Thompson, Ian M.

Abstract Registry-based epidemiologic studies suggest associations between chronic inflammatory intestinal diseases and pancreatic ductal adenocarcinoma (PDAC). As genetic susceptibility contributes to a large proportion of chronic inflammatory intestinal diseases, we hypothesize that the genomic regions surrounding established genome-wide associated variants for these chronic inflammatory diseases are associated with PDAC. We examined the association between PDAC and genomic regions (±500 kb) surrounding established common susceptibility variants for ulcerative colitis, Crohn's disease, inflammatory bowel disease, celiac disease, chronic pancreatitis, and primary sclerosing cholangitis. We analyzed summary statistics from genome-wide association studies data for 8,384 cases and 11,955 controls of European descent from two large consortium studies using the summary data-based adaptive rank truncated product method to examine the overall association of combined genomic regions for each inflammatory disease group. Combined genomic susceptibility regions for ulcerative colitis, Crohn disease, inflammatory bowel disease, and chronic pancreatitis were associated with PDAC at P values < 0.05 (0.0040, 0.0057, 0.011, and 3.4 × 10−6, respectively). After excluding the 20 PDAC susceptibility regions (±500 kb) previously identified by GWAS, the genomic regions for ulcerative colitis, Crohn disease, and inflammatory bowel disease remained associated with PDAC (P = 0.0029, 0.0057, and 0.0098, respectively). Genomic regions for celiac disease (P = 0.22) and primary sclerosing cholangitis (P = 0.078) were not associated with PDAC. Our results support the hypothesis that genomic regions surrounding variants associated with inflammatory intestinal diseases, particularly, ulcerative colitis, Crohn disease, inflammatory bowel disease, and chronic pancreatitis are associated with PDAC. Significance: The joint effects of common variants in genomic regions containing susceptibility loci for inflammatory bowel disease and chronic pancreatitis are associated with PDAC and may provide insights to understanding pancreatic cancer etiology.

Abstract Background: Obesity and diabetes are major modifiable risk factors for pancreatic cancer. Interactions between genetic variants and diabetes/obesity have not previously been comprehensively investigated in pancreatic cancer at the genome-wide level. Methods: We conducted a gene–environment interaction (GxE) analysis including 8,255 cases and 11,900 controls from four pancreatic cancer genome-wide association study (GWAS) datasets (Pancreatic Cancer Cohort Consortium I–III and Pancreatic Cancer Case Control Consortium). Obesity (body mass index ≥30 kg/m2) and diabetes (duration ≥3 years) were the environmental variables of interest. Approximately 870,000 SNPs (minor allele frequency ≥0.005, genotyped in at least one dataset) were analyzed. Case–control (CC), case-only (CO), and joint-effect test methods were used for SNP-level GxE analysis. As a complementary approach, gene-based GxE analysis was also performed. Age, sex, study site, and principal components accounting for population substructure were included as covariates. Meta-analysis was applied to combine individual GWAS summary statistics. Results: No genome-wide significant interactions (departures from a log-additive odds model) with diabetes or obesity were detected at the SNP level by the CC or CO approaches. The joint-effect test detected numerous genome-wide significant GxE signals in the GWAS main effects top hit regions, but the significance diminished after adjusting for the GWAS top hits. In the gene-based analysis, a significant interaction of diabetes with variants in the FAM63A (family with sequence similarity 63 member A) gene (significance threshold P < 1.25 × 10−6) was observed in the meta-analysis (PGxE = 1.2 ×10−6, PJoint = 4.2 ×10−7). Conclusions: This analysis did not find significant GxE interactions at the SNP level but found one significant interaction with diabetes at the gene level. A larger sample size might unveil additional genetic factors via GxE scans. Impact: This study may contribute to discovering the mechanism of diabetes-associated pancreatic cancer.

5022 Background: Radical cystectomy (RC) is the standard of care for patients with BCG-unresponsive high risk non-muscle invasive bladder cancer (NMIBC), but many patients are unfit for surgery or elect bladder preservation. Based on the reported efficacy of atezolizumab in metastatic urothelial carcinoma and the known expression of PD-L1 in NMIBC after BCG therapy, this trial was designed to evaluate the activity of atezolizumab in BCG-unresponsive high risk NMIBC. Methods: This single arm phase II registration trial testing systemic atezolizumab (1200 mg IV) every 3 weeks for one year aimed to enroll 135 (70 CIS and 65 non-CIS) eligible patients with histologically proven BCG-unresponsive high risk NMIBC who were unfit for or declined RC. Here we report on the subset with CIS (with or without concomitant Ta/T1) among patients who received at least one protocol treatment. The primary endpoint was pathological complete response (CR) rate at 6 months as defined by mandatory biopsy with a null hypothesis of 30% and alternative of 50% with a 1-sided alpha = 0.05 and 96% power. The 3 month CR rate, defined by cytology, cystoscopy and for-cause biopsy, is reported here as a secondary endpoint, in addition to safety. Results: Seventy-five eligible CIS patients were enrolled. Two received no treatment and are not evaluable. Of 73, median patient age was 73.4 years and median number of prior BCG doses was 12. Concomitant Ta/T1 tumor was found in 30 (41.1%) patients, including T1 disease in 16 (21.9%). A CR was observed in 30 (41.1%; 95% CI 29.7%, 53.2%) patients at 3 months and 19 (26.0%; 95% CI 16.5%, 37.6%) at 6 months. Any possibly or probably treatment-related adverse event (AE) was observed in 61 (83.6%) patients. The most frequent AEs were fatigue 36 (49.3%), pruritis 8 (11.0%), hypothyroidism 8 (11.0%), and nausea 8 (11.0%). Grade 3-5 AEs occurred in 9 (12.3%) patients and there was one treatment-related death (myasthenia gravis with respiratory failure and sepsis). Conclusion: The observed response to atezolizumab at 3 and 6 months in patients with BCG-unresponsive CIS was similar to that reported in recent similar trials and meets the benchmark for initial CR defined by the FDA guidance. This trial provided no new safety concerns. The duration of response will determine if this is a suitable treatment option for patients with BCG-unresponsive high risk CIS. Clinical trial information: 02844816 .

TPS586 Background: Chemoradiotherapy(CRT) is a SOC for patients with muscle invasive bladder cancer (MIBC) who refuse or are not fit for radical cystectomy. Radiotherapy and chemotherapy are known to increases the PD-L1 expression in bladder cancer. Based on these observations, we hypothesized that addition of atezolizumab to CRT will increase its efficacy. Methods: This is a randomized phase III trial testing CRT with and without atezolizumab for 6 months in 475 patients with MIBC. Pts will be stratified on performance status (0-1 vs. 2); clinical stage (T2 vs T3/T4a, chemotherapy(cisplatin vs 5FU+mitomycin vs gemcitabine); and radiation field (bladder only vs small pelvis). Patients will undergo biopsy 18 week from registration. If they have residual disease they will be taken off protocol treatment and can proceed with alternative SOC option including radical cystectomy. Patients will be followed for 5 years. The primary end point of the study is bladder intact event –free survival (BIEFS). The event is comprised of: recurrence or residual muscle-invasive bladder cancer at 18 weeks or later, clinical evidence of nodal or metastatic disease, radical cystectomy, or death due to any cause. This composite endpoint is reflective of the intent of bladder preservation strategy with radical cystectomy included as one of the outcomes. Secondary end points include overall survival, modified event free survival, pathologic response at 18 weeks, metastasis free survival, cancer specific survival, rate of salvage cystectomy, rate of adverse event and QOL & PRO end points. The expected 3 year BIEFS for the control arm is 52%. The study leadership concluded that a 12% improvement in this endpoint is meaningful for this patient population. With a sample size of 475 patients the study has 85% power to detect the improvement from 52% to 64% in the BIEFS at 3 years (hazard ratio=0.68). The study team will perform translational studies evaluating tumor tissue, whole blood and urine for molecular and immunologic markers of immune response and response to RT. Successful completion of this trial could lead to a new treatment paradigm for patients with muscle invasive bladder cancer. Clinical trial information: NCT03775265.

TPS4591 Background: Radical cystectomy is the standard of care for patients with BCG-unresponsive high risk non-muscle invasive bladder cancer (NMIBC). Based on the reported efficacy of atezolizumab in metastatic urothelial carcinoma and the known expression of PD-L1 expression in NMIBC after BCG therapy, this trial will evaluate the activity of atezolizumab in BCG-unresponsive high risk NMIBC. Methods: This is a single arm phase II trial testing systemic atezolizumab (1200 mg IV) every 3 weeks for one year in 135 patients with BCG-unresponsive high risk NMIBC. The study will enroll 70 patients with CIS (with or without concomitant Ta/T1) and 65 with Ta/T1 only. Patients with CIS at baseline will undergo mandatory repeat biopsy at 6 months, and all other patients only for suspected recurrence. Patients with persistent CIS, high grade Ta/T1 recurrence or progression to muscle invasive or metastatic disease will be taken off treatment. The co-primary endpoints are: (1) complete response (CR) at 6 months in the CIS subgroup, and (2) event-free survival (EFS) at 18 months in the overall population. A hierarchical approach will be used to test the two co-primary endpoints. Secondary endpoints include duration of CR as well as progression-free, cystectomy-free, bladder cancer-specific and overall survival in all patients. Response will be correlated to expression of PD-L1 and CD8 by IHC, and to molecular subtypes and immune signatures by RNA-sequencing. Results: If ≥28 (40%) CIS patients respond, the agent will be considered promising. This design has a significance level of 4.6%, and a power of 96%. If the lower bound of the 90% confidence interval of the 18-month EFS excludes 20%, the investigators will conclude the regimen significantly improves EFS relative to historical data (type I error rate 0.05 and statistical power 0.93). Conclusion:Successful completion of this trial could lead to a new treatment paradigm for patients with BCG-unresponsive high risk NMIBC. Funding: NIH/NCI grants: CA180888, CA180819, CA180820, CA180821, and CA180863. Clinical trial information: NCT02844816.

TPS527 Background: Radical cystectomy is the standard of care for patients with BCG-unresponsive high risk non-muscle invasive bladder cancer (NMIBC). Based on the reported efficacy of atezolizumab in metastatic urothelial carcinoma and the known expression of PD-L1 expression in NMIBC after BCG therapy, this trial will evaluate the activity of atezolizumab in BCG-unresponsive high risk NMIBC. Methods: This is a single arm phase II trial testing systemic atezolizumab (1200 mg IV) every 3 weeks for one year in 135 patients with BCG-unresponsive high risk NMIBC. The study will enroll 70 patients with CIS (with or without concomitant Ta/T1) and 65 with Ta/T1 only. Patients with CIS at baseline will undergo mandatory repeat biopsy at 6 months, and all other patients only for suspected recurrence. Patients with persistent CIS, high grade Ta/T1 recurrence or progression to muscle invasive or metastatic disease will be taken off treatment. The co-primary endpoints are: (1) complete response (CR) at 6 months in the CIS subgroup, and (2) event-free survival (EFS) at 18 months in the overall population. A hierarchical approach will be used to test the two co-primary endpoints. Secondary endpoints include duration of CR as well as progression-free, cystectomy-free, bladder cancer-specific, and overall survival in all patients. Response will be correlated to expression of PD-L1 and CD8 by IHC, and to molecular subtypes and immune signatures by RNA-sequencing. If ≥28 (40%) CIS patients respond, the agent will be considered promising. This design has a significance level of 4.6%, and a power of 96%. If the lower bound of the 90% confidence interval of the 18-month EFS excludes 20%, the investigators will conclude the regimen significantly improves EFS relative to historical data (type I error rate 0.05 and statistical power 0.93). Successful completion of this trial could lead to a new treatment paradigm for patients with BCG-unresponsive high risk NMIBC. Funding: NIH/NCI grants: CA180888, CA180819, CA180820, CA180821, and CA180863. Clinical trial registry: NCT02844816 Clinical trial information: NCT02844816.

Chronic Helicobacter pylori ( H. pylori) infection is a major gastric adenocarcinoma (GA) risk factor. GA disproportionately affects U.S. Hispanics compared with non-Hispanic Whites (NHWs). Since H. pylori infection studies in Hispanics are few, infection rates in Hispanic and NHW men in Bexar County were compared, and relationships with ethnicity and obesity examined. Age- and zip code-matched participants from a community-dwelling cohort were randomly selected. Sera from 284 men were analyzed by enzyme immunoassay for H. pylori antibodies. Adjusted risk ratio estimation for matched data was conducted to identify differences. Hispanics had a markedly higher prevalence of infection (30.3%) than NHWs (9.2%). Matched risk ratio (mRR) analyses revealed a strong association between H. pylori seropositivity and Hispanic ethnicity (mRR = 3.31; 95% CI [1.91, 5.73], adjusted by BMI, smoking status, and family history of cancer (mRR range = 3.28-3.89). BMI mRRs (range = 1.19-1.22) were significant in all models. In this cohort, Hispanic men had higher H. pylori infection rates than NHWs, and parallel the disproportionately higher rates of GA; obesity contributes to this higher prevalence. Future studies should address country of origin, acculturation, and other factors influencing obesity to further elucidate risk of GA in Hispanic populations.

Abstract Background: The Prostate Cancer Prevention Trial (PCPT) was a 7-year randomized, double-blind, placebo-controlled trial of the efficacy of finasteride for the prevention of prostate cancer with a primary outcome of histologically determined prevalence of prostate cancer at the end of 7 years. Methods: A systematic modeling process using logistic regression identified factors available at year 6 that are associated with end-of-study (EOS) biopsy adherence at year 7, stratified by whether participants were ever prompted for a prostate biopsy by year 6. Final models were evaluated for discrimination. At year 6, 13,590 men were available for analysis. Results: Participants were more likely to have the EOS biopsy if they were adherent to study visit schedules and procedures and/or were in good health (P < 0.01). Participants at larger sites and/or sites that received retention and adherence grants were also more likely to have the EOS biopsy (P < 0.05). Conclusions: Our results show good adherence to study requirements 1 year before the EOS biopsy was associated with greater odds that a participant would comply with the invasive EOS requirement. Impact: Monitoring adherence behaviors may identify participants at risk of nonadherence to more demanding study end points. Such information could help frame adherence intervention strategies in future trials. Cancer Epidemiol Biomarkers Prev; 23(8); 1638–48. ©2014 AACR.