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1.  A Bayesian adaptive design with biomarkers for targeted therapies 
Targeted therapies are becoming increasingly important for the treatment of various diseases. Biomarkers are a critical component of a targeted therapy as they can be used to identify patients who are more likely to benefit from a treatment. Targeted therapies, however, have created major challenges in the design, conduct, and analysis of clinical trials. In traditional clinical trials, treatment effects for various biomarkers are typically evaluated in an exploratory fashion and only limited information about the predictive values of biomarkers obtained.
New study designs are required, which effectively evaluate both the diagnostic and the therapeutic implication of biomarkers.
The Bayesian approach provides a useful framework for optimizing the clinical trial design by directly integrating information about biomarkers and clinical outcomes as they become available. We propose a Bayesian covariate-adjusted response-adaptive randomization design, which utilizes individual biomarker profiles and patient's clinical outcomes as they become available during the course of the trial, to assign the most efficacious treatment to individual patients. Predictive biomarker subgroups are determined adaptively using a partial least squares regression approach.
A series of simulation studies were conducted to examine the operating characteristics of the proposed study design. The simulation studies show that the proposed design efficiently identifies patients who benefit most from a targeted therapy and that there are substantial savings in the sample size requirements when compared to alternative designs.
The design does not control for the type I error in the traditional sense and a positive result should be confirmed by conducting an independent phase III study focusing on the selected biomarker profile groups.
We conclude that the proposed design may serve a useful role in the early efficacy phase of targeted therapy development.
PMCID: PMC3788617  PMID: 20571131
2.  Predicting hepatic steatosis in a racially and ethnically diverse cohort of adolescent girls 
The Journal of pediatrics  2014;165(2):319-325.e1.
To develop a risk assessment model for early detection of hepatic steatosis using common anthropometric and metabolic markers.
Study design
Cross-sectional study of 134 girls, age 11–22 years (mean 13.3±2), Ethnicity: 27% Hispanic, 73% Non-Hispanic; Race: 64% Caucasian, 31% African-American, 5% Asian, from a middle school and clinics (Madison, WI). Fasting glucose, fasting insulin, alanine aminotransferase (ALT), body mass index (BMI), waist circumference (WC) and other metabolic markers were assessed. Hepatic fat was quantified using magnetic resonance proton density fat fraction (MR-PDFF). Hepatic steatosis was defined as MR-PDFF >5.5%. Outcome measures were sensitivity, specificity, and positive predictive value (PPV) of BMI, WC, ALT, fasting insulin and ethnicity as predictors of hepatic steatosis, individually and combined, in a risk assessment model. Classification and regression tree methodology constructed a decision tree for predicting hepatic steatosis.
MR-PDFF revealed hepatic steatosis in 16% of subjects (27% overweight, 3% non-overweight). Hispanic ethnicity conferred an odds ratio of 4.26 (CI 1.65–11.04, p=0.003) for hepatic steatosis. BMI and ALT did not independently predict hepatic steatosis. A BMI > 85% combined with ALT > 65 U/L had 9% sensitivity, 100% specificity and 100% PPV. Lowering ALT to 24 U/L increased sensitivity to 68%, but reduced PPV to 47%. A risk assessment model incorporating fasting insulin, total cholesterol, WC, and ethnicity increased sensitivity to 64%, specificity to 99% and PPV to 93%.
A risk assessment model can increase specificity, sensitivity, and PPV for identifying risk of hepatic steatosis and guide efficient use of biopsy or imaging for early detection and intervention.
PMCID: PMC4131842  PMID: 24857521
Hepatic Steatosis; Nonalcoholic hepatic steatosis; Metabolic Syndrome; Child and Adolescent
3.  Real-Time Immune Monitoring to Guide Plasmid DNA Vaccination Schedule Targeting Prostatic Acid Phosphatase (PAP) in Patients with Castration-Resistant Prostate Cancer 
We have previously reported that a DNA vaccine encoding prostatic acid phosphatase (PAP) could elicit PAP-specific T cells in patients with early recurrent prostate cancer. In the current pilot trial we sought to evaluate whether prolonged immunization with regular booster immunizations, or “personalized” schedules of immunization determined using real-time immune monitoring, could elicit persistent, antigen-specific T cells, and whether treatment was associated with changes in PSA doubling time (PSA DT).
16 patients with castration-resistant, non-metastatic prostate cancer received six immunizations at two-week intervals, and then either quarterly (Arm 1) or as determined by multi-parameter immune monitoring (Arm 2).
Patients were on study a median of 16 months; four received 24 vaccinations. Only one event associated with treatment > grade 2 was observed. 6/16 (38%) remained metastasis-free at 2 years. PAP-specific T cells were elicited in 12/16 (75%), predominantly of a Th1 phenotype, which persisted in frequency and phenotype for at least one year. IFNγ-secreting T-cell responses measured by ELISPOT were detectable in 5/13 individuals at one year, and this was not statistically different between study arms. The overall median fold change in PSA DT from pre-treatment to post-treatment was 1.6 (range 0.6–7.0, p=0.036).
Repetitive immunization with a plasmid DNA vaccine was safe and elicited Th1-biased antigen-specific T cells that persisted over time. Modifications in the immunization schedule based on real-time immune monitoring did not increase the frequency of patients developing effector and memory T-cell responses with this DNA vaccine.
PMCID: PMC4102643  PMID: 24850844
DNA vaccine; prostate cancer; prostatic acid phosphatase; clinical trial; immune monitoring
4.  Distinct Innate Immune Phagocyte Responses to Aspergillus fumigatus Conidia and Hyphae in Zebrafish Larvae 
Eukaryotic Cell  2014;13(10):1266-1277.
Aspergillus fumigatus is the most common filamentous fungal pathogen of immunocompromised hosts, resulting in invasive aspergillosis (IA) and high mortality rates. Innate immunity is known to be the predominant host defense against A. fumigatus; however, innate phagocyte responses to A. fumigatus in an intact host and their contributions to host survival remain unclear. Here, we describe a larval zebrafish A. fumigatus infection model amenable to real-time imaging of host-fungal interactions in live animals. Following infection with A. fumigatus, innate phagocyte populations exhibit clear preferences for different fungal morphologies: macrophages rapidly phagocytose conidia and form aggregates around hyphae, while the neutrophil response is dependent upon the presence of hyphae. Depletion of macrophages rendered host larvae susceptible to invasive disease. Moreover, a zebrafish model of human leukocyte adhesion deficiency with impaired neutrophil function also resulted in invasive disease and impaired host survival. In contrast, macrophage-deficient but not neutrophil-deficient larvae exhibited attenuated disease following challenge with a less virulent (ΔlaeA) strain of A. fumigatus, which has defects in secondary metabolite production. Taking these results together, we have established a new vertebrate model for studying innate immune responses to A. fumigatus that reveals distinct roles for neutrophils and macrophages in mediating host defense against IA.
PMCID: PMC4187654  PMID: 24879123
5.  A Randomized Phase II Trial Evaluating Different Schedules of Zoledronic Acid on Bone Mineral Density in Patients With Prostate Cancer Beginning Androgen Deprivation Therapy 
Clinical genitourinary cancer  2013;11(4):10.1016/j.clgc.2013.04.029.
Although androgen deprivation therapy for prostate cancer is associated with an increased risk of osteoporosis, the optimal timing and schedule of zoledronic acid has not been identified. This phase II trial randomized 44 men beginning androgen deprivation therapy to 3 schedules of zoledronic acid administration. Earlier or more frequent administration of zoledronic acid was found to stabilize and improve bone mineral density in men treated with androgen deprivation therapy.
To assess the effects of timing and schedule of zoledronic acid (ZA) administration on bone mineral density (BMD) in patients beginning androgen deprivation therapy (ADT) for the treatment of recurrent prostate cancer.
Patients and Methods
In this randomized, 3-arm trial, we evaluated changes in BMD after 3 different ZA administration schedules in men with recurrent prostate cancer who were beginning ADT. Forty-four patients were enrolled and randomized to receive a single dose of ZA given 1 week before beginning ADT (arm 1), a single dose of ZA given 6 months after beginning ADT (arm 2), or monthly administration of ZA starting 6 months after beginning ADT, for a total of 6 doses (arm 3).
Patients who received ZA before ADT had a significant improvement in BMD at the total proximal femur and trochanter after 6 months compared with the other groups. In addition, only patients in the arm that received multiple doses improved lumbar spine BMD while on ADT, with these findings persisting to 24 months. However, this group also experienced more grade 1 adverse events.
Analysis of these data suggests that ZA administration before initiation of ADT was superior to treatment 6 months after starting ADT in maintaining BMD. In addition, monthly ZA administration can increase BMD above baseline but is associated with more adverse events. Further study is needed to examine whether the timing and frequency of ZA therapy in patients on ADT can reduce fracture risk.
PMCID: PMC3836858  PMID: 23835291
Androgen deprivation; Bone mineral density; Gamma delta T cells; Prostate cancer; Zoledronic acid
6.  Effects of collagen deposition on passive and active mechanical properties of large pulmonary arteries in hypoxic pulmonary hypertension 
Proximal pulmonary artery (PA) stiffening is a strong predictor of mortality in pulmonary hypertension. Collagen accumulation is mainly responsible for PA stiffening in hypoxia-induced pulmonary hypertension (HPH) in mouse models. We hypothesized that collagen cross-linking and the type I isoform are the main determinants of large PA mechanical changes during HPH, which we tested by exposing mice that resist type I collagen degradation (Col1a1R/R) and littermate controls (Col1a1+/+) to hypoxia for 10 days with or without β-aminopropionitrile (BAPN) treatment to prevent cross-link formation. Static and dynamic mechanical tests were performed on isolated PAs with smooth muscle cells (SMC) in passive and active states. Percentages of type I and III collagen were quantified by histology; total collagen content and cross-linking were measured biochemically. In the SMC passive state, for both genotypes, hypoxia tended to increase PA stiffness and damping capacity, and BAPN treatment limited these increases. These changes were correlated with collagen cross-linking (p<0.05). In the SMC active state, hypoxia increased PA dynamic stiffness and BAPN had no effect in Col1a1+/+ mice (p<0.05). PA stiffness did not change in Col1a1R/R mice. Similarly, damping capacity did not change for either genotype. Type I collagen accumulated more in Col1a1+/+ mice whereas type III collagen increased more in Col1a1R/R mice during HPH. In summary, PA passive mechanical properties (both static and dynamic) are related to collagen cross-linking. Type I collagen turnover is critical to large PA remodeling during HPH when collagen metabolism is not mutated and type III collagen may serve as a reserve.
PMCID: PMC3745811  PMID: 23377784
cross-linking; type I and III collagen; extralobar pulmonary artery stiffening; pulmonary hypertension; viscoelasticity
7.  Multiphoton Microscopy of Endogenous Fluorescence Differentiates Normal, Precancerous, and Cancerous Squamous Epithelial Tissues 
Cancer research  2005;65(4):1180-1186.
This study characterizes the morphologic features and the endogenous fluorescence in the stratified squamous epithelia of the 7,12-dimethylbenz(a)anthracene-treated hamster cheek pouch model of carcinogenesis using multiphoton laser scanning microscopy (MPLSM). MPLSM allows high-resolution, three-dimensional image data to be collected deeper within thick tissue samples with reduced phototoxicity compared with single-photon imaging. Three-dimensional image stacks of normal (n = 13), precancerous (dysplasia, n = 12; carcinoma in situ, n = 9) and cancerous tissue [nonpapillary squamous cell carcinoma (SCC), n = 10, and papillary SCC, n = 7] sites in the hamster cheek pouch were collected in viable, unsectioned tissue biopsies at a two-photon excitation wavelength of 780 nm. Five features were quantified from the MPLSM images. These included nuclear density versus depth, keratin layer thickness, epithelial thickness, and the fluorescence per voxel in the keratin and epithelial layers. Statistically significant differences in all five features were found between normal and both precancerous and cancerous tissues. The only exception to this was a lack of statistically significant differences in the keratin fluorescence between normal tissues and papillary SCCs. Statistically significant differences were also observed in the epithelial thickness of dysplasia and carcinoma in situ, and in the keratin layer thickness of dysplasia and SCCs (both nonpapillary and papillary). This work clearly shows that three-dimensional images from MPLSM of endogenous tissue fluorescence can effectively distinguish between normal, precancerous, and cancerous epithelial tissues. This study provides the groundwork for further exploration into the application of multi-photon fluorescence endoscopy in a clinical setting.
PMCID: PMC4189807  PMID: 15735001
8.  Using a Bayesian Latent Class Model to Evaluate the Utility of Investigating Persons with Negative Polymerase Chain Reaction Results for Pertussis 
American Journal of Epidemiology  2013;178(2):309-318.
Pertussis remains difficult to control. Imperfect sensitivity of diagnostic tests and lack of specific guidance regarding interpretation of negative test results among patients with compatible symptoms may contribute to its spread. In this study, we examined whether additional pertussis cases could be identified if persons with negative pertussis test results were routinely investigated. We conducted interviews among 250 subjects aged ≤18 years with pertussis polymerase chain reaction (PCR) results reported from 2 reference laboratories in Wisconsin during July–September 2010 to determine whether their illnesses met the Centers for Disease Control and Prevention's clinical case definition (CCD) for pertussis. PCR validity measures were calculated using the CCD as the standard for pertussis disease. Two Bayesian latent class models were used to adjust the validity measures for pertussis detectable by 1) culture alone and 2) culture and/or more sensitive measures such as serology. Among 190 PCR-negative subjects, 54 (28%) had illnesses meeting the CCD. In adjusted analyses, PCR sensitivity and the negative predictive value were 1) 94% and 99% and 2) 43% and 87% in the 2 types of models, respectively. The models suggested that public health follow-up of reported pertussis patients with PCR-negative results leads to the detection of more true pertussis cases than follow-up of PCR-positive persons alone. The results also suggest a need for a more specific pertussis CCD.
PMCID: PMC3968301  PMID: 23735308
Bayesian analysis; Bordetella pertussis; pertussis; polymerase chain reaction; predictive value of tests; public health surveillance; sensitivity; whooping cough
9.  Ethnic Differences in the Effects of Hepatic Fat Deposition on Insulin Resistance in Non-Obese Middle School Girls 
Obesity (Silver Spring, Md.)  2013;22(1):243-248.
In non-obese youth, to investigate whether hepatic fat deposition and its metabolic consequences vary between ethnic groups.
Design Methods
Thirty-two non-obese girls (12 Hispanic White [H] and 20 non-Hispanic White [NHW] girls), aged 11–14 years old were recruited. Outcome measures were MRI measured hepatic proton density fat fraction (hepatic PDFF), BMI Z-score, waist circumference, fasting insulin, glucose, adiponectin, sex hormone binding globulin [SHBG], ALT, AST, and triglycerides, and HOMA-IR.
There were no significant differences in mean BMI Z-scores (p=0.546) or hepatic PDFF (p=0.275) between H and NHW girls; however, H girls showed significant correlations between hepatic PDFF and markers of IR (fasting insulin, HOMA-IR, adiponectin, SHBG, triglycerides; all p<0.05), while NHW girls showed no significant correlations. Matched by hepatic PDFF or BMI-Z score, H girls had more evidence of IR for a given hepatic PDFF (mean insulin, HOMA-IR, and SHBG; all p<0.05) or BMI-Z score (mean insulin and HOMA-IR; all p<0.01) than NHW girls.
In non-obese female youth, ethnicity-related differences in effects of hepatic fat on IR are evident, so that in H girls, a given amount of hepatic fat appears to result in a more predictable and greater degree of IR than in NHW girls.
PMCID: PMC3946962  PMID: 23804504
Ethnicity; Non-obese; Insulin Resistance; Hepatic Steatosis
10.  Changes in Large Pulmonary Arterial Viscoelasticity in Chronic Pulmonary Hypertension 
PLoS ONE  2013;8(11):e78569.
Conduit pulmonary artery (PA) stiffening is characteristic of pulmonary arterial hypertension (PAH) and is an excellent predictor of mortality due to right ventricular (RV) overload. To better understand the impact of conduit PA stiffening on RV afterload, it is critical to examine the arterial viscoelastic properties, which require measurements of elasticity (energy storage behavior) and viscosity (energy dissipation behavior). Here we hypothesize that PAH leads to frequency-dependent changes in arterial stiffness (related to elasticity) and damping ratio (related to viscosity) in large PAs. To test our hypothesis, PAH was induced by the combination of chronic hypoxia and an antiangiogenic compound (SU5416) treatment in mice. Static and sinusoidal pressure-inflation tests were performed on isolated conduit PAs at various frequencies (0.01–20 Hz) to obtain the mechanical properties in the absence of smooth muscle contraction. Static mechanical tests showed significant stiffening of large PAs with PAH, as expected. In dynamic mechanical tests, structural stiffness (κ) increased and damping ratio (D) decreased at a physiologically relevant frequency (10 Hz) in hypertensive PAs. The dynamic elastic modulus (E), a material stiffness, did not increase significantly with PAH. All dynamic mechanical properties were strong functions of frequency. In particular, κ, E and D increased with increasing frequency in control PAs. While this behavior remained for D in hypertensive PAs, it reversed for κ and E. Since these novel dynamic mechanical property changes were found in the absence of changes in smooth muscle cell content or contraction, changes in collagen and proteoglycans and their interactions are likely critical to arterial viscoelasticity in a way that has not been previously described. The impact of these changes in PA viscoelasticity on RV afterload in PAH awaits further investigation.
PMCID: PMC3819365  PMID: 24223157
11.  Phase I trial of tremelimumab in combination with short-term androgen deprivation in patients with PSA-recurrent prostate cancer 
Cancer Immunology, Immunotherapy  2011;61(7):1137-1147.
CTLA-4 blockade has demonstrated antitumor efficacy in human clinical trials. The antitumor mechanism is presumably mediated in part by the expansion of tumor-specific T cells. Androgen deprivation, the cornerstone of treatment for patients with metastatic prostate cancer, has been shown to elicit prostate tissue apoptosis and lymphocytic inflammation. We hypothesized that treatment with androgen deprivation, followed by an anti-CTLA-4 antibody, could augment a tumor-specific immune response elicited by androgen deprivation. We report here the results of a phase I trial evaluating a humanized monoclonal antibody targeting CTLA-4, CP-675,206 (tremelimumab), in combination with androgen deprivation using an antiandrogen. Eligible patients were those with PSA-recurrent prostate cancer after primary surgery and/or radiation therapy, not previously treated with androgen deprivation, and without radiographic evidence of metastatic disease. Subjects were treated in two cycles, 3 months apart, in which they received bicalutamide 150 mg daily days 1–28 and tremelimumab on day 29. The primary endpoint of the trial was safety. Secondary endpoints included measures of PSA kinetics and identification of a maximum tolerated dose. Eleven patients were enrolled and completed at least 1 year of follow-up. Dose-limiting toxicities included grade 3 diarrhea and skin rash. No favorable changes in PSA doubling time were observed in a period shortly after completing treatment; however, three patients experienced a prolongation in PSA doubling time detectable several months after completing treatment. The identification of delayed, prolonged favorable changes in serum PSA suggests that future studies could explore this combination in studies evaluating time to disease progression.
PMCID: PMC3349783  PMID: 22210552
Tremelimumab; Anti-CTLA-4 monoclonal antibody; Bicalutamide; Prostate cancer; Clinical trial
12.  Inpatient Hospitalization of Oncology Patients: Are We Missing an Opportunity for End-of-Life Care? 
Journal of Oncology Practice  2012;9(1):51-54.
The authors conclude that the inpatient oncology service predominantly cares for a population nearing the end of life; therefore, goals should include symptom control and end-of-life planning.
Despite advances in the care of patients with cancer over the last 10 years, cancer remains the second leading cause of death in the United States. Many patients receive aggressive, in-hospital end-of-life care at high cost. There are few data on outcomes after unplanned hospitalization of patients with metastatic cancer.
In 2000 and 2010, data were collected on admissions, interventions, and survival for patients admitted to an academic inpatient medical oncology service.
The 2000 survey included 191 admissions of 151 unique patients. The 2010 survey assessed 149 admissions of 119 patients. Lung, GI, and breast cancers were the most common cancer diagnoses. In the 2010 assessment, pain was the most common chief complaint, accounting for 28%. Although symptoms were the dominant reason for admission in 2010, procedures and imaging were common in both surveys. The median survival of patients after discharge was 4.7 months in 2000 and 3.4 months in 2010. Despite poor survival in this patient population, hospice was recommended in only 23% and 24% of patients in 2000 and 2010, respectively. Seventy percent of patients were discharged home without additional services.
On the basis of our data, an unscheduled hospitalization for a patient with advanced cancer strongly predicts a median survival of fewer than 6 months. We believe that hospital admission represents an opportunity to commence and/or consolidate appropriate palliative care services and end-of-life care.
PMCID: PMC3545663  PMID: 23633971
13.  Maintenance rituximab following induction chemo-immunotherapy for mantle cell lymphoma: long-term follow-up of a pilot study from the Wisconsin Oncology Network 
Leukemia & lymphoma  2011;52(9):1675-1680.
Mantle cell lymphoma (MCL) is challenging to manage, with a median survival of 3–5 years. While intensive strategies are often appropriate for younger patients, these approaches are often not appropriate for older patients. In 2006, we reported our initial results using modified R-hyperCVAD (rituximab with hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) with maintenance rituximab. The complete response rate was 64%, and median progression-free survival (PFS) 37 months. Herein, we update our results, now with a median follow-up of 62 months. The median PFS is unchanged and the median overall survival (OS) is 70 months. The proportion of patients surviving at 5 years is 62%, comparable to studies using intensive strategies in similar patient populations. No late toxicities were noted in our cohort. These long-term results suggest that the modified R-hyperCVAD regimen with maintenance rituximab is an excellent option for older patients with newly diagnosed mantle cell lymphoma.
PMCID: PMC3489168  PMID: 21864042
Mantle cell lymphoma; non-Hodgkin’s lymphoma; rituximab maintenance; modified R-hyperCVAD
14.  Pilot trial of interleukin-2 and zoledronic acid to augment γδ T cells as treatment for patients with refractory renal cell carcinoma 
Cancer immunology, immunotherapy : CII  2011;60(10):1447-1460.
Prior to the advent of VEGF-targeted therapies, renal cell carcinoma (RCC) was among the few solid tumors shown to respond to cytokine-based therapies such as interleukin-2 (IL-2) and interferon alpha. Previous work has shown that aminobisphosphonates, including zoledronic acid (ZA), are capable of activating human Vγ9 Vδ2 T cells in vitro, and these cells can be further expanded with IL-2. Moreover, these Vγ9 Vδ2 T cells have cytolytic activity in vitro to multiple human tumor cell lines. In the current report, we have conducted a pilot trial in patients with metastatic RCC, evaluating different doses of ZA in combination with low-dose IL-2 to determine whether combining these agents can promote in vivo proliferation of Vγ9 Vδ2 T cells and elicit an antitumor response. In 12 patients evaluated, no objective clinical responses were observed by RECIST criteria; however, two patients experienced prolonged stable disease. A modest increase in Vγ9 Vδ2 T-cell frequency could be detected by Day 8 of therapy in four of the nine patients who received at least one cycle of therapy, but not to the magnitude anticipated from preclinical models. Repeated administration of IL-2 and ZA resulted in both a diminished in vivo percentage of Vγ9 Vδ2 T cells as well as impaired expansion in vitro after the first cycle of therapy. These results suggest that repeated administration of IL-2 and ZA, at the doses and schedules used in this trial, may actually inhibit the proliferative capacity of Vγ9 Vδ2 T cell in patients with metastatic RCC.
PMCID: PMC3177972  PMID: 21647691
Vγ9 Vδ2 lymphocyte; Interleukin-2; Zoledronic acid; Renal cell carcinoma
15.  Enhancement of radiation response with bevacizumab 
Vascular endothelial growth factor (VEGF) plays a critical role in tumor angiogenesis. Bevacizumab is a humanized monoclonal antibody that neutralizes VEGF. We examined the impact on radiation response by blocking VEGF signaling with bevacizumab.
Human umbilical vein endothelial cell (HUVEC) growth inhibition and apoptosis were examined by crystal violet assay and flow cytometry, respectively. In vitro HUVEC tube formation and in vivo Matrigel assays were performed to assess the anti-angiogenic effect. Finally, a series of experiments of growth inhibition on head and neck (H&N) SCC1 and lung H226 tumor xenograft models were conducted to evaluate the impact of bevacizumab on radiation response in concurrent as well as sequential therapy.
The anti-angiogenic effect of bevacizumab appeared to derive not only from inhibition of endothelial cell growth (40%) but also by interfering with endothelial cell function including mobility, cell-to-cell interaction and the ability to form capillaries as reflected by tube formation. In cell culture, bevacizumab induced a 2 ~ 3 fold increase in endothelial cell apoptosis following radiation. In both SCC1 and H226 xenograft models, the concurrent administration of bevacizumab and radiation reduced tumor blood vessel formation and inhibited tumor growth compared to either modality alone. We observed a siginificant tumor reduction in mice receiving the combination of bevacizumab and radiation in comparison to mice treated with bevacizumab or radiation alone. We investigated the impact of bevacizumab and radiation treatment sequence on tumor response. In the SCC1 model, tumor response was strongest with radiation followed by bevacizumab with less sequence impact observed in the H226 model.
Overall, these data demonstrate enhanced tumor response when bevacizumab is combined with radiation, supporting the emerging clinical investigations that are combining anti-angiogenic therapies with radiation.
PMCID: PMC3537546  PMID: 22538017
Anti-angiogenesis; VEGF; Bevacizumab; Radiation
16.  Survival of gastrointestinal stromal tumor patients in the imatinib era: life raft group observational registry 
BMC Cancer  2012;12:90.
Gastrointestinal stromal tumors (GIST), one of the most common mesenchymal tumors of the gastrointestinal tract, prior to routine immunohistochemical staining and the introduction of tyrosine kinase inhibitors, were often mistaken for neoplasms of smooth muscle origin such as leiomyomas, leiomyosarcomas or leiomyoblastomas. Since the advent of imatinib, GIST has been further delineated into adult- (KIT or PDGFRα mutations) and pediatric- (typified by wild-type GIST/succinate dehydrogenase deficiencies) types. Using varying gender ratios at age of diagnosis we sought to elucidate prognostic factors for each sub-type and their impact on overall survival.
This is a long-term retrospective analysis of a large observational study of an international open cohort of patients from a GIST research and patient advocacy's lifetime registry. Demographic and disease-specific data were voluntarily supplied by its members from May 2000-October 2010; the primary outcome was overall survival. Associations between survival and prognostic factors were evaluated by univariate Cox proportional hazard analyses, with backward selection at P < 0.05 used to identify independent factors.
Inflections in gender ratios by age at diagnosis in years delineated two distinct groups: above and below age 35 at diagnosis. Closer analysis confirmed the above 35 age group as previously reported for adult-type GIST, typified by mixed primary tumor sites and gender, KIT or PDGFRα mutations, and shorter survival times. The pediatric group (< age 18 at diagnosis) was also as previously reported with predominantly stomach tumors, females, wild-type GIST or SDH mutations, and extended survival. "Young adults" however formed a third group aged 18-35 at diagnosis, and were a clear mix of these two previously reported distinct sub-types.
Pediatric- and adult-type GIST have been previously characterized in clinical settings and these observations confirm significant prognostic factors for each from a diverse real-world cohort. Additionally, these findings suggest that extra diligence be taken with "young adults" (aged 18-35 at diagnosis) as pediatric-type GIST may present well beyond adolescence, particularly as these distinct sub-types have different causes, and consequently respond differently to treatments.
PMCID: PMC3364851  PMID: 22429770
17.  Gender and race influence metabolic benefits of fitness in children: a cross-sectional study 
Increasing obesity and poor cardiovascular fitness (CVF) contribute to higher rates of type 2 diabetes mellitus (T2DM) in children. While the relative contributions of fitness and body fat on development of insulin resistance (IR) in children and adolescents remains unresolved, gender- and race-specific differences likely exist in the degree to which CVF influences IR and risk for T2DM. Better understanding of how gender and race affect interactions between body fat, CVF, and metabolic health would be helpful in designing effective and targeted strategies to reduce obesity-associated disease risk. We evaluated whether metabolic benefits of fitness on reducing inflammation and insulin resistance (IR) are affected by gender and race.
This cross-sectional study included 203 healthy children (mean age 12.2 y, 50% male, 46% non-Hispanic white (NHW), 54% racially diverse (RD)). Fasting insulin, glucose, hsCRP, and adiponectin were measured; race was self-reported; cardiovascular fitness (CVF) was evaluated by the Progressive Aerobic Cardiovascular Endurance Run. Associations between inflammation and gender, race, and CVF were evaluated using analysis of covariance. Multivariate regression analysis identified independent predictors of IR.
Fitness and inflammation were inversely related in both males and females (p < 0.01); this effect was marginally stronger in RD children (p = 0.06) and non-overweight males (p = 0.07). High BMI (p < 0.001), low fitness (p = 0.006), and (female) gender (p = 0.003) were independently associated with higher HOMA-IR. In males, BMI and fitness, but not race independently predicted HOMA-IR. In females, BMI and race, but not fitness independently predicted HOMA-IR.
In middle school children, the beneficial effects of fitness vary based on gender and race. High CVF has an enhanced anti-inflammatory effect in male and RD children. While BMI is the strongest predictor of IR in the study group as a whole, fitness is a significant predictor of IR only in males, and race is a significant predictor of IR only in females.
PMCID: PMC3353855  PMID: 22420715
Gender; Race; Cardiovascular Fitness; Insulin Resistance
18.  Antibody Responses to Prostate-Associated Antigens in Patients with Prostatitis and Prostate Cancer 
The Prostate  2011;71(2):134-146.
An important focus of tumor immunotherapy has been the identification of appropriate antigenic targets. Serum-based screening approaches have led to the discovery of hundreds of tumor-associated antigens recognized by IgG. Our efforts to identify immunologically recognized proteins in prostate cancer have yielded a multitude of antigens, however prioritizing these antigens as targets for evaluation in immunotherapies has been challenging. In this report, we set out to determine whether the evaluation of multiple antigenic targets would allow the identification of a subset of antigens that are common immunologic targets in patients with prostate cancer.
Using a phage immunoblot approach, we evaluated IgG responses in patients with prostate cancer (n=126), patients with chronic prostatitis (n=45), and men without prostate disease (n=53).
We found that patients with prostate cancer or prostatitis have IgG specific for multiple common antigens. A subset of 23 proteins was identified to which IgG were detected in 38% of patients with prostate cancer and 33% patients with prostatitis versus 6% of controls (p<0.001 and p=0.003, respectively). Responses to multiple members were not higher in patients with advanced disease, suggesting antibody immune responses occur early in the natural history of cancer progression.
These findings suggest an association between inflammatory conditions of the prostate and prostate cancer, and suggest that IgG responses to a panel of commonly recognized prostate antigens could be potentially used in the identification of patients at risk for prostate cancer or as a tool to identify immune responses elicited to prostate tissue.
PMCID: PMC2978272  PMID: 20632317
IgG; autoantibody; prostate cancer; prostatitis; high-throughput immunoblot
Estrogen receptor beta (ERβ) has been detected in NSCLC cell lines and tumor specimens. The ER down-regulator, fulvestrant, blocked estradiol-stimulation of tumor growth and gene transcription in NSCLC preclinical models and showed additive effects with the EGFR inhibitor gefitinib. The safety and tolerability of combination therapy with the EGFR inhibitor, gefitinib, and fulvestrant was explored.
Post-menopausal women with advanced NSCLC received gefitinib 250 mg po daily and fulvestrant 250 mg IM monthly.
Twenty-two patients were enrolled. Eight patients had adenocarcinoma, 6 NSCLC-NOS, 4 squamous cell, and 4 BAC. Seven patients were never smokers. Eight patients received ≥ 2 lines of prior chemotherapy, 6 received one prior chemotherapy, and 8 were treatment naive. One patient experienced grade 4 dyspnea possibly related to treatment; all other grade 3/4 toxicities were unrelated to treatment. Twenty patients were evaluable for response: 3 PRs were confirmed (response rate of 15%, 95% CI: 5% – 36%). The median PFS, OS, and estimated 1 yr OS were 12 wks (3–112 wks), 38.5 weeks (7–135 wks), and 41% (95% CI 20–62%), respectively. Survival outcomes did not differ by prior lines of therapy. A subset analysis revealed that OS in the 8 patients whose tumors exhibited at least 60% ERβ nuclear IHC staining measured 65.5 weeks, while that of the 5 patients with ERβ staining of less than 60% was 21 weeks. One patient with BAC and a PR had an EGFR L858R mutation in exon 21. There was no correlation between ERβ IHC expression and histology or smoking history.
Combination therapy with gefitinib and fulvestrant in this population was well-tolerated and demonstrated disease activity.
PMCID: PMC3164240  PMID: 18701186
epidermal growth factor receptor; hormonal treatment; non-small cell lung cancer; sex; age; estrogen receptor
We sought to determine whether the combination of propofol and fentanyl results in lower propofol doses and fewer adverse cardiopulmonary events than propofol and placebo for lumbar puncture (LP) in children with acute hematologic malignancies.
Randomized, controlled, double blind, crossover study.
Pediatric Sedation Program
Children with acute leukemia or lymphoma receiving sedation for LP.
Each patient received two sedations in random order, one with propofol/placebo and one with propofol/fentanyl. The study investigator and patient/parent were blinded to placebo or fentanyl. Data collected included patient age and diagnosis, propofol dose and adverse events. Adverse events included oxygen saturation < 94%, airway obstruction, apnea, hypotension and bradycardia (< 5% mean for age). Logistic regression analysis was utilized to assess probability of adverse events and the Wilcoxon Signed Rank and McNemar’s tests were used for paired comparisons.
Measurements and Main Results
Twenty-two patients were enrolled. Fourteen patients were male and 8 were female. Each patient was studied twice for a total of 44 sedations. The median age was 5.0 years (range 2.2–17.2 years). All procedures were successfully completed. The median total dose of propofol was 5.05 mg/kg (range 2.4–10.2 mg/kg) for propofol/placebo versus 3.00 mg/kg (range 1.4–10.5 mg/kg) for propofol/fentanyl (p < 0.001). Twelve adverse events occurred in 11 of 22 patients (50.0%) propofol/placebo compared to 6 of 22 (18.2%) propofol/fentanyl (p= 0.02). The most common adverse event was hypotension.
The combination of propofol and fentanyl versus propofol alone for LP sedation in children with acute hematologic malignancies resulted in lower propofol doses and fewer adverse events.
PMCID: PMC3076743  PMID: 18838923
propofol; fentanyl; pediatric oncology; procedural sedation
21.  A Phase II Study of Oxaliplatin, 5-Fluorouracil, Leucovorin, and High-Dose Capecitabine in Patients With Metastatic Colorectal Cancer 
Clinical colorectal cancer  2010;9(3):157-161.
Capecitabine has shown similar efficacy to 5-fluorouracil (5-FU); a regimen containing 2 weeks of capecitabine/oxaliplatin (CapOx) has demonstrated noninferiority to infusional 5-FU/oxaliplatin/leucovorin (FOLFOX) for the treatment of metastatic colorectal cancer (mCRC). This phase II study explores the efficacy and safety of a 2-day course of oxaliplatin/capecitabine (2DOC), with oxaliplatin given on day 1 and capecitabine given orally every 8 hours in high doses over 6 doses, mimicking FOLFOX6.
Patients and Methods
This phase II study was conducted by the University of Wisconsin Carbone Cancer Center. Eligible patients with mCRC received oxaliplatin 100 mg/m2 intravenously (I.V.) over 2 hours followed by leucovorin 20 mg/m2 I.V. bolus and 5-FU 400 mg/m2 I.V. bolus on day 1 and day 15. Capecitabine was administered at 1500 mg/m2 orally every 8 hours over 6 doses starting on day 1 and day 15.
A total of 45 patients were enrolled; 44 were evaluated for response. Seventeen patients (39%) had objective responses. Median time to progression was 6.8 months, and median overall survival (OS) was 17.5 months. The most common side effects were grade 1/2 neuropathy, fatigue, and nausea. Severe hand-foot syndrome (HFS) was rare.
The overall response rate with the 2DOC regimen is similar to published CapOx regimens, and time to progression and OS are similar. The incidence of HFS, diarrhea, and mucositis were lower compared with published results of 2-week schedules of capecitabine. The 2DOC regimen merits further study as a more convenient regimen than infusional 5-FU with less HFS when compared with a 2-week administration of capecitabine.
PMCID: PMC3058720  PMID: 20643620
2DOC; FOLFOX6; Irinotecan; Neutropenia; Thrombocytopenia
23.  The maximum tolerated dose and biologic effects of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) in combination with irinotecan for patients with refractory solid tumors 
3-AP is a ribonucleotide reductase inhibitor and has been postulated to act synergistically with other chemotherapeutic agents. This study was conducted to determine the toxicity and antitumor activity of 3-AP with irinotecan. Correlative studies included pharmacokinetics and the effects of ABCB1 and UGT1A1 polymorphisms.
The treatment plan consisted of irinotecan on day 1 with 3-AP on days 1-3 of a 21-day cycle. Starting dose was irinotecan 150 mg/m2 and 3-AP 85 mg/m2/d. Polymorphisms of ABCB1 were evaluated by pyrosequencing. Drug concentrations were determined by HPLC.
Twenty-three patients were enrolled, 10 men and 13 women. Tumor types included 7 patients with pancreatic cancer, 4 with lung cancer, 2 with cholangiocarcinoma, 2 with mesothelioma, 2 with ovarian cancer, and 6 with other malignancies. Two patients experienced dose-limiting toxicity (DLT) at dose level 1, requiring amendment of the dose escalation scheme. Maximal tolerated dose (MTD) was determined to be 3-AP 60 mg/m2/d and irinotecan 200 mg/m2. DLTs consisted of hypoxia, leukopenia, fatigue, infection, thrombocytopenia, dehydration and ALT elevation. One partial response in a patient with refractory non-small cell lung cancer was seen. Genotyping suggests that patients with wild-type ABCB1 have a higher rate of grade 3 or 4 toxicity than those with ABCB1 mutations.
The MTD for this combination was 3-AP 60 mg/m2/d on days 1-3 and irinotecan 200 mg/m2 on day 1 every 21 days. Antitumor activity in a patient with refractory non-small cell lung cancer was noted at level 1.
PMCID: PMC2921466  PMID: 20127092
Triapine®; 3-AP; irinotecan; ABCB1; UGT1A1
24.  Safety and Immunological Efficacy of a DNA Vaccine Encoding Prostatic Acid Phosphatase in Patients With Stage D0 Prostate Cancer 
Journal of Clinical Oncology  2009;27(25):4047-4054.
Prostatic acid phosphatase (PAP) is a prostate tumor antigen. We have previously demonstrated that a DNA vaccine encoding PAP can elicit antigen-specific CD8+ T cells in rodents. We report here the results of a phase I/IIa trial conducted with a DNA vaccine encoding human PAP in patients with stage D0 prostate cancer.
Patients and Methods
Twenty-two patients were treated in a dose-escalation trial with 100 μg, 500 μg, or 1,500 μg plasmid DNA, coadministered intradermally with 200 μg granulocyte-macrophage colony-stimulating factor as a vaccine adjuvant, six times at 14-day intervals. All patients were observed for 1 year after treatment.
No significant adverse events were observed. Three (14%) of 22 patients developed PAP-specific IFNγ-secreting CD8+ T-cells immediately after the treatment course, as determined by enzyme-linked immunospot. Nine (41%) of 22 patients developed PAP-specific CD4+ and/or CD8+ T-cell proliferation. Antibody responses to PAP were not detected. Overall, the prostate-specific antigen (PSA) doubling time was observed to increase from a median 6.5 months pretreatment to 8.5 months on-treatment (P = .033), and 9.3 months in the 1-year post-treatment period (P = .054).
The demonstration that a DNA vaccine encoding PAP is safe, elicits an antigen-specific T-cell response, and may be associated with an increased PSA doubling time suggests that a multi-institutional phase II trial designed to evaluate clinical efficacy is warranted.
PMCID: PMC2734418  PMID: 19636017
25.  Dose-escalation study of fixed-dose rate gemcitabine combined with capecitabine in advanced solid malignancies 
To define dose limiting toxicities (DLTs) and the maximum tolerated dose (MTD) of capecitabine with fixed-dose rate (FDR) gemcitabine.
Eligible adults (advanced solid tumor; performance status ≤ 2) received capecitabine 500mg/m2 PO BID days 1-14 and FDR gemcitabine (400-1000mg/m2 escalated by 200mg/m2 increments) at 10 mg/m2/min days 1 and 8 on a 21-day cycle. A traditional 3+3 cohort design was used to determine the MTD.
Thirty patients (median age 59 years) were enrolled. The predominant grade ≥ 3 toxicity was myelosuppression, particularly neutropenia. At dose level 4 (1000 mg/m2 gemcitabine), two out of five evaluable patients had a DLT (grade 4 neutropenia ≥ 7 days). At dose level 3 (800 mg/m2 gemcitabine), one patient had a DLT (grade 3 neutropenia ≥ 7 days) among six evaluable patients. Therefore, the MTD and recommended phase II dose was designated as capecitabine 500 mg/m2 PO BID days 1-14 with 800 mg/m2 FDR gemcitabine days 1 and 8 infused at 10 mg/m2/min on a 21-day cycle. Partial responses occurred in pretreated patients with esophageal, renal cell and bladder carcinomas.
This regimen was well tolerated and may deserve evaluation in advanced gastrointestinal and genitourinary carcinomas.
PMCID: PMC2676212  PMID: 18841362
capecitabine; gemcitabine; phase I; fixed-dose rate

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