The use of supraclavicular free flap with vascularized lymph node transfer for treatment of lymphedema: A prospective study of 100 consecutive cases

BACKGROUND AND OBJECTIVES

Vascularized lymph node transfer (VLNT) is gaining popularity for treatment of lymphedema. The purpose of this study was to evaluate the flap and the donor site morbidity of the supraclavicular (SC) VLNT.

METHODS

A review of a prospective database was performed for patients who had undergone SC VLNT to treat upper or lower extremity lymphedema. Flap and donor site complications were registered for each patient. A detailed technical surgical approach is explained.

RESULTS

One hundred consecutive patients with lower or upper extremity lymphedema underwent SC VLNT (84% from the right side) with a mean of 11-months follow-up (range 3-19 months). There were no flap loss but three flaps (3%) required re-exploration due to venous congestion of the skin paddle. Two patients had local infection and three patients developed chyle leak (3%) at the donor site but resolved spontaneously. No donor site secondary lymphedema was noted.

CONCLUSIONS

This is the largest prospective series of SC free flap VLNT for treatment of lymphedema. Low flap and donor site morbidity makes this flap an appealing source of lymph node transfer for lymphedema treatment. J. Surg. Oncol. 2017;115:68-71. © 2016 Wiley Periodicals, Inc.

Abstract 2634: Prognostic value of obesity-related genes methylation in localized renal cell carcinoma patients

Obesity is an established risk factor for renal cell carcinoma (RCC): more than 40% of RCC cases in US are attributed to excessive body weight. Growing evidence suggests that obesity may also be associated with the prognosis of RCC. The molecular mechanism linking obesity and RCC is not well understood. In the present study, we evaluated the association between promoter CpG island methylation of 20 obesity-related genes and RCC. A total of 275 newly diagnosed and previously untreated Caucasian RCC patients were included. For the discovery population, 75 tissue pairs of RCC tumors and normal adjacent tissues from the surrounding kidney were used and for the validation population an additional 200 pairs were included. Pyrosequencing was used to determine CpG site methylation on bisulfite-treated genomic DNA. We used Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confident intervals (CIs) for the association of CpG methylation with recurrence and Kaplan-Meier curve to plot disease free survival (DFS) time by different CpG site methylation. The average age of the patients was 59 years and they were largely males; ∼50% were never smokers. Most of the cases were clear cell RCC (ccRCC) and clinical stage I. Among the 20 markers, LEP, LEPR and NPY were significantly hypermethylated in tumor tissues compared to normal tissues (p<0.0001) in the discovery set. Similar results were obtained in the validation set. Moreover, LEPR methylation in tumors was associated with recurrence. When patients were dichotomized into high and low methylation groups according to the median value of LEPR methylation, high LEPR methylation was associated with a significantly higher risk of recurrence (HR = 2.4, 95% CI, 1.03-5.8), adjusted by age, gender, clinical stage, grade, smoking status, BMI, hypertension and histology. The Kaplan-Meier analysis showed a shorter 5-year DFS probability for the patients with high LEPR methylation level (34.7%) compared with low methylation (41.7%) (LogRank, p = 0.032). The MST was 39 months in high methylation group and 47 months in low methylation. Our results suggest that LEPR hypermethylation in tumors is associated with recurrence in RCC patients and thus LEPR may provide a functional link between obesity and RCC. Future studies are needed to elucidate the biology underlying the association of LEPR methylation and RCC recurrence. This work was supported in part by the National Institutes of Health (grant R01 CA170298) and the Center for Translational and Public Health Genomics, Duncan Family Institute for Cancer Prevention, The University of Texas MD Anderson Cancer Center.

Citation Format: Julia Mendoza-Perez, Jian Gu, Nizar M. Tannir, Surena Matin, Jose A. Karam, Maosheng Huang, Shu Xiang, David W. Chang, Christopher G. Wood, Luis A. Herrera, Xifeng Wu. Prognostic value of obesity-related genes methylation in localized renal cell carcinoma patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2634.

Coping and quality of life of patients following microsurgical treatment for breast cancer–related lymphedema

Breast cancer–related lymphedema is associated with numerous adverse outcomes. This study investigated the extent clinical factors, lymphedema symptoms, lymphedema-related appearance, and coping strategies predicted quality of life. Female patients who underwent microsurgical treatment for lymphedema ( n = 54) participated. Lymphedema symptoms were associated with physical and functional well-being, but not emotional and social well-being. Clinical factors and lymphedema-related appearance were not significantly associated with quality of life. Compared to adaptive coping strategies, maladaptive coping strategies (e.g. denial, venting, self-blame) were more strongly associated with quality of life. This suggests psychosocial interventions aimed at modifying maladaptive coping behaviors can potentially improve quality of life for this patient population.

Pathway analysis of bladder cancer genome-wide association study identifies novel pathways involved in bladder cancer development

Genome-wide association studies (GWAS) are designed to identify individual regions associated with cancer risk, but only explain a small fraction of the inherited variability. Alternative approach analyzing genetic variants within biological pathways has been proposed to discover networks of susceptibility genes with additional effects. The gene set enrichment analysis (GSEA) may complement and expand traditional GWAS analysis to identify novel genes and pathways associated with bladder cancer risk. We selected three GSEA methods: Gen-Gen, Aligator, and the SNP Ratio Test to evaluate cellular signaling pathways involved in bladder cancer susceptibility in a Texas GWAS population. The candidate genetic polymorphisms from the significant pathway selected by GSEA were validated in an independent NCI GWAS. We identified 18 novel pathways (P < 0.05) significantly associated with bladder cancer risk. Five of the most promising pathways (P ≤ 0.001 in any of the three GSEA methods) among the 18 pathways included two cell cycle pathways and neural cell adhesion molecule (NCAM), platelet-derived growth factor (PDGF), and unfolded protein response pathways. We validated the candidate polymorphisms in the NCI GWAS and found variants of RAPGEF1, SKP1, HERPUD1, CACNB2, CACNA1C, CACNA1S, COL4A2, SRC, and CACNA1C were associated with bladder cancer risk. Two CCNE1 variants, rs8102137 and rs997669, from cell cycle pathways showed the strongest associations; the CCNE1 signal at 19q12 has already been reported in previous GWAS. These findings offer additional etiologic insights highlighting the specific genes and pathways associated with bladder cancer development. GSEA may be a complementary tool to GWAS to identify additional loci of cancer susceptibility.

Genomic DNA Hypomethylation and Risk of Renal Cell Carcinoma: A Case-Control Study

PURPOSE

Genomic DNA hypomethylation is a hallmark of most cancer genomes, promoting genomic instability and cell transformation. In the present study, we sought to determine whether global DNA methylation in peripheral blood is associated with risk of renal cell carcinoma (RCC).

EXPERIMENTAL DESIGN

A retrospective case-control study consisting of 889 RCC cases and an equal number of age, gender, and ethnicity-matched controls was applied. Global DNA methylation was measured as 5-mC% content. Logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) for the association between DNA methylation level and the risk of RCC.

RESULTS

The median 5-mC% was significantly lower in cases than in healthy controls (P< 0.001). In multivariate logistic regression analysis, individuals in the lowest tertile (T1) of 5-mC% had higher risk of RCC with OR of 1.40 (95% CI, 1.06-1.84), compared with individuals in the highest tertile (T3;Pfor trend= 0.02). When stratified by RCC risk factors, associations between hypomethylation and increased RCC risk appeared to be stronger among males (OR, 1.61;Pfor trend= 0.01), younger age (OR, 1.47;Pfor trend= 0.03), never smokers (OR, 1.55;Pfor trend= 0.02), family history of other cancer (OR, 1.64;Pfor trend= 1.22E-03), and late stage (OR, 2.06,Pfor trend= 4.98E-04). Additionally, we observed significant interaction between gender and 5-mC% in elevating RCC risk (Pfor interaction= 0.03).

CONCLUSIONS

Our findings suggest an association between global DNA hypomethylation and RCC risk. To establish global DNA hypomethylation as a risk factor for RCC, future prospective studies are warranted. This study may provide further understanding of the etiology of RCC tumorigenesis.

Abstract 3056: Mitochondrial DNA copy number and risk of second primary tumors in long-term breast cancer survivors

Background. Mitochondria is constantly exposed to reactive oxygen species (ROS), an important factor in carcinogenesis. Altered mitochondrial DNA (mtDNA) copy number in peripheral blood has been associated with increased risks of several cancers, including breast cancer. However, the association of mtDNA copy number with clinical outcomes of breast cancer has not been reported. This study aimed to assess the association of mtDNA copy number with second primary tumors (SPT) in long-term breast cancer survivors.

Methods. We measured mtDNA by quantitative PCR in patients in 68 long-term breast cancer survivors with SPT, 100 long-term breast cancer survivors without SPT and 97 newly diagnosed breast cancer cases. Cases with and without SPT were matched by years since diagnosis, age at time of sample collection and race. Differences between mtDNA copy number among groups were analyzed using the Wilcoxon rank sum test.

Results. MtDNA copy number was significantly higher in long-term breast cancer survivors (either with SPT or not SPT) compared with newly diagnosed breast cancer patients (Mean (SD), 1.03 ± 0.25 vs 0.95 ± 0.27; p = 0.005). We did not observe significant differences of mtDNA copy number between long-term survivors with SPT and without SPT. However, in stratified analyses by epidemiological and clinical variables, we observed lower mtDNA copy number in HER2-positive long-term survivors with SPT than those without SPT (0.84 ± 0.13 vs 1.27 ± 0.44; p = 0.010) and in pre-menopause long-term survivors with SPT than those without SPT (0.95 ± 0.20 vs 1.06 ± 0.22; p = 0.034). A borderline significance of mtDNA copy number between SPT and non-SPT ER-negative long-term survivors was also noted (0.90 ± 0.17 vs 1.18 ± 0.41, p = 0.056).

Conclusion. Higher mtDNA copy number was found in long-term breast cancer survivors compared to newly diagnosed cases. There were significant associations between lower mtDNA copy number and SPT in long-term breast cancer survivors who are HER2+ or are pre-menopause. These results indicate a role of mtDNA copy number in long-term breast cancer survivorship.

Citation Format: Miguel Santibanez, Alma Rodriguez, Michelle A. Hildebrandt, David W. Chang, Xifeng Wu. Mitochondrial DNA copy number and risk of second primary tumors in long-term breast cancer survivors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3056. doi:10.1158/1538-7445.AM2015-3056

Abstract 2953: Genomic DNA hypomethylation as an independent risk factor for renal cell carcinoma

Renal cell carcinoma (RCC) is the most lethal genitourinary cancer. Cigarette smoking, hypertension and obesity are the major risk factors for RCC; however, much of the etiology of this disease remains to be elucidated. Genomic DNA hypomethylation is a hallmark of most cancer genomes, promoting genomic instability and cell transformation. In the present study, we sought to determine whether global DNA methylation in peripheral blood is associated with risk of RCC. A case control study consisting of 889 RCC cases and an equal number of age, gender, and ethnicity-matched controls was conducted. Genomic DNA was isolated from peripheral blood and global DNA methylation was measured as 5-mC% content using an antibody-based immune assay. Logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) for the association between DNA methylation level and the risk of RCC. The median age was 59.29±10.42 for cases and 59.39±10.30 for controls. Over two-thirds (67% in both cases and controls) were males, about half (50.2% in cases and 52.2% in controls) were never smokers, the vast majority (84.8% in both cases and controls) were Caucasian. BMI, physical activity, hypertension and family history of cancer were significantly different between cases and controls. RCC cases are more likely than controls to have high blood pressure level (p = 5.81E-15), higher BMI (p = 0.011), low physical activity (p = 1.48E-20), and a family history of cancer (other than kidney cancer) (p = 5.42E-07). The median methylation level in controls was 3.97, significantly higher than the median level of 3.64 in cases (p&lt;0.001 Wilcoxon rank-sum test). In multivariate logistic regression analysis adjusted by age, gender, ethnicity, smoking status, and hypertension, individuals in the lowest tertile (T1) and middle tertile (T2) of 5-mC% had higher risks of RCC with ORs of 1.42 (95%CI 1.12-1.81) and 1.14 (95% CI 0.89-1.45), respectively, compared to individuals in the highest tertile (T3) of methylation (p for trend 0.004). When stratified by RCC risk factors, associations between hypomethylation and increased RCC risks were stronger among males (OR 1.64, 95%CI 1.21-2.21), younger individuals (OR 1.54, 95%CI 1.10-2.15), never-smokers (OR 1.61, 95%CI 1.14-2.28) and African-Americans (OR 2.75, 95%CI 0.75-10.08). These findings suggest for the first time that global DNA hypomethylation in peripheral blood is independently associated with RCC risk. The results may provide better understanding of the etiology of RCC tumorigenesis and in combination with modifiable risk factors and other potential biomarkers, may help identify high risk individuals for screening and early detection of RCC. This work was supported in part by the National Institutes of Health (grant R01 CA170298) and the Center for Translational and Public Health Genomics, Duncan Family Institute for Cancer Prevention, The University of Texas M D Anderson Cancer Center.

Citation Format: Julia Mendoza Perez, Jian Gu, Nizar M. Tannir, Surena Matin, Jose A. Karam, David W. Chang, Luis A. Herrera, Christopher G. Wood, Xifeng Wu. Genomic DNA hypomethylation as an independent risk factor for renal cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2953. doi:10.1158/1538-7445.AM2015-2953

Mitochondrial DNA Content as Risk Factor for Bladder Cancer and Its Association with Mitochondrial DNA Polymorphisms

Mitochondrial DNA (mtDNA) content has been shown to be associated with cancer susceptibility. We identified 926 bladder cancer patients and compared these with 926 healthy controls frequency matched on age, gender, and ethnicity. Patients diagnosed with bladder cancer had significantly decreased mtDNA content when compared with control subjects (median, 0.98 vs. 1.04, P < 0.001). Low mtDNA content (i.e., less than the median in control subjects) was associated with a statistically significant increased risk of bladder cancer, when compared with high mtDNA content [Odds ratio (OR), 1.37; 95% confidence interval (CI), 1.13-1.66; P < 0.001). In a trend analysis, a statistically significant dose-response relationship was detected between lower mtDNA content and increasing risk of bladder cancer (Ptrend <0.001). When stratified by host characteristics, advanced age (>65 years), male sex and positive smoking history were significantly associated with low mtDNA content and increased risk of bladder cancer. We identified two unique mtDNA polymorphisms significantly associated with risk of bladder cancer: mitot10464c (OR, 1.39; 95% CI, 1.00-1.93; P = 0.048) and mitoa4918g (OR, 1.40; 95% CI, 1.00-1.95; P = 0.049). Analysis of the joint effect of low mtDNA content and unfavorable mtDNA polymorphisms revealed a 2.5-fold increased risk of bladder cancer (OR, 2.50; 95% CI, 1.60-3.94; P < 0.001). Significant interaction was observed between mitoa4918g and mtDNA content (Pinteraction = 0.028). Low mtDNA content was associated with increased risk of bladder cancer and we identified new susceptibility mtDNA alleles associated with increased risk that require further investigation into the biologic underpinnings of bladder carcinogenesis.

Genetic Variations in Glutathione Pathway Genes Predict Cancer Recurrence in Patients Treated with Transurethral Resection and Bacillus Calmette-Guerin Instillation for Non-muscle Invasive Bladder Cancer

BACKGROUND

Glutathione (GSH) is an important molecule involved in cell detoxification and antioxidation and may affect cancer development or outcome. We hypothesized that genetic variation in the GSH pathway might influence the clinical outcome of patients who have non-muscle invasive bladder cancer (NMIBC).

METHODS

A total of 114 single nucleotide polymorphisms (SNPs) in 21 GSH pathway genes were genotyped in 414 NMIBC patients treated with transurethral resection alone (TUR) and both TUR and intravesical bacillus Calmette-Guérin instillation (BCG) therapy. The effect of each SNP on time to recurrence was estimated using the multivariate Cox proportional hazards model. Cumulative effect and survival tree analyses were performed to determine the joint effects of unfavorable genotypes and gene-gene interactions on bladder cancer prognosis.

RESULTS

Seven SNPs showed significant associations with cancer recurrence in the TUR group and 15 SNPs showed significant associations with recurrence in the BCG group. The most significant SNP in the TUR group was rs3746162 in GPX4, whose variant genotype conferred a 5.4-fold increased risk of recurrence compared with wild-type (hazard ratio [HR] = 5.43, 95 % confidence interval [CI] = 2.19-13.46), whereas the most significant SNP in the BCG group was rs7265992 in GSS (HR 3.43, 95 % CI 1.56-7.56). The risk of recurrence increased with the number of unfavorable genotypes in both groups. Within treatment group, stratified analyses by tumor grade also indicated predictive variants.

CONCLUSIONS

Genetic variants in GSH pathway may influence cancer recurrence in NMIBC patients receiving curative treatment.

Genetic and intermediate phenotypic susceptibility markers of gastric cancer in Hispanic Americans: a case-control study

BACKGROUND

Hispanics are the largest nonwhite ethnic group in the US population, and they have higher incidence and mortality rates for gastric cancer (GC) than whites and Asians. Studies have identified several genetic susceptibility loci and intermediate phenotypic biomarkers for GC in whites and Asians. No studies have evaluated genetic susceptibility and intermediate phenotypic biomarkers in Hispanics.

METHODS

In a case-control study of 132 Hispanic patients with GC (cases) and a control group of 125 Hispanics (controls), the authors evaluated the association of 5 single nucleotide polymorphisms (SNPs) that predispose whites and/or Asians to GC and of 2 intermediate phenotypic markers in peripheral blood leukocytes, ie, telomere length and mitochondrial DNA (mtDNA) copy number, with the GC risk.

RESULTS

The variant C allele of the reference SNP rs2294008 in the PSCA gene was associated with a significantly reduced risk of GC (per allele-adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.33-0.77; P = .002). Leukocyte mtDNA copy numbers were significantly lower in GC cases (mean ± standard deviation, 0.91 ± 0.28) than in controls (1.29 ± 0.42; P < .001). When individuals were dichotomized into high and low mtDNA copy number groups based on the median mtDNA copy number value in the controls, those who had a low mtDNA copy number had a significantly increased risk of GC (aOR, 11.00; 95% CI, 4.79-25.23; P < .001) compared with those who had a high mtDNA copy number. Telomere length was not associated significantly with the risk of GC (aOR, 1.21; 95% CI, 0.65-2.27; P = .551).

CONCLUSIONS

Hispanics share certain genetic susceptibility loci and intermediate phenotypic GC biomarkers with whites and Asians and may also have distinct genetic susceptibility factors.

Telomere length in peripheral blood leukocytes and lung cancer risk: a large case-control study in Caucasians

Telomere dysfunction is a crucial event in malignant transformation and tumorigenesis. Telomere length in peripheral blood leukocytes has been associated with lung cancer risk, but the relationship has remained controversial. In this study, we investigated whether the association might be confounded by study of different histological subtypes of lung cancer. We measured relative telomere lengths in patients in a large case-control study of lung cancer and performed stratified analyses according to the two major histologic subtypes [adenocarcinoma and squamous cell carcinoma (SCC)]. Notably, patients with adenocarcinoma had longer telomeres than controls, whereas patients with SCC had shorter telomeres compared with controls. Long telomeres were associated with increased risk of adenocarcinoma, with the highest risk associated with female sex, younger age (<60 years), and lighter smoking (<30 pack-years). In contrast, long telomeres were protective against SCC, particularly in male patients. Our results extend the concept that telomere length affects risk of lung cancer in a manner that differs with histologic subtype.

Genetic variants of the Wnt signaling pathway as predictors of recurrence and survival in early-stage non-small cell lung cancer patients

Early-stage non-small cell lung cancer (NSCLC) is potentially curative. Nevertheless, many patients will show disease recurrence after curative treatment. The Wnt signaling pathway is a developmental and stem cell pathway that plays an important role in tumorigenesis and may affect cancer progression. We hypothesize that genetic variants of the Wnt pathway may influence clinical outcome in early-stage NSCLC patients. We genotyped 441 functional and tagging single nucleotide polymorphisms (SNPs) from 54 genes of the Wnt pathway in 535 early-stage NSCLC patients treated with curative intent therapy including surgery and chemotherapy. For validation, 4 top SNPs were genotyped in 301 early-stage NSCLC patients from the Mayo Clinic. Cox proportional hazard model and combined SNP analyses were performed to identify significant SNPs correlated with recurrence-free and overall survival. Results from discovery group showed a total of 40 SNPs in 20 genes correlated with disease recurrence (P < 0.05). After correction for multiple comparisons, rs2536182 near Wnt16 remained significant (q < 0.1), which was validated in the replication population. Thirty-nine SNPs in 16 genes correlated with overall survival (P < 0.05) in the discovery group, and seven remained significant after multiple comparisons were considered (q < 0.1). In patients receiving surgery-only treatment, rs10898563 of FZD4 gene was associated with both recurrence-free and overall survival. Joint SNP analyses identified predictive markers for recurrence stratified by treatment. Our findings suggest inherited genetic variation in the Wnt signaling pathway may contribute to variable clinical outcomes for patients with early-stage NSCLC.

Plastic Surgeon Expertise in Predicting Breast Reconstruction Outcomes for Patient Decision Analysis

BACKGROUND

Decision analysis offers a framework that may help breast cancer patients make good breast reconstruction decisions. A requirement for this type of analysis is information about the possibility of outcomes occurring in the form of probabilities. The purpose of this study was to determine if plastic surgeons are good sources of probability information, both individually and as a group, when data are limited.

METHODS

Seven plastic surgeons were provided with pertinent medical information and preoperative photographs of patients, and were asked to assign probabilities to predict number of revisions, complications, and final aesthetic outcome using a questionnaire designed for the study. Logarithmic strictly proper scoring was used to evaluate the surgeons' abilities to predict breast reconstruction outcomes. Surgeons' responses were analyzed for calibration and confidence in their answers.

RESULTS

As individuals, there was variation in surgeons' ability to predict outcomes. For each prediction category, a different surgeon was more accurate. As a group, surgeons possessed knowledge of future events despite not being well calibrated in their probability assessments. Prediction accuracy for the group was up to six-fold greater than that of the best individual.

CONCLUSIONS

The use of individual plastic surgeon-elicited probability information is not encouraged unless the individual's prediction skill has been evaluated. In the absence of this information, a group consensus on the probability of outcomes is preferred. Without a large evidence base for calculating probabilities, estimates assessed from a group of plastic surgeons may be acceptable for purposes of breast reconstruction decision analysis.

MicroRNA expression signatures during malignant progression from Barrett's esophagus to esophageal adenocarcinoma

Barrett's esophagus is the precursor lesion of esophageal adenocarcinoma, whose progression follows sequential stages. However, the low progression rate and the inadequacy and subjective interpretation of histologic grading in predicting Barrett's esophagus progression call for more objective biomarkers that can improve risk prediction. We conducted a genome-wide profiling of 754 human microRNAs (miRNA) in 35 normal epithelium, 34 Barrett's esophagus, and 36 esophageal adenocarcinoma tissues using TaqMan real-time PCR-based profiling. Unsupervised hierarchical clustering using 294 modestly to highly expressed miRNAs showed clear clustering of two groups: normal epithelium versus Barrett's esophagus/esophageal adenocarcinoma tissues. Moreover, there was an excellent clustering of Barrett's metaplasia (without dysplasia) tissues from normal epithelium tissues. However, Barrett's esophagus tissues of different stages and esophageal adenocarcinoma tissues were interspersed. There were differentially expressed miRNAs at different stages. The majority of miRNA aberrations involved upregulation of expression in Barrett's esophagus and esophageal adenocarcinoma tissues, with the most dramatic alterations occurring at the Barrett's metaplasia stage. Known oncomiRs, such as miR-21, miR-25, and miR-223, and tumor suppressor miRNAs, including miR-205, miR-203, let-7c, and miR-133a, showed progressively altered expression from Barrett's esophagus to esophageal adenocarcinoma. We also identified a number of novel miRNAs that showed progressively altered expression, including miR-301b, miR-618, and miR-23b. The significant miRNA alterations that were exclusive to esophageal adenocarcinoma but not Barrett's esophagus included miR-375 downregulation and upregulation of five members of the miR-17-92 and its homologue clusters, which may become promising biomarkers for esophageal adenocarcinoma development.

γ-H2AX level in peripheral blood lymphocytes as a risk predictor for bladder cancer

Identification of susceptibility to double-strand breaks (DSBs) may provide valuable information about individual bladder cancer (BC) risk. The formation of γ-H2AX foci is a highly sensitive marker for DNA DSBs induction. We assessed whether levels of γ-H2AX in peripheral blood lymphocytes (PBL) obtained after stimulation by ionizing radiation (IR) are able to predict BC risk. Patients were enrolled from an ongoing BC case-control study. Baseline- and IR-induced H2AX phosphorylation was assessed in PBL from 174 newly diagnosed and untreated BC patients and from 174 matched control subjects by a novel, image-based, high-throughput phenotypic assay. The ratio of γ-H2AX level of IR-treated cells to that of non-treated cells (baseline) was used as the parameter to assess the sensitivity to the mutagen. The mean γ-H2AX ratios were significantly higher for cases than for controls (1.43±0.14 versus 1.35±0.12; P = 8.45×10(-8)). This trend was irrespective of age, sex and smoking status. The risk estimates of BC for induced DSBs by tertile distributions in controls showed also a significant trend for increased risk at the highest tertile for the whole cohort (odds ratio = 5.16; 95% confidence interval = 2.69, 9.89; P = 7.78 × 10(-7)) as well as for each category. Our findings suggest that a higher susceptibility to induction of DSBs as measured by the γ-H2AX assay is significantly associated with an increased risk for BC. This might help to identify individuals at high risk for this cancer, adding new perspectives to established epidemiological and genetic risk factors. Further research of the role of γ-H2AX in biological processes of BC is warranted.

Genome-wide association study of genetic predictors of overall survival for non-small cell lung cancer in never smokers

To identify the genetic factors that influence overall survival in never smokers who have non-small cell lung carcinoma (NSCLC), we conducted a consistency meta-analysis study using genome-wide association approaches for overall survival in 327 never smoker patients with NSCLC from The University of Texas MD Anderson Cancer Center (Houston, TX) and 293 cases from the Mayo Clinic (Rochester, MN). We then conducted a two-pronged validation of the top 25 variants that included additional validation in 1,256 patients with NSCLC from Taiwan and assessment of expression quantitative trait loci (eQTL) and differential expression of genes surrounding the top loci in 70 tumors and matched normal tissues. A total of 94 loci were significant for overall survival in both MD Anderson and Mayo studies in the consistency meta-analysis phase, with the top 25 variants reaching a P value of 10(-6). Two variants of these 25 were also significant in the Taiwanese population: rs6901416 [HR, 1.44; 95% confidence interval (CI), 1.01-2.06] and rs10766739 (HR, 1.23; 95%CI, 1.00-1.51). These loci resulted in a reduction of median survival time of at least eight and five months in three populations, respectively. An additional six variants (rs4237904, rs7976914, rs4970833, rs954785, rs485411, and rs10906104) were validated through eQTL analysis that identified significant correlations with expression levels of six genes (LEMD3, TMBIM, ATXN7L2, SHE, ITIH2, and NUDT5, respectively) in normal lung tissue. These genes were also significantly differentially expressed between the tumor and normal lung tissue. These findings identify several novel, candidate prognostic markers for NSCLC in never smokers, with eQTL analysis suggesting a potential biologic mechanism for a subset of these observed associations.

Mapping superficial lymphatic territories in the rabbit

Little is known about the anatomy of the lymphatic system in the rabbit with regard to relationships between the lymphatic vessel and lymph node. According to our previous studies in human cadavers and canines, the superficial lymphatic system could be divided into lymphatic territories. The aim of this study was to completely map the superficial lymphatic system in the rabbit. We used our microinjection technique and histological analysis for dissecting studies and recently developed indocyanine green (ICG) fluorescent lymphography for demonstrating dynamic lymph flow in living rabbits. Real-time ICG fluorescent lymphography was performed in two living New Zealand White rabbits, and direct dye microinjection of the lymphatic vessels was performed in eight dead rabbits. To assess the relationships between the vascular and lymphatic systems in rabbits, we performed radiocontrast injection into arteries in two dead rabbits prior to the lymphatic injection. The ICG fluorescent lymphography revealed eight lymphatic territories in the preauricular, submandibular, root of the lateral neck, axillary, lumbar, inguinal, root of the tail, and popliteal regions. We injected blue acrylic dye into every lymphatic vessel 0.1 mm in diameter or larger. We then dissected and chased the stained lymphatic vessels proximally until the vessels connected to the first tier lymph node. This procedure was repeated throughout the body until all the relationships between the lymphatic vessels and lymph nodes were defined. The lymphatic system of the rabbit could be defined as eight lymphatic territories, each with its own lymphatic vessels and lymph node.

Abstract 2554: Constitutive short telomere length and lung cancer risk: a large case- control study

Background: Telomeres plays a key role in the maintenance of chromosomal stability and integrity. Telomere dysfunction is a common crucial event in malignant transformation and tumorigenesis. Short telomere length in surrogate tissues (peripheral blood leukocytes, or PBLs) has been associated with increased risks of several cancers. In this study, we used a large case control study to evaluate the association of overall telomere length in PBLs with the risk of lung cancer.

Methods: We measured the overall telomere lengths in PBLs using real-time quantitative PCR method in a large case-control study with 769 Caucasian lung cancer cases and 769 age, gender, and ethnicity matched healthy controls Wilcoxon rank sum test was used to compare the differences between case patients and control subjects. Unconditional multivariate logistic regression analysis was used to assess the association between telomere length and lung cancer risk. In addition, the effect of age, gender and smoking status was evaluated and correlation analyses between variables were performed.

Results: As expected, telomere length was inversely correlated with age in both cases and controls. Lung cancer patients had significantly shorter overall telomere lengths (mean ± standard deviation: 1.20 ±0.37 versus 1.25 ±0.35 p =0.002) than controls, which was only evident in men (1.15 ±0.36 versus 1.24 ±0.36 p &lt;0.001) but not in women. Multivariate logistic regression analysis showed that short overall telomere length was associated with a dose-dependent increase in lung cancer risk. Compared to the individuals within the highest quartile of telomere length, the OR for those within the 3rd, 2nd and 1st quartiles was 0.88 (95% CI 0.65-1.18), 1.08 (95% CI 0.80-1.44) and 1.49 (95% CI 1.12-1.99), respectively (p for trend &lt; 0.001). This effect was more pronounced in current and former smokers (p for trend &lt; 0.001) than in nonsmokers. There was a significant interaction between smoking and overall telomere length in elevating lung cancer risk (p for interaction &lt;0.001).

Conclusions: This is the largest epidemiological study to evaluate constitutive telomere length and lung cancer risk. Our data strongly support the role of telomere dysfunction in lung carcinogenesis, highlighting its specific interaction with smoking.

Citation Format: Beatriz Sanchez-Espiridion, Jian Gu, David W. Chang, Joe Y. Chang, Charles Lu, Jack A. Roth, Xifeng Wu. Constitutive short telomere length and lung cancer risk: a large case- control study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2554. doi:10.1158/1538-7445.AM2013-2554

Genetic variations in micro-RNA biogenesis genes and clinical outcomes in non-muscle-invasive bladder cancer

Micro-RNAs (miRNAs) are small non-coding RNA molecules, which can act as either oncogenes or tumor suppressors. Dysregulated expression of miRNA genes have been implicated in the development of many different cancers. We hypothesize that genetic variations in miRNA biogenesis genes may be associated with the prognosis of bladder cancer. We genotyped 76 single nucleotide polymorphisms (SNPs) in eight miRNA biogenesis genes in 421 patients with non-muscle-invasive bladder cancer (NMIBC). We analyzed the associations of SNPs with recurrence and progression in all patients as well as stratified by treatment: transurethral resection (TUR) alone or TUR plus intravesical bacillus Calmette-Guérin (BCG) instillation. Two SNPs were significantly associated with tumor recurrence in TUR only subgroup after adjustment for multiple comparisons (Q < 0.1). The most significant SNP was rs197412 in DDX20: the variant allele conferred a decreased risk of recurrence [hazard ratio (HR) = 0.58, 95% confidence interval (95% CI) = 0.40-0.82]. This SNP was validated in a separate group of 586 NMIBC patients and the pooled HR was 0.62 (95% CI = 0.48-0.81, P < 0.001). Two linked SNPs (rs2073778 and rs720012) in DGCR8 showed significant association with tumor progression (HR = 4.00, 95% CI = 1.53-10.46, P = 0.005). A strong gene-dosage effect was observed with higher risk for tumor recurrence and progression with increasing number of unfavorable genotypes. Haplotype and survival tree analyses further characterized the association of miRNA-related SNPs with tumor recurrence and progression. Taken together, our results indicate that genetic variants in miRNA biogenesis pathway may influence bladder cancer clinical outcome in NMIBC patients.