PRRT neuroendocrine tumor response monitored using circulating transcript analysis: the NETest.

PURPOSE: Peptide receptor radionuclide therapy (PRRT) is effective for metastatic/inoperable neuroendocrine tumors (NETs). Imaging response assessment is usually efficient subsequent to treatment completion. Blood biomarkers such as PRRT Predictive Quotient (PPQ) and NETest are effective in real-time. PPQ predicts PRRT efficacy; NETest monitors disease. We prospectively evaluated: (1) NETest as a surrogate biomarker for RECIST; (2) the correlation of NETest levels with PPQ prediction. METHODS: Three independent 177Lu-PRRT-treated GEP-NET and lung cohorts (Meldola, Italy: n = 72; Bad-Berka, Germany: n = 44; Rotterdam, Netherlands: n = 41). Treatment response: RECIST1.1 (responder (stable, partial, and complete response) vs non-responder). Blood sampling: pre-PRRT, before each cycle and follow-up (2-12 months). PPQ (positive/negative) and NETest (0-100 score) by PCR. Stable < 40; progressive > 40). CgA (ELISA) as comparator. Samples de-identified, measurement and analyses blinded. Kaplan-Meier survival and standard statistics. RESULTS: One hundred twenty-two of the 157 were evaluable. RECIST stabilization or response in 67%; 33% progressed. NETest significantly (p < 0.0001) decreased in RECIST "responders" (- 47 ± 3%); in "non-responders," it remained increased (+ 79 ± 19%) (p < 0.0005). NETest monitoring accuracy was 98% (119/122). Follow-up levels > 40 (progressive) vs stable (< 40) significantly correlated with mPFS (not reached vs. 10 months; HR 0.04 (95%CI, 0.02-0.07). PPQ response prediction was accurate in 118 (97%) with a 99% accurate positive and 93% accurate negative prediction. NETest significantly (p < 0.0001) decreased in PPQ-predicted responders (- 46 ± 3%) and remained elevated or increased in PPQ-predicted non-responders (+ 75 ± 19%). Follow-up NETest categories stable vs progressive significantly correlated with PPQ prediction and mPFS (not reached vs. 10 months; HR 0.06 (95%CI, 0.03-0.12). CgA did not reflect PRRT treatment: in RECIST responders decrease in 38% and in non-responders 56% (p = NS). CONCLUSIONS: PPQ predicts PRRT response in 97%. NETest accurately monitors PRRT response and is an effective surrogate marker of PRRT radiological response. NETest decrease identified responders and correlated (> 97%) with the pretreatment PPQ response predictor. CgA was non-informative.

PRRT genomic signature in blood for prediction of 177Lu-octreotate efficacy.

BACKGROUND: Peptide receptor radionuclide therapy (PRRT) utilizes somatostatin receptor (SSR) overexpression on neuroendocrine tumors (NET) to deliver targeted radiotherapy. Intensity of uptake at imaging is considered related to efficacy but has low sensitivity. A pretreatment strategy to determine individual PRRT response remains a key unmet need. NET transcript expression in blood integrated with tumor grade provides a PRRT predictive quotient (PPQ) which stratifies PRRT "responders" from "non-responders". This study clinically validates the utility of the PPQ in NETs. METHODS: The development and validation of the PPQ was undertaken in three independent 177Lu-PRRT treated cohorts. Specificity was tested in two separate somatostatin analog-treated cohorts. Prognostic value of the marker was defined in a cohort of untreated patients. The developmental cohort included lung and gastroenteropancreatic [GEP] NETs (n = 72) from IRST Meldola, Italy. The majority were GEP (71%) and low grade (86% G1-G2). Prospective validation cohorts were from Zentralklinik Bad Berka, Germany (n = 44), and Erasmus Medical Center, Rotterdam, Netherlands (n = 42). Each cohort included predominantly well differentiated, low grade (86-95%) lung and GEP-NETs. The non-PRRT comparator cohorts included SSA cohort I, n = 28 (100% low grade, 100% GEP-NET); SSA cohort II, n = 51 (98% low grade; 76% GEP-NET); and an untreated cohort, n = 44 (64% low grade; 91% GEP-NET). Baseline evaluations included clinical information (disease status, grade, SSR) and biomarker (CgA). NET blood gene transcripts (n = 8: growth factor signaling and metabolism) were measured pre-therapy and integrated with tumor Ki67 using a logistic regression model. This provided a binary output: "predicted responder" (PPQ+); "predicted non-responder" (PPQ-). Treatment response was evaluated using RECIST criteria [Responder (stable, partial and complete response) vs Non-Responder)]. Sample measurement and analyses were blinded to study outcome. Statistical evaluation included Kaplan-Meier survival and standard test evaluation analyses. RESULTS: In the developmental cohort, 56% responded to PRRT. The PPQ predicted 100% of responders and 84% of non-responders (accuracy: 93%). In the two validation cohorts (response: 64-79%), the PPQ was 95% accurate (Bad Berka: PPQ + =97%, PPQ- = 93%; Rotterdam: PPQ + =94%, PPQ- = 100%). Overall, the median PFS was not reached in PPQ+ vs PPQ- (10-14 months; HR: 18-77, p < 0.0001). In the comparator cohorts, the predictor (PPQ) was 47-50% accurate for SSA-treatment and 50% as a prognostic. No differences in PFS were respectively noted (PPQ+: 10-12 months vs. PPQ-: 9-15 months). CONCLUSION: The PPQ derived from circulating NET specific genes and tumor grade prior to the initiation of therapy is a highly specific predictor of the efficacy of PRRT with an accuracy of 95%.

Aspirin Use and Reduced Risk of Pancreatic Cancer.

BACKGROUND: Few options besides the avoidance of smoking and obesity are available to prevent pancreatic cancer. The association between aspirin use and risk of pancreatic cancer has been inconsistent across studies. METHODS: We performed a population-based study of 761 case and 794 control subjects frequency matched on sex and age during 2006 to 2011 in Shanghai, China. Participants were asked about episodes of regular use of aspirin, tablets per day or week, and ages that the use started and stopped. Data were analyzed by unconditional logistic regression, with adjustments for age, sex, education, body mass index, years of cigarette smoking, cigarettes smoked per day, Helicobacter pylori CagA seropositivity, ABO blood group, and history of diabetes mellitus. Meta-regression was carried out to summarize the literature. RESULTS: Ever-regular use of aspirin was associated with lowered risk of pancreatic cancer: OR = 0.54; 95% confidence interval (CI), 0.40-0.73; P = 10-4.2 Risk decreased 8% per each cumulative year of use: ORtrend = 0.92; 95% CI, 0.87-0.97; P = 0.0034. Across this and 18 published studies of this association, the OR for ever-regular use decreased with increasingly more recent mid-study year, for any aspirin type (Ptrend = 10-5.1), and for low-dose aspirin (Ptrend = 0.0014). CONCLUSIONS: Regular use of aspirin thus appears to reduce risk of pancreatic cancer by almost half. IMPACT: People who take aspirin for prevention of other diseases likely also reduce their risk of pancreatic cancer. Aside from benefits for both cardiovascular disease and certain cancers, long-term aspirin use entails some risks of bleeding complications, which necessitates risk-benefit analysis for individual decisions about use. Cancer Epidemiol Biomarkers Prev; 26(1); 68-74. ©2016 AACR.

Detectable Symptomatology Preceding the Diagnosis of Pancreatic Cancer and Absolute Risk of Pancreatic Cancer Diagnosis.

The survival duration for pancreatic cancer is short. Given its low lifetime risk (1.5%), established factors for the disease have insufficient specificity to identify individuals at high risk of nonfamilial cancer, and prediagnostic signs and symptoms are vague and not limited to pancreatic causes. We considered whether statistical models that incorporated both risk factors and prediagnosis symptomatology could improve prediction enough to provide practical risk estimates. We combined US Surveillance Epidemiology and End Results (SEER) incidence data from 2008 to 2010 with regression models from representative case-control data from Connecticut (2005-2009) to estimate age- and sex-specific 5-year absolute risks of pancreatic cancer diagnosis. Our risk model included current cigarette smoking (adjusted odds ratio (OR) = 3.3, 95% confidence interval (CI): 2.1, 5.0), current use of proton pump-inhibitor antiheartburn medications (OR = 6.2, 95% CI: 1.7, 23), recent diagnosis of diabetes mellitus (OR = 4.8, 95% CI: 2.2, 11), recent diagnosis of pancreatitis (OR = 19, 95% CI: 3.1, 120), Jewish ancestry (OR = 1.8, 95% CI: 1.1, 3.1), and ABO blood group other than O (OR = 1.3, 95% CI: 1.0, 1.8). In total, 0.87% of controls with combinations of these factors had estimated 5-year absolute risks greater than 5%, and for some, the risks reached more than 10%. Combining risk factors for pancreatic cancer with detectable prediagnostic symptomatology can allow investigators to begin to identify small segments of the population with risks sufficiently high enough to make screening efforts among them potentially useful.

Case-control study of aspirin use and risk of pancreatic cancer.

BACKGROUND: Pancreas-cancer prognosis is dismal, with 5-year survival less than 5%. Significant relationships between aspirin use and decreased pancreas-cancer incidence and mortality have been shown in four of 13 studies. METHODS: To evaluate further a possible association between aspirin use and risk of pancreatic cancer, we used data from a population-based Connecticut study conducted from January 2005 to August 2009, of 362 pancreas-cancer cases frequency matched to 690 randomly sampled controls. RESULTS: Overall, regular use of aspirin was associated with reduced risk of pancreatic cancer [odds ratio (OR), 0.52; 95% confidence interval (CI), 0.39-0.69]. Increments of decreasing risk of pancreatic cancer were observed for each year of low-dose or regular-dose aspirin use (OR, 0.94; 95% CI, 0.91-0.98 and OR, 0.98; 95% CI, 0.96-1.01, respectively) and for increasing years in the past that low-dose or regular-dose aspirin use had started (OR, 0.95; 95% CI, 0.92-0.99 and OR, 0.98; 95% CI, 0.96-1.00, respectively). Reduced risk of pancreatic cancer was seen in most categories of calendar time period of aspirin use, for both low-dose aspirin and regular-dose aspirin use. Relative to continuing use at the time of interview, termination of aspirin use within 2 years of interview was associated with increased risk of pancreatic cancer (OR, 3.24; 95% CI, 1.58-6.65). CONCLUSIONS: Our results provide some support that a daily aspirin regimen may reduce risk of developing pancreatic cancer. IMPACT: Long-term aspirin use has benefits for both cardiovascular disease and cancer, but appreciable bleeding complications that necessitate risk-benefit analysis for individual applications.

Helicobacter pylori seropositivities and risk of pancreatic carcinoma.

BACKGROUND: Pathophysiologic actions of Helicobacter pylori colonization on gastric acidity have been hypothesized to modulate the effect of pancreatic carcinogens, through CagA-negative organism strain type, hyperchlorhydria and increased risk of pancreatic cancer, or CagA-positive strain, hypochlorhydria and decreased risk of pancreatic cancer. We aimed to determine H. pylori strain-specific associations with pancreatic cancer in a population in which colonization by CagA-positive strains is common. METHODS: We carried out a large population-based case-control study of pancreatic carcinoma in Shanghai, China. Venipuncture specimens were obtained from a representative sample of 761 case patients and 794 randomly selected control subjects matched by category of age and gender. Antibody seropositivity for H. pylori and its virulence protein CagA were determined by commercial enzyme-linked immunosorbent IgG assays. RESULTS: Compared with individuals seronegative for both H. pylori and CagA, decreased pancreas-cancer risk was seen for CagA seropositivity [adjusted OR, 0.68; 95% confidence interval (CI), 0.54-0.84], whereas some increased risk was suggested for CagA-negative H. pylori seropositivity (OR, 1.28; 95% CI, 0.76-2.13). No risk interactions were observed between CagA seropositivity and gender, cigarette smoking, or age-21 body mass index. CONCLUSIONS: Similar to what has been seen in animal models, our results provide suggestive evidence in humans for the involvement of gastric acidity, through its bidirectional modification according to colonization by H. pylori CagA strain type, in the risk of pancreatic carcinoma. IMPACT: H. pylori colonization may have diverse effects on cancer risk, depending on the organism strain type as well as on the particular cancer site.

Genetic effects and modifiers of radiotherapy and chemotherapy on survival in pancreatic cancer.

OBJECTIVES: Germ-line genetic variation may affect clinical outcomes of cancer patients. We applied a candidate-gene approach to evaluate the effect of putative markers on survival of patients with pancreatic cancer. We also examined gene-radiotherapy and gene-chemotherapy interactions, aiming to explain interindividual differences in treatment outcomes. METHODS: In total, 211 patients with pancreatic cancer were recruited in a population-based study. Sixty-four candidate genes associated with cancer survival or treatment response were selected from existing publications. Genotype information was obtained from a previous genome-wide association study data set. The main effects of genetic variation and gene-specific treatment interactions on overall survival were examined by proportional hazards regression models. RESULTS: Fourteen genes showed evidence of association with pancreatic cancer survival. Among these, rs1760217, located at the DPYD gene; rs17091162 at SERPINA3; and rs2231164 at ABCG2 had the lowest P of 10(-4.60), 0.0013, and 0.0023, respectively. We also observed that 2 genes, RRM1 and IQGAP2, had significant interactions with radiotherapy in association with survival, and 2 others, TYMS and MET, showed evidence of interaction with 5-fluorouracil and erlotinib, respectively. CONCLUSIONS: Our study suggested significant associations between germ-line genetic polymorphisms and overall survival in pancreatic cancer, as well as survival interactions between various genes and radiotherapy and chemotherapy.

ABO blood group, Helicobacter pylori seropositivity, and risk of pancreatic cancer: a case-control study.

Carriage of a non-O ABO blood group and colonization by Helicobacter pylori are thought to be risk factors for pancreatic cancer. We examined these associations in a population-based case-control study of 373 case patients and 690 control subjects frequency matched on sex and age. Control subjects were selected by random-digit dialing. Seropositivity for H pylori and its virulence protein CagA was determined by enzyme-linked immunosorbent assay (ELISA). Increased risk of pancreatic cancer was associated with non-O blood group (adjusted odds ratio [OR] = 1.37, 95% confidence interval [CI] = 1.02 to 1.83, P = .034) and CagA-negative H pylori seropositivity (OR = 1.68, 95% CI = 1.07 to 2.66, P = .025), but no association was observed for CagA seropositivity (OR = 0.77, 95% CI = 0.52 to 1.16). An association between pancreatic cancer risk and CagA-negative H pylori seropositivity was found among individuals with non-O blood type but not among those with O blood type (OR = 2.78, 95% CI = 1.49 to 5.20, P = .0014; OR = 1.28, 95% CI = 0.62 to 2.64, P = .51, respectively). This study demonstrates an association between pancreatic cancer and H pylori colonization, particularly for individuals with non-O blood types.