Impact of navigators on completion of steps in the kidney transplant process: a randomized, controlled trial

BACKGROUND AND OBJECTIVES

Many patients with ESRD, particularly minorities and women, face barriers in completing the steps required to obtain a transplant. These eight sequential steps are as follows: medical suitability, interest in transplant, referral to a transplant center, first visit to center, transplant workup, successful candidate, waiting list or identify living donor, and receive transplant. This study sought to determine the effect of navigators on completion of steps.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Cluster randomized, controlled trial at 23 Ohio hemodialysis facilities. One hundred sixty-seven patients were recruited between January 2009 and August 2009 and were followed for up to 24 months or until study end in February 2011. Trained kidney transplant recipients met monthly with intervention participants (n=92), determined their step in the transplant process, and provided tailored information and assistance in completing the step. Control participants (n=75) continued to receive usual care. The primary outcome was the number of transplant process steps completed.

RESULTS

Starting step did not significantly differ between the two groups. By the end of the trial, intervention participants completed more than twice as many steps as control participants (3.5 versus 1.6 steps; difference, 1.9 steps; 95% confidence interval, 1.3-2.5 steps). The effect of the intervention on step completion was similar across race and sex subgroups.

CONCLUSIONS

Use of trained transplant recipients as navigators resulted in increased completion of transplant process steps.

Effects on postoperative salivary cortisol of relaxation/music and patient teaching about pain management

The physiological and psychological stress of surgery and postoperative pain can leave patients more susceptible to infection and complications. The present study was designed to determine whether two interventions, patient teaching (PT) for pain management and relaxation/music (RM), reduced cortisol levels, an indicator of stress, following abdominal surgery. Patients (18-75 years) were randomly assigned to receive PT, RM, a combination of the two, or usual care; the 205 patients with both pre- and posttest cortisol values were analyzed. A 2 × 2 factorial design was used to compare groups for PT effects and RM effects. Stress was measured by salivary cortisol before and after 20-min tests of the interventions in the morning and afternoon of postoperative Day 2. Saliva was stimulated with lemon juice and analyzed with high-sensitivity salivary cortisol enzyme immunoassay. Comparisons using analysis of covariance (ANCOVA), controlling for baseline levels, showed no PT effect or RM effect on cortisol in the morning or afternoon. Post hoc ANCOVA showed no significant effects when intervention groups were compared to the control group. Although in previous studies, RM reduced pain and music reduced cortisol on Day 1, in the present study the cortisol response to surgery was not attenuated by PT or RM on Day 2. The RM intervention can be used for pain but needs to be further tested for effects on plasma cortisol in abdominal surgery patients on their first postoperative day.

Effect of an iPod video intervention on consent to donate organs: a randomized trial

BACKGROUND

The gap between the supply of organs available for transplantation and demand is growing, especially among ethnic groups.

OBJECTIVE

To evaluate the effect of a video designed to address concerns of ethnic groups about organ donation.

DESIGN

Cluster randomized, controlled trial. Randomization was performed by using a random-number table with centralized allocation concealment. Participants and investigators assessing outcomes were not blinded to group assignment. (ClinicalTrials.gov registration number: NCT00870506)

SETTING

Twelve branches of the Ohio Bureau of Motor Vehicles in northeastern Ohio.

PARTICIPANTS

952 participants aged 15 to 66 years.

INTERVENTION

Video (intervention; n = 443) or usual Bureau of Motor Vehicles license practices (control; n = 509).

MEASUREMENTS

The primary outcome was the proportion of participants who provided consent for organ donation on a newly acquired driver's license, learner's permit, or state identification card. Secondary outcomes included willingness to make a living kidney donation to a family member in need and personal beliefs about donation.

RESULTS

More participants who viewed the video consented to donate organs than control participants (84% vs. 72%; difference, 12 percentage points [95% CI, 6 to 17 percentage points]). The video was effective among black participants (76% vs. 54%; difference, 22 percentage points [CI, 9 to 35 percentage points]) and white participants (88% vs. 77%; difference, 11 percentage points [CI, 5 to 15 percentage points]). At the end of the trial, fewer intervention than control participants reported having insufficient information about organ donation (34% vs. 44%; difference, -10 percentage points [CI, -16 to -4 percentage points]), wanting to be buried with all of their organs (14% vs. 25%; difference, -11 percentage points [CI, -16 to -6 percentage points]), and having conflicts with organ donation (7% vs. 11%; difference, -4 percentage points [CI, -8 to -2 percentage points]).

LIMITATION

How the observed increases in consent to donate organs might translate into a greater organ supply in the region is unclear.

CONCLUSION

Exposure to a brief video addressing concerns that ethnic groups have about organ donation just before obtaining a license, permit, or identification card increased consent to donate organs among white and black participants.

PRIMARY FUNDING SOURCE

National Institutes of Health and the Robert Wood Johnson Foundation.

Quality assessment in oncology

The movement to improve healthcare quality has led to a need for carefully designed quality indicators that accurately reflect the quality of care. Many different measures have been proposed and continue to be developed by governmental agencies and accrediting bodies. However, given the inherent differences in the delivery of care among medical specialties, the same indicators will not be valid across all of them. Specifically, oncology is a field in which it can be difficult to develop quality indicators, because the effectiveness of an oncologic intervention is often not immediately apparent, and the multidisciplinary nature of the field necessarily involves many different specialties. Existing and emerging comparative effectiveness data are helping to guide evidence-based practice, and the increasing availability of these data provides the opportunity to identify key structure and process measures that predict for quality outcomes. The increasing emphasis on quality and efficiency will continue to compel the medical profession to identify appropriate quality measures to facilitate quality improvement efforts and to guide accreditation, credentialing, and reimbursement. Given the wide-reaching implications of quality metrics, it is essential that they be developed and implemented with scientific rigor. The aims of the present report were to review the current state of quality assessment in oncology, identify existing indicators with the best evidence to support their implementation, and propose a framework for identifying and refining measures most indicative of true quality in oncologic care.

Validity and power of missing data imputation for extreme sampling and terminal measures designs in mediation analysis

Several authors have acknowledged that testing mediational hypotheses between treatments, genes, physiological measures, and behaviors may substantially advance our understanding of how these associations operate. In psychiatric research, the costs of measuring the putative mediator or the outcome can be prohibitive. Extreme sampling designs have been validated as methods for reducing study costs by increasing power per subject measured on the more expensive variable when assessing bivariate relationships. However, there exist concerns about how missing data can potentially bias the results. Additionally, most mediation analysis techniques presuppose the joint measurement of mediators and outcomes for all subjects. There have been limited methodological developments for techniques that can evaluate putative mediators in studies that have employed extreme sampling, resulting in missing data. We demonstrate that extreme (selective) sampling strategies can be beneficial in the context of mediation analyses. Handling the missing data with maximum likelihood (ML) resulted in minimal power loss and unbiased parameter estimates. We must be cautious, though, in recommending the ML approach for extreme sampling designs because it yielded inflated Type 1 error rates under some null conditions. Yet, the use of extreme sampling designs and methods to handle the resultant missing data presents a viable research strategy.

Estimating overall exposure effects for zero-inflated regression models with application to dental caries

Zero-inflated (ZI) models, which may be derived as a mixture involving a degenerate distribution at value zero and a distribution such as negative binomial (ZINB), have proved useful in dental and other areas of research by accommodating 'extra' zeroes in the data. Used in conjunction with generalised linear models, they allow covariate-adjusted inference of an exposure effect on the mixing probability and on the mean for the non-degenerate distribution. However, these models do not directly provide covariate-adjusted inference for the overall exposure effect. Focusing on the ZINB and ZI beta binomial models, we propose an approach that uses model-predicted values for each person under each exposure state. This 'average predicted value' method allows covariate-adjusted estimation of flexible functions of exposure group means such as the difference or ratio. A second approach considers a log link for both components of the ZINB to allow a direct approach to estimation. We apply these new methods to a study of dental caries in very low birth weight adolescents. Simulation studies show good bias and robustness properties for both approaches under various scenarios. Robustness diminishes when there is exposure group imbalance for a covariate with a large effect.

Prospective randomized trial of 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC) versus paclitaxel and FAC (TFAC) in patients with operable breast cancer: impact of taxane chemotherapy on locoregional control

A previous randomized trial (CALGB 9344/Intergroup 0148) compared four cycles of adjuvant doxorubicin/cyclophosphamide (AC) to four cycles of AC plus four cycles of paclitaxel (AC + T) and demonstrated that the addition of paclitaxel improved locoregional control (LRC) in patients with node-positive breast cancer. However, it could not be determined whether it was the paclitaxel or the increased duration of chemotherapy that led to this improvement. The present study aimed to analyze whether the addition of paclitaxel to a doxorubicin-based regimen improves LRC in a cohort of patients who all received eight total cycles of chemotherapy. Five hundred eleven women with operable breast cancer were randomized on a single-institution prospective trial to receive 5-fluorouracil, doxorubicin, cyclophosphamide (FAC) × 8 cycles (n = 252) or FAC × 4 cycles plus paclitaxel × 4 cycles (TFAC) (n = 259). Rates of LRC and overall survival (OS) were analyzed. Median follow-up was 124 months (range 5-167 months). The 10-year LRC rate was 92.6 versus 93.1% in the FAC versus TFAC arms, respectively (P = 0.26). The LRC between treatment arms did not differ when analyzed by locoregional treatment group: breast conservation therapy (BCT), mastectomy alone (M), and mastectomy + radiation (M + RT). The 10-year LRC rates were 95.1% (FAC) versus 91.2% (TFAC) after BCT (P = 0.98), 89.5% (FAC) versus 93.4% (TFAC) after M (P = 0.24), and 94.7% (FAC) versus 96.5% (TFAC) after M + RT (P = 0.59). Additionally, there was no difference in OS between the treatment arms, with 10-year OS rates of 78.4% (FAC) versus 81.7% (TFAC) (P = 0.93). The addition of paclitaxel to a doxorubicin-based regimen had no impact on LRC, regardless of the type of local therapy received. Historically inferior LRC with AC chemotherapy alone versus AC + T may have been due to an inadequate duration of systemic therapy and not due to the absence of paclitaxel.

Patients with only 1 positive hormone receptor have increased locoregional recurrence compared with patients with estrogen receptor-positive progesterone receptor-positive disease in very early stage breast cancer

BACKGROUND

Estrogen receptor (ER) and progesterone receptor (PR) are important prognostic and predictive biomarkers in breast cancer. Patients with tumors positive for either receptor are generally considered hormone receptor-positive for treatment decisions. However, some data suggest that patients with ER(+) /PR(-) or ER(-) /PR(+) tumors may have worse outcomes than those with ER(+) /PR(+) tumors. Few data correlate these biomarkers with locoregional (LR) recurrence.

METHODS

The authors retrospectively reviewed records of 635 patients with T1a,bN0 disease who received definitive treatment at their institution between 1997 and 2002 and had archival tissue blocks for prospective assessment of ER/PR expression. They compared clinical outcomes of the 479 patients with ER(+) /PR(+) disease to the 156 patients with ER(+) /PR(-) or ER(-) /PR(+) disease.

RESULTS

LR recurrence rates were higher in patients with 1 receptor positive compared with ER(+) /PR(+) (7-year rate: 8.8% vs 2.5%, P = .024). There was no difference between the 2 groups in the rates of distant metastasis (DM) (P = .531) or overall survival (P = .491). One positive receptor predicted for LR recurrence in patients who did not receive hormonal therapy (P = .046), but not in patients who received hormonal therapy (P = .296). On multivariate analysis, 1 positive receptor predicted for LR recurrence in the overall group (hazard ratio, 2.81; 95% confidence interval, 1.06-7.48; P = .038).

CONCLUSIONS

Patients with T1a,bN0 breast cancer with only 1 positive hormone receptor have increased rates of LR recurrence compared with patients with ER(+) /PR(+) disease, although this difference may be reduced or eliminated with systemic treatment. In contrast, the authors found no evidence of an increased rate of DM in these patients with favorable disease stage.

Generalized causal mediation analysis

The goal of mediation analysis is to assess direct and indirect effects of a treatment or exposure on an outcome. More generally, we may be interested in the context of a causal model as characterized by a directed acyclic graph (DAG), where mediation via a specific path from exposure to outcome may involve an arbitrary number of links (or "stages"). Methods for estimating mediation (or pathway) effects are available for a continuous outcome and a continuous mediator related via a linear model, while for a categorical outcome or categorical mediator, methods are usually limited to two-stage mediation. We present a method applicable to multiple stages of mediation and mixed variable types using generalized linear models. We define pathway effects using a potential outcomes framework and present a general formula that provides the effect of exposure through any specified pathway. Some pathway effects are nonidentifiable and their estimation requires an assumption regarding the correlation between counterfactuals. We provide a sensitivity analysis to assess the impact of this assumption. Confidence intervals for pathway effect estimates are obtained via a bootstrap method. The method is applied to a cohort study of dental caries in very low birth weight adolescents. A simulation study demonstrates low bias of pathway effect estimators and close-to-nominal coverage rates of confidence intervals. We also find low sensitivity to the counterfactual correlation in most scenarios.

Dental caries and enamel defects in very low birth weight adolescents

OBJECTIVES

The purpose of this study was to examine developmental enamel defects and dental caries in very low birth weight adolescents with high risk (HR-VLBW) and low risk (LR-VLBW) compared to full-term (term) adolescents.

METHODS

The sample consisted of 224 subjects (80 HR-VLBW, 59 LR-VLBW, 85 term adolescents) recruited from an ongoing longitudinal study. Sociodemographic and medical information was available from birth. Dental examination of the adolescent at the 14-year visit included: enamel defects (opacity and hypoplasia); decayed, missing, filled teeth of incisors and molars (DMFT-IM) and of overall permanent teeth (DMFT); Simplified Oral Hygiene Index for debris/calculus on teeth, and sealant presence. A caregiver questionnaire completed simultaneously assessed dental behavior, access, insurance status and prevention factors. Hierarchical analysis utilized the zero-inflated negative binomial model and zero-inflated Poisson model.

RESULTS

The zero-inflated negative binomial model controlling for sociodemographic variables indicated that the LR-VLBW group had an estimated 75% increase (p < 0.05) in number of demarcated opacities in the incisors and first molar teeth compared to the term group. Hierarchical modeling indicated that demarcated opacities were a significant predictor of DMFT-IM after control for relevant covariates. The term adolescents had significantly increased DMFT-IM and DMFT scores compared to the LR-VLBW adolescents.

CONCLUSION

LR-VLBW was a significant risk factor for increased enamel defects in the permanent incisors and first molars. Term children had increased caries compared to the LR-VLBW group. The effect of birth group and enamel defects on caries has to be investigated longitudinally from birth.

Modeling patient-centered communication: oncologist relational communication and patient communication involvement in breast cancer adjuvant therapy decision-making

OBJECTIVE

Relational communication refers to those messages communicators naturally express that carry meaning about the type and quality of relationship they share. It is expected that patients of oncologists who express positive relational communication will be more communicatively involved in their office visits, and regret their decision for adjuvant therapy following surgery less.

METHODS

One hundred eighty (180) audio-recorded discussions between oncologists (n=40) and early stage (I-III) breast cancer patients were coded with the Siminoff Communication Content and Affect Program (SCCAP). The data were used to test the relationships between patient demographics, oncologist relational communication, patient communication involvement and self-reported patient decision regret.

RESULTS

After controlling for clinician clusters, oncologists' verbal (i.e., confirming messages) and nonverbal (i.e., direct and inclusive speech) relational communication is indirectly associated with lower patient decision regret via the mediating effect of greater patient communication involvement.

CONCLUSION

Clinician relational communication provides an influential affective climate for decision-making that appears to have important effects on patients' decision confidence.

PRACTICE IMPLICATIONS

Clinicians should recognize the potential of their own relational messages to facilitate patients' communication involvement in decision-making during cancer care.

Chemoradiotherapy in locally advanced, unresectable non-small cell lung cancer

Chemoradiation is the major treatment option in unresectable, locally advanced non-small cell lung cancer. Many clinical trials have evaluated the efficacy of different combinations of chemotherapy and radiotherapy in this heterogeneous patient population. Early clinical trials showed a survival advantage of sequential chemo-RT compared to radiation alone. Subsequent trials demonstrated that concurrent chemo-RT improved survival over sequential chemo-RT. More recent studies have suggested that there is no advantage to adding induction chemotherapy prior to concurrent chemo-RT, or to adding consolidation chemotherapy after concurrent chemo-RT. Various clinical trials have used different chemotherapy regimens, though there is still no consensus about those which are most effective. Additionally, different radiotherapeutic strategies have included hyperfractionation vs. standard fractionation, use of 3-dimensional techniques, and altering total radiation dose. As these methods are being perfected, much attention has turned toward the use of molecularly targeted therapies. This review summarizes recent clinical trials examining the role of chemo-RT in locally advanced non-small cell lung cancer and the movement toward personalized medicine.

Mediation analysisvia potential outcomes models

This paper develops a causal or manipulation model framework for mediation analysis based on the concept of potential outcome. Using this framework, we provide new definitions and measures of mediation. Effects of manipulations are modeled via the linear structural model. Corresponding structural equation models (SEMs), in conjunction with two-stage least-squares estimation and the delta method, are used to perform inference. The methods are applied to data from a study of nursing interventions for postoperative pain. We address the cases of more than two treatment groups, and an interaction among mediators. For the latter, a sensitivity analysis approach to handle unidentified parameters is described. Interpretative advantages of the potential outcomes framework for mediation are emphasized.

Cytoplasmic clusterin expression is associated with longer survival in patients with resected non small cell lung cancer

BACKGROUND

Clusterin is a glycoprotein that has been implicated in many processes, including apoptosis, cell cycle regulation, and DNA repair. Previous studies have examined the prognostic value of clusterin expression in various malignancies. In the present study, we examined clusterin staining in tumors resected from patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Tumor specimens were obtained for 113 patients with completely resected NSCLC from paraffin-embedded tissue microarrays and stained with an antibody specific for clusterin. Staining patterns were observed and graded based on intensity and then correlated with clinical data.

RESULTS

Positive cytoplasmic clusterin staining was observed in 44 patients, and weak/negative staining was observed in 62 patients. Patients who had tumors that stained positive for cytoplasmic clusterin had significantly longer survival in multivariate analysis (hazard ratio 0.487, 95% confidence interval 0.27-0.89). A correlation was also observed for recurrence-free survival, which approached statistical significance (hazard ratio 0.345, 95% confidence interval 0.12-1.02). In univariate analysis, patients with clusterin-positive tumors had a 63% 3-year survival, whereas patients with clusterin-negative tumors had a 42% 3-year survival (P = 0.0108); clusterin-positive tumors also had significantly less recurrence (P = 0.0231).

CONCLUSIONS

Cytoplasmic clusterin staining is present in a substantial number of NSCLC tumors and may be a biomarker for longer survival in patients with surgically resected NSCLC.

Prospective randomized double-blind trial of bilateral thalamic deep brain stimulation in adults with Tourette syndrome

Object

The severity of Tourette syndrome (TS) typically peaks just before adolescence and diminishes afterward. In some patients, however, TS progresses into adulthood, and proves to be medically refractory. The authors conducted a prospective double-blind crossover trial of bilateral thalamic deep brain stimulation (DBS) in five adults with TS.

Methods

Bilateral thalamic electrodes were implanted. An independent programmer established optimal stimulator settings in a single session. Subjective and objective results were assessed in a double-blind randomized manner for 4 weeks, with each week spent in one of four states of unilateral or bilateral stimulation. Results were similarly assessed 3 months after unblinded bilateral stimulator activation while repeated open programming sessions were permitted.

Results

In the randomized phase of the trial, a statistically significant (p < 0.03, Friedman exact test) reduction in the modified Rush Video-Based Rating Scale score (primary outcome measure) was identified in the bilateral on state. Improvement was noted in motor and sonic tic counts as well as on the Yale Global Tic Severity Scale and TS Symptom List scores (secondary outcome measures). Benefit was persistent after 3 months of open stimulator programming. Quality of life indices were also improved. Three of five patients had marked improvement according to all primary and secondary outcome measures.

Conclusions

Bilateral thalamic DBS appears to reduce tic frequency and severity in some patients with TS who have exhausted other available means of treatment.

Inhibition of poly(ADP-ribose) polymerase enhances cell death and improves tumor growth delay in irradiated lung cancer models

PURPOSE

Poly(ADP-ribose) polymerase-1 (PARP-1) is the founding member of a family of enzymes that catalyze the addition of ADP-ribose units to proteins that mediate DNA repair pathways. Ionizing radiation induces DNA strand breaks, suggesting that PARP-1 inhibition may sensitize tumor cells to radiation.

EXPERIMENTAL DESIGN

We investigated the combination of PARP-1 inhibition with radiation in lung cancer models. ABT-888, a novel potent PARP-1 inhibitor, was used to explore the effects of PARP-1 inhibition on irradiated tumors and tumor vasculature.

RESULTS

ABT-888 reduced clonogenic survival in H460 lung cancer cells, and inhibited DNA repair as shown by enhanced expression of DNA strand break marker histone gamma-H2AX. Both apoptosis and autophagy contributed to the mechanism of increased cell death. Additionally, ABT-888 increased tumor growth delay at well-tolerated doses in murine models. For a 5-fold increase in tumor volume, tumor growth delay was 1 day for ABT-888 alone, 7 days for radiation alone, and 13.5 days for combination treatment. Immunohistochemical staining of tumor sections revealed an increase in terminal deoxyribonucleotide transferase-mediated nick-end labeling apoptotic staining, and a decrease in Ki-67 proliferative staining after combination treatment. Matrigel assay showed a decrease in in vitro endothelial tubule formation with ABT-888/radiation combination treatment, and von Willebrand factor staining of tumor sections revealed decreased vessel formation in vivo, suggesting that this strategy may also target tumor angiogenesis.

CONCLUSIONS

We conclude that PARP-1 inhibition shows promise as an effective means of enhancing tumor sensitivity to radiation, and future clinical studies are needed to determine the potential of ABT-888 as a radiation enhancer.

Inhibition of survivin and aurora B kinase sensitizes mesothelioma cells by enhancing mitotic arrests

PURPOSE

Survivin, a member of the inhibitor of apoptosis gene family, has also been shown to regulate mitosis. It binds Aurora B kinase and the inner centromere protein to form the chromosome passenger complex. Both Aurora B and survivin are overexpressed in many tumors. In this study, we examined whether irradiation affected survivin and Aurora B expression in mesothelioma cells, and how inhibition of these molecules affected radiosensitivity.

METHODS AND MATERIALS

ZM447439 and survivin antisense oligonucleotides were used to inhibit survivin and Aurora B kinase respectively. Western blot was performed to determine the expression of survivin, Aurora B, phosphorylated-histone H3 (Ser 10), and caspase cleavage. Multinucleated cells were counted using flow cytometry, and cell survival after treatment was determined using clonogenic assay.

RESULTS

At 3-Gy irradiation an increase was observed in levels of survivin and Aurora B as well as the kinase activity of Aurora B, with an increase in G2/M phase. The radiation-induced upregulation of these molecules was effectively attenuated by antisense oligonucleotides against survivin and a small-molecule inhibitor of Aurora B, ZM447439. Dual inhibition of survivin and Aurora B synergistically radiosensitized mesothelioma cells with a dose enhancement ratio of 2.55. This treatment resulted in increased formation of multinucleated cells after irradiation but did not increase levels of cleaved caspase 3.

CONCLUSION

Inhibition of survivin and Aurora B induces mitotic cell arrest in mesothelioma cells after irradiation. These two proteins may be potential therapeutic targets for the enhancement of radiotherapy in malignant pleural mesothelioma.

Estimating Treatment Effect Heterogeneity for Binary Outcomes via Dirichlet Multinomial Constraints

In a randomized two-group parallel trial the mean causal effect is typically estimated as the difference in means or proportions for patients receiving, say, either treatment (T) or control (C). Treatment effect heterogeneity (TEH), or unit-treatment interaction, the variability of the causal effect (defined in terms of potential outcomes) across individuals, is often ignored. Since only one of the outcomes, either Y(T) or Y(C), is observed for each unit in such studies, the TEH is not directly estimable. For convenience, it is often assumed to be minimal or zero. We are particularly interested in the 'treatment risk' for binary outcomes, that is, the proportion of individuals who would succeed on C but fail on T. Previous work has shown that the treatment risk can be bounded (Albert, Gadbury and Mascha, 2005), and that the confidence interval width around it can be narrowed using clustered or correlated data (Mascha and Albert, 2006). Without further parameter constraints, treatment risk is unidentifiable. We show, however, that the treatment risk can be directly estimated when the four underlying population counts comprising the joint distribution of the potential outcomes, Y(T) and Y(C), follow constraints consistent with the Dirichlet multinomial. We propose a test of zero treatment risk and show it to have good size and power. Methods are applied to both a randomized as well as a non-randomized study. Implications for medical decision-making at the policy and individual levels are discussed.

PDGFR-beta expression in small cell lung cancer patients

BACKGROUND

Platelet derived growth factor (PDGF) and PDGFR-beta are expressed and have been found to have prognostic value in several human cancers. Data in non-small-cell cancer cell lines have suggested that PDGFR is a therapeutic target for drug development. In the current study PDGFR-beta expression and prognostic value in small cell lung cancer (SCLC) was investigated.

METHODS AND MATERIALS

Paraffin-embedded tissue blocks from 53 patients with limited and extensive stage SCLC were obtained for immunohistochemical staining. Tumors from each patient were sampled 3 times and stained with PDGFR-beta specific antibody. Patients were divided into low and high staining groups based on intensity.

RESULTS

There was high intensity PDGFR-beta staining in 20 patients with SCLC. Another 29 expressed low intensity PDGFR-beta staining, with only 4 patients showing no PDGFR-beta staining. There was no statistically significant difference in 5 year overall survival between patients with low levels of PDGFR-beta staining vs. those with high level staining SCLC tumors (p = 0.538).

CONCLUSIONS

The present study found that the majority of SCLC patients express, at least, a low level of PDGF-beta. However, the level of PDGFR-beta expression was not a statistically significant predictor of 5 year overall survival in SCLC.

Inhibition of signal transducer and activator of transcription 3 activity results in down-regulation of Survivin following irradiation

Signal transducer and activator of transcription 3 (Stat3) and Survivin are constitutively up-regulated in various human tumor cells. We previously found Survivin to be significantly reduced in response to radiation in human umbilical vein endothelial cells (HUVEC) but not in tumor cell lines. In this study, we examined the effect of Stat3 on Survivin expression in irradiated HUVECs and breast cancer cells. We also studied how inhibition of Stat3 and Survivin activity affects cell survival and angiogenesis following irradiation. We determined that Survivin was significantly increased by overexpression of an active Stat3 (Stat3-C). Following irradiation, the level of phospho-Stat3 Tyr(705), but not phospho-Stat3 Ser(727), was reduced in HUVECs, whereas it remained unchanged in irradiated breast cancer cells. Correspondingly, Stat3 DNA-binding activity following irradiation was specifically down-regulated in HUVECs but not in breast cancer cells. Mutation of Tyr(705) abolished radiation-induced down-regulation of Survivin. Clonogenic and endothelial cell morphogenesis assays suggested that DN-Stat3 and DN-Survivin together resulted in the greatest radiosensitization of MDA-MB-231, decreasing angiogenesis and cell survival. In summary, Stat3 modulates Survivin, and both are potential therapeutic targets for radiation sensitization in breast cancer.

E-cadherin promoter polymorphisms are not associated with the aggressiveness of prostate cancer in Caucasian patients

BACKGROUND

-160C-->A and -347G-->GA polymorphisms in the promoter region decrease E-cadherin gene transcription. Decreased E-cadherin expression predicts poor outcome among patients with cancer. We sought to investigate whether -160C-->A and/or -347G-->GA polymorphisms were associated with the aggressiveness of prostate cancer.

METHODS

TaqMan single nucleotide polymorphism genotyping assay (Applied Biosystems, Foster City, CA) was used to detect -160C-->A and -347G-->GA polymorphisms in deoxyribonucleic acid from the paraffin-embedded prostate tissues of 98 Caucasian patients.

RESULTS

The genotype frequencies were -160C/C: 48% (47 of 98); -160C/A: 44% (43 of 98); -160A/A: 8% (8 of 98); -347G/G: 68% (67 of 98); -347G/GA: 28% (27 of 98); and -347GA/GA: 4% (4 of 98). Using the chi-square test, we found that the polymorphisms -160C-->A and -347G-->GA were not related to other clinical and pathologic parameters (i.e., age, prostate-specific antigen level, Gleason grade, and clinical stage) (P > 0.05). In combination analysis, there was no significant relationship between patients with both -160C/C and -347G/G, and these same parameters (P > 0.05). Using the log-rank test, we found no significant difference in relapse-free survival and overall survival between patients with -160C/C and those with -160A/C or -160A/A (P = 0.0764 and 0.2746, respectively), and also no significant difference between patients with -347G/G and those with -347GA/G or -347GA/GA (P = 0.9416 and 0.7367, respectively). There was also no significant difference in relapse-free survival and overall survival between patients with homozygosities of -160C/-347G and patients with other genotypes (P = 0.1418 and 0.2434, respectively).

CONCLUSION

We conclude that E-cadherin -160C-->A and/or -347G-->GA polymorphisms are not associated with the aggressiveness of prostate cancer in Caucasian patients.

Vascular endothelial growth factor tyrosine kinase inhibitor AZD2171 and fractionated radiotherapy in mouse models of lung cancer

The vascular endothelial growth factor receptor (VEGFR) tyrosine kinases are being explored as targets for antiangiogenic cancer therapy. Radiotherapy also inhibits tumor growth and affects vasculature. We investigated the combination of the potent VEGFR tyrosine kinase inhibitor AZD2171 and ionizing radiation in cell culture and mouse models of lung cancer. We show that ionizing radiation induces expression of phosphorylated VEGFR-2 (Flk-1) in endothelial cells and that this phosphorylation is inhibited by AZD2171. Human umbilical vascular endothelial cells become more sensitive to radiation after treatment with AZD2171 as determined by clonogenic assay. Matrigel assay showed a decrease in in vitro endothelial tubule formation with AZD2171/radiation combination treatment. When similar combination was applied to the H460 lung cancer xenograft model in nude mice, loss of radiation-induced phosphorylated Flk-1 was observed in the combination treatment group, which also showed a large decrease in tumor vascular density by staining of the von Willebrand factor. H460 tumor growth delay was enhanced in the combination treatment group compared with the groups treated with AZD2171 or radiation alone. Additionally, after therapy, Ki67 index showed >4-fold reduction of tumor proliferation in the combination therapy group, which also showed increased intratumoral apoptotic index by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. In conclusion, AZD2171 sensitizes lung tumor xenografts to radiation and inhibits angiogenesis both in vitro and in vivo. When used as a radiation enhancer, AZD2171 has the potential to improve tumor growth delay by inhibiting tumor proliferation and promoting apoptosis. Clinical trials are needed to determine the potential of this combination therapy in patients with locally advanced lung cancer.

Inhibition of mammalian target of rapamycin or apoptotic pathway induces autophagy and radiosensitizes PTEN null prostate cancer cells

The phosphatidylinositol 3-kinase/Akt pathway plays a critical role in oncogenesis, and dysregulation of this pathway through loss of PTEN suppression is a particularly common phenomenon in aggressive prostate cancers. The mammalian target of rapamycin (mTOR) is a downstream signaling kinase in this pathway, exerting prosurvival influence on cells through the activation of factors involved in protein synthesis. The mTOR inhibitor rapamycin and its derivatives are cytotoxic to a number of cell lines. Recently, mTOR inhibition has also been shown to radiosensitize endothelial and breast cancer cells in vitro. Because radiation is an important modality in the treatment of prostate cancer, we tested the ability of the mTOR inhibitor RAD001 (everolimus) to enhance the cytotoxic effects of radiation on two prostate cancer cell lines, PC-3 and DU145. We found that both cell lines became more vulnerable to irradiation after treatment with RAD001, with the PTEN-deficient PC-3 cell line showing the greater sensitivity. This increased susceptibility to radiation is associated with induction of autophagy. Furthermore, we show that blocking apoptosis with caspase inhibition and Bax/Bak small interfering RNA in these cell lines enhances radiation-induced mortality and induces autophagy. Together, these data highlight the emerging importance of mTOR as a molecular target for therapeutic intervention, and lend support to the idea that nonapoptotic modes of cell death may play a crucial role in improving tumor cell kill.