 MA and 22 PR completed the FFQ. Mean age was 49±10 y in MA and 59±9 y in PR (p&lt;0.05). Most women were overweight or obese (65% in MA and 91% in PR; p&gt;0.05). Daily intake of fruits/100% fruit juices was 2.8 cups in MA and 1.2 cups in PR daily (p&gt;0.05), which is higher than guidelines. Vegetable intake was higher in MA (2.6 cups) compared to PR (0.8 cups; p&lt;0.05), and only MA met the guidelines. Intake of starchy vegetables (e.g., potatoes) was higher in PR than MA (0.6 vs. 0.4 cups, respectively; p&lt;0.001) and it was higher than guidelines. Intake of beans was similar between groups (0.46 cups in MA and 0.44 cups in PR). Intake of whole grains was higher in MA (0.54 oz) than in PR (0.23 oz) and dairy products intake was higher in PR (1.2 cups) than in MA (0.7 cups; p&lt;0.001), but both were below the guidelines. Estimated contribution of calories from solid fats and added sugars (SoFAs) was 30% in PR and 32% in MA, which is higher than guidelines (14%). Added sugar was higher in PR (9.2 tsp) compared to MA (5.2 tsp; p&lt;0.01).

Conclusion: PR met the recommendations for fruits, starchy vegetables, and beans while MA met the recommendations for fruits, vegetables, starchy vegetables and beans. Both groups had intakes below the recommendations for whole grains and dairy products but above for SoFAS. MA and PR female breast cancer survivors have different dietary patterns, but could benefit from similar targeted interventions to reduce consumption of SoFAS, and to increase the proportion of whole grains consumed. Larger studies are needed to confirm these results but these preliminary results could help design interventions specifically targeted to each group to improve diet quality, which could potentially prevent cancer recurrence in this group.

This project was partially supported by the following NIH awards U54 CA 96297; P30 CA016672; NCR (2G12-RR003051), NIMHHD (8G12-MD007600), and the Center for Energy Balance in Cancer Prevention and Survivorship, Duncan Family Institute.

Citation Format: Cristina Palacios, Carrie R. Daniel, Maribel Tirado-Gómez, Velda Gonzalez-Mercado, Liliana Liliana, Jose Lozada, Daniel C. Hughes, Sara Strom, Karen Basen-Engquist. Dietary patterns in Puerto Rican and Mexican-American breast cancer survivors: A pilot study. [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr B14.

The prostate cancer susceptibility variant rs2735839 near KLK3 gene is associated with aggressive prostate cancer and can stratify gleason score 7 patients

PURPOSE

Gleason score (GS) 7 prostate cancer is a heterogeneous disease with different clinical behavior. We sought to identify genetic biomarkers that may predict the aggressiveness of GS 7 diseases.

EXPERIMENTAL DESIGN

We genotyped 72 prostate cancer susceptibility SNPs identified in genome-wide association studies in 1,827 white men with histologically confirmed prostate adenocarcinoma. SNPs associated with disease aggressiveness were identified by comparing high-aggressive (GS ≥8) and low-aggressive (GS ≤6) cases. The significant SNPs were then tested to see whether they could further stratify GS 7 prostate cancer.

RESULTS

Three SNPs-rs2735839, rs10486567, and rs103294-were associated with biopsy-proven high-aggressive (GS ≥8) prostate cancer (P < 0.05). Furthermore, the frequency of the variant allele (A) at rs2735839 was significantly higher in patients with biopsy-proven GS 4+3 disease than in those with GS 3 + 4 disease (P = 0.003). In multivariate logistic regression analysis, patients carrying the A allele at rs2735839 exhibited a 1.85-fold (95% confidence interval, 1.31-2.61) increased risk of being GS 4 + 3 compared with those with GS 3 + 4. The rs2735839 is located 600 base pair downstream of the KLK3 gene (encoding PSA) on 19q13.33 and has been shown to modulate PSA level, providing strong biologic plausibility for its association with prostate cancer aggressiveness.

CONCLUSIONS

We confirmed the association of the rs2735839 with high-aggressive prostate cancer (GS ≥8). Moreover, we reported for the first time that rs2735839 can stratify GS 7 patients, which would be clinically important for more accurately assessing the clinical behavior of the intermediate-grade prostate cancer and for tailoring personalized treatment and posttreatment management.

Perception of tobacco use prevention and cessation among faculty members in Latin American and Caribbean dental schools

Rates of tobacco use are increasing in the regions of Latin America and the Caribbean (LAC). Unfortunately, tobacco cessation education is not a standard component of the dental curriculum in LAC dental schools. The objective of this study was to identify the perceptions of LAC dental faculty members regarding the tobacco use prevention and cessation (TUPAC) competencies that should be addressed in the dental curricula. Dental deans and faculty completed a web-based questionnaire in Spanish, Portuguese, French, or English. The questionnaire contained 32 competencies grouped into the five A's (Ask, Advise, Assess, Assist, and Arrange) of tobacco cessation and six supplementary questions for identifying barriers to providing TUPAC education to dental students. Respondents indicated the degree to which they believed each competency should be incorporated into the dental curricula using a five-point Likert scale ("1" = strongly disagree to "5" = strongly agree). Responses were obtained from 390 faculty members (66 % South America, 18 % Mexico/Central America, 16 % the Caribbean). Of the respondents, 2, 12, and 83 % reported that smoking was allowed in clinical environments, other indoor environments, and outdoor environments of their dental schools, respectively. Mean importance ratings for each of the competencies were as follows: Ask (4.71), Advise (4.54), Assess (4.41), Assist (4.07), and Arrange (4.01). Overall, LAC dental educators agree that TUPAC training should be incorporated into the dental curricula. Assist and Arrange competencies were rated lower, relative to other competencies. Tobacco use among dental educators and high rates of on-campus smoking could potentially pose barriers to promoting cessation interventions in the LAC dental schools.

Abstract 5038: Telomere length linking social contexts and cancer risk in Mexican Americans

Social contexts have a strong impact on chronic disease risk, including cancer, but how these influences “get under the skin” remains unclear. We hypothesize that telomere length may serve as the molecular link between social contexts and cancer risk. Using quantitative real-time PCR, we measured relative telomere length (TL) on baseline whole blood DNA samples collected from 6,574 participants of the ongoing Mano-a-Mano Mexican American Cohort study. We found that TL decreased linearly with increasing age (P-trend&lt;0.001). In multivariable-adjusted Cox proportional-hazard regression models, longer TL was directly associated with a 2.66-fold increased risk of all-cancer incidence (95% CI= 1.40-5.03). TL was positively associated with several acculturation-related variables. For example, participants with a higher acculturative score with greater stays in the US had a longer TL among participants older than the median age of 38 (P=0.05 and 0.04, respectively). Participants born in the US and with at least a high school education were also more likely to have a longer TL. Among the modifiable risk factors, TL was inversely associated with sedentary or sitting time among women (P=0.01) and among young participants (P=0.01). In other chronic diseases, we found that longer TL was associated with diabetes and gallbladder disease in older participants (P=0.04 and 0.01, respectively). Our results suggest that TL may mediate the relationship between acculturation and related risk factors such as physical inactivity, education, and cancer risk among Mexican Americans. This is our first step in a continuum of research focused on understanding how social and behavioral disparities influence biological pathways in cancer development.

Citation Format: Lixia Han, Hua Zhao, Sara Strom, Carrie R. Daniel, David Chang, Hui Zhang, Yuanqing Ye, Jian Gu, Wong-Ho Chow, Xifeng Wu. Telomere length linking social contexts and cancer risk in Mexican Americans. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5038. doi:10.1158/1538-7445.AM2014-5038

Targeted prostate cancer screening in BRCA1 and BRCA2 mutation carriers: results from the initial screening round of the IMPACT study

BACKGROUND

Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls) is an international consortium of 62 centres in 20 countries evaluating the use of targeted PCa screening in men with BRCA1/2 mutations.

OBJECTIVE

To report the first year's screening results for all men at enrollment in the study.

DESIGN, SETTING AND PARTICIPANTS

We recruited men aged 40-69 yr with germline BRCA1/2 mutations and a control group of men who have tested negative for a pathogenic BRCA1 or BRCA2 mutation known to be present in their families. All men underwent prostate-specific antigen (PSA) testing at enrollment, and those men with PSA >3 ng/ml were offered prostate biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

PSA levels, PCa incidence, and tumour characteristics were evaluated. The Fisher exact test was used to compare the number of PCa cases among groups and the differences among disease types.

RESULTS AND LIMITATIONS

We recruited 2481 men (791 BRCA1 carriers, 531 BRCA1 controls; 731 BRCA2 carriers, 428 BRCA2 controls). A total of 199 men (8%) presented with PSA >3.0 ng/ml, 162 biopsies were performed, and 59 PCas were diagnosed (18 BRCA1 carriers, 10 BRCA1 controls; 24 BRCA2 carriers, 7 BRCA2 controls); 66% of the tumours were classified as intermediate- or high-risk disease. The positive predictive value (PPV) for biopsy using a PSA threshold of 3.0 ng/ml in BRCA2 mutation carriers was 48%-double the PPV reported in population screening studies. A significant difference in detecting intermediate- or high-risk disease was observed in BRCA2 carriers. Ninety-five percent of the men were white, thus the results cannot be generalised to all ethnic groups.

CONCLUSIONS

The IMPACT screening network will be useful for targeted PCa screening studies in men with germline genetic risk variants as they are discovered. These preliminary results support the use of targeted PSA screening based on BRCA genotype and show that this screening yields a high proportion of aggressive disease.

PATIENT SUMMARY

In this report, we demonstrate that germline genetic markers can be used to identify men at higher risk of prostate cancer. Targeting screening at these men resulted in the identification of tumours that were more likely to require treatment.

Clinical characteristics, response to therapy, and survival of African American patients diagnosed with chronic lymphocytic leukemia: joint experience of the MD Anderson Cancer Center and Duke University Medical Center

BACKGROUND

Little is known regarding racial disparities in characteristics and outcomes among patients with chronic lymphocytic leukemia (CLL).

METHODS

The characteristics and outcomes of untreated African American (AA) patients with CLL (n = 84) were analyzed and compared with a reference nonblack (NB) patient population (n = 1571).

RESULTS

At the time of presentation, AA patients had lower median hemoglobin levels (12.9 g/dL vs 13.7 g/dL), higher β2 microglobulin levels (2.7 mg/dL vs 2.4 mg/dL), greater frequency of constitutional symptoms (27% vs 10%), unmutated immunoglobulin heavy-chain variable region (IGHV) mutation status (65% vs 47%), ζ-chain-associated protein kinase 70 (ZAP70) expression (58% vs 32%), and deletion of chromosome 17p or chromosome 11q (28% vs 17%; P ≤ 02 for each comparison). Fifty-one percent of AA patients and 39% of NB patients required first-line therapy and 91% and 88%, respectively, received chemoimmunotherapy. Overall response rates to treatment were 85% for AA patients and 94% for NB patients (P = .06); and the complete response rates were 56% and 58%, respectively (P = .87). The median survival of AA patients was shorter compared with that of NB patients (event-free survival: 36 months vs 61 months; P = .007; overall survival: 152 months vs not reached; P = .0001). AA race was an independent predictor of shorter event-free and overall survival in multivariable regression models.

CONCLUSIONS

The current results indicated that AA patients with CLL have more unfavorable prognostic characteristics and shorter survival compared with their NB counterparts.

Global patterns of prostate cancer incidence, aggressiveness, and mortality in men of african descent

Prostate cancer (CaP) is the leading cancer among men of African descent in the USA, Caribbean, and Sub-Saharan Africa (SSA). The estimated number of CaP deaths in SSA during 2008 was more than five times that among African Americans and is expected to double in Africa by 2030. We summarize publicly available CaP data and collected data from the men of African descent and Carcinoma of the Prostate (MADCaP) Consortium and the African Caribbean Cancer Consortium (AC3) to evaluate CaP incidence and mortality in men of African descent worldwide. CaP incidence and mortality are highest in men of African descent in the USA and the Caribbean. Tumor stage and grade were highest in SSA. We report a higher proportion of T1 stage prostate tumors in countries with greater percent gross domestic product spent on health care and physicians per 100,000 persons. We also observed that regions with a higher proportion of advanced tumors reported lower mortality rates. This finding suggests that CaP is underdiagnosed and/or underreported in SSA men. Nonetheless, CaP incidence and mortality represent a significant public health problem in men of African descent around the world.

Dietary energy balance modulates prostate cancer progression in Hi-Myc mice

Male Hi-Myc mice were placed on three dietary regimens [30% calorie restriction (CR), overweight control (modified AIN76A with 10 kcal% fat), and a diet-induced obesity regimen (DIO) 60 kcal% fat]. All diet groups had approximately similar incidence of hyperplasia and low-grade prostatic intraepithelial neoplasia in the ventral prostate at 3 and 6 months of age. However, 30% CR significantly reduced the incidence of in situ adenocarcinomas at 3 months compared with the DIO group and at 6 months compared with both the overweight control and DIO groups. Furthermore, the DIO regimen significantly increased the incidence of adenocarcinoma with aggressive stromal invasion, as compared with the overweight control group (96% vs. 65%, respectively; P = 0.02) at the 6-month time point. In addition, at both 3 and 6 months, only in situ carcinomas were observed in mice maintained on the 30% CR diet. Relative to overweight control, DIO increased whereas 30% CR reduced activation of Akt, mTORC1, STAT3, and NFκB (p65) in ventral prostate. DIO also significantly increased (and 30% CR decreased) numbers of T-lymphocytes and macrophages in the ventral prostate compared with overweight control. The mRNA levels for interleukin (IL) 1α, IL1β, IL6, IL7, IL23, IL27, NFκB1 (p50), TNFα, and VEGF family members were significantly increased in the ventral prostate of the DIO group compared with both the overweight control and 30% CR diet groups. Collectively, these findings suggest that enhanced growth factor (Akt/mTORC1 and STAT3) and inflammatory (NFκB and cytokines) signaling may play a role in dietary energy balance effects on prostate cancer progression in Hi-Myc mice.

Abstract B94: Relationship of overweight and diabetes with prostate cancer stages in Mexican Americans: A population-based case-control study

Objective: Hispanics have lower incidence and mortality rates of prostate cancer (PCa) than non-Hispanics whites; however, they are more likely to be diagnosed with and die from advanced stage PCa. Obesity (BMI ≥ 30 kg/m2) is positively associated with high-grade and advanced stage disease and mortality while the inverse is true for diabetes. Compared to non-Hispanic whites (NHW), little is known about the association of overweight (BMI ≥ 25 kg/m2), obesity, diabetes, and their simultaneous presence with different stages of PCa in Hispanics. The role of these independent factors and their simultaneous presence on PCa in Mexican-Americans warrants a detailed investigation as this population has a higher prevalence of overweight, physician-diagnosed diabetes, and overweight adults with diagnosed diabetes than NHW's. This understudied population is one of the fastest growing ethnic populations in the US. To the best of our knowledge, there are no studies on the relationship of overweight, diabetes and their simultaneous presence with localized and advanced PCa in Mexican-Americans.

Materials and methods: We conducted a population-based case-control study in Mexican-American men residing in southeast Texas. Men diagnosed with histologically confirmed adenocarcinoma of the prostate (n=237) were included. Controls (n=245) were identified through random-digit dialing and frequency-matched to cases on age (±5 years). BMI, diabetes and hypertension were self-reported. Abdominal obesity was defined by waist circumference ≥ 102 cm. We identified overweight among men with self-reported diabetes to investigate their effect on PCa stage. Multivariate logistic regression was used to estimate independent associations between these factors with localized and advanced PCa.

Results: Although none of the multivariate associations were statistically significant, the direction and strength of the observed associations were consistent with previous epidemiological studies. After adjusting for PCa risk factors (age, education, family history of PCa, physical activity, smoking, alcohol consumption, PSA screening and birth place), obesity was positively and diabetes inversely associated with localized and advanced PCa. Overweight reduced the risk of localized PCa, but increased the risk of advanced PCa. Men who were overweight with self-reported diabetes had a reduced risk for both, localized and advanced PCa. Similar results were observed for abdominal obesity. On the other hand, hypertension and being born in the US (USA vs. Mexico) consistently increased the risk for localized and advanced disease.

Conclusion: High prevalence of obesity, overweight, diabetes and their simultaneous effect among Mexican-American men seem to influence PCa stage differentially. Since these factors have opposite effects on PCa, it is important to be cautious when inferring conclusions when both of them are present. It is possible that different BMI cut-off points and biological mechanisms are playing a role in these associations.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B94.

Impact of XPC LL Variant on Head and Neck Cancer Survival

Objective: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Several genetic polymorphisms have been shown to increase the risk of HNSCC. In this study we investigated how these genetic variations affect survival of HNSCC patients.

Method: DNA from blood lymphocytes of 180 HNSCC patients were analyzed for polymorphisms of DNA repair and carcinogen-metabolizing genes. The association between polymorphisms with time to recurrence and survival were analyzed.

Results: There was no association between the variants analyzed and time to disease recurrence. However, increased survival that approached statistical significance was observed in patients with XPC LL genotype. They had a longer survival compared with patients with XPC LS and XPC SS genotypes (mean survival LL = 283 months, LS = 60 months, SS = 72 months; log rank P = .06), especially in men ( P = .047).

Conclusion: The genetic variant XPC LL of the DNA repair gene XPC is associated with increased survival of HNSCC in those patients managed with treatment modalities that target DNA (ie, cisplatin and radiation). Larger and more comprehensive studies are needed to validate these findings.

Validation of genome-wide prostate cancer associations in men of African descent

BACKGROUND

Genome-wide association studies (GWAS) have identified numerous prostate cancer susceptibility alleles, but these loci have been identified primarily in men of European descent. There is limited information about the role of these loci in men of African descent.

METHODS

We identified 7,788 prostate cancer cases and controls with genotype data for 47 GWAS-identified loci.

RESULTS

We identified significant associations for SNP rs10486567 at JAZF1, rs10993994 at MSMB, rs12418451 and rs7931342 at 11q13, and rs5945572 and rs5945619 at NUDT10/11. These associations were in the same direction and of similar magnitude as those reported in men of European descent. Significance was attained at all reported prostate cancer susceptibility regions at chromosome 8q24, including associations reaching genome-wide significance in region 2.

CONCLUSION

We have validated in men of African descent the associations at some, but not all, prostate cancer susceptibility loci originally identified in European descent populations. This may be due to the heterogeneity in genetic etiology or in the pattern of genetic variation across populations.

IMPACT

The genetic etiology of prostate cancer in men of African descent differs from that of men of European descent.

Targeted prostate cancer screening in men with mutations in BRCA1 and BRCA2 detects aggressive prostate cancer: preliminary analysis of the results of the IMPACT study

OBJECTIVE

To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), was established. This is the first multicentre screening study targeted at men with a known genetic predisposition to prostate cancer. A preliminary analysis of the data is reported.

PATIENTS AND METHODS

Men aged 40-69 years from families with BRCA1 or BRCA2 mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA > 3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation.

RESULTS

In total, 300 men were recruited (205 mutation carriers; 89 BRCA1, 116 BRCA2 and 95 controls) over 33 months. At the baseline screen (year 1), 7.0% (21/300) underwent a prostate biopsy. Prostate cancer was diagnosed in ten individuals, a prevalence of 3.3%. The positive predictive value of PSA screening in this cohort was 47·6% (10/21). One prostate cancer was diagnosed at year 2. Of the 11 prostate cancers diagnosed, nine were in mutation carriers, two in controls, and eight were clinically significant.

CONCLUSIONS

The present study shows that the positive predictive value of PSA screening in BRCA mutation carriers is high and that screening detects clinically significant prostate cancer. These results support the rationale for continued screening in such men.

Abstract 943: Obesity, P13k/Akt/mTOR signaling and prostate carcinogenesis in HiMyc mice

Obesity has increased over the last 30 years in the U.S. and is associated with increased mortality rates for various cancers, including prostate cancer. In contrast, calorie restriction (CR) has been shown to act as a potent inhibitor of tumorigenesis. While this association between dietary energy balance and cancer has been clearly established, the mechanisms underlying these effects are poorly understood. To study the role of obesity and dietary fat in prostate cancer, we have used the HiMyc transgenic mouse model, a well-characterized model for the study of prostate carcinogenesis. For the current studies, HiMyc mice at weaning were placed on three dietary regimens [30% CR, 10kcal% fat (AIN76A), 60 kcal% fat], therefore generating lean, overweight and obese phenotypes. Groups of mice were then sacrificed at 3 and 6 months of age and urogenital tracts were removed and embedded in paraffin for histological analyses. In separate groups of mice, ventral prostate (VP) was removed and used to generate protein lysates for Western blot analyses. Histopathologic evaluation revealed a variety of lesions, with the severity of the lesion correlating with caloric intake. All diet groups had approximately similar incidence of hyperplasia and low grade PIN at 3 and 6 months of age. However, the different energy diets primarily affected the progression of premalignant lesions to malignant lesions in the ventral prostate. At 6 months, diet induced obesity (DIO; 60 kcal% fat) significantly increased the incidence of adenocarcinoma with aggressive stromal invasion, as compared to the overweight control group (96% vs. 65% respectively, p=0.0221), while only in situ carcinomas but no invasive adenocarcinomas were observed in mice maintained on the CR diet. Immunohistochemistry was performed on additional sections to evaluate differences in activation or total levels of Akt, mTOR, P-S6 ribosomal, angiogenesis markers and cell cycle markers. DIO increased, while CR reduced activation of signaling through both Akt and mTOR. Similar effects were observed for levels of cyclin D1 and CD31 proteins. Western blot analyses performed on protein lysates from VP of mice maintained on the same dietary regimen for 6 months confirmed these differential effects of dietary energy balance on Akt and mTOR signaling. The observed changes in signaling appeared to be due, at least in part, to changes in signaling through the insulin-like growth factor 1 receptor (IGF-1R) as a result of altered levels of circulating IGF-1. Taken together, these findings suggest that pathways activated by obesity, such as the Akt and mTOR pathways, may be key targets for preventing and controlling obesity-related prostate cancer progression. Supported by grant CA 107588 and MD Anderson Prostate Spore grant CA 140388.

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 943.

Abstract 4210: Gsta4 modifies susceptibility to skin tumor development in mice and humans

The incidence of non-melanoma skin cancer (NMSC) is equivalent to that of all other human cancers combined, and genetic factors contribute to risk of the disease. Using genetic crosses of skin tumor promotion sensitive DBA/2 mice with relatively resistant C57BL/6 mice, loci that modify susceptibility to tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) have been mapped to chromosomes (chr) 1, 2, 9, and 19. Here, we show that Glutathione S-transferase alpha 4 (Gsta4), which maps to skin tumor promotion susceptibility locus Psl1.2 on chr 9, was expressed at significantly different levels in the epidermis of C57BL/6 versus DBA/2 mice following treatment with diverse promoting agents. Gsta4 expression was dramatically upregulated in the epidermis of C57BL/6 mice, but not DBA/2 mice, following treatment with TPA, okadaic acid, chrysarobin, or ultraviolet light. Gsta4 deficient mice were more susceptible to skin tumor development in the two-stage skin carcinogenesis protocol providing compelling evidence that Gsta4 underlies the effect of Psl1.2 on susceptibility to skin tumor promotion by TPA. A number of polymorphisms were detected in the putative promoter region of Gsta4 in C57BL/6 versus DBA/2 mice, and ongoing studies are addressing the genetic basis of strain-specific expression of Gsta4 during tumor promotion. Finally, inheritance of polymorphisms in GSTA4 was associated with risk of NMSC in human populations, further supporting Gsta4/GSTA4 as a gene that modifies susceptibility to skin tumor development. Supported by NIH grant ES016623.

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 4210.

ADME transcriptome in Hispanic versus White donor livers: Evidence of a globally enhanced NR1I3 (CAR, constitutive androstane receptor) gene signature in Hispanics

Previous studies have found that, compared with Whites, Hispanic donor livers had elevated expression of CYP2 enzymes, gene products regulated by the constitutive androstane receptor (CAR). The objectives of the current study were to determine (1) the CAR activation signature in human liver (2) whether other drug detoxification (absorption, distribution, metabolism and excretion (ADME)) genes were differentially expressed in Hispanic versus White livers, and (3) the extent of overlap in the CAR and Hispanic liver transcriptomes. The CAR transcriptome (ADME genes differentially expressed following phenobarbital versus vehicle treatment of human hepatocytes) and the Hispanic liver transcriptome (ADME genes differentially expressed in Hispanic versus White livers) were identified using Affymetrix oligonucleotide arrays. Quantitative real-time polymerase chain reaction (PCR) was used to verify candidate genes in a larger sample size. Comparison of the CAR and Hispanic liver ADME transcriptomes revealed a significant association between the gene changes. Sixty-four per cent of the ADME genes induced more than twofold by phenobarbital were also induced in Hispanics, and 14% of the ADME genes repressed more than twofold by phenobarbital were repressed in Hispanics. In conclusion, compared with Whites, Hispanic donor livers have increased expression of many genes that are transcriptionally regulated by CAR. This result has practical implications to the drug treatment of Hispanic patients.

Other malignancies in chronic lymphocytic leukemia/small lymphocytic lymphoma

PURPOSE

Other malignancies have been reported to occur with increased frequency in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The aim of this study was to determine the frequency, outcomes, and factors associated with other cancers in patients with CLL/SLL.

PATIENTS AND METHODS

We reviewed the records of consecutive patients with previously untreated CLL/SLL seen at The University of Texas M. D. Anderson Cancer Center from 1985 to 2005. The number of second cancers observed was compared with the number expected from the Surveillance, Epidemiology, and End Results database.

RESULTS

Among 2,028 patients, 324 (16%) had a history of other cancers and 227 (11.2%) developed other malignancies during the follow-up period. Overall, 625 cancers were observed in 551 patients, including skin (30%), prostate (13%), breast (9%), melanoma (8%), lymphoma (8%), gastrointestinal (9%), lung (6%), and other cancers (17%). The risk of a second cancer was 2.2 times higher than the expected risk. The response rates in patients with and without a history of other cancers were 86% and 92%, respectively (P = .04), and the 5-year survival rates were 70% and 82%, respectively (P < .001). In Cox analysis, independent factors predicting development of new cancers were older age, male sex, and elevated levels of beta2-microglobulin, lactate dehydrogenase, and creatinine. In patients who were treated for CLL/SLL, the treatment regimen did not affect the risk of subsequent cancer (P = .49).

CONCLUSION

Patients with CLL/SLL have more than twice the risk of developing a second cancer and an increased frequency of certain cancer types. Awareness of risk factors could permit early detection.

Abstract A107: Polymorphisms in nucleotide excision repair pathway and acute myeloid leukemia outcome

A107

Acute myeloid leukemia (AML), the most common leukemia in adults is frequently associated with genetic abnormalities. Based on pre-treatment cytogenetics, AML patients are classified into favorable, intermediate and poor subgroups. Cytogenetics are good predictors of treatment outcome for the favorable and poor subgroups. However, for patients with intermediate cytogenetics, optimal treatment is uncertain. For these patients incorporating genetic markers to the existing prognostic factors might be helpful to identify subgroups of patients. Variants in genes within the nucleotide excision repair (NER) pathway may lead to inter-individual differences in DNA repair capacity which could eventually influence AML outcome. We studied the role of 5 polymorphisms (ERCC1 Gln504Lys, XPD Lys751Gln, XPC Ala499Val, XPC Lys939Gln, and CCNH Val270Ala) within this pathway on overall and disease-free survival among 170 adult de-novo AML patients with intermediate cytogenetics [diploid karyotypes (n = 117) and non-diploid karyotypes (n = 53)], treated with induction chemotherapy. Kaplan-Meier methods and Cox proportional hazards models were performed. After a median follow-up of 16 months, 56% of diploid patients died compared to 71% among the non-diploid group (Log Rank p= 0.03). Among patients with diploid karyotypes, after adjusting for clinical and socio-demographic characteristics (age, sex, ethnicity, WBC, performance status, and smoking), XPD Lys751Gln and XPC Ala499Val were found to be independently associated with overall survival. Patients with the XPD Lys751Gln/Gln751Gln genotype were twice more likely to have died than those with the wild genotype (HR: 1.97; 95% CI: 1.09 - 3.55). XPC Ala499Val/Val499Val patients had a 75% increased mortality compared to those with the wild genotype (HR: 1.75; 95% CI: 1.02 - 2.98). Patients carrying both (XPD Lys751Gln/Gln751Gln and XPC Ala499Val/Val499Val) had significantly shorter survival compared to those with the wild genotype (HR: 3.49; 95% CI: 1.58 - 7.68). 21% of the AML patients with diploid cytogenetics carried both risk variants. No significant associations were observed for disease-free survival in AML patients. Our results suggest that polymorphic variants in NER repair enzymes may modulate AML outcome in patients with diploid cytogenetics. Patients with the high risk genotype combination could have diminished DNA repair capacity, which in turn, could result in greater susceptibility to genotoxic effects of treatment decreasing overall survival. These findings could in the future be used in selecting treatment strategies for patients with normal cytogenetics.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):A107.

The ratio of matrix metalloproteinase to E-cadherin expression: a pilot study to assess mRNA and protein expression among African American prostate cancer patients

BACKGROUND

We assessed the expression of Matrix Metalloproteinase (MMP) to E-cadherin (M/E ratio) to determine the correlation of gene expression with pathologic variables and outcome in a cohort of African American (AA) prostate cancer patients.

METHODS

Tumors from formalin-fixed, paraffin embedded RP specimens were examined. Gleason scores were 6, 7, and >or=8 in 7, 16, 13 tumors, respectively. Pathologic stage was organ confined (pT2) in 18 and advanced (>pT2) in 18 tumors. A colorimetric mRNA in situ hybridization (ISH) assay was performed using biotinylated anti-sense oligonucleotide probes for MMP 2 and 9, as well as for E-cadherin gene transcripts. Immunohistochemistry (IHC) was performed utilizing specific monoclonal antibodies to detect the above genes. Image analysis was performed to determine the intensity of both mRNA and protein expression. Two reviewers analyzed ISH gene expression independently.

RESULTS

The M/E expression ratio was significantly increased at the invasive edge (but not the center) of tumors of higher Gleason score (P = 0.02 and 0.0008) and pathologic stage (P = 0.0001 and <0.0001) when examined by both ISH and IHC. Significant variability in ISH staining interpretation was noted within and among the two study reviewers. An M/E ratio >2.5 was associated with biochemical recurrence after radical prostatectomy in addition to tumor pathologic stage subsequent to univariate statistical analysis.

CONCLUSIONS

The M/E ratio characterizes an important aspect of the molecular phenotype associated with the histologic progression of prostate cancer among African American prostate cancer patients. A larger comparative study is required to determine potential racial variation and prognostic significance of gene expression.

Dietary energy balance modulates signaling through the Akt/mammalian target of rapamycin pathways in multiple epithelial tissues

The prevalence of obesity, an established risk factor for several types of cancer, has increased steadily over the past several decades in the United States. New targets and strategies for offsetting the effect of obesity on cancer risk are urgently needed. In the present study, we examined the effect of dietary energy balance manipulation on steady-state signaling in multiple epithelial tissues, with a focus on the Akt and mammalian target of rapamycin (mTOR) pathways. For these experiments, male FVB/N and C57BL/6 and female ICR mice were maintained on a control (10 kcal% fat) diet, a diet-induced obesity (DIO; 60 kcal% fat) regimen, or a 30% calorie restriction (CR) regimen for 15 to 17 weeks. Relative to the control group, the DIO regimen increased, whereas CR decreased, circulating insulin-like growth factor-I (IGF-I) as has previously been reported. Western blot analyses showed that the DIO regimen enhanced, whereas CR inhibited, activation of Akt and mTOR, regardless of epithelial tissue or genetic background. In contrast, activation of AMP-activated protein kinase was modulated by dietary energy balance manipulation in the liver but not in the epidermis or dorsolateral prostate. Western blot analyses of epidermal extracts taken from ICR mice also revealed reduced activation of both the IGF-I receptor and epidermal growth factor receptor in CR mice, compared with control mice or mice maintained on the DIO regimen. Taken together, these novel findings suggest that dietary energy balance modulates signaling through cell-surface receptors (i.e., IGF-I receptor and epidermal growth factor receptor), affecting activation of multiple downstream pathways including Akt and mTOR, thus providing important dietary and pharmacologic targets for disrupting the obesity-cancer link.

Hyperglycemia and obesity in patients (pts) with acute lymphoblastic leukemia (ALL): Association with prevalence, response, and survival

7074

Increasing evidence suggests associations between obesity, diabetes and/or hyperglycemia (DM/HG) and solid tumors. Less is known about the relationship of these metabolic factors to the hematologic malignancies. To determine the prevalence of DM/HG and obesity in pts with ALL and whether these are predictors of response and survival, we conducted a retrospective chart review of 299 pts with newly diagnosed ALL, who were evaluated at our institution between November 1999 and May 2005 and received hyper-CVAD therapy: fractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone alternating with methotrexate and high-dose cytarabine. Median age was 43 yrs (range 15–83). Sixty-one percent of pts were male, and 39% female. Seventy-four percent had a diagnosis (dx) of precursor B cell ALL (22% Ph+), 18% Burkitt's ALL, 6% lymphoblastic lymphoma, 2% other. Prior to therapy, the overall prevalence of DM/HG (diabetes based on reported dx prior to ALL-dx, and hyperglycemia based on baseline serum glucose ≥200 mg/dL) was 16%. Pts with DM/HG were significantly older than those without DM/HG (median age 57 yrs vs. 40 yrs, p<0.001). Complete remission (CR) rate and the CR duration (CRD) were similar in the DM/HG vs. non-DM/HG group. However, the mean CRD was 80 wks in the HG separately group and 121 wks in the non-HG group (p=0.04). The mean CRD was 102 wks in the obese pts and 124 wks in the non-obese pts (p=.04). In univariate analysis, DM/HG, obesity, and older age were associated with shorter overall survival (OS). Mean OS of pts with DM/HG was 134 vs. 194 wks for pts without DM/HG, (p=0.2). Mean OS of obese pts was 136 vs. 199 wks for non-obese pts, (p=0.01). In a multivariable Cox regression model, the only factors that remained significant for survival were age, obesity, and white blood cell count (WBC). There was no significant difference in OS by leukemia diagnosis. In conclusion, the prevalence data suggests that DM/HG may be involved in the development of ALL. However, DM/HG has no impact on survival, probably because of its strong correlation with age. The association of obesity with shorter OS warrants further investigation.

No significant financial relationships to disclose.

Thyroid hormone and breast carcinoma. Primary hypothyroidism is associated with a reduced incidence of primary breast carcinoma

BACKGROUND

To investigate the role of primary hypothyroidism (HYPT) on breast carcinogenesis, the authors evaluated 1) the association between HYPT and a diagnosis of invasive breast carcinoma and 2) the clinicopathologic characteristics of breast carcinoma in patients with HYPT.

METHODS

For this retrospective chart review study, 1136 women with primary breast carcinoma (PBC) were identified from the authors' departmental data base. These women (cases) were frequency-matched for age (+/- 5 years) and ethnicity with 1088 healthy participants (controls) who attended a breast carcinona screening clinic. Women with HYPT who were receiving thyroid-replacement therapy before they were diagnosed with breast carcinoma or before the screening visit were identified.

RESULTS

The mean ages of cases and controls (51.6 years vs. 51.0 years, respectively; P = 0.30) and their menopausal status (65.4% premenopausal vs. 62% postmenopausal; P = 0.10) were comparable. Two hundred forty-two women in the case group (10.9%) with HYPT were identified. The prevalence of this condition was significantly greater the control group compared with the case group (14.9% vs. 7.0%, respectively; P < 0.001). PBC patients were 57% less likely to have HYPT compared with their healthy counterparts (odds ratio, 0.43l 95% confidence interval, 0.33-0.57). Seventy-eight white patients with PBC had HYPT and, compared with women who were euthyroid, they were older at the time of diagnosis (58.8 years vs. 51.1 years; P < 0.001), were more likely to have localized disease (95.0% vs. 85.9% clinical T1 or T2 disease, respectively; P = 0.025), and were more likely to have no pathologic lymph node involvement (62.8% vs. 54.4%; P = 0.15).

CONCLUSIONS

Primary HYPT was associated with a reduced risk for PBC and a more indolent invasive disease. These data suggest a possible biologic role for thyroid hormone in the etiology of breast carcinoma and indicate areas of research for the prevention and treatment of breast carcinoma.

Acquired PTPN11 mutations occur rarely in adult patients with myelodysplastic syndromes and chronic myelomonocytic leukemia

Myelodysplastic syndromes (MDS) are comprised of a heterogeneous group of stem cell disorders characterized by ineffective hematopoiesis and susceptibility to transform to acute myeloid leukemia. The molecular pathways underlying disease initiation and evolution are still largely unknown. We recently demonstrated that acquired mutations in PTPN11 are a major event in JMML and occur with variable prevalence in children with other hematologic malignancies, including MDS. Here, we investigated contribution of PTPN11 mutations to adult MDS and CMML pathogenesis. Our results indicate that PTPN11 lesions might play a role in adult MDS/CMML pathogenesis but do not represent a major molecular event.

A case-control analysis of lymphocytic chromosome 9 aberrations in lung cancer

Cytogenetic aberrations on chromosome 9 have been reported to be one of the most frequent genetic changes in lung tumorigenesis. Although many of these changes have been detected in lung carcinoma specimens, there is growing evidence showing the concordance between chromosomal alterations in primary lung tumors and peripheral blood lymphocytes (PBLs). We investigated whether spontaneous aberrations on chromosome 9 in PBLs are associated with the presence of lung cancer and with a family history of cancer. A personal interview, to construct a detailed epidemiologic profile including family history of cancer, was conducted on 174 lung cancer cases and 162 matched controls. One hundred metaphases from PBLs of each subject were analyzed for chromosome 9 aberrations using the whole chromosome painting technique. Overall, the mean proportion of individuals with chromosome 9 abnormalities in their PBLs was significantly higher in cases (96.0%) than in controls (60.5%) (p < 0.05). After adjustment by age, gender, ethnicity, family size, and pack-years, there was a 16.63-fold significantly elevated odds ratio (OR) for lung cancer associated with chromosome 9 aberrations. When subjects were categorized by frequencies of the chromosome 9 lesions, we observed significantly increased odds ratios of 11.13 (4.66, 26.58) and 27.45 (11.15, 67.54) for individuals with 1 chromosome 9 aberration and >/=2 chromosome 9 aberrations, respectively. By performing family history analyses, we further observed that control individuals with chromosome 9 aberrations were more likely to report a family history of any cancer (OR = 1.67 [0.84, 3.32]) and lung cancer (OR = 2.49 [0.81, 7.67]). Our findings suggest that chromosome 9 aberrations in PBLs might be considered a marker of lung cancer predisposition and may be associated with familial aggregation of cancer.

Disrupted bile acid homeostasis reveals an unexpected interaction among nuclear hormone receptors, transporters, and cytochrome P450

Sister of P-glycoprotein (SPGP) is the major hepatic bile salt export pump (BSEP). BSEP/SPGP expression varies dramatically among human livers. The potency and hierarchy of bile acids as ligands for the farnesyl/bile acid receptor (FXR/BAR) paralleled their ability to induce BSEP in human hepatocyte cultures. FXR:RXR heterodimers bound to IR1 elements and enhanced bile acid transcriptional activation of the mouse and human BSEP/SPGP promoters. In FXR/BAR nullizygous mice, which have dramatically reduced BSEP/SPGP levels, hepatic CYP3A11 and CYP2B10 were strongly but unexpectedly induced. Notably, the rank order of bile acids as CYP3A4 inducers and activators of pregnane X receptor/steroid and xenobiotic receptor (PXR/SXR) closely paralleled each other but was markedly different from their hierarchy and potency as inducers of BSEP in human hepatocytes. Moreover, the hepatoprotective bile acid ursodeoxycholic acid, which reverses hydrophobic bile acid hepatotoxicity, activates PXR and efficaciously induces CYP3A4 (a bile-metabolizing enzyme) in primary human hepatocytes thus providing one mechanism for its hepatoprotection. Because serum and urinary bile acids increased in FXR/BAR -/- mice, we evaluated hepatic transporters for compensatory changes that might circumvent the profound decrease in BSEP/SPGP. We found weak MRP3 up-regulation. In contrast, MRP4 was substantially increased in the FXR/BAR nullizygous mice and was further elevated by cholic acid. Thus, enhanced hepatocellular concentrations of bile acids, due to the down-regulation of BSEP/SPGP-mediated efflux in FXR nullizygous mice, result in an alternate but apparent compensatory up-regulation of CYP3A, CYP2B, and some ABC transporters that is consistent with activation of PXR/SXR by bile acids.

The human pregnane X receptor: genomic structure and identification and functional characterization of natural allelic variants

The pregnane X receptor (PXR)/steroid and xenobiotic receptor (SXR) transcriptionally activates cytochrome P4503A4 (CYP3A4) when ligand activated by endobiotics and xenobiotics. We cloned the human PXR gene and analysed the sequence in DNAs of individuals whose CYP3A phenotype was known. The PXR gene spans 35 kb, contains nine exons, and mapped to chromosome 13q11-13. Thirty-eight single nucleotide polymorphisms (SNPs) were identified including six SNPs in the coding region. Three of the coding SNPs are non-synonymous creating new PXR alleles [PXR*2, P27S (79C to T); PXR*3, G36R (106G to A); and PXR*4, R122Q (4321G to A)]. The frequency of PXR*2 was 0.20 in African Americans and was never found in Caucasians. Hepatic expression of CYP3A4 protein was not significantly different between African Americans homozygous for PXR*1 compared to those with one PXR*2 allele. PXR*4 was a rare variant found in only one Caucasian person. Homology modelling suggested that R122Q, (PXR*4) is a direct DNA contact site variation in the third alpha-helix in the DNA binding domain. Compared with PXR*1, and variants PXR*2 and PXR*3, only the variant PXR*4 protein had significantly decreased affinity for the PXR binding sequence in electromobility shift assays and attenuated ligand activation of the CYP3A4 reporter plasmids in transient transfection assays. However, the person heterozygous for PXR*4 is normal for CYP3A4 metabolism phenotype. The relevance of each of the 38 PXR SNPs identified in DNA of individuals whose CYP3A basal and rifampin-inducible CYP3A4 expression was determined in vivo and/or in vitro was demonstrated by univariate statistical analysis. Because ligand activation of PXR and upregulation of a system of drug detoxification genes are major determinants of drug interactions, it will now be useful to extend this work to determine the association of these common PXR SNPs to human variation in induction of other drug detoxification gene targets.

Sequence diversity in CYP3A promoters and characterization of the genetic basis of polymorphic CYP3A5 expression

Variation in the CYP3A enzymes, which act in drug metabolism, influences circulating steroid levels and responses to half of all oxidatively metabolized drugs. CYP3A activity is the sum activity of the family of CYP3A genes, including CYP3A5, which is polymorphically expressed at high levels in a minority of Americans of European descent and Europeans (hereafter collectively referred to as 'Caucasians'). Only people with at least one CYP3A5*1 allele express large amounts of CYP3A5. Our findings show that single-nucleotide polymorphisms (SNPs) in CYP3A5*3 and CYP3A5*6 that cause alternative splicing and protein truncation result in the absence of CYP3A5 from tissues of some people. CYP3A5 was more frequently expressed in livers of African Americans (60%) than in those of Caucasians (33%). Because CYP3A5 represents at least 50% of the total hepatic CYP3A content in people polymorphically expressing CYP3A5, CYP3A5 may be the most important genetic contributor to interindividual and interracial differences in CYP3A-dependent drug clearance and in responses to many medicines.

Neonatal outcome of preimplantation genetic diagnosis by polar body removal: the first 109 infants

CONTEXT

Our center developed the technique of preimplantation genetic diagnosis (PGD) by sequential polar body removal (PBR) for the diagnosis of Mendelian disorders and aneuploidies. This study examines the obstetric and neonatal outcome of the first 109 live births after PGD by PBR.

OBJECTIVE

To determine if there were any observable effects of PGD by PBR on perinatal morbidity and mortality, birth defects, and growth parameters.

DESIGN

Data on perinatal outcome were gathered for the first 109 infants by parental reporting and confirmed by telephone interview and chart review when indicated. In infants >6 months old, a follow-up telephone interview was performed establishing the developmental milestones attained by the child.

SETTING

A research center conducting an institutional review board-approved research protocol in PGD.

PATIENTS

All patients who had PGD by PBR who had clinical pregnancies.

MAIN OUTCOME MEASURES

Gestational age, mode of delivery, perinatal mortality, birth weight, birth length, the presence of birth defects, and developmental milestones.

RESULTS

There was no significant decrease in birth length or weight, or the frequency of small for gestational age infants. No specific pattern of birth defects was observed.

CONCLUSION

Thus far, there are no observable detrimental effects of PGD by PBR on children born after the procedure.

Obstetric outcomes in 102 pregnancies after preimplantation genetic diagnosis

OBJECTIVE

We sought to determine whether preimplantation genetic diagnosis is associated with particular pregnancy or delivery complications.

STUDY DESIGN

A total of 102 consecutive pregnancies after preimplantation genetic diagnosis by polar body removal performed at Illinois Masonic Medical Center resulting in 114 live births were analyzed. All patients were given a delivery and newborn questionnaire, and attempts were made to contact and question them regarding any pregnancy complications and type of delivery. Permission was obtained to examine medical records and discuss the patient's pregnancy with her obstetrician when questions existed with respect to complications or indication for cesarean delivery.

RESULTS

Delivery and newborn questionnaires were completed or telephone contact was achieved for 100 of the 102 pregnancies. There were 85 singleton, 9 twin, and 7 triplet pregnancies. Of the 7 triplet gestations, 3 couples elected multifetal pregnancy reduction to twins and healthy triplets were born to 4 couples between 32 and 36 weeks by cesarean delivery. Of the 80 singleton deliveries, 60 (75%) progressed to term. Of these 60 term singleton deliveries, 34 were vaginal, 23 were cesarean (40%), and 3 delivery types were unknown. The incidence of small-for-gestational-age infants was 3% for neonates in the 60 term singleton deliveries and 7% in the entire cohort of 80 singleton deliveries. Only 3 pregnancy complications (other than premature delivery) were reported more than once. There were 3 instances each of gestational diabetes, intrauterine growth restriction, and pregnancy-induced hypertension. There was 1 case each of HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome, congestive heart failure, mild oligohydramnios, and abruptio placentae. The indications for cesarean delivery were (in descending order) failure of labor to progress (n = 7), fetal distress (n = 4), placenta previa (n = 4), elective repeat cesarean delivery (n = 4), triplets (n = 3), uterine scarring (n = 3), 1 twin in the breech position (n = 3), failed forceps delivery (n = 2), and a variety of other indications that occurred in only 1 patient each. All preimplantation genetic diagnoses were confirmed by prenatal or postnatal testing. No diagnostic errors were made in this cohort of patients or in any patients undergoing preimplantation genetic diagnosis having polar body removal in our center.

CONCLUSIONS

Preimplantation genetic diagnosis is associated with a risk of multiple gestations, cesarean delivery, and placenta previa. Cesarean delivery rates and multiple gestation rates are comparable to those of patients undergoing in vitro fertilization in general. The preimplantation genetic diagnosis itself does not seem to cause an increased risk for any particular pregnancy complication, with the possible exception of placenta previa, which was seen in 4% of patients.