Racial Equity in Living Donor Kidney Transplant Centers, 2008-2018

Importance

It is unclear whether center-level factors are associated with racial equity in living donor kidney transplant (LDKT).

Objective

To evaluate center-level factors and racial equity in LDKT during an 11-year time period.

Design, Setting, and Participants

A retrospective cohort longitudinal study was completed in February 2023, of US transplant centers with at least 12 annual LDKTs from January 1, 2008, to December 31, 2018, identified in the Health Resources Services Administration database and linked to the US Renal Data System and the Scientific Registry of Transplant Recipients.

Main Outcomes and Measures

Observed and model-based estimated Black-White mean LDKT rate ratios (RRs), where an RR of 1 indicates racial equity and values less than 1 indicate a lower rate of LDKT of Black patients compared with White patients. Estimated yearly best-case center-specific LDKT RRs between Black and White individuals, where modifiable center characteristics were set to values that would facilitate access to LDKT.

Results

The final cohorts of patients included 394 625 waitlisted adults, of whom 33.1% were Black and 66.9% were White, and 57 222 adult LDKT recipients, of whom 14.1% were Black and 85.9% were White. Among 89 transplant centers, estimated yearly center-level RRs between Black and White individuals accounting for center and population characteristics ranged from 0.0557 in 2008 to 0.771 in 2018. The yearly median RRs ranged from 0.216 in 2016 to 0.285 in 2010. Model-based estimations for the hypothetical best-case scenario resulted in little change in the minimum RR (from 0.0557 to 0.0549), but a greater positive shift in the maximum RR from 0.771 to 0.895. Relative to the observed 582 LDKT in Black patients and 3837 in White patients, the 2018 hypothetical model estimated an increase of 423 (a 72.7% increase) LDKTs for Black patients and of 1838 (a 47.9% increase) LDKTs for White patients.

Conclusions and Relevance

In this cohort study of patients with kidney failure, no substantial improvement occurred over time either in the observed or the covariate-adjusted estimated RRs. Under the best-case hypothetical estimations, modifying centers' participation in the paired exchange and voucher programs and increased access to public insurance may contribute to improved racial equity in LDKT. Additional work is needed to identify center-level and program-specific strategies to improve racial equity in access to LDKT.

Does treatment at a level I trauma center reduce disparities in patient outcomes for open tibia fractures? A retrospective analysis of the National trauma Databank

Background

Race and insurance status are independent predictors of healthcare outcomes following lower-extremity trauma. Level 1 trauma centers show better outcomes overall, but it is has not been extensively studied as to whether they specifically lower complication rates and shorten length of stay in those with Black race, with low socioeconomic status, and/or a lack of private health insurance. We performed a study with the objective of determining whether Level I trauma centers can improve the complication rate of those shown to be at high risk of experiencing adverse outcomes due to socioeconomic differences.

Hypothesis

Level 1 trauma centers will be successful in mitigating the disparity in complication rates and length of stay associated with racial and socioeconomic differences among trauma patients experiencing an open tibia fracture.

Patients and methods

The National Trauma Databank was reviewed from 2008 to 2015, identifying 81,855 encounters with an open tibia fracture, and 33,047 at a Level I trauma center. Regression models determined effects of race and insurance status on outcomes by trauma center while controlling for confounders.

Results

Black race [OR 1.36, 95% CI, 1.17-1.58; p < 0.05] and "other" race [OR 1.28, 95% CI, 1.07-1.52; p < 0.05] were associated with higher odds of injury-specific complications. Patients without private insurance and of non-White or Black race in comparison to White patients had a significantly longer length of stay [coefficient 1.66, 95% CI, 1.37-1.94; p < 0.001]. These differences persisted in patients treated at an American College of Surgeons (ACS) Level I trauma center.

Discussion

Treatment at an ACS Level I trauma center did not reduce the independent effects of race and insurance status on outcomes after open tibia fracture, emphasizing the need to recognize this disparity and improve care for at-risk populations.

Experiential Learning Methods for Biostatistics Students: A Model for Embedding Student Interns in Academic Health Centers

This manuscript describes an experiential learning program for future collaborative biostatisticians (CBs) developed within an academic medical center. The program is a collaborative effort between the Biostatistics, Epidemiology, and Research Design (BERD) Methods Core and the Master of Biostatistics (MB) program, both housed in the Department of Biostatistics and Bioinformatics at Duke University School of Medicine and supported in partnership with the Duke Clinical and Translational Science Institute. To date, the BERD Core Training and Internship Program (BCTIP) has formally trained over 80 students to work on collaborative teams that are integrated throughout the Duke School of Medicine. This manuscript focuses on the setting for the training program, the experiential learning model on which it is based, the structure of the program, and lessons learned to date.

Decisional Conflict About Kidney Failure Treatment Modalities Among Adults With Advanced CKD

Rationale & Objective

Choosing from multiple kidney failure treatment modalities can create decisional conflict, but little is known about this experience before decision implementation. We explored decisional conflict about treatment for kidney failure and its associated patient characteristics in the context of advanced chronic kidney disease (CKD).

Study Design

Cross-sectional study.

Setting & Participants

Adults (N = 427) who had advanced CKD, received nephrology care in Pennsylvania-based clinics, and had no history of dialysis or transplantation.

Predictors

Participants' sociodemographic, physical health, nephrology care/knowledge, and psychosocial characteristics.

Outcomes

Participants' results on the Sure of myself; Understand information; Risk-benefit ratio; Encouragement (SURE) screening test for decisional conflict (no decisional conflict vs decisional conflict).

Analytical Approach

We used multivariable logistic regression to quantify associations between aforementioned participant characteristics and decisional conflict. We repeated analyses among a subgroup of participants at highest risk of kidney failure within 2 years.

Results

Most (76%) participants reported treatment-related decisional conflict. Participant characteristics associated with lower odds of decisional conflict included complete satisfaction with patient-kidney team treatment discussions (OR, 0.16; 95% CI, 0.03-0.88; P = 0.04), attendance of treatment education classes (OR, 0.38; 95% CI, 0.16-0.90; P = 0.03), and greater treatment-related decision self-efficacy (OR, 0.97; 95% CI, 0.94-0.99; P < 0.01). Sensitivity analyses showed a similarly high prevalence of decisional conflict (73%) and again demonstrated associations of class attendance (OR, 0.26; 95% CI, 0.07-0.96; P = 0.04) and decision self-efficacy (OR, 0.95; 95% CI, 0.91-0.99; P = 0.03) with decisional conflict.

Limitations

Single-health system study.

Conclusions

Decisional conflict was highly prevalent regardless of CKD progression risk. Findings suggest efforts to reduce decisional conflict should focus on minimizing the mismatch between clinical practice guidelines and patient-reported engagement in treatment preparation, facilitating patient-kidney team treatment discussions, and developing treatment education programs and decision support interventions that incorporate decision self-efficacy-enhancing strategies.

Screening for Eustachian Tube Dysfunction in Clinical Practice Using the Eustachian Tube Dysfunction Questionnaire-7

OBJECTIVES/HYPOTHESIS

To evaluate the ability of the Eustachian Tube Dysfunction Questionnaire-7 (ETDQ-7) to discriminate between patients with Eustachian tube dysfunction (ETD) and Non-ETD diagnoses, and identify symptom information to improve ability to discriminate these groups.

STUDY DESIGN

Cohort study.

METHODS

Pilot retrospective study with consecutive adult patients presenting to otology clinics and one general otolaryngology clinic in an academic health system. Patients were administered ETDQ-7 with eight additional symptom items. Electronic health records were reviewed for demographic and diagnostic information. Patients were grouped into diagnosis categories: 1) True ETD, 2) experiencing ear fullness (EF) not due to ETD, and 3) Control patients without ETD-related disorders or EF. ETDQ-7 and symptom item scores were compared by the diagnosis group. Receiver-operative characteristics curves and area under the curve (AUC) were generated for each ETD diagnosis group based on ETDQ-7 and symptom scores.

RESULTS

Of the 108 patients included in this study 74 (68.5%) were diagnosed with ETD. Patients with ETD had higher (indicating worse symptom burden) overall ETDQ-7 scores than Control group (Median [Q1, Q3] 3.0, [1.7, 4.1]; versus 1.5 [1.0, 3.4] P = .008). There was no statistically significant difference between overall ETDQ-7 scores for ETD and Non-ETD EF patients (P = .389). The AUC for the ETDQ-7 in discriminating ETD from other conditions that cause EF was 0.569; the addition of 8 symptom questions to the ETDQ-7 improved AUC to 0.801.

CONCLUSION

Additional patient-reported symptom information may improve the ability to discriminate ETD from other similarly presenting diagnoses when using ETDQ-7.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Response to Powell et al., "Do Hearing Aids Prevent Falls? Commentary on Study From the National Health and Nutrition Examination Survey"

PURPOSE

This letter serves to respond to Powell et al.'s (2021) letter to the editor regarding our recent publication, "Preliminary Evidence on the Impact of Hearing Aid Use on Falls Risk in Individuals With Self-Reported Hearing Loss." In our letter, we respond to key concerns and commentary raised by the authors.

Adjusting for selection bias due to missing data in electronic health records-based research

While electronic health records data provide unique opportunities for research, numerous methodological issues must be considered. Among these, selection bias due to incomplete/missing data has received far less attention than other issues. Unfortunately, standard missing data approaches (e.g. inverse-probability weighting and multiple imputation) generally fail to acknowledge the complex interplay of heterogeneous decisions made by patients, providers, and health systems that govern whether specific data elements in the electronic health records are observed. This, in turn, renders the missing-at-random assumption difficult to believe in standard approaches. In the clinical literature, the collection of decisions that gives rise to the observed data is referred to as the data provenance. Building on a recently-proposed framework for modularizing the data provenance, we develop a general and scalable framework for estimation and inference with respect to regression models based on inverse-probability weighting that allows for a hierarchy of missingness mechanisms to better align with the complex nature of electronic health records data. We show that the proposed estimator is consistent and asymptotically Normal, derive the form of the asymptotic variance, and propose two consistent estimators. Simulations show that naïve application of standard methods may yield biased point estimates, that the proposed estimators have good small-sample properties, and that researchers may have to contend with a bias-variance trade-off as they consider how to handle missing data. The proposed methods are motivated by an on-going, electronic health records-based study of bariatric surgery.

Preliminary Evidence on the Impact of Hearing Aid Use on Falls Risk in Individuals With Self-Reported Hearing Loss

Purpose Falls are considered a significant public health issue, and hearing loss has been shown to be an independent risk factor for falls. The primary objective of this study was to determine if hearing aid use modified (reduced) the association. We hypothesized that routine hearing aid use would reduce the impact of hearing loss on the odds of falling. If hearing aid users have reduced odds of falling, then that would have an important impact on falls prevention health care. Method Data from 8,091 individuals 40 years of age and older who completed National Health and Nutrition Examination Survey (NHANES) cycles 1999-2004 were used. NHANES comprises a series of cross-sectional studies, each of which is representative of the total civilian noninstitutionalized population of children and adults in the United States, enabling unbiased national estimates of health that can be independently reproduced. Self-reported hearing, hearing aid status, falls history, and comorbidities were extracted and analyzed using regression modeling. Results The 8,091 individuals were grouped based on a self-reported history of falls in the last year. Self-reported hearing loss was significantly associated with odds of falling. Categorizing individuals based on routine hearing aid use was included as an interaction term in the fully adjusted models and was not significant, suggesting no difference in falls based on hearing aid status. Conclusions The unique results of the current study show that when examining self-reported hearing in a nationally representative sample, hearing aid use does not appear to mitigate or modify the association between self-reported hearing and falls. Future research designs are highlighted to address limitations identified using NHANES data for this research and focus on the use of experimental designs to further understand the association between hearing loss and falls, including whether hearing loss may be a modifiable risk factor for falls. Supplemental Material https://doi.org/10.23641/asha.14642784.

A three-tier system for evaluation of organ procurement organizations' willingness to pursue and utilize nonideal donor lungs

Lungs from "nonideal," but acceptable donors are underutilized; however, organ procurement organization (OPO) metrics do not reflect the extent to which OPO-specific practices contribute to these trends. We developed a comprehensive system to evaluate nonideal lung donor avoidance, or risk aversion among OPOs. Adult donors in the UNOS registry who donated ≥1 organ for transplantation between 2007 and 2018 were included. Nonideal donors had any of age>50, smoking history ≥20 pack-years, PaO₂ /FiO₂ ratio ≤350, donation after circulatory death, or increased risk status. OPO-level risk aversion in donor pursuit, consent attainment, lung recovery, and transplantation was assessed. Among 83916 donors, 70372 (83.9%) were nonideal. Unadjusted OPO-level rates of nonideal donor pursuit ranged from 81 to 100%. In a three-tier system of overall risk aversion, tier 3 OPOs (least risk-averse) had the highest rates of nonideal donor pursuit, consent attainment, lung recovery, and transplantation. Tier 1 OPOs (most risk-averse) had the lowest rates of donor pursuit, consent attainment, and lung recovery, but higher rates of transplantation compared to tier 2 OPOs (moderately risk-averse). Risk aversion varies among OPOs and across the donation process. OPO evaluations should reflect early donation process stages to best differentiate over- and underperforming OPOs and encourage optimal OPO-specific performance.

Exploring Factors Associated With Morbidity and Mortality in Patients With Do-Not-Resuscitate Orders: A National Surgical Quality Improvement Program Database Analysis Within Surgical Groups

BACKGROUND

Anesthesiologists caring for patients with do-not-resuscitate (DNR) orders may have ethical concerns because of their resuscitative wishes and may have clinical concerns because of their known increased risk of morbidity/mortality. Patient heterogeneity and/or emphasis on mortality outcomes make previous studies among patients with DNR orders difficult to interpret. We sought to explore factors associated with morbidity and mortality among patients with DNR orders, which were stratified by surgical subgroups.

METHODS

Exploratory retrospective cohort study in adult patients undergoing prespecified colorectal, vascular, and orthopedic surgeries was performed using the American College of Surgeons National Surgical Quality Improvement Program Participant Use File data from 2010 to 2013. Among patients with preoperative DNR orders (ie, active DNR order written in the patient's chart before surgery), factors associated with 30-day mortality, increased length of stay, and inpatient death were determined via penalized regression. Unadjusted and adjusted estimates for selected variables are presented.

RESULTS

After selection as above, 211,420 patients underwent prespecified procedures, and of those, 2755 (1.3%) had pre-existing DNR orders and met above selection to address morbidity/mortality aims. By specialty, of these patients with a preoperative DNR, 1149 underwent colorectal, 870 vascular, and 736 orthopedic surgery. Across groups, 36.2% were male and had a mean age 79.9 years (range 21-90). The 30-day mortality was 15.4%-27.2% and median length of stay was 6-12 days. Death at discharge was 7.0%, 13.1%, and 23.0% in orthopedics, vascular, and colorectal patients with a DNR, respectively. The strongest factors associated with increased odds of 30-day mortality were preoperative septic shock in colorectal patients, preoperative ascites in vascular patients, and any requirement of mechanical ventilation at admission in orthopedic patients.

CONCLUSIONS

In patients with DNR orders undergoing common surgical procedures, the association of characteristics with morbidity and mortality varies in both direction and magnitude. The DNR order itself should not be the defining measure of risk.

How and when informative visit processes can bias inference when using electronic health records data for clinical research

OBJECTIVE

Electronic health records (EHR) data have become a central data source for clinical research. One concern for using EHR data is that the process through which individuals engage with the health system, and find themselves within EHR data, can be informative. We have termed this process informed presence. In this study we use simulation and real data to assess how the informed presence can impact inference.

MATERIALS AND METHODS

We first simulated a visit process where a series of biomarkers were observed informatively and uninformatively over time. We further compared inference derived from a randomized control trial (ie, uninformative visits) and EHR data (ie, potentially informative visits).

RESULTS

We find that only when there is both a strong association between the biomarker and the outcome as well as the biomarker and the visit process is there bias. Moreover, once there are some uninformative visits this bias is mitigated. In the data example we find, that when the "true" associations are null, there is no observed bias.

DISCUSSION

These results suggest that an informative visit process can exaggerate an association but cannot induce one. Furthermore, careful study design can, mitigate the potential bias when some noninformative visits are included.

CONCLUSIONS

While there are legitimate concerns regarding biases that "messy" EHR data may induce, the conditions for such biases are extreme and can be accounted for.

African Americans' discussions about living-donor kidney transplants with family or friends: Who, what, and why not?

BACKGROUND

Although discussions with family or friends can improve access to living-donor kidney transplantation (LDKT), they remain an understudied step in the LDKT process.

METHODS

Among 300 African American transplant candidates, we examined how sociodemographic, clinical, LDKT-related, and psychosocial characteristics related to the occurrence of LDKT discussions with family or friends. We also analyzed the relation between discussion occurrence and donor activation on transplant candidates' behalves (at least one donor inquiry or completed donor evaluation in the medical record). We assessed associations of discussion characteristics (context, content, and perceptions) with donor activation among discussants, and we identified discussion barriers among non-discussants.

RESULTS

Most candidates (90%) had discussed LDKT. Only family functioning was statistically significantly associated with discussion occurrence. Specifically, family dysfunction was associated with 62% lower odds of discussion than family function. Family functioning, discussion occurrence, and different discussion characteristics were statistically significantly related to donor activation. The most prevalent discussion barrier was never having thought about discussing LDKT.

CONCLUSIONS

Family functioning affected the likelihood of discussing LDKT, and family functioning, discussion occurrence, and discussion characteristics were associated with donor activation. Advancing understanding of how family functioning and LDKT discussions affect progression to LDKT may benefit interventions to increase LDKT.

Clinician adherence to the clinical practice guideline: Acute otitis externa

OBJECTIVES/HYPOTHESIS

Over 10 years have passed since the Clinical Practice Guideline: Acute Otitis Externa (CPG-AOE) was first published, and it has been several years since its update. We sought to assess clinicians' adherence as well as referral patterns.

STUDY DESIGN

Survey.

METHODS

A 23-question survey was distributed to regional primary care clinicians evaluating demographic data, perception of the clinical practice guideline (CPG), adherence, and details of specialist referral. Statistical analysis was performed to compare adherence and referral patterns using the Fisher exact test or the χ2 test.

RESULTS

One hundred seventeen clinicians completed the survey. Fifteen respondents (12.8%) had reviewed the CPG. The recommendations with the least reported adherence were pain management (39.1%) and accounting for prior radiotherapy as a modifying factor (43.0%). The recommendations of prescribing ototopical therapy and avoiding systemic antimicrobials in uncomplicated acute otitis externa had adherence of 94.0% and 83.8%, respectively. When analyzed by provider type (e.g., resident, nurse practitioner/physician assistant), there were no significant differences in adherence. No significant differences in adherence were observed based on previous review of the CPG. When reporting frequency of specialist referral, the majority of respondents selected rarely (53.9%). The most favored reason for referral was symptoms >4 weeks (86.3%).

CONCLUSIONS

Of the providers who responded, very few had reviewed the CPG-AOE. Despite the added emphasis on pain management in the CPG update, this recommendation had the lowest adherence. Rates of adherence were similar across provider types and did not differ significantly if the CPG was reviewed. Efforts at improved provider education should be considered to increase adherence to the CPG.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:1565-1571, 2020.

Associations of perceived information adequacy and knowledge with pursuit of live donor kidney transplants and living donor inquiries among African American transplant candidates

We studied associations between perceived adequacy of live donor kidney transplant (LDKT) information or knowledge with pursuit of LDKT or receipt of live donor inquiries among 300 African American kidney transplant candidates. Participants reported via questionnaire how informed or knowledgeable they felt regarding LDKT. Participants also reported their pursuit of LDKT, categorized as "low" (no discussion with family or friends about LDKT and no identified donor), "intermediate" (discussed LDKT with family but no identified donor) or "high" (discussed LDKT with family and identified a potential donor). We reviewed participants' electronic health records to identify potential donors' transplant center inquiries on participants' behalves. A minority of participants reported they felt "very" or "extremely" well informed about LDKT (39%) or had "a great deal" of LDKT knowledge (38%). Participants perceiving themselves as "very" or "extremely" (vs "not" or "slightly") well informed about LDKT had statistically significantly greater odds of intermediate or high (vs low) pursuit of LDKT (odds ratio [95% confidence interval] 2.71 [1.02-7.17]). Perceived LDKT knowledge was not associated with pursuit of LDKT. Neither perceived information adequacy nor knowledge was associated with living donor inquiries. Efforts to better understand the role of education in the pursuit of LDKT among African American transplant candidates are needed.

Kidney Donor Profile Index Is a Reliable Alternative to Liver Donor Risk Index in Quantifying Graft Quality in Liver Transplantation

Background.

The most established metric for estimating graft survival from donor characteristics in liver transplantation is the liver donor risk index (LDRI). The LDRI is calculated from donor and transplant-related variables, including cold ischemic time. Because cold ischemic time is unknown at the time of organ offer, LDRI is not available for organ acceptance decisions. In contrast, the kidney donor profile index (KDPI) is derived purely from donor variables known at the time of offer and thus calculated for every deceased donor in the United States. The similarity in donor factors included in LDRI and KDPI led us to hypothesize that KDPI would reliably approximate LDRI in estimating graft survival in liver transplantation.

Methods.

The United Network of Organ Sharing registry was queried for adults who underwent deceased donor liver transplantation from 2002 to 2016. The cohort was divided into quintiles of KDPI and LDRI, and graft survival was calculated according to Kaplan Meier. Hazard ratios for LDRI and KDPI were estimated from Cox proportional hazards models, and Uno’s concordance statistic was compared.

Results.

In our analysis of 63 906 cases, KDPI closely approximated LDRI in estimating liver graft survival, with an equivalent concordance statistic of 0.56.

Conclusions.

We conclude that KDPI can serve as a reasonable alternative to LDRI in liver acceptance decisions.

There is no impact of exposure measurement error on latency estimation in linear models

Identification of the latency period for the effect of a time-varying exposure is key when assessing many environmental, nutritional, and behavioral risk factors. A pre-specified exposure metric involving an unknown latency parameter is often used in the statistical model for the exposure-disease relationship. Likelihood-based methods have been developed to estimate this latency parameter for generalized linear models but do not exist for scenarios where the exposure is measured with error, as is usually the case. Here, we explore the performance of naive estimators for both the latency parameter and the regression coefficients, which ignore exposure measurement error, assuming a linear measurement error model. We prove that, in many scenarios under this general measurement error setting, the least squares estimator for the latency parameter remains consistent, while the regression coefficient estimates are inconsistent as has previously been found in standard measurement error models where the primary disease model does not involve a latency parameter. Conditions under which this result holds are generalized to a wide class of covariance structures and mean functions. The findings are illustrated in a study of body mass index in relation to physical activity in the Health Professionals Follow-Up Study.

Associations of Video Head Impulse Test and Caloric Testing among Patients with Vestibular Schwannoma

OBJECTIVE

To determine relationships between caloric testing (CT) and video head impulse testing (vHIT) among patients with unilateral vestibular schwannoma (VS). To describe the distribution of CT and vHIT measurements and assess associations with tumor size and self-perceived handicapping effects.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral hospital.

SUBJECTS AND METHODS

Subjects were adults with presumed unilateral VS between 2014 and 2017. Interventions were CT and vHIT. Primary outcomes were vHIT value (abnormal <0.8) and CT value (abnormal >25%). Secondary outcomes were tumor size and Dizziness Handicap Inventory scores.

RESULTS

Fifty-one individuals had complete data for CT and vHIT. The odds of abnormal gain increases by 2.18 for every 10% increase in unilateral weakness on CT (range, 1.44-3.34; P < .001). A significant negative correlation between CT and gain exists (r_s = -0.64, P < .001). Odds of observing saccades increased by 2.68 for every 10% increase in unilateral weakness (range, 1.48-4.85; P = .001). This association was larger in magnitude for overt than covert saccades (odds ratios, 2.48 and 1.59, respectively). Tumor size was significantly associated with an increase in caloric weakness (β = 0.135, P < .001). With every 10-mm increase of tumor size, odds of abnormal gain on vHIT increased 4.13 (range, 1.46-11.66; P = .007). Mean Dizziness Handicap Inventory score was 19.7 (σ = 22), without association to caloric weakness, gain, or tumor size.

CONCLUSION

CT and vHIT both effectively assess vestibular function for patients with VS and correlate to tumor size. These findings are important as vHIT has a lower overall cost, improved patient tolerance, and demonstrated reliability.

The Impact of Ergonomics on Recruitment to Surgical Fields: A Multi-Institutional Survey Study

BACKGROUND

Awareness of ergonomics in surgery is growing, but whether musculoskeletal (MSK) injuries in surgery influence trainee career choices remains unknown. This study aimed to characterize medical students' MSK pain during surgical rotations and determine whether ergonomics influence student interest in surgical fields.

METHODS

An online survey was administered to medical students in North Carolina. Students were asked about specialty interest, MSK pain on surgical rotations, and deterrents from surgical fields. Students were exposed to literature about ergonomics in surgery then queried again about relative specialty interest (medical versus surgical). Differences in specialty interest before and after the exposure were compared using a Wilcoxon signed-rank test.

RESULTS

Of 243 participants, 44.0% were interested in pursuing a surgical specialty. Overall, 75.3% reported MSK pain during their surgical rotation, with the average daily pain score highest during surgery rotations compared to all other clinical rotations. The worst pain was reported in the feet and low back while "standing in the operating room" (81.2%) or "retracting" (59.4%). Among students initially interested in surgery but whose interest changed to a medical specialty during medical school, "physical demands of the field" was a common deterrent (36.4%). After exposure to literature regarding the incidence of MSK injuries in surgery, student interest in surgical fields on a 10-point scale significantly decreased (average -0.5 points; P < 0.01).

CONCLUSIONS

High incidence of MSK injury among surgeons may be one factor deterring medical students from surgical careers. Ergonomic interventions may be important both to improve surgeon longevity and maintain the surgical workforce.

Adding the Team into T1 Translational Research: A Case Study of Multidisciplinary Team Science in the Evaluation of Biomarkers of Prostate Cancer Risk and Prognosis

BACKGROUND

Given translational research challenges, multidisciplinary team science is promoted to increase the likelihood of moving from discovery to health effect. We present a case study documenting the utility of multidisciplinary team science in prostate cancer tissue biomarker validation.

METHODS

We used primary data generated by a team consisting of a pathologist, cancer biologists, a biostatistician, and epidemiologists. We examined their contributions by phase of biomarker evaluation to identify when, through the practice of team science, threats to internal validity were recognized and solved. Next, we quantified the extent of bias avoided in evaluating the association of Ki67 (immunohistochemistry), stromal cell telomere length (fluorescence in situ hybridization), and microRNA (miRNA) (miR-21, miR-141, miR-221; quantitative RT-PCR) with prostate cancer risk or recurrence in nested case-control studies.

RESULTS

Threats to validity were tissue storage time (Ki67, miRNA) and laboratory equipment maintenance (telomeres). Solutions were all in the data analysis phase and involved using tissue storage-time specific cutpoints and/or batch-specific cutpoints. Bias in the regression coefficient for quantiles of each biomarker ranged from 24% to 423%, and the coefficient for the test for trend ranged from 15% to 910%. The interpretation of the associations changed as follows: Ki67, null to positive; stromal cell telomere length, null to positive; miR-21 and miR-141 remained null; miR-221, weak to moderate inverse.

CONCLUSIONS

In this case study, we documented the inferential benefits of multidisciplinary team science when the team's collaboration and coordination led to the identification of threats to validity and the implementation of appropriate solutions.

Current or recent smoking is associated with more variable telomere length in prostate stromal cells and prostate cancer cells

BACKGROUND

Current and recent smoking have been associated with a greater risk of prostate cancer recurrence and mortality, though the underlying mechanism is unknown.

METHODS

To determine if telomere shortening, which has been associated with poor outcomes, may be a potential underlying mechanism, we prospectively evaluated the association between smoking status and telomere length in 567 participants in the Health Professionals Follow-up Study, who were surgically treated for prostate cancer. Using tissue microarrays (TMA), we measured telomere length in cancer and benign tissue, specifically stromal cells in the same TMA spot using a telomere-specific fluorescence in situ hybridization assay. Smoking status was collected via questionnaire 2-years before diagnosis. Adjusting for age, pathologic stage and grade, the median and standard deviation of the per-cell telomere signals were determined for each man for stromal cells and cancer cells by smoking categories. In sub-analyses, we restricted to men without major co-morbidities diagnosed before prostate cancer.

RESULTS

Overall, there were no associations between smoking status and telomere length or variability in stromal cells or cancer cells. However, among men without comorbidities, current smokers and former smokers who quit <10 years ago had the most variable telomere length in stromal cells (29.3% more variable than never smokers; P-trend = 0.0005) and in cancer cells (27.7% more variable than never smokers; P-trend = 0.05). Among men without comorbidities, mean telomere length did not differ by smoking status in stromal cells or cancer cells.

CONCLUSION

Telomere variability in prostate cells may be one mechanism through which smoking influences poor prostate cancer outcomes.

The effect of risk factor misclassification on the partial population attributable risk

The partial population attributable risk (pPAR) is used to quantify the population-level impact of preventive interventions in a multifactorial disease setting. In this paper, we consider the effect of nondifferential risk factor misclassification on the direction and magnitude of bias of pPAR estimands and related quantities. We found that the bias in the uncorrected pPAR depends nonlinearly and nonmonotonically on the sensitivities, specificities, relative risks, and joint prevalence of the exposure of interest and background risk factors, as well as the associations between these factors. The bias in the uncorrected pPAR is most dependent on the sensitivity of the exposure. The magnitude of bias varies over a large range, and in a small region of the parameter space determining the pPAR, the direction of bias is away from the null. In contrast, the crude PAR can only be unbiased or biased towards the null by risk factor misclassification. The semiadjusted PAR is calculated using the formula for the crude PAR but plugs in the multivariate-adjusted relative risk. Because the crude and semiadjusted PARs continue to be used in public health research, we also investigated the magnitude and direction of the bias that may arise when using these formulae instead of the pPAR. These PAR estimators and their uncorrected counterparts were calculated in a study of risk factors for colorectal cancer in the Health Professionals Follow-up Study, where it was found that because of misclassification, the pPAR for low folate intake was overestimated with a relative bias of 48%, when red meat and alcohol intake were treated as misclassified risk factors that are not modified, and when red meat was treated as the modifiable risk factor, the estimated value of the pPAR went from 14% to 60%, further illustrating the extent to which misclassification can bias estimates of the pPAR.

Prevalence estimation when disease status is verified only among test positives: Applications in HIV screening programs

The first goal of the United Nations' 90-90-90 HIV/AIDS elimination strategy is to ensure that, by 2020, 90% of HIV-positive people know their HIV status. Estimating the prevalence of HIV among people eligible for screening allows assessment of the number of additional cases that might be diagnosed through continued screening efforts in this group. Here, we present methods for estimating prevalence when HIV status is verified by a gold standard only among those who test positive on an initial, imperfect screening test with known sensitivity and specificity. We develop maximum likelihood estimators and asymptotic confidence intervals for use in 2 scenarios: when the total number of test negatives is known (Scenario 1) and unknown (Scenario 2). We derive Bayesian prevalence estimators to account for non-negligible uncertainty in previous estimates of the sensitivity and specificity. The Scenario 1 estimator consistently outperformed the Scenario 2 estimator in simulations, demonstrating the use of recording the number of test negatives in public health screening programs. For less accurate tests (sensitivity and specificity < 90%), the performance of the 2 estimators was comparable, suggesting that, under these circumstances, prevalence can still be estimated with adequate precision when the number of test negatives is unknown. However, use of the Bayesian approach to account for uncertainty in the sensitivity and specificity is especially recommended for the Scenario 2 estimator, which was particularly sensitive to misspecification of these values. R code for implementing these methods is available at hsph.harvard.edu/donna-spiegelman/software.

Racial/Ethnic Differences in the Associations of Overall and Central Body Fatness with Circulating Hormones and Metabolic Factors in US Men

BACKGROUND

Racial/ethnic disparities in the associations of body fatness with hormones and metabolic factors remain poorly understood. Therefore, we evaluated whether the associations of overall and central body fatness with circulating sex steroid hormones and metabolic factors differ by race/ethnicity.

METHODS

Data from 1,243 non-Hispanic white (NHW), non-Hispanic black (NHB) and Mexican-American (MA) adult men in the third national health and nutrition examination survey (NHANES III) were analyzed. Waist circumference (central body fatness) was measured during the physical examination. Percent body fat (overall body fatness) was calculated from bioelectrical impedance. Associations were estimated by using weighted linear regression models to adjust the two measures of body fatness for each other.

RESULTS

Waist circumference, but not percent body fat was inversely associated with total testosterone and SHBG in all three racial/ethnic groups after their mutual adjustment (all P < 0.0001). Percent body fat (P = 0.02), but not waist circumference was positively associated with total estradiol in NHB men; no association was present in NHW and MA men (P-interaction = 0.04). Waist circumference, but not body fat was strongly positively associated with fasting insulin (all P < 0.0001) and inversely associated with HDL cholesterol (all P ≤ 0.003) in all three racial/ethnic groups. Both percent body fat and waist circumference were positively associated with leptin (all P < 0.0001) in all three racial/ethnic groups.

CONCLUSIONS

There was no strong evidence in the associations of sex hormones and metabolic factors with body fatness in different racial/ethnic groups. These findings should be further explored in prospective studies to determine their relevance in racial/ethnic disparities of chronic diseases.

Differential long-term stability of microRNAs and RNU6B snRNA in 12-20 year old archived formalin-fixed paraffin-embedded specimens

Background

The quantitative analysis of microRNA (miRNA) gene expression in archived formalin-fixed, paraffin embedded (FFPE) tissues has been instrumental to identifying their potential roles in cancer biology, diagnosis, and prognosis. However, it remains unclear whether miRNAs remain stable in FFPE tissues stored for long periods of time.

Methods

Here we report Taqman real-time RT-PCR quantification of miR-21, miR-141, miR-221, and RNU6B small nuclear RNA (snRNA) levels from 92 radical prostatectomy specimens stored for 12–20 years in FFPE blocks. The relative stability of each transcript over time was assessed using general linear models. The correlation between transcript quantities, sample age, and RNA integrity number (RIN) were determined utilizing Spearman rank correlation.

Results

All transcript levels linearly decreased with sample age, demonstrating a clear loss of miRNA stability and RNU6B snRNA stability over time. The most rapid rates of degradation were observed for RNU6B and miR-21, while miR-141 and miR-221 were more stable. RNA quality was not correlated with sample age or with miR-21, miR-221, or RNU6B snRNA levels. Conversely, miR-141 levels increased with RNA quality.

Conclusions

MiRNA and snRNA levels gradually decreased over an eight year period in FFPE tissue blocks. Sample age was the most consistent feature associated with miRNA stability. The reference snRNA, RUN6B, was more rapidly degraded when compared to miR-141 and miR-221 miRNAs. Various miRNAs demonstrated differential rates of degradation. Quantitative miRNA studies from long-term archived FFPE tissues may therefore benefit from epidemiologic study design or statistical analysis methods that take into account differential storage-dependent transcript degradation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-3008-4) contains supplementary material, which is available to authorized users.

Inflammation in Benign Prostate Tissue and Prostate Cancer in the Finasteride Arm of the Prostate Cancer Prevention Trial

BACKGROUND

A previous analysis of the placebo arm of the Prostate Cancer Prevention Trial (PCPT) reported 82% overall prevalence of intraprostatic inflammation and identified a link between inflammation and higher-grade prostate cancer and serum PSA. Here, we studied these associations in the PCPT finasteride arm.

METHODS

Prostate cancer cases (N = 197) detected either on a clinically indicated biopsy or on protocol-directed end-of-study biopsy, and frequency-matched controls (N = 248) with no cancer on an end-of-study biopsy were sampled from the finasteride arm. Inflammation in benign prostate tissue was visually assessed using digital images of hematoxylin and eosin-stained sections. Logistic regression was used for statistical analysis.

RESULTS

In the finasteride arm, 91.6% of prostate cancer cases and 92.4% of controls had at least one biopsy core with inflammation in benign areas (P < 0.001 for difference compared with placebo arm). Overall, the odds of prostate cancer did not differ by prevalence [OR, 0.90; 95% confidence interval (CI), 0.44-1.84] or extent (P trend = 0.68) of inflammation. Inflammation was not associated with higher-grade disease (prevalence: OR, 1.07; 95% CI, 0.43-2.69). Furthermore, mean PSA concentration did not differ by the prevalence or extent of inflammation in either cases or controls.

CONCLUSION

The prevalence of intraprostatic inflammation was higher in the finasteride than placebo arm of the PCPT, with no association with higher-grade prostate cancer.

IMPACT

Finasteride may attenuate the association between inflammation and higher-grade prostate cancer. Moreover, the missing link between intraprostatic inflammation and PSA suggests that finasteride may reduce inflammation-associated PSA elevation.

Circulating total testosterone and PSA concentrations in a nationally representative sample of men without a diagnosis of prostate cancer

BACKGROUND

The association between serum sex steroid hormones and PSA in a general population has not been described.

METHODS

Included were 378 men aged 40-85 years who participated in the National Health and Nutrition Examination Survey in 2001-2004, who did not have a prostate cancer diagnosis, and had not had a recent biopsy, rectal examination, cystoscopy, or prostate infection or inflammation. Serum total PSA, total testosterone, androstanediol glucuronide (3α-diol-G), estradiol, and sex hormone binding globulin (SHBG) concentrations were previously measured. Free testosterone was estimated by mass action. We applied sampling weights and calculated geometric mean PSA concentration by hormone quintiles adjusting for age and race/ethnicity, and also for body mass index, waist circumference, smoking, diabetes, and mutually for hormones. We estimated the OR of PSA ≥2.5 ng/ml per hormone quintile using logistic regression.

RESULTS

Geometric mean PSA increased across testosterone quintiles after age and race/ethnicity (Q1: 0.80, Q5: 1.14 ng/ml; P-trend = 0.002) and multivariable (Q1: 0.79, Q5: 1.16 ng/ml; P-trend = 0.02) adjustment; patterns were similar for free testosterone and 3α-diol-G. SHBG was inversely associated with PSA only after multivariable adjustment (Q1: 1.32, Q5: 0.82 nmol/L; P-trend = 0.01). Estradiol and PSA were not associated. The OR of PSA ≥2.5 ng/ml was 1.54 (95% CI 1.18-2.01) per testosterone quintile after age and race/ethnicity adjustment, and 1.78 (95% CI 1.16-2.73) after multivariable adjustment.

CONCLUSIONS

In this nationally representative sample, men with higher testosterone had higher PSA even after taking into account other hormones and modifiable factors. Men with higher SHBG had lower PSA, but only after multivariable adjustment.

Prostate stromal cell telomere shortening is associated with risk of prostate cancer in the placebo arm of the Prostate Cancer Prevention Trial

BACKGROUND

Telomeres are repetitive nucleoproteins that help maintain chromosomal stability by inhibiting exonucleolytic degradation, prohibiting inappropriate homologous recombination, and preventing chromosomal fusions by suppressing double-strand break signals. We recently observed that men treated for clinically localized prostate cancer with shorter telomeres in their cancer-associated stromal cells, in combination with greater variation in cancer cell telomere lengths, were significantly more likely to progress to distant metastases, and die from their disease. Here, we hypothesized that shorter stromal cell telomere length would be associated with prostate cancer risk at time of biopsy.

METHODS

Telomere-specific fluorescence in situ hybridization (FISH) analysis was performed in normal-appearing stromal, basal epithelial, and luminal epithelial cells in biopsies from men randomized to the placebo arm of the Prostate Cancer Prevention Trial. Prostate cancer cases (N = 32) were either detected on a biopsy performed for cause or at the end of the study per trial protocol, and controls (N = 50), defined as negative for cancer on an end-of-study biopsy performed per trial protocol (e.g., irrespective of indication), were sampled. Logistic regression was used to estimate the association between mean telomere length of the particular cell populations, cell-to-cell telomere length variability, and risk of prostate cancer.

RESULTS

Men with short stromal cell telomere lengths (below median) had 2.66 (95% CI 1.04-3.06; P = 0.04) times the odds of prostate cancer compared with men who had longer lengths (at or above median). Conversely, we did not observe statistically significant associations for short telomere lengths in normal-appearing basal (OR = 2.15, 95% CI 0.86-5.39; P= 0 .10) or luminal (OR = 1.15, 95% CI 0.47-2.80; P = 0.77) cells.

CONCLUSIONS

These findings suggest that telomere shortening in normal stromal cells is associated with prostate cancer risk. It is essential to extend and validate these findings, while also identifying the cellular milieu that comprises the subset of cells with short telomeres within the prostate tumor microenvironment.

A group randomized controlled trial integrating obesity prevention and control for postpartum adolescents in a home visiting program

Background

Adolescence represents a critical period for the development of overweight that tracks into adulthood. This risk is significantly heightened for adolescents that become pregnant, many of whom experience postpartum weight retention. The aim of this study was to evaluate Balance Adolescent Lifestyle Activities and Nutrition Choices for Energy (BALANCE), a multicomponent obesity prevention intervention targeting postpartum adolescents participating in a national home visiting child development-parent education program.

Methods

A group randomized, nested cohort design was used with 1325 adolescents, 694 intervention and 490 control, (mean age = 17.8 years, 52 % underrepresented minorities) located across 30 states. Participatory methods were used to integrate lifestyle behavior change strategies within standard parent education practice. Content targeted replacement of high-risk obesogenic patterns (e.g. sweetened drink and high fat snack consumption, sedentary activity) with positive behaviors (e.g. water intake, fruit and vegetables, increased walking). Parent educators delivered BALANCE through home visits, school based classroom-group meetings, and website activities. Control adolescents received standard child development information. Phase I included baseline to posttest (12 months); Phase II included baseline to follow-up (24 months).

Results

When compared to the control group, BALANCE adolescents who were ≥12 weeks postpartum were 89 % more likely (p = 0.02) to maintain a normal BMI or improve an overweight/obese BMI by 12 months; this change was not sustained at 24 months. When compared to the control group, BALANCE adolescents significantly improved fruit and vegetable intake (p = .03). In stratified analyses, water intake improved among younger BALANCE teens (p = .001) and overweight/obese BALANCE teens (p = .05) when compared to control counterparts. There were no significant differences between groups in sweetened drink and snack consumption or walking.

Conclusion

Prevention of postpartum weight retention yields immediate health benefits for the adolescent mother and may prevent the early development or progression of maternal obesity, which contributes to the intergenerational transmission of obesity to her offspring. Implementing BALANCE through a national home visiting organization may hold promise for promoting positive lifestyle behaviors associated with interruption of the progression of maternal obesity.

Trial registration

ClinicalTrails.gov NCT01617486.

Prediagnostic Obesity and Physical Inactivity Are Associated with Shorter Telomere Length in Prostate Stromal Cells

Obesity and inactivity have been associated with advanced-stage prostate cancer, and poor prostate cancer outcomes, though the underlying mechanism(s) is unknown. To determine whether telomere shortening, which has been associated with lethal prostate cancer, may be a potential underlying mechanism, we prospectively evaluated the association between measures of adiposity, physical activity, and telomere length in 596 participants in the Health Professionals Follow-up Study, who were surgically treated for prostate cancer. Using tissue microarrays, we measured telomere length in cancer and benign cells using a telomere-specific FISH assay. Adiposity and activity were assessed via questionnaire within 2 years of diagnosis. Adjusting for age, pathologic stage, and grade, the median and SD of the per cell telomere signals were determined for each man for stromal cells and cancer cells by adiposity and activity categories. Overweight/obese men (54%) were similar to normal weight men on most factors, but had higher Gleason sum and lower activity levels. Overweight/obese men had 7.4% shorter telomeres in stromal cells than normal weight men (P = 0.06). The least active men had shorter telomeres in stromal cells than more active men (Ptrend = 0.002). Men who were overweight/obese and the least active had the shortest telomeres in stromal cells (20.7% shorter; P = 0.0005) compared with normal weight men who were the most active. Cancer cell telomere length and telomere length variability did not differ by measures of adiposity or activity. Telomere shortening in prostate cells may be one mechanism through which lifestyle influences prostate cancer risk and outcomes.

Intraprostatic inflammation is positively associated with serum PSA in men with PSA <4 ng ml(-1), normal DRE and negative for prostate cancer

BACKGROUND

Biopsies performed for elevated serum PSA often show inflammatory infiltrates. However, the influence of intraprostatic inflammation on serum PSA in men without biopsy indication and negative for prostate cancer has not been described in detail.

METHODS

We studied 224 men in the placebo arm of the Prostate Cancer Prevention Trial (PCPT) who underwent end-of-study biopsy per trial protocol, had PSA <4 ng ml(-1), normal digital rectal examination and a biopsy negative for cancer. We analyzed data from hematoxylin and eosin-stained slides containing a mean of three biopsy cores. Inflammation measures included the extent (percentage of tissue area with inflammation) and intensity (product of scores for extent and grade) of total, acute and chronic inflammation in the entire tissue area examined, and by tissue compartment. We calculated median measures of inflammation by prebiopsy serum PSA tertile (>0 to ≤0.8, >0.8 to ≤1.5 and >1.5 to <4.0 ng ml(-1)). We estimated the association between percentage of tissue area with inflammation and natural logarithm of PSA using linear regression adjusting for age at biopsy.

RESULTS

Median percentage of tissue area with inflammation increased from 2 to 5 to 9.5% across PSA tertiles (P-trend <0.0001). For every 5% increase in tissue area with inflammation, log PSA increased by 0.061 ng ml(-1) (P=0.0002). Median extent and intensity scores increased across PSA tertiles in luminal and intraepithelial compartments for acute inflammation and in stromal and intraepithelial compartments for chronic inflammation (all P-trend ≤0.05).

CONCLUSIONS

In men without clinical suspicion of prostate cancer, greater overall inflammation, luminal and intraepithelial acute inflammation and stromal and intraepithelial chronic inflammation were associated with higher serum PSA.

Investigation of miR-21, miR-141, and miR-221 expression levels in prostate adenocarcinoma for associated risk of recurrence after radical prostatectomy

BACKGROUND

MicroRNAs (miRNAs) are small non-coding RNAs that regulate a broad array of cellular and disease processes. Several miRNAs are differentially expressed in cancer and many are being considered as biomarkers for predicting clinical outcomes. Here we quantified the expression of three miRNAs, miR-21, miR-141, and miR-221, from prostate cancer surgical specimens and evaluated their association with disease recurrence after primary therapy.

METHODS

A pilot nested case-control study was designed from a large cohort of men who underwent radical prostatectomy between 1993 and 2001. Total RNA was extracted from malignant prostate tissue of 59 cases (recurrence) and 59 controls. Cases and controls were matched on age, race, pathologic stage, and grade. The relative expression of each miRNA was then determined for each sample by quantitative real-time RT-PCR. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) of recurrence for tertiles of miRNA expression. We noted block storage time effects and thus, used separate tertile cutpoints based on the controls by calendar year of prostatectomy.

RESULTS

Lower miR-221 expression was associated with a higher risk of recurrence; the ORs were 3.21 for the lowest tertile and 2.63 for the middle tertile compared with the highest tertile of expression (P-trend = 0.02). This pattern was unchanged after multivariable adjustment (P-trend = 0.05). No statistically significant trends were observed for miR-21 or miR-141 after multivariable adjustment.

CONCLUSIONS

Based on this small pilot study, men with localized prostate cancers with lower miR-221 expression may have a greater risk for recurrence after surgery.

Do environmental factors modify the genetic risk of prostate cancer?

BACKGROUND

Many SNPs influence prostate cancer risk. To what extent genetic risk can be reduced by environmental factors is unknown.

METHODS

We evaluated effect modification by environmental factors of the association between susceptibility SNPs and prostate cancer in 1,230 incident prostate cancer cases and 1,361 controls, all white and similar ages, nested in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Trial. Genetic risk scores were calculated as number of risk alleles for 20 validated SNPs. We estimated the association between higher genetic risk (≥12 SNPs) and prostate cancer within environmental factor strata and tested for interaction.

RESULTS

Men with ≥12 risk alleles had 1.98, 2.04, and 1.91 times the odds of total, advanced, and nonadvanced prostate cancer, respectively. These associations were attenuated with the use of selenium supplements, aspirin, ibuprofen, and higher vegetable intake. For selenium, the attenuation was most striking for advanced prostate cancer: compared with <12 alleles and no selenium, the OR for ≥12 alleles was 2.06 [95% confidence interval (CI), 1.67-2.55] in nonusers and 0.99 (0.38-2.58) in users (Pinteraction = 0.031). Aspirin had the most marked attenuation for nonadvanced prostate cancer: compared with <12 alleles and nonusers, the OR for ≥12 alleles was 2.25 (1.69-3.00) in nonusers and 1.70 (1.25-2.32) in users (Pinteraction = 0.009). This pattern was similar for ibuprofen (Pinteraction = 0.023) and vegetables (Pinteraction = 0.010).

CONCLUSIONS

This study suggests that selenium supplements may reduce genetic risk of advanced prostate cancer, whereas aspirin, ibuprofen, and vegetables may reduce genetic risk of nonadvanced prostate cancer.

IMPACT

The effect of genetic factors on prostate cancer risk may vary by lifestyle interventions.

A peripheral circulating TH1 cytokine profile is inversely associated with prostate cancer risk in CLUE II

BACKGROUND

TH1 cytokines, such as IFNγ and TNFα, and potentially innate cytokines, such as IL6, can potentiate the immune response to tumor. Cytokines, such as IL1β, IL8, and IL10, may suppress anticancer immunity. Thus, we prospectively evaluated the association between peripheral-cytokine concentrations and prostate cancer.

METHODS

We conducted an age-race matched case-control study (268 pairs) of incident prostate cancer in CLUE-II. We measured plasma IFNγ, IL10, IL12p70, IL1β, IL6, IL8, and TNFα concentrations using an ultrasensitive multiplex kit. ORs and 95% confidence intervals (CI) were calculated using conditional logistic regression.

RESULTS

The OR of prostate cancer decreased across quartiles of IFNγ (highest vs. lowest quartiles: OR, 0.49; 95% CI, 0.30-0.81; Ptrend = 0.006), TNFα (OR, 0.56; 95% CI, 0.33-0.96; Ptrend = 0.01), and IL6 (OR, 0.46; 95% CI, 0.26-0.79; Ptrend = 0.007). Higher TNFα (OR, 0.28; 95% CI, 0.09-0.85; Ptrend = 0.01) and IL6 (OR, 0.20; 95% CI, 0.06-0.67; Ptrend = 0.003) concentrations were associated with lower Gleason sum ≥7 disease risk. Other cytokines were not as clearly associated with risk.

CONCLUSIONS

Men with a prediagnostic circulating TH1 profile and higher IL6 may have a lower risk of prostate cancer, including aggressive disease. Whether this profile reflects (i) an intraprostatic immune environment in benign tissue that protects against prostate cancer, (ii) the immune milieu in response to a prostate adenocarcinoma that inhibits tumor growth and detectability, and/or (iii) a systemic immune profile that mediates the influence of modifiable factors on risk, warrants additional study.

IMPACT

Identifying specific inflammatory cytokines associated with prostate cancer may lead to improved prevention and treatment strategies.

Overexpression of α (1,6) fucosyltransferase associated with aggressive prostate cancer

Aberrant protein glycosylation is known to be associated with the development of cancers. The aberrant glycans are produced by the combined actions of changed glycosylation enzymes, substrates and transporters in glycosylation synthesis pathways in cancer cells. To identify glycosylation enzymes associated with aggressive prostate cancer (PCa), we analyzed the difference in the expression of glycosyltransferase genes between aggressive and non-aggressive PCa. Three candidate genes encoding glycosyltransferases that were elevated in aggressive PCa were subsequently selected. The expression of the three candidates was then further evaluated in androgen-dependent (LNCaP) and androgen-independent (PC3) PCa cell lines. We found that the protein expression of one of the glycosyltransferases, α (1,6) fucosyltransferase (FUT8), was only detected in PC3 cells, but not in LNCaP cells. We further showed that FUT8 protein expression was elevated in metastatic PCa tissues compared to normal prostate tissues. In addition, using tissue microarrays, we found that FUT8 overexpression was statistically associated with PCa with a high Gleason score. Using PC3 and LNCaP cells as models, we found that FUT8 overexpression in LNCaP cells increased PCa cell migration, while loss of FUT8 in PC3 cells decreased cell motility. Our results suggest that FUT8 may be associated with aggressive PCa and thus is potentially useful for its prognosis.

Chronic inflammation in benign prostate tissue is associated with high-grade prostate cancer in the placebo arm of the prostate cancer prevention trial

BACKGROUND

Chronic inflammation is hypothesized to influence prostate cancer development, although a definitive link has not been established.

METHODS

Prostate cancer cases (N = 191) detected on a for-cause (clinically indicated) or end-of-study (protocol directed) biopsy, and frequency-matched controls (N = 209), defined as negative for cancer on an end-of-study biopsy, were sampled from the placebo arm of the Prostate Cancer Prevention Trial. Inflammation prevalence and extent in benign areas of biopsy cores were visually assessed using digital images of hematoxylin and eosin-stained sections. Logistic regression was used to estimate associations.

RESULTS

Of note, 86.2% of cases and 78.2% of controls had at least one biopsy core (of three assessed) with inflammation in benign areas, most of which was chronic. Men who had at least one biopsy core with inflammation had 1.78 [95% confidence interval (CI), 1.04-3.06] times the odds of prostate cancer compared with men who had zero cores with inflammation. The association was stronger for high-grade disease (Gleason sum 7-10, N = 94; OR, 2.24; 95% CI, 1.06-4.71). These patterns were present when restricting to cases and controls in whom intraprostatic inflammation was the least likely to have influenced biopsy recommendation because their prostate-specific antigen (PSA) was low (<2 ng/mL at biopsy).

CONCLUSION

Inflammation, most of which was chronic, was common in benign prostate tissue, and was positively associated with prostate cancer, especially high grade. The association did not seem to be due to detection bias.

IMPACT

This study supports an etiologic link between inflammation and prostate carcinogenesis, and suggests an avenue for prevention by mitigating intraprostatic inflammation.

GSTP1 promoter methylation is associated with recurrence in early stage prostate cancer

PURPOSE

Recurrent prostate cancer remains a major problem. Staging, grading and prostate specific antigen level at surgery are helpful but still imperfect predictors of recurrence. For this reason there is an imperative need for additional biomarkers that add to the prediction of currently used prognostic factors.

MATERIALS AND METHODS

We evaluated the extent of promoter methylation of genes previously reported as aberrantly methylated in prostate cancer (AIM1, APC, CCND2, GPX3, GSTP1, MCAM, RARβ2, SSBP2 and TIMP3) by quantitative fluorogenic methylation-specific polymerase chain reaction. We used cancer tissue from a nested case-control study of 452 patients surgically treated for prostate cancer. Recurrence cases and controls were compared and the association between methylation extent and recurrence risk was estimated by logistic regression adjusting for patient age at prostatectomy, prostatectomy year, stage, grade, surgical margins and preprostatectomy prostate specific antigen. All statistical tests were 2-sided with p ≤0.05 considered statistically significant.

RESULTS

The extent of GSTP1 methylation was higher in patients with recurrence than in controls (p = 0.01), especially patients with early disease, ie organ confined or limited extraprostatic extension (p = 0.001). After multivariate adjustment GSTP1 promoter methylation at or above the median was associated with an increased risk of recurrence, including in men with early disease (each p = 0.05).

CONCLUSIONS

Greater GSTP1 promoter methylation in cancer tissue was independently associated with the risk of recurrence in patients with early prostate cancer. This suggests that GSTP1 promoter methylation may be a potential tissue based recurrence marker.

Association of C-peptide and leptin with prostate cancer incidence in the Health Professionals Follow-up Study

PURPOSE

Hyperinsulinemia is hypothesized to influence prostate cancer risk. Thus, we evaluated the association of circulating C-peptide, which is a marker of insulin secretion, and leptin, which is secreted in response to insulin and influences insulin sensitivity, with prostate cancer risk.

METHODS

We identified prostate cancer cases (n = 1,314) diagnosed a mean of 5.4 years after blood draw and matched controls (n = 1,314) in the Health Professionals Follow-up Study. Plasma C-peptide and leptin concentrations were measured by ELISA. Odds ratios (ORs) and 95 % confidence intervals (CI) were estimated taking into account the matching factors age and history of a PSA test before blood draw and further adjusting for body mass index, diabetes, and other factors.

RESULTS

Neither C-peptide (quartile [Q]4 vs. Q1: OR 1.05, 95 % CI 0.82-1.34, p-trend = 0.95) nor leptin (Q4 vs. Q1: OR 0.85, 95 % CI 0.65-1.12, p-trend = 0.14) was associated with prostate cancer risk. Further, neither was associated with risk of advanced or lethal disease (n = 156 cases; C-peptide: Q4 vs. Q1, OR 1.18, 95 % CI 0.69-2.03, p-trend = 0.78; leptin: Q4 vs. Q1, OR 0.74, 95 % CI 0.41-1.36, p-trend = 0.34).

CONCLUSIONS

In this large prospective study, circulating C-peptide and leptin concentrations were not clearly associated with risk of prostate cancer overall or aggressive disease. Well into the PSA era, our findings do not appear to be supportive of the hypothesis that hyperinsulinemia influences risk of total or aggressive prostate cancer.

Association of PTEN protein loss with upgrading of prostate cancer from biopsy to radical prostatectomy

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Background: Active surveillance is increasingly recommended for men with low-risk Gleason Score 3+3=6 (GS 6) prostate cancer. Yet, approximately one-third of patients with GS 6 cancer on biopsy are upgraded to higher GS at radical prostatectomy (RP). Previous studies have shown that clinical-pathologic parameters (age, prostate-specific antigen [PSA], prostate volume, extent of disease) are weak predictors of GS6 tumor upgrade. Our goal was to investigate the utility of PTEN as a molecular marker to predict upgrading in GS 6 biopsies. Methods: In a retrospective case-control study, 71 patients with GS 6 tumors on needle biopsy that were upgraded to GS 7 or higher cancer at RP (cases) were compared to 103 patients whose GS 6 tumors on needle biopsy were not upgraded at RP (controls). The most extensively involved needle core biopsy from each case was immunostained and scored for PTEN protein loss using a previously validated immunohistochemical (IHC) assay and binary scoring system. Confirmatory fluorescence in situ hybridization (FISH) was used to assess for PTEN gene deletion in biopsies with PTEN protein loss. The correlation of upgrading with PTEN loss and with clinical-pathologic variables was assessed by logistic regression. Results: Patients with upgraded cancers were older than controls (61.8 vs. 59.3 years), had higher mean pre-operative PSA levels (6.53 vs. 5.26 ng/mL), and a higher fraction of biopsy cores involved by tumor (0.42 vs, 0.36). However, of all pathologic variables, PTEN protein loss by IHC was most predictive of upgrading. Overall, PTEN protein loss was found in 18.3% (13 out of 71) of upgraded cases compared to 6.8% (7 out of 103) of controls (p=0.02). In the cases with PTEN protein loss, FISH confirmed homozygous PTEN deletion in 90% (9 out of 10) of upgraded tumors compared to 67% (4 out of 6) of interpretable not upgraded controls. On multivariate analyses, even after adjusting for age, preoperative PSA, clinical stage and race, GS 6 tumors with PTEN protein loss on biopsy were significantly more likely to be upgraded at RP compared to those without PTEN loss with odds ratio (OR) = 3.04 (1.08-8.55; p=0.035). Conclusions: In prostate needle biopsies, PTEN IHC may help distinguish men with low risk cancer from men with intermediate or higher risk cancers.

The association between circulating high-sensitivity C-reactive protein concentration and pathologic measures of colonic inflammation

PURPOSE

C-reactive protein (CRP), an inflammation marker, is associated with colorectal cancer (CRC) risk in some prospective studies. Whether increased CRP is indicative of colonic inflammation, a possible CRC cause, or of other sources of inflammation (e.g., adiposity), is unknown. Thus, we evaluated the association between CRP and colonic mucosal measures of inflammation.

METHODS

151 adults undergoing colonoscopy provided a blood sample and random left- and right-side colonic mucosal biopsies. Height and weight were measured, and lifestyle information was collected. High-sensitivity C-reactive protein (hsCRP) was measured by immunoturbidometric assay. A gastrointestinal pathologist evaluated biopsies for seven colonic inflammation measures. Of 119 participants with complete information, 24 had an inflammatory bowel disease (IBD) history and were analyzed separately. We calculated the number of colonic inflammation measures present in both biopsies, and separately for right and left biopsies. Adjusted geometric mean hsCRP was calculated using linear regression, overall, by demographic and lifestyle factors, and inflammation measures.

RESULTS

Most participants had ≥ 1 colonic inflammation measure (0: 21 %, 1: 39 %, ≥ 2: 40 %). Adjusted mean hsCRP did not increase with increasing number of inflammation measures (0: 1.67; 1: 1.33; ≥ 2: 1.01 mg/L; p trend = 0.21). Obese (2.03 mg/L) and overweight (1.61 mg/L) participants had higher adjusted mean hsCRP than normal-weight participants (0.62 mg/L; p trend <0.0001). Patterns were similar for participants with a history of IBD.

CONCLUSIONS

hsCRP concentration was not associated with colonic inflammation, although hsCRP increased with adiposity. The hsCRP-CRC association may be explained by residual confounding by other risk factors, such as adiposity, rather than by CRP marking colonic inflammation.

Abstract PR06: Prediagnostic obesity and inactivity are associated with shorter telomere length in prostate cancer-associated stromal cells

Background: Meta-analyses and some cohort studies support that obese men are more likely to develop high-grade and advanced stage prostate cancer, recur after treatment, and die of this cancer. Physical activity, independent of body mass index, has been inversely associated with the development of advanced prostate cancer in some prospective studies. Mechanisms underlying these observations remain unknown. Previously, we showed that shorter telomere length in prostate-cancer associated stromal cells, especially in combination with greater variability in telomere length in cancer cells, was associated with a significantly increased risk of prostate cancer death after prostatectomy. Given this finding and because telomeres shorten with each round of replication, we hypothesized that obesity-associated growth factors influence telomere length, and might explain the more aggressive prostate cancer phenotype in obese men.

Methods: We conducted a cross-sectional study of 596 men surgically treated for prostate cancer who participated in the Health Professionals Follow-up Study. Tissue microarrays containing areas of adenocarcinoma and benign tissue were stained using a telomere-specific FISH probe and using DAPI for total nuclear DNA. Image analysis was used to quantify telomeric signals in individual cancer and benign cells. Body mass index (BMI) and total physical activity were collected via questionnaire 2-years before the diagnosis. BMI was categorized into normal (≥25 kg/m2) and overweight/obese (&gt;25 kg/m2). Total physical activity was categorized into tertiles. Adjusting for pathologic stage, grade and other factors, median and standard deviation of the telomere signal normalized to DAPI were determined for each man for cancer cells and cancer-associated stromal cells by categories of BMI and physical activity.

Results: Overweight/obese men (54%) were similar to normal weight men on demographics and pathologic stage, but had higher Gleason sum and were less active than normal weight men. Overweight/obese men had shorter mean telomere length in cancer-associated stromal cells (7.5% shorter) than normal weight men (p=0.055). The least active men also had shorter mean telomere length in cancer-associated stromal cells than more active men (p-trend=0.004). Men who were overweight/obese and the least active had the shortest mean telomere length in cancer-associated stromal cells (20.7% shorter) compared to normal weight men who were the most active, who had the longest mean telomere length (p=0.0005). Cancer cell telomere length variability did not differ by BMI or activity level.

Conclusions: Increased weight and decreased activity were associated with shorter mean telomere length in cancer-associated stromal cells. Telomere shortening in prostate cells may be one mechanism through which lifestyle influences prostate cancer risk and outcomes.

Funding: Prostate Cancer Foundation, DOD, NIH/NCI, Seraph Foundation

This abstract is also presented as Poster B43.

Citation Format: Corinne E. Joshu, Sarah B. Peskoe, Christopher M. Heaphy, Stacey A. Kenfield, Lorelei A. Mucci, Edward Giovanucci, Meir J. Stampfer, Ghil Suk Yoon, Thomas Lee, Jessica L. Hicks, Angelo M. De Marzo, Alan K. Meeker, Elizabeth A. Platz. Prediagnostic obesity and inactivity are associated with shorter telomere length in prostate cancer-associated stromal cells. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr PR06.

Prostate cancer cell telomere length variability and stromal cell telomere length as prognostic markers for metastasis and death

Current prognostic indicators are imperfect predictors of outcome in men with clinically localized prostate cancer. Thus, tissue-based markers are urgently needed to improve treatment and surveillance decision-making. Given that shortened telomeres enhance chromosomal instability and such instability is a hallmark of metastatic lesions, we hypothesized that alterations in telomere length in the primary cancer would predict risk of progression to metastasis and prostate cancer death. To test this hypothesis, we conducted a prospective cohort study of 596 surgically treated men who participated in the ongoing Health Professionals Follow-up Study. Men who had the combination of more variable telomere length among prostate cancer cells (cell-to-cell) and shorter telomere length in prostate cancer-associated stromal (CAS) cells were substantially more likely to progress to metastasis or die of their prostate cancer. These findings point to the translational potential of this telomere biomarker for prognostication and risk stratification for individualized therapeutic and surveillance strategies.

SIGNIFICANCE

In this prospective study, the combination of more variable telomere length among cancer cells and shorter telomere length in CAS cells was strongly associated with progression to metastasis and prostate cancer death, pointing to the translational potential for prognostication and risk stratifi cation for individualized therapeutic and surveillance strategies.

Serum prostate-specific antigen (PSA) concentration is positively associated with rate of disease reclassification on subsequent active surveillance prostate biopsy in men with low PSA density

OBJECTIVE

To investigate the association between serum prostate-specific antigen (PSA) concentration at active surveillance (AS) entry and disease reclassification on subsequent AS biopsy ('biopsy reclassification') in men with low PSA density (PSAD). To investigate whether a clinically meaningful PSA threshold for AS eligibility/ineligibility for men with low PSAD can be identified based on risk of subsequent biopsy reclassification.

PATIENTS AND METHODS

We included men enrolled in the Johns Hopkins AS Study (JHAS) who had a PSAD of <0.15 ng/mL/g (640 men). We estimated the incidence rates (IRs; per 100 person years) and hazard ratios (HR) of biopsy reclassification (Gleason score ≥ 7, any Gleason pattern 4 or 5, ≥3 positive cores, or ≥50% cancer involvement/biopsy core) for categories of serum PSA concentration at the time of entry into AS. We generated predicted IRs using Poisson regression to adjust for age and prostate volume, mean percentage free PSA (ratio of free to total PSA) and maximum percentage biopsy core involvement with cancer.

RESULTS

The unadjusted IRs (per 100 person years) of biopsy reclassification across serum PSA concentration at entry into JHAS showed, in general, an increase; however, the pattern was not linear with higher IRs in the group ≥ 4 to <6 ng/mL (14.2, 95% confidence interval [CI] 11.8-17.2%) when compared with ≥6 to <8 ng/mL (8.4, 95% CI 5.7-12.3%) but almost similar IRs when compared with the group ≥ 8 to <10 ng/mL (14.8, 95% CI 8.4-26.1%). The adjusted predicted IRs of reclassification showed a similar non-linear increase in IRs, whereby the rates around 4 ng/mL were similar to the rates around 10 ng/mL.

CONCLUSION

Risk for biopsy reclassification increased non-linearly across PSA concentration in men with low PSAD, whereby no obvious clinically meaningful threshold could be identified. This information could be incorporated into decision-making for AS. However, longer follow-up times are needed to warrant final conclusions.

Abstract 3618: Peripheral cytokine profiles and prostate cancer risk in CLUE II

Background

Recent evidence suggests a role for inflammation in the etiology of prostate cancer. Cytokines are important regulators of immune response, including in cancer. In the context of cancer, Th1 cytokines, such as interferon gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and, to some extent, interleukin (IL)-6, can elicit immune reactions to tumor cells. IL-1β, IL-8, IL-10, and IL-12p70 may suppress immune response to a tumor. Immune profile may be an important prognostic factor for disease-free survival in cancer patients. Whether the circulating cytokine profile influences prostate cancer incidence is understudied. Thus, we evaluated the cytokine-prostate cancer association prospectively.

Methods

We conducted an age-race matched case-control study (268 pairs) of inflammatory cytokines (IFN-γ, IL-10, IL-12-p70, IL-1β, IL-6, IL-8, and TNF-α), measured using the ultrasensitive Meso Scale Discovery (MSD) platform, and incident prostate cancer in CLUE II. Cases were identified by cancer registry linkage. The odds ratio (OR) and 95% confidence interval (95% CI) of prostate cancer by quartile of cytokine was calculated using matched and multivariable-adjusted conditional logistic regression.

Results

Median concentrations of IFN-γ (p=0.002), TNF-α (p=0.04), and IL-6 (p=0.06) were lower in cases than controls. Concentrations of the other cytokines did not differ by case status. The multivariable-adjusted OR of prostate cancer decreased across quartiles of IFN-γ (p-trend=0.004), TNF-α (p-trend=0.03), and IL-6 (p-trend=0.005). After their mutual adjustment, the patterns of association remained the same. Of note, the highest (vs lowest) quartile of TNF-α (p=0.03) and IL-6 (p=0.001) was associated with lower risk of metastatic prostate cancer with high Gleason sum ≥7. Overall prostate cancer risk did not change across quartiles of the other cytokines, including IL-10, a Th2 cytokine. However, in normal weight men, higher IL-10 concentration was inversely associated with prostate cancer (highest vs lowest quartiles: OR=0.36; 95% CI: 0.19-0.68), whereas in overweight and obese men, IL-10 was not inversely associated with risk (OR=1.32; 95% CI: 0.87-1.97; p-interaction=0.001). Significant interactions with BMI were not observed for the other cytokines.

Conclusion

Men with a prediagnostic circulating cytokine profile indicative of Th1 immune response may have a lower risk of prostate cancer, including aggressive disease. Whether this circulating cytokine profile reflects 1) the intraprostatic immune environment in benign tissue that protects against the development of prostate cancer, 2) the immune milieu in response to a yet undetected prostate adenocarcinoma that inhibits its growth and thus detectability, and/or 3) a systemic immune profile that mediates the influence of modifiable factors on prostate cancer risk, warrants additional study. The IL-10-obesity interaction also warrants further study.

Citation Format: Nrupen A. Bhavsar, Jay J. Bream, Alan K. Meeker, Charles G. Drake, Sarah B. Peskoe, Angelo M. De Marzo, William B. Isaacs, Elizabeth A. Platz. Peripheral cytokine profiles and prostate cancer risk in CLUE II. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3618. doi:10.1158/1538-7445.AM2013-3618

Abstract 3614: Are circulating testosterone and PSA levels associated in a nationally representative sample of men without a diagnosis of prostate cancer

Background: PSA-based prostate cancer screening is controversial, in part, because of imperfect specificity, especially for aggressive disease. PSA production by prostate luminal epithelial cells is under androgenic regulation. However, the association between circulating androgen and PSA levels is unclear in general populations. Knowledge of this association may enhance clinical decision-making for an elevated screening serum PSA.

Methods: Included were 378 men, 40-85 years who participated in the National Health and Nutrition Examination Survey in 2001-04, who did not have a prior prostate cancer diagnosis, and who had not had a recent biopsy, exam, or infection of the prostate. Serum levels of PSA (Hybritech), testosterone, androstanediol glucuronide (AAG), estradiol, and sex hormone binding globulin (SHBG; carries testosterone and estradiol in circulation) (immunoassay) were previously measured. Free testosterone was estimated by mass action. We calculated geometric mean PSA levels and 95% confidence intervals by hormone quintiles. We applied sampling weights, and adjusted for age and race/ethnicity, and also for BMI, waist circumference, smoking, diabetes, and mutually for the hormones. We stratified by age, race/ethnicity, and adiposity. We estimated the OR of a mildly elevated PSA (≥2.5 ng/mL) per hormone quintile by logistic regression.

Results: Geometric mean PSA level increased across testosterone quintiles after age and race/ethnicity adjustment (Q1: 0.80, Q5: 1.14 ng/mL; p-trend=0.001) and after further multivariable adjustment (Q1: 0.80, Q5: 1.15 ng/mL; p-trend=0.022). The same patterns were observed for free testosterone and AAG. SHBG was not associated with PSA after age and race/ethnicity adjustment (p-trend=0.85), but was strongly inversely associated after multivariable adjustment (Q1: 1.30, Q5: 0.81 nmol/L; p-trend=0.007). Estradiol and PSA levels were not associated. While PSA levels differed by age, by race/ethnicity, and by adiposity, the same sized increasing association for testosterone and PSA was seen within strata of age, of race/ethnicity, and of adiposity. The OR of PSA ≥2.5 ng/mL per testosterone quintile was 1.52 (95% CI 1.16-1.98) after age and race/ethnicity adjustment, and 1.74 (95% CI 1.13-2.68) after multivariable adjustment; SHBG explained the OR shift. The multivariable-adjusted OR of PSA ≥2.5 ng/mL per SHBG quintile was 0.60 (95% CI 0.37-1.00).

Conclusions: In this nationally representative sample, men with higher testosterone had higher PSA, even after taking into account other hormones and modifiable factors. Men with higher SHBG had lower PSA, but only after multivariable adjustment. This information on testosterone and SHBG may be incorporated into algorithms for determining next steps following an elevated screening PSA.

Funding: MD Cigarette Restitution Fund; NIH Intramural Research Program

Citation Format: Sarah B. Peskoe, William G. Nelson, Corinne E. Joshu, Sabine Rohrmann, Katherine A. McGlynn, Elizabeth A. Platz. Are circulating testosterone and PSA levels associated in a nationally representative sample of men without a diagnosis of prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3614. doi:10.1158/1538-7445.AM2013-3614

Racial/ethnic differences in serum sex steroid hormone concentrations in US adolescent males

OBJECTIVE

Contrary to the hypothesis that the racial/ethnic disparity in prostate cancer has a hormonal basis, we did not observe a difference in serum testosterone concentration between non-Hispanic black and white men in the Third National Health and Nutrition Examination Survey (NHANES III), although non-Hispanic black men had a higher estradiol level. Unexpectedly, Mexican-American men had the highest testosterone level. Next, we evaluated whether the same patterns are observed during adolescence, the time of prostate maturation.

METHODS

We measured serum testosterone, estradiol, and sex hormone-binding globulin (SHBG) by immunoassay in 134 males aged 12-19 in NHANES III. Mean concentrations were compared by race/ethnicity adjusting for age, Tanner stage, percent body fat, waist, physical activity, tobacco smoke, and the other hormones.

RESULTS

After multivariable adjustment, in the 12-15-year-old males, testosterone concentration was lower in non-Hispanic blacks than whites (p = 0.043), SHBG concentration did not significantly differ between the two groups. Mexican-Americans had the highest testosterone (versus non-Hispanic black: p = 0.002) and lowest SHBG (versus non-Hispanic white: p = 0.010; versus non-Hispanic black: p = 0.047) concentrations. Estradiol concentration was lower in non-Hispanic blacks (p = 0.11) and Mexican-Americans (p = 0.033) compared with non-Hispanic whites. After multivariable adjustment, in the 16-19-year-old males, testosterone, estradiol, and SHBG concentrations did not differ between non-Hispanic blacks and whites. Mexican-Americans had the highest testosterone concentration (versus non-Hispanic white: p = 0.08), but did not differ from the other groups on estradiol and SHBG concentrations. In both age groups, these patterns were generally present, but less pronounced after adjusting for age and Tanner stage only.

CONCLUSION

In adolescent males, non-Hispanic blacks did not have a higher testosterone concentration than non-Hispanic whites, and Mexican-Americans had the highest testosterone concentration, patterns similar to adult males.

Loss of PTEN expression is associated with increased risk of recurrence after prostatectomy for clinically localized prostate cancer

PTEN (phosphatase and tensin homolog on chromosome 10) is one of the most frequently lost tumor suppressor genes in human cancers and it has been described in more than two-thirds of patients with advanced/aggressive prostate cancer. Previous studies suggest that, in prostate cancer, genomic PTEN loss is associated with tumor progression and poor prognosis. Thus, we evaluated whether immunohistochemical PTEN expression in prostate cancer glands was associated with higher risk of recurrence, using a nested case-control study that included 451 men who recurred and 451 men who did not recur with clinically localized prostate cancer treated by radical prostatectomy. Recurrence was defined as biochemical recurrence (serum prostate-specific antigen >0.2 ng/ml) or clinical recurrence (local recurrence, systemic metastases, or prostate cancer-related death). Cases and controls were matched on pathological T stage, Gleason score, race/ethnicity, and age at surgery. Odds ratios of recurrence and 95% confidence intervals were estimated using conditional logistic regression to account for the matching factors and to adjust for year of surgery, preoperative prostate-specific antigen concentrations, and status of surgical margins. Men who recurred had a higher proportion of PTEN negative expression (16 vs 11%, P=0.05) and PTEN loss (40 vs 31%, P=0.02) than controls. Men with markedly decreased PTEN staining had a higher risk of recurrence (odds ratio=1.67; 95% confidence intervals 1.09, 2.57; P=0.02) when compared with all other men. In summary, in patients with clinically localized prostate cancer treated by prostatectomy, decreased PTEN expression was associated with an increased risk of recurrence, independent of known clinicopathological factors.

Incidence and progression of lower urinary tract symptoms in a large prospective cohort of United States men

PURPOSE

To support trials testing lifestyle interventions for lower urinary tract symptoms, often a consequence of benign prostatic hyperplasia, we estimated the incidence and progression rates of lower urinary tract symptoms in United States men unselected for benign prostatic hyperplasia.

MATERIALS AND METHODS

We studied men in the HPFS (Health Professionals Follow-Up Study) whom we asked to report periodically by mailed survey whether they had undergone surgery or used medications for lower urinary tract symptoms and to complete the International Prostate Symptom Score survey. For incidence we included 25,879 men with an International Prostate Symptom Score of 0 to 7 and no surgery history who were followed from 1992 to 2008. Incident moderate or worse lower urinary tract symptoms (6,058) were defined as an International Prostate Symptom Score of 15 or greater, surgery, or medication use. Modest or worse lower urinary tract symptoms were similarly defined but with an International Prostate Symptom Score of 8 or greater (11,352). For progression we included 9,628 men with an International Prostate Symptom Score of 8 to 14 and no surgery who were followed from when they first reported an International Prostate Symptom Score of 8 to 14 until 2008. Progression to severe lower urinary tract symptoms (2,557) was defined as an International Prostate Symptom Score of 20 or greater, surgery, or medication use. We estimated age specific and age standardized rates.

RESULTS

Incidence and progression rates increased with age (p trend <0.0001), and progression rates were higher than incidence rates. The age standardized rates were incidence of moderate to worse lower urinary tract symptoms 18.5, incidence of modest or worse lower urinary tract symptoms 40.5 and progression to severe lower urinary tract symptoms 44.9 per 1,000 man-years.

CONCLUSIONS

The incidence and progression rates of lower urinary tract symptoms are high and increase steeply as men age. These rates may be used for planning adequately powered trials to test lifestyle interventions for lower urinary tract symptoms well before surgical or pharmacological treatment is indicated.