Browsing by Author "Zhang, Jianjun"
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Item A Blood-based Metabolite Signature for Personalized Risk Assessment of Pancreatic Cancer(Scientific Archives, 2024) León-Letelier, Ricardo A.; Chen, Yihui; Ballaro, Riccardo; Irajizad, Ehsan; Do, Kim-An; Maitra, Anirban; Zhang, Jianjun; Schmidt, C. Max; Fahrmann, Johannes F.; Surgery, School of MedicineItem Applications of Time to Event Analysis in Clinical Data(2021-12) Xu, Chenjia; Gao, Sujuan; Liu, Hao; Zang, Yong; Zhang, Jianjun; Zhao, YiSurvival analysis has broad applications in diverse research areas. In this dissertation, we consider an innovative application of survival analysis approach to phase I dose-finding design and the modeling of multivariate survival data. In the first part of the dissertation, we apply time to event analysis in an innovative dose-finding design. To account for the unique feature of a new class of oncology drugs, T-cell engagers, we propose a phase I dose-finding method incorporating systematic intra-subject dose escalation. We utilize survival analysis approach to analyze intra-subject dose-escalation data and to identify the maximum tolerated dose. We evaluate the operating characteristics of the proposed design through simulation studies and compare it to existing methodologies. The second part of the dissertation focuses on multivariate survival data with semi-competing risks. Time-to-event data from the same subject are often correlated. In addition, semi-competing risks are sometimes present with correlated events when a terminal event can censor other non-terminal events but not vice versa. We use a semiparametric frailty model to account for the dependence between correlated survival events and semi-competing risks and adopt penalized partial likelihood (PPL) approach for parameter estimation. In addition, we investigate methods for variable selection in semi-parametric frailty models and propose a double penalized partial likelihood (DPPL) procedure for variable selection of fixed effects in frailty models. We consider two penalty functions, least absolute shrinkage and selection operator (LASSO) and smoothly clipped absolute deviation (SCAD) penalty. The proposed methods are evaluated in simulation studies and illustrated using data from Indianapolis-Ibadan Dementia Project.Item Association between Urinary Phytoestrogens and C-reactive Protein in the Continuous National Health and Nutrition Examination Survey(Taylor & Francis, 2017) Reger, Michael K.; Zollinger, Terrell W.; Liu, Ziyue; Jones, Josette; Zhang, Jianjun; Epidemiology, School of Public HealthObjective: A reduced risk of some cancers and cardiovascular disease associated with phytoestrogen intake may be mediated through its effect on serum C-reactive protein (CRP; an inflammation biomarker). Therefore, this study examined the associations between urinary phytoestrogens and serum CRP. Methods: Urinary phytoestrogen and serum CRP data obtained from 6009 participants aged ≥ 40 years in the continuous National Health and Nutrition Examination Survey during 1999–2010 were analyzed. Results: After adjustment for confounders, urinary concentrations of total and all individual phytoestrogens were inversely associated with serum concentrations of CRP (all p < 0.004). The largest reductions in serum CRP (mg/L) per interquartile range increase in urinary phytoestrogens (ng/mL) were observed for total phytoestrogens (β = −0.18; 95% confidence interval [CI], −0.22, −0.15), total lignan (β = −0.15; 95% CI, −0.18, −0.12), and enterolactone (β = −0.15; 95% CI, −0.19, −0.12). A decreased risk of having high CRP concentrations (≥3.0 mg/L) for quartile 4 vs quartile 1 was also found for total phytoestrogens (OR = 0.63; 95% CI, 0.53, 0.73), total lignan (OR = 0.64; 95% CI, 0.54, 0.75), and enterolactone (OR = 0.59; 95% CI, 0.51, 0.69). Conclusion: Urinary total and individual phytoestrogens were significantly inversely associated with serum CRP in a nationally representative sample of the U.S. population.Item Association of Plasma Aflatoxin With Persistent Detection of Oncogenic Human Papillomaviruses in Cervical Samples From Kenyan Women Enrolled in a Longitudinal Study(BMC, 2023-06-06) Tong, Yan; Tonui, Philip; Orang’o, Omenge; Zhang, Jianjun; Maina, Titus; Muthoka, Kapten; Groopman, John; Smith, Joshua; Madeen, Erin; Ermel, Aaron; Loehrer, Patrick; Brown, Darron R.; Biostatistics, School of Public HealthBackground: Cervical cancer is caused by oncogenic human papillomaviruses (HR-HPV) and is common among Kenyan women. Identification of factors that increase HR-HPV persistence is critically important. Kenyan women exposed to aflatoxin have an increased risk of HR-HPV detection in cervical specimens. This analysis was performed to examine associations between aflatoxin and HR-HPV persistence. Methods: Kenyan women were enrolled in a prospective study. The analytical cohort for this analysis included 67 HIV-uninfected women (mean age 34 years) who completed at least two of three annual study visits and had an available blood sample. Plasma aflatoxin was detected using ultra-high pressure liquid chromatography (UHPLC)-isotope dilution mass spectrometry. Annual cervical swabs were tested for HPV (Roche Linear Array). Ordinal logistic regression models were fitted to examine associations of aflatoxin and HPV persistence. Results: Aflatoxin was detected in 59.7% of women and was associated with higher risk of persistent detection of any HPV type (OR = 3.03, 95%CI = 1.08-8.55, P = 0.036), HR-HPV types (OR = 3.63, 95%CI = 1.30-10.13, P = 0.014), and HR-HPV types not included in the 9-valent HPV vaccine (OR = 4.46, 95%CI = 1.13-17.58, P = 0.032). Conclusions: Aflatoxin detection was associated with increased risk of HR-HPV persistence in Kenyan women. Further studies, including mechanistic studies are needed to determine if aflatoxin synergistically interacts with HR-HPV to increase cervical cancer risk.Item Associations between Intake of Calcium, Magnesium, and Phosphorus and Risk of Pancreatic Cancer: A Population-Based, Case-Control Study in Minnesota(Cambridge UP, 2021) Fan, Hao; Yu, Yunpeng; Nan, Haocheng; Hoyt, Margaret; Reger, Michael K.; Prizment, Anna; Anderson, Kristin E.; Zhang, Jianjun; Epidemiology, School of Public HealthExperimental studies suggest that abnormal levels of calcium, magnesium, and phosphorus are implicated in pancreatic carcinogenesis. We investigated the associations between intakes of these minerals and the risk of pancreatic cancer in a case-control study conducted in 1994-1998. Cases of pancreatic cancer (n150) were recruited from all hospitals in the metropolitan area of the Twin Cities and Mayo Clinic, Minnesota. Controls (n459) were randomly selected from the general population and frequency matched to cases by age, sex, and race. All dietary variables were adjusted for energy intake using the residual method prior to data analysis. Logistic regression was performed to evaluate the associations between intake of three nutrients examined and the risk of pancreatic cancer. Total intake of calcium (936 vs. 1026 mg/day) and dietary intake of magnesium (315 vs. 331 mg/day) and phosphorus (1350 vs. 1402 mg/day) were significantly lower in cases than in controls. After adjustment for confounders, there were not significant associations of total and dietary intakes of calcium, magnesium, and phosphorus with the risk of pancreatic cancer. In addition, no significant interactions exist between intakes of these minerals and total fat on pancreatic cancer risk. In conclusion, the present study does not suggest that intakes of calcium, magnesium, and phosphorus were significantly associated with the risk of pancreatic cancer.Item Associations between serum micronutrients and all-cause, cancer, and cardiovascular mortality in a national representative population: Mediated by inflammatory biomarkers(Elsevier, 2025) Liu, Chunliang; Wongsonegoro, Harrison; Sheng, Tianchen; Fan, Hao; Zhang, Jianjun; Epidemiology, Richard M. Fairbanks School of Public HealthBackground: Micronutrient intake was inversely associated with cancer and cardiovascular risk in previous studies, but obtained results were inconsistent and the biological mechanisms for this potential protective effect remain elusive. Therefore, we investigated the associations of serum vitamin C, 25(OH)D, α-tocopherol, β-carotene, lycopene, folate, and iron with all-cause, cancer, and cardiovascular mortality. We further evaluated whether these associations were mediated through altered inflammatory responses. Methods: Data were obtained from 11,539 participants aged ≥40 years in the National Health and Nutrition Examination Survey (NHANES) in 2001-2006 and 2017-2018. Mortality status of the participants with an average follow-up of 10.5 years was ascertained from the linked mortality files of the National Death Index. Cox proportional hazards regression was performed to evaluate mortality risk in relation to serum micronutrients, while mediation analysis was used to assess the mediating effects of serum C-reactive protein and white blood cell count on the associations of interest. Results: After adjustment for confounders, serum levels of vitamin C, 25(OH)D, β-carotene, and lycopene were associated with a reduced risk of death from all causes, cancer, and cardiovascular disease. For example, HRs (95 % CIs) for quartiles 2, 3, and 4 vs. quartile 1 of 25(OH)D were, respectively, 0.72 (0.62, 0.83), 0.70 (0.62, 0.79), and 0.66 (0.56, 0.78) (p-trend: <0.0001) for all-cause mortality, 0.68 (0.52, 0.91), 0.54 (0.39, 0.73), and 0.48 (0.32, 0.71) (p-trend: 0.0001) for cancer mortality, and 0.64 (0.50, 0.83), 0.66 (0.53, 0.83), and 0.59 (0.42, 0.82) (p-trend: 0.0012) for cardiovascular mortality. Additionally, serum C-reactive protein significantly mediated 5.3%-20.4 %, 4.5%-18.1 %, and 3.3%-15.7 % of the associations of vitamin C, 25(OH)D, β-carotene, and lycopene with all-cause, cancer, and cardiovascular mortality, respectively. Conclusion: This study suggested that serum levels of several antioxidants and vitamin D were inversely associated with all-cause, cancer, and cardiovascular mortality, mediated in part by mitigated inflammatory responses.Item Associations between Two Dietary Quality Scores and Pancreatic Cancer Risk in a US National Prospective Cohort Study(Taylor & Francis, 2024) Hoyt, Margaret; Song, Yiqing; Gao, Sujuan; O'Palka, Jacquelynn; Zhang, Jianjun; Biostatistics and Health Data Science, Richard M. Fairbanks School of Public HealthObjective Most previous studies investigated the associations between intake of individual nutrients and risk of disease, which failed to consider the potential interactions and correlations between various nutrients contained in food. Although dietary quality scores provide a comprehensive evaluation of the entire diet, it remains elusive whether they are associated with the risk of pancreatic cancer. Methods Dietary intake data collected with the Dietary Questionnaire (DQX) and Diet History Questionnaire (DHQ) were used to calculate HEI-2015 and DQI-R scores for participants in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. A high score indicates an increased intake of adequacy components and a decreased intake of moderation components. This study included 252 cases of pancreatic cancer documented from 58,477 persons during a median follow-up of 12.2 years in the DQX cohort and 372 cases of pancreatic cancer ascertained from 101,721 persons during a median follow-up of 8.9 years in the DHQ cohort. Cox proportional hazards regression analysis was performed to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the associations between the two dietary quality scores and pancreatic cancer risk. Results After adjustment for confounders, HEI-2015 and DQI-R scores were not significantly associated with pancreatic cancer risk. However, a significantly lower risk was observed for overweight persons with a higher HEI-2015 score in the DQX cohort (HR [95% CI] comparing the highest with lowest tertile: 0.52 [0.32, 0.85], p for trend = 0.009) and those with higher scores of some individual components. Conclusion Collectively, overall dietary quality is not associated with an altered risk of pancreatic cancer in this US population.Item Circulating Leptin and Branched Chain Amino Acids – Correlation with Intraductal Papillary Mucinous Neoplasm Dysplastic Grade(Springer Verlag, 2019-05) Yip-Schneider, Michele T.; Simpson, Rachel; Carr, Rosalie A.; Wu, Huangbing; Fan, Hao; Liu, Ziyue; Korc, Murray; Zhang, Jianjun; Schmidt, C. Max; Surgery, School of MedicineBackground: The most common type of mucinous pancreatic cyst that may progress to pancreatic cancer is intraductal papillary mucinous neoplasm (IPMN). Low-risk IPMN with low-/moderate-grade dysplasia may be safely watched, whereas high-risk IPMN with high-grade dysplasia or invasive components should undergo resection. However, there is currently no reliable means of making this distinction. We hypothesize that blood concentrations of insulin resistance biomarkers may aid in the differentiation of low- and high-risk IPMN. Methods: Plasma/serum was collected from consented patients undergoing pancreatic resection. IPMN diagnosis and dysplastic grade were confirmed by surgical pathology. The study included 235 IPMN (166 low/moderate grade, 39 high grade, 30 invasive). Circulating levels of leptin, branched chain amino acids (BCAA), and retinol-binding protein-4 (RBP-4) were measured by enzyme-linked immunoassay and correlated with surgical pathology. Results: Circulating leptin levels (mean ± SE) were significantly higher in patients with low/moderate IPMN than in high-grade/invasive IPMN (15,803 ± 1686 vs. 10,275 ± 1228 pg/ml; p = 0.0086). Leptin levels were positively correlated with BMI (r = 0.65, p < 0.0001) and were higher in females (p < 0.0001). Stratified analysis showed that mean leptin levels were significantly different between low/moderate and high/invasive IPMNs only in females (24,383 ± 2748 vs. 16,295 ± 2040 pg/ml; p = 0.020). Conversely, circulating BCAA levels were lower in low/moderate IPMN than in high-grade/invasive IPMN (0.38 ± 0.007 vs. 0.42 ± 0.01 mM; p = 0.011). No significant differences in RBP-4 levels were observed. Conclusions: Circulating leptin in females and BCAA correlates with IPMN dysplastic grade and, if combined with clinical characteristics, have the potential to improve clinical decision-making.Item Circulating Thrombospondin-2 enhances prediction of malignant intraductal papillary mucinous neoplasm(Elsevier, 2018) Simpson, Rachel E.; Yip-Schneider, Michele T.; Wu, Huangbing; Fan, Hao; Liu, Ziyue; Korc, Murray; Zhang, Jianjun; Schmidt, C. Max; Surgery, School of MedicineBackground IPMNs are cystic pancreatic lesions with variable malignant potential. Thrombospondin-2 (THBS2)—an endogenous, anti-angiogenic matrix glycoprotein—may modulate tumor progression. We hypothesized that circulating levels of THBS2 could aid in preoperative prediction of malignant IPMN. Methods Preoperative serum/plasma samples were procured from patients undergoing surgery. Circulating levels of THBS2 were measured (enzyme-linked immunosorbent assay) and compared to surgical pathology IPMN dysplastic grade. Results 164 patients underwent THBS2 testing (100 Low/Moderate-IPMN; 64 High-Grade/Invasive-IPMN). Circulating THBS2 (mean ± SD) was greater in High-Grade/Invasive-IPMN than Low/Moderate-grade IPMN (26.6 ± 12.7 ng/mL vs. 20.4 ± 8.2 ng/mL; P < 0.001). THBS2 (AUC = 0.65) out-performed CA19-9 (n = 144; AUC = 0.59) in predicting IPMN grade. The combination of THBS2, CA19-9, radiographic main-duct involvement, main-duct diameter, age, sex, and BMI (AUC 0.82; n = 137) provided a good prediction model for IPMN grade. Conclusion Circulating THBS2 is correlated with IPMN dysplasia grade. THBS2 alone did not strongly predict IPMN grade but rather strengthened prediction models for High-Grade/Invasive IPMN when combined with other clinical/biomarker data.Item Contributions of the Microbiome-Derived Metabolome for Risk Assessment and Prognostication of Pancreatic Cancer(Oxford University Press, 2024) León-Letelier, Ricardo A.; Dou, Rongzhang; Vykoukal, Jody; Yip-Schneider, Michele T.; Maitra, Anirban; Irajizad, Ehsan; Wu, Ranran; Dennison, Jennifer B.; Do, Kim-An; Zhang, Jianjun; Schmidt, C. Max; Hanash, Samir; Fahrmann, Johannes F.; Epidemiology, Richard M. Fairbanks School of Public HealthBackground: Increasing evidence implicates microbiome involvement in the development and progression of pancreatic ductal adenocarcinoma (PDAC). Studies suggest that reflux of gut or oral microbiota can lead to colonization in the pancreas, resulting in dysbiosis that culminates in release of microbial toxins and metabolites that potentiate an inflammatory response and increase susceptibility to PDAC. Moreover, microbe-derived metabolites can exert direct effector functions on precursors and cancer cells, as well as other cell types, to either promote or attenuate tumor development and modulate treatment response. Content: The occurrence of microbial metabolites in biofluids thereby enables risk assessment and prognostication of PDAC, as well as having potential for design of interception strategies. In this review, we first highlight the relevance of the microbiome for progression of precancerous lesions in the pancreas and, using liquid chromatography-mass spectrometry, provide supporting evidence that microbe-derived metabolites manifest in pancreatic cystic fluid and are associated with malignant progression of intraductal papillary mucinous neoplasm(s). We secondly summarize the biomarker potential of microbe-derived metabolite signatures for (a) identifying individuals at high risk of developing or harboring PDAC and (b) predicting response to treatment and disease outcomes. Summary: The microbiome-derived metabolome holds considerable promise for risk assessment and prognostication of PDAC.