Increased Lifetime Risk of Intestinal Complications and Extraintestinal Manifestations in Crohn's Disease and Ulcerative Colitis

Patients with Crohn's disease (CD) or ulcerative colitis (UC) have high morbidity rates owing to debilitating intestinal complications and extraintestinal manifestations (EIMs). We retrospectively identified patients in the Truven MarketScan databases with an incident CD or UC diagnosis from January 2008 to September 2015 to quantify the incremental lifetime risk of experiencing an intestinal complication or EIM after CD or UC diagnosis. Seven intestinal complications and 13 categories of EIMs by site were identified, and lifetime risk of experiencing an intestinal complication or EIM from age at CD or UC diagnosis to end of life was estimated using parametric models. Results were compared with controls' propensity score matched by age, sex, health plan, and pre-index Charlson Comorbidity Index. The CD or UC incremental risk was calculated using the difference in rates between CD or UC patients and matched controls. A total of 34,692 CD patients and 48,196 UC patients with 1:1 matched controls were included. CD and UC patients had an increased lifetime risk of intestinal complications, which varied across ages, inflammatory bowel disease (IBD) types, and categories of intestinal complications and EIMs. CD and UC patients aged 0 to 11 years had the highest incremental lifetime risk for all 7 intestinal complications and the majority of EIMs, with blood EIMs associated with the highest incremental risk (CD: 32%; UC: 21%). CD and UC patients of all ages have a higher lifetime risk of experiencing intestinal complications and EIMs than patients without CD or UC. When evaluating the burden of disease on patients with IBD, it is important to include the burden of these intestinal complications and EIMs in the assessment.

Lifetime Economic Burden of Crohn's Disease and Ulcerative Colitis by Age at Diagnosis

BACKGROUND & AIMS

Understanding the burden of Crohn's disease (CD) and ulcerative colitis (UC) is important for measuring treatment value. We estimated lifetime health care costs incurred by patients with CD or UC by age at diagnosis.

METHODS

We collected data from 78,620 patients with CD, 85,755 with UC, and propensity score-matched control subjects from the Truven Health MarketScan insurance claims databases (2008‒2015). Total medical (inpatient, outpatient) and pharmacy costs were captured. Cost variations over a lifetime were estimated in cost-state Markov models by age at diagnosis, adjusted to 2016 U.S. dollars and discounted at 3% per annum. We measured lifetime total and lifetime incremental cost (the difference between costs of CD or UC patients vs matched controls).

RESULTS

For CD, the lifetime incremental cost was $707,711 among patients who received their diagnosis at 0‒11 years, and $177,614 for patients 70 years or older, averaging $416,352 for a diagnosis at any age. Lifetime total cost was $622,056, consisting of outpatient ($273,056), inpatient ($164,298), pharmacy ($163,722), and emergency room (ER) ($20,979) costs. For UC, the lifetime incremental cost was $369,955 among patients who received their diagnosis at 0‒11 years, and $132,396 for individuals 70 years or older, averaging $230,102 for a diagnosis at any age. Lifetime total cost was $405,496, consisting of outpatient ($163,670), inpatient ($123,190), pharmacy ($105,142), and ER ($13,493) costs. Therefore, the prevalent populations of patients with CD or UC in the United States in 2016 are expected to incur lifetime total costs of $498 billion and $377 billion, respectively.

CONCLUSIONS

Using a Markov model, we estimated lifetime costs for patients with CD or UC to exceed previously published estimates. Individuals who receive a diagnosis of CD or UC at an early age (younger than 11 years) incur the highest lifetime cost burden. Advancing management strategies may significantly improve patient outcomes and reduce lifetime health care spending.

Share of Oncology Versus Nononcology Spending in Episodes Defined by the Centers for Medicare & Medicaid Services Oncology Care Model

PURPOSE

Performance-based payments to oncology providers participating in the Centers for Medicare & Medicaid Services (CMS) Oncology Care Model (OCM) are based, in part, on overall spending in 6-month episodes of care, including spending unrelated to oncology care. The amount of spending likely to occur outside of oncologists' purview is unknown.

METHODS

Following the OCM definition of an episode, we used SEER-Medicare data from 2006 to 2013 to identify episodes of cancer care for the following diagnoses: breast cancer (BC), non-small-cell lung cancer, renal cell carcinoma, multiple myeloma (MM), and chronic myeloid leukemia. Claims were categorized by service type and, separately, whether the content fell within the purview of oncology providers (classified as oncology, with all other claims nononcology). We calculated the shares of episode spending attributable to oncology versus nononcology services.

RESULTS

The percentage of oncology spending within OCM episodes ranged from 62.4% in BC to 85.5% in MM. The largest source of oncology spending was antineoplastic drug therapy, ranging from 21.8% of total episode spending in BC to 67.6% in chronic myeloid leukemia. The largest source of nononcology spending was acute hospitalization and inpatient physician costs, ranging from 6.6% of overall spending for MM to 10.4% for non-small-cell lung cancer; inpatient oncology spending contributed roughly similar shares to overall spending.

CONCLUSION

Most spending in OCM-defined episodes was attributable to services related to cancer care, especially antineoplastic drug therapy. Inability to control nononcology spending may present challenges for practices participating in the OCM, however.

The economic burden of switching targeted disease-modifying anti-rheumatic drugs among rheumatoid arthritis patients

AIMS

To estimate real world healthcare costs and resource utilization of rheumatoid arthritis (RA) patients associated with targeted disease modifying anti-rheumatic drugs (tDMARD) switching in general and switching to abatacept specifically.

MATERIALS AND METHODS

RA patients initiating a tDMARD were identified in IMS PharMetrics Plus health insurance claims data (2010-2016), and outcomes measured included monthly healthcare costs per patient (all-cause, RA-related) and resource utilization (inpatient stays, outpatient visits, emergency department [ED] visits). Generalized linear models were used to assess (i) average monthly costs per patient associated with tDMARD switching, and (ii) among switchers only, costs of switching to abatacept vs tumor necrosis factor inhibitors (TNFi) or other non-TNFi. Negative binomial regressions were used to determine incident rate ratios of resource utilization associated with switching to abatacept.

RESULTS

Among 11,856 RA patients who initiated a tDMARD, 2,708 switched tDMARDs once and 814 switched twice (to a third tDMARD). Adjusted average monthly costs were higher among patients who switched to a second tDMARD vs non-switchers (all-cause: $4,785 vs $3,491, p < .001; RA-related: $3,364 vs $2,297, p < .001). Monthly RA-related costs were higher for patients switching to a third tDMARD compared to non-switchers remaining on their second tDMARD ($3,835 vs $3,383, p < .001). Switchers to abatacept had significantly lower RA-related monthly costs vs switchers to TNFi ($3,129 vs $3,436, p = .021), and numerically lower all-cause costs ($4,444 vs $4,741, p = 0.188). Switchers to TNFi relative to abatacept had more frequent inpatient stays after switch (incidence rate ratio (IRR) = 1.85, p = .031), and numerically higher ED visits (IRR = 1.32, p = .093). Outpatient visits were less frequent for TNFi switchers (IRR = 0.83, p < .001) compared to switchers to abatacept.

LIMITATIONS AND CONCLUSIONS

Switching to another tDMARD was associated with higher healthcare costs. Switching to abatacept, however, was associated with lower RA-related costs, fewer inpatient stays, but more frequent outpatient visits compared to switching to a TNFi.

Cost variation and savings opportunities in the Oncology Care Model

OBJECTIVES

This study seeks to identify service categories that present the greatest opportunities to reduce spending in oncology care episodes, as defined by the CMS Oncology Care Model (OCM). Regional variation in spending for similar patients is often interpreted as evidence that resources can be saved, because higher-spending regions could achieve savings by behaving more like their lower-spending counterparts.

STUDY DESIGN

We used Surveillance, Epidemiology, and End Results Medicare data from 2006-2013 for this retrospective observational cohort study. Analysis focused on patients with non-small cell lung cancer, advanced (stage III or IV) breast cancer, renal cell carcinoma, multiple myeloma, or chronic myeloid leukemia.

METHODS

Episodes were identified for patients with the 5 included cancers, following the episode definition used in the OCM. We estimated standardized episode-level spending for a standard patient across subcategories of care for each hospital referral region (HRR) defined by the Dartmouth Atlas. The contribution of each subcategory to interregional variation in total spending reflects that subcategory's potential to yield savings.

RESULTS

Chemotherapy and acute inpatient hospital care tended to be the highest contributors to interregional variation. Imaging, nonchemotherapy Part B drugs, physician evaluation and management services, and diagnostics were negligible contributors to interregional variation for all 5 cancers.

CONCLUSIONS

Chemotherapy and inpatient hospital care offer the most potential to reduce spending within OCM-defined episodes. Other sources of savings differ by type of cancer. Assuming patient outcomes are not compromised, low-spending HRRs may be models for lowering cost in cancer care.

Greater Spending Associated with Improved Survival for Some Cancers in OCM-Defined Episodes

BACKGROUND

Previous research finds significant variation in spending and utilization across regions, with little evidence of differences in outcomes. While such findings have been interpreted as evidence that spending can be reduced without compromising patient outcomes, the link between spending variation and outcomes remains a critical question.

OBJECTIVE

To use evidence from geographic variations in spending and an individual-level survival analysis to test whether spending within oncology care episodes is associated with survival, where episodes are defined as in the Center for Medicare and Medicaid Innovation's Oncology Care Model (OCM).

METHODS

In this retrospective cohort analysis, patient data from the Surveillance, Epidemiology and End Results Medicare (SEER-Medicare) database for 2007-2013 were linked to hospital referral regions (HRRs) using ZIP codes. Patients in the SEER program are a part of selected population-based cancer registries throughout the United States whose records are linked to Medicare enrollment and claims data (93% of elderly registry patients were successfully linked to Medicare data). Episodes of cancer care were defined as in the OCM: 6 months following a triggering chemotherapy claim. We analyzed episodes of care for 5 tumor types: advanced breast cancer (BC), non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), multiple myeloma (MM), and chronic myeloid leukemia (CML). We removed the effects of differentials in Medicare payment rates, which were mostly geographic. Regression analysis was then used to calculate standardized spending levels for each HRR, that is, spending adjusted for differences in patient and episode characteristics. To examine the effect of spending during OCM-defined episodes on individual-level survival, we used Cox regression with patient characteristics and standardized HRR spending per episode as covariates. To address concerns that may arise from multiple comparisons across the 5 tumor types, we used the Benjamini-Hochberg procedure to control the false discovery rate.

RESULTS

Our analysis showed significant differences in standardized spending across HRRs. Compared with spending at the 20th percentile episode, spending at the 80th percentile ranged from 25% higher ($57,392 vs. $45,995 for MM) to 47% higher ($36,920 vs. $24,127 for RCC), indicating practice style variation across regions. The hazard of dying for patients with NSCLC and MM statistically significantly decreased by 7% (HR = 0.93, P = 0.006) and 13% (HR = 0.87, P = 0.019), respectively, for a $10,000 increase in standardized spending (in 2013 U.S. dollars). For the 3 other cancers, spending effects were not statistically significant. After using the Benjamini-Hochberg procedure with a 5% false discovery rate, the effects of increased spending on improved survival for NSCLC and MM remained statistically significant.

CONCLUSIONS

The association we found between spending and survival suggests caution may be warranted for physicians, pharmacists, other health care professionals, and policymakers involved in efforts to reduce across-the-board spending within OCM-defined episodes for at least 2 of the 5 cancers studied.

DISCLOSURES

Funding for this research was provided by Novartis Pharmaceuticals to Precision Health Economics in support of research design, analysis, and technical writing services. The funder provided input on study design and comments on the draft report. Baumgardner, Shahabi, and Linthicum are employees of Precision Health Economics (PHE), a health care consultancy to the insurance and life science industries, including firms that market oncology therapies. Vine was an employee of PHE at the time of this research. Zacker is an employee of and shareholder in Novartis Pharmaceuticals. Lakdawalla is a consultant to PHE and holds equity in its parent company, Precision Medicine Group.

Assessing Variation in the Cost of Palivizumab for Respiratory Syncytial Virus Prevention in Preterm Infants

BACKGROUND

The variability in cost of palivizumab treatment, indicated for prevention of respiratory syncytial virus (RSV) infections in high-risk infants, has not been robustly estimated in prior studies. This study aimed to determine the cost variations of palivizumab from a US payer perspective for otherwise healthy preterm infants born 29-35 weeks gestational age (wGA) using infant characteristics and applied dosing regimens.

METHODS

Fenton Growth Charts were merged with World Health Organization Child Growth Standards to estimate preterm infant growth patterns. The merged growth chart was applied to infants who received palivizumab from a prospective, observational registry to determine future body weight using each infant's wGA and birth weight. Using quarter 3 (Q3) 2016-Q2 2017 vial cost, treatment costs at monthly dosing intervals were estimated using expected weights and averaged by age to derive expected mean 2016-2017 RSV seasonal costs per infant under various dosing scenarios.

RESULTS

Given different dosing scenarios (two to five doses), birth month, and growth patterns for preterm infants 29-35 wGA, the estimated average 2016-2017 seasonal cost of palivizumab treatment ranged from $3221 to $12,568. Outpatient-only cost (excluding first dose at hospital discharge) ranged from $1733 to $11,862. The main drivers of costs were dosing regimen (74% of variance), dosing interacted with birth month (17%), and wGA (6%).

CONCLUSION

The considerable variability in the average cost of palivizumab treatment for preterm infants is driven by choice of dosing regimen, wGA, and birth month. Therefore, when estimating the cost of palivizumab, it is important to consider both infant characteristics at each dose and potential dosing regimens.

Novel Gene Expression Signature Predictive of Clinical Recurrence After Radical Prostatectomy in Early Stage Prostate Cancer Patients

BACKGROUND

Current clinical tools have limited accuracy in differentiating patients with localized prostate cancer who are at risk of recurrence from patients with indolent disease. We aimed to identify a gene expression signature that jointly with clinical variables could improve upon the prediction of clinical recurrence after RP for patients with stage T2 PCa.

METHODS

The study population includes consented patients who underwent a radical retropubic prostatectomy (RP) and bilateral pelvic lymph node dissection at the University of Southern California in the PSA-era (1988-2008). We used a nested case-control study of 187 organ-confined patients (pT2N0M0): 154 with no recurrence ("controls") and 33 with clinical recurrence ("cases"). RNA was obtained from laser capture microdissected malignant glands representative of the overall Gleason score of each patient. Whole genome gene expression profiles (29,000 transcripts) were obtained using the Whole Genome DASL HT platform (Illumina, Inc). A gene expression signature of PCa clinical recurrence was identified using stability selection with elastic net regularized logistic regression. Three existing datasets generated with the Affymetrix Human Exon 1.0ST array were used for validation: Mayo Clinic (MC, n = 545), Memorial Sloan Kettering Cancer Center (SKCC, n = 150), and Erasmus Medical Center (EMC, n = 48). The areas under the ROC curve (AUCs) were obtained using repeated fivefold cross-validation.

RESULTS

A 28-gene expression signature was identified that jointly with key clinical variables (age, Gleason score, pre-operative PSA level, and operation year) was predictive of clinical recurrence (AUC of clinical variables only was 0.67, AUC of clinical variables, and 28-gene signature was 0.99). The AUC of this gene signature fitted in each of the external datasets jointly with clinical variables was 0.75 (0.72-0.77) (MC), 0.90 (0.86-0.94) (MSKCC), and 0.82 (0.74-0.91) (EMC), whereas the AUC for clinical variables only in each dataset was 0.72 (0.70-0.74), 0.86 (0.82-0.91), and 0.76 (0.67-0.85), respectively.

CONCLUSIONS

We report a novel gene-expression based classifier identified using agnostic approaches from whole genome expression profiles that can improve upon the accuracy of clinical indicators to stratify early stage localized patients at risk of clinical recurrence after RP. Prostate 76:1239-1256, 2016. © 2016 Wiley Periodicals, Inc.

Predictors of time to biochemical recurrence in a radical prostatectomy cohort within the PSA-era

INTRODUCTION

We sought to determine predictors for early and late biochemical recurrence following radical prostatectomy among localized prostate cancer patients.

METHODS

The study included localized prostate cancer patients treated with radical prostatectomy (RP) at the University of Southern California from 1988 to 2008. Competing risks regression models were used to determine risk factors associated with earlier or late biochemical recurrence, defined using the median time to biochemical recurrence in this population (2.9 years after radical prostatectomy).

RESULTS

The cohort for this study included 2262 localized prostate cancer (pT2-3N0M0) patients who did not receive neoadjuvant or adjuvant therapies. Of these patients, 188 experienced biochemical recurrence and a subset continued to clinical recurrence, either within (n=19, 10%) or following (n=13, 7%) 2.9 years after RP. Multivariable stepwise competing risks analysis showed Gleason score ≥7, positive surgical margin status, and ≥pT3a stage to be associated with biochemical recurrence within 2.9 years following surgery. Predictors of biochemical recurrence after 2.9 years were Gleason score 7 (4+3), preoperative prostate-specific antigen (PSA) level, and ≥pT3a stage.

CONCLUSIONS

Higher stage was associated with biochemical recurrence at any time following radical prostatectomy. Particular attention may need to be made to patients with stage ≥pT3a, higher preoperative PSA, and Gleason 7 prostate cancer with primary high-grade patterns when considering longer followup after RP.

Tobacco smoking, polymorphisms in carcinogen metabolism enzyme genes, and risk of localized and advanced prostate cancer: results from the California Collaborative Prostate Cancer Study

The relationship between tobacco smoking and prostate cancer (PCa) remains inconclusive. This study examined the association between tobacco smoking and PCa risk taking into account polymorphisms in carcinogen metabolism enzyme genes as possible effect modifiers (9 polymorphisms and 1 predicted phenotype from metabolism enzyme genes). The study included cases (n = 761 localized; n = 1199 advanced) and controls (n = 1139) from the multiethnic California Collaborative Case-Control Study of Prostate Cancer. Multivariable conditional logistic regression was performed to evaluate the association between tobacco smoking variables and risk of localized and advanced PCa risk. Being a former smoker, regardless of time of quit smoking, was associated with an increased risk of localized PCa (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 1.0-1.6). Among non-Hispanic Whites, ever smoking was associated with an increased risk of localized PCa (OR = 1.5; 95% CI = 1.1-2.1), whereas current smoking was associated with risk of advanced PCa (OR = 1.4; 95% CI = 1.0-1.9). However, no associations were observed between smoking intensity, duration or pack-year variables, and advanced PCa. No statistically significant trends were seen among Hispanics or African-Americans. The relationship between smoking status and PCa risk was modified by the CYP1A2 rs7662551 polymorphism (P-interaction = 0.008). In conclusion, tobacco smoking was associated with risk of PCa, primarily localized disease among non-Hispanic Whites. This association was modified by a genetic variant in CYP1A2, thus supporting a role for tobacco carcinogens in PCa risk.

Sexual function after non-nerve-sparing radical cystoprostatectomy: a comparison between ileal conduit urinary diversion and orthotopic ileal neobladder substitution

OBJECTIVE

To compare the erectile function (EF) and sexual desire (SD) in men after radical cystoprostatectomy (RCP) who had either an ileal conduit urinary diversion or orthotropic ileal neobladder substitution.

MATERIALS AND METHODS

Eighty one sexually active men with bladder cancer were enrolled in this prospective study. After RCP according to patients' preferences they underwent either ileal conduit urinary diversion (n = 41) or orthotropic ileal neobladder substitution (n = 40). EF and SD were assessed using International Index of Erectile Function (IIEF) questionnaire. Patients were assessed at 4-week before surgery and were followed up at 1, 6, and 12-month postoperatively using the same questionnaire.

RESULTS

Postoperatively the EF and SD domains deteriorated significantly in both groups, but in a small proportion of the patients submitted to ileal neobladder they gradually improved with time (P = 0.006). At 12-month postoperative period, 4 (9.8 %) and 14 (35.0 %) patients in ileal conduit and ileal neobladder groups were able to achieve erections hard enough for vaginal penetration and maintained their erection to completion of intercourse, respectively (P = 0.006). Among patients in the ileal conduit and ileal neobladder groups, additional 4 (9.8 %) and 7 (17.1 %) patients were able to get some erection, but were unable to maintain their erection to completion of intercourse (P = 0.02). At 12-month follow up period 24.4 % of the ileal conduit and 45.0 % of the ileal neobladder patients rated their sexual desire very high or high (P = 0.01).

CONCLUSION

When performed properly, orthotopic ileal neobladder substitution after RCP offers better long-term results in terms of EF and SD.

Analysis of risk factors associated with microvascular free flap failure using a multi-institutional database

BACKGROUND

There are numerous factors that may contribute to microvascular free flap failure. Although technical issues are dominant factors, patient and clinical characteristics are also contributory. The aim of this study was to investigate non-technical variables associated with microsurgical free flap failure using a multi-institutional dataset.

METHODS

Utilizing the American College of Surgeons' National Surgical Quality Improvement Program (NSQIP) database, we identified all patients who underwent microvascular free tissue transfer from 2005 through 2009. Univariate analysis was performed to determine the association of flap failure with the following factors: age, gender, ethnicity, body mass index, intraoperative transfusion, diabetes, smoking, alcohol, American Society of Anesthesiologists classification, year of operation, operative time, number of flaps, and type of reconstruction. Factors with a significance of P < 0.2 in the univariate analysis were included in the multivariate logistic regression model to identify independent risk factors.

RESULTS

A total of 639 patients underwent microsurgical free flap reconstruction with 778 flaps over the 4-year study period; 139 patients had two free flaps during the same operation. The overall incidence of flap failure was 4.4% (34/778) (95% confidence interval [CI]: 3.0%, 6.2%). Operative time was identified as an independent risk factor for free flap failure. After adjusting for other factors, those whose operative time was equal to or greater than the 75th percentile (625.5 min) were twice as likely to experience flap failure (AOR 2.09; 95% CI: 1.01-4.31; P = 0.045). None of the other risk factors studied were significant contributors.

CONCLUSIONS

In this series, the overall flap loss rate of was 4.4%. Operative time was a significant independent risk factor for flap failure.

Quality of life after radical cystectomy for bladder cancer in men with an ileal conduit or continent urinary diversion: A comparative study

AIM

To investigate quality of life (QoL) domains with three forms of urinary diversions, including ileal conduit, MAINZ pouch, and orthotopic ileal neobladder after radical cystectomy in men with muscle-invasive bladder cancer.

MATERIALS AND METHODS

In a prospective study, 149 men underwent radical cystectomy and urinary diversion (70 ileal conduit, 16 MAINZ pouch, and 63 orthotopic ileal neobladder). Different domains of QoL, including general and physical conditions, psychological status, social status, sexual life, diversion-related symptoms, and satisfaction with the treatment were assessed using an author constructed questionnaire. Assessment was performed at three months postoperatively.

RESULTS

In questions addressing psychological status, social status, and sexual life, patients with continent diversion had a more favorable outcome (P = 0.002, P = 0.01, and P = 0.002, respectively). The rate of erectile dysfunction did not differ significantly between the three groups (P = 0.21). The rate and global satisfaction was higher with the MAINZ pouch (68.7%) and ileal neobladder (76.2%) as compared with the ileal conduit group (52.8%) (P = 0.002).

CONCLUSION

Continent urinary diversion after radical cystectomy provides better results in terms of QoL as compared with ileal conduit diversion.

Identification of 23 new prostate cancer susceptibility loci using the iCOGS custom genotyping array

Prostate cancer is the most frequently diagnosed cancer in males in developed countries. To identify common prostate cancer susceptibility alleles, we genotyped 211,155 SNPs on a custom Illumina array (iCOGS) in blood DNA from 25,074 prostate cancer cases and 24,272 controls from the international PRACTICAL Consortium. Twenty-three new prostate cancer susceptibility loci were identified at genome-wide significance (P < 5 × 10(-8)). More than 70 prostate cancer susceptibility loci, explaining ∼30% of the familial risk for this disease, have now been identified. On the basis of combined risks conferred by the new and previously known risk loci, the top 1% of the risk distribution has a 4.7-fold higher risk than the average of the population being profiled. These results will facilitate population risk stratification for clinical studies.

A meta-analysis of genome-wide association studies to identify prostate cancer susceptibility loci associated with aggressive and non-aggressive disease

Genome-wide association studies (GWAS) have identified multiple common genetic variants associated with an increased risk of prostate cancer (PrCa), but these explain less than one-third of the heritability. To identify further susceptibility alleles, we conducted a meta-analysis of four GWAS including 5953 cases of aggressive PrCa and 11 463 controls (men without PrCa). We computed association tests for approximately 2.6 million SNPs and followed up the most significant SNPs by genotyping 49 121 samples in 29 studies through the international PRACTICAL and BPC3 consortia. We not only confirmed the association of a PrCa susceptibility locus, rs11672691 on chromosome 19, but also showed an association with aggressive PrCa [odds ratio = 1.12 (95% confidence interval 1.03-1.21), P = 1.4 × 10(-8)]. This report describes a genetic variant which is associated with aggressive PrCa, which is a type of PrCa associated with a poorer prognosis.

Glutathione-S-transferase (GST) polymorphisms are associated with relapse after radical prostatectomy

BACKGROUND

Organ confined prostate cancer (PCa) can be cured by radical retropubic prostatectomy (RRP); however, some tumors will still recur. Current tools fail to identify patients at risk of recurrence. Glutathione-S-transferases (GSTs) are involved in the metabolism of carcinogens, hormones and drugs. Thus, genetic polymorphisms that modify the GST activities may modify the risk of PCa recurrence.

METHODS

We retrospectively recruited Argentine PCa patients treated with RRP to study the association between GST polymorphisms and PCa biochemical relapse after RRP. We genotyped germline DNA in 105 patients for: GSTP1 c.313A>G (p.105 Ile>Val, rs1695) by PCR-RFLP; and GSTT1 null and GSTM1 null polymorphisms by multiplex PCR. Kaplan-Meier curves and Cox proportional hazard models were used to evaluate these associations.

RESULTS

Patients with GSTP1 c.313GG genotype showed shorter biochemical relapse-free survival (BRFS) (P = 0.003) and higher risk for recurrence in unadjusted (Hazard ratio (HR) = 3.16, 95% confidence interval (95% CI) = 1.41-7.06, P = 0.005) and multivariate models (HR = 3.01, 95% CI = 1.13-8.02, P = 0.028). We did not find significant associations for GSTT1 and GSTM1 genotypes. In addition, we found shorter BRFS (P = 0.010) and increased risk for recurrence for patients having two or more risk alleles when we combined the genotypes of the three GSTs in multivariate models (HR = 3.06, 95% CI = 1.20-7.80, P = 0.019).

CONCLUSIONS

Our results give support to the implementation of GSTs genotyping for personalized therapies as a novel alternative for PCa management for patients who undergo RRP. To the best of our knowledge, this is the first study that examined GST polymorphisms in PCa progression in Argentine men. Replication of our findings in larger cohort is warranted.

Abstract B79: Tobacco smoking, polymorphisms in xenobiotic metabolism enzyme genes, and prostate cancer risk and survival

Introduction: The association between tobacco smoking and prostate cancer (PCa) risk and progression remains unclear. This study examined the association between tobacco smoking and risk of localized and advanced PCa, PCa-specific mortality, and overall mortality in African-American, Hispanic and non-Hispanic White men. Polymorphisms in xenobiotic metabolism enzyme genes were further examined as possible modifiers of associations with smoking.

Methods: Using data from the California Collaborative Prostate Cancer Study, a multiethnic population-based case-control study conducted in Los Angeles County (631 advanced and 533 localized cases; 594 controls) and the San Francisco Bay Area (568 advanced and 208 localized cases; 545 controls), we evaluated associations between tobacco smoking and risk of localized and advanced PCa using conditional logistic regression. Cox proportional hazards regression models and Kaplan Meier curves with log-rank tests were used to assess associations with PCa-specific and all-cause mortality. Median follow-up time for cases was 8.8 years (IQR: 6.2-9.9). We also investigated the role of 12 metabolism enzyme single nucleotide polymorphisms from 7 genes as potential modifiers of the relationship between tobacco smoking and PCa risk and progression using interaction models.

Results: After adjusting for age, PCa family history, body mass index, alcohol consumption, intake of meat cooked at high temperature, and use of snuffing/chewing tobacco, non-Hispanic Whites who were former smokers had an increased risk of localized PCa when compared to never smokers (OR=1.52, 95%CI: 1.11-2.09, p&lt;0.01). Risk increased with younger age at first tobacco use (p-trend&lt;0.01), duration of tobacco smoking (p-trend=0.01), number of daily cigarettes smoked (p-trend=0.02), and cigarette pack-years (p-trend=0.03). Current smoking was associated with an increased risk of advanced PCa (OR=1.41, 95%CI: 1.02-1.94, p=0.037) among non-Hispanic Whites, but a decreased risk among Hispanics (OR=0.48, 95%CI: 0.23-0.99, p=0.047). No significant trends were seen for any of the smoking variables among Hispanics or African-Americans. A CYP1A2 polymorphism (rs7662551) modified the relationship between smoking status and PCa risk; the addition of each C-allele increased risk for localized (p-interaction=0.01) and advanced (p-interaction=0.03) PCa, particularly among current smokers. Tobacco smoking was not associated with PCa-specific mortality. For all-cause mortality, increased risk was associated with current smoking, duration of smoking, cigarette pack-years, and young age at first smoking. Kaplan Meier survival probabilities for current smokers were 77% from all-cause mortality and 89% from PCa-specific mortality.

Conclusions: We observed that tobacco smoking was associated with risk of localized and advanced PCa primarily among Non-Hispanic Whites. Moreover, we observed that tobacco smoking was associated with all-cause mortality, albeit no associations were observed for PCa-specific mortality. Genetic variation in CYP1A2 seems to modify the relationship of tobacco smoking status and PCa risk, but not mortality.

Citation Format: Ahva Shahabi, Roman Corral, Chelsea Catsburg, Amit D. Joshi, Jocelyn Koo, Esther M. John, Sue A. Ingles, Mariana C. Stern. Tobacco smoking, polymorphisms in xenobiotic metabolism enzyme genes, and prostate cancer risk and survival. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr B79.

A systematic review and meta-analysis of complications associated with acellular dermal matrix-assisted breast reconstruction

BACKGROUND

Multiple outcome studies have been published on the use of acellular dermal matrix (ADM) in breast reconstruction with disparate results. The purpose of this study was to conduct a systematic review and meta-analysis to determine an aggregate estimate of risks associated with ADM-assisted breast reconstruction.

METHODS

The MEDLINE, Web of Science, and Cochrane Library databases were queried, and relevant articles published up to September 2010 were analyzed based on specific inclusion criteria. Seven complications were studied including seroma, cellulitis, infection, hematoma, skin flap necrosis, capsular contracture, and reconstructive failure. A pooled random effects estimate for each complication and 95% confidence intervals (CI) were derived. For comparisons of ADM and non-ADM, the pooled random effects odds ratio (OR) and 95% CI were derived. Heterogeneity was measured using the I2 statistic.

RESULTS

Sixteen studies met the inclusion criteria. The pooled complication rates were seroma (6.9%; 95% CI, 5.3%-8.8%), cellulitis (2.0%; 95% CI, 1.2%-3.1%), infection (5.7%; 95% CI, 4.3%-7.3%), skin flap necrosis (10.9%; 95% CI, 8.7%-13.5%), hematoma (1.3%; 95% CI, 0.6%-2.4%), capsular contracture (0.6%; 95% CI, 0.1%-1.7%), and reconstructive failure (5.1%; 95% CI, 3.8%-6.7%). Five studies reported findings for both the ADM and non-ADM patients and were used in the meta-analysis to calculate pooled OR. ADM-assisted breast reconstructions had a higher likelihood of seroma (pooled OR, 3.9; 95% CI, 2.4-6.2), infection (pooled OR, 2.7; 95% CI, 1.1-6.4), and reconstructive failure (pooled OR, 3.0; 95% CI, 1.3-6.8) than breast reconstructions without the use of ADM. The relation of ADM use to hematoma (pooled OR, 2.0; 95% CI, 0.8-5.2), cellulitis (pooled OR, 2.0; 95% CI, 0.9-4.3), and skin flap necrosis (pooled OR, 1.9; 95% CI, 0.6-5.4) was inconclusive.

CONCLUSIONS

In the studies evaluated, ADM-assisted breast reconstructions exhibited a higher likelihood of seroma, infection, and reconstructive failure than prosthetic-based breast reconstructions using traditional musculofascial flaps. ADM is associated with a lower rate of capsular contracture. A careful risk/benefit analysis should be performed when choosing to use ADM in implant-based breast reconstruction.

Abstract B59: Predictors of early versus late biochemical recurrence after open radical prostatectomy in a patient cohort with T2/T3N0M0 prostate cancer treated within the PSA-era

Introduction: Patients treated with radical prostatectomy (RP) differ in their risk of prostate cancer (PCa) recurrence. By determining factors associated with an increased risk of biochemical (PSA) recurrence (BCR), patients can be provided with personalized care to prevent disease progression. Identifying which patients are at risk of earlier versus later BCR after surgery is of interest in order to guide monitoring of disease progression and treatment options.

Objectives: We evaluated variables associated with PCa progression among a patient population treated with RP. In particular, we examined factors associated with earlier BCR (≤5 years post-RP) versus later BCR (&gt;5 years post-RP) taking into account potential differences across racial/ethnic groups present in this population.

Methods: An IRB approved database was used to obtain data on a patient population at USC/Norris Comprehensive Cancer Center with pathologically confirmed localized PCa (T2/T3) without lymph node involvement who underwent RP in the PSA era (1988-2009). We analyzed data on 2,485 patients after excluding individuals treated with neo-adjuvant hormonal therapy. Kaplan Meier and Cox regression analyses were used to evaluate biochemical recurrence-free survival (BCRFS) and risk of BCR adjusting for clinical variables.

Results: Among the 2,485 patients, 268 (11%) experienced BCR. Of these individuals, 212 (79%) had BCR ≤5 years after RP versus 56 (21%) &gt;5 years after surgery. The median (range) of follow-up time among patients without any recurrence is 7.45 (2.0-20.4) years and among patients with BCR is 2.9(0.17-15.12) years. The racial distribution is 2,163 (87%) Non-Hispanic White (NHW), 126 (5%) Hispanic, 95 (4%) African-American, and 78 (3%) Asian/Pacific Islander, with 23 patients excluded due to unknown race. Compared to other racial/ethnic groups, more African-American men were diagnosed when younger than 65 years old (66%) (p&lt;0.001). Similarly, 75% of African-Americans who experienced BCR were less than age 65. The 5 and 10 year BCRFS for this cohort are 91% and 88% respectively. For patients who remained BCR-free at 5 years after RP, their BCRFS at 10 years was 97%. The strongest BCR predictors for individuals who had recurrence within 5 years or less post-RP were T3 pathological stage (extracapsular extension or seminal vesicle invasion), positive surgical margins, and Gleason score 7-10. Among those who experienced BCR after 5 years post-RP, the strongest predictors included total PSA values &gt;10-20 ng/ml, Gleason score 8-10, 61-65 years of age at diagnosis, and extracapsular extension. Radiation therapy and race/ethnicity were not significantly associated with BCR in the multivariate Cox regression for either BCR group.

Conclusions: Certain clinical characteristics of localized prostate cancer patients may be useful in determining who is at risk of earlier or later BCR following RP. These data can improve prognosis by providing guidance in determining the appropriate length of time to monitor disease progression and possible treatment options for patients.

Citation Format: Ahva Shahabi, Inderbir S. Gill, Gary Lieskovsky, Eila C. Skinner, Siamak Daneshmand, Jacek Pinski, Mariana C. Stern. Predictors of early versus late biochemical recurrence after open radical prostatectomy in a patient cohort with T2/T3N0M0 prostate cancer treated within the PSA-era [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr B59.

Recruitment and retention of African American and Latino preadolescent females into a longitudinal biobehavioral study

OBJECTIVE

Addressing recruitment challenges faced by researchers when the intended participants are young individuals from minority communities is crucial to prevent increases in study costs, prolonged length of the study, and loss of generalizability that may occur due to the resulting higher attrition rates. This article focuses on understanding the differences in census-tract level income, education, and socioeconomic status of young Latina and African American female participants and non-participants during the first 26 months of recruitment (June 2006-August 2008) in a longitudinal biobehavioral study.

DESIGN

The Transitions Study examines the psychological and physiological determinants influencing the decrease in physical activity during puberty among Latina and African American girls aged 8 to 11 years within the greater Los Angeles area. Recruitment and retention through five main steps in the process were examined: telephone contact, telephone screening, consent, clinical screening, and baseline overnight visit.

RESULTS

As of August 2008, the recruitment pool consisted of 110 African Americans (17.8%) and 373 Latinas (60.4%); of these, only 40 Latinas and 11 African American girls completed the final step into the study. African Americans were less willing to provide their phone numbers, but more likely to be reached at initial phone contact than Latino families.

CONCLUSIONS

Understanding the heterogeneity within minority populations, population characteristics, through careful and timely analyses, could be used to adjust recruitment and retention strategies in a study involving minority youth.

Identification of seven new prostate cancer susceptibility loci through a genome-wide association study

Prostate cancer (PrCa) is the most frequently diagnosed cancer in males in developed countries. To identify common PrCa susceptibility alleles, we previously conducted a genome-wide association study in which 541,129 SNPs were genotyped in 1,854 PrCa cases with clinically detected disease and in 1,894 controls. We have now extended the study to evaluate promising associations in a second stage in which we genotyped 43,671 SNPs in 3,650 PrCa cases and 3,940 controls and in a third stage involving an additional 16,229 cases and 14,821 controls from 21 studies. In addition to replicating previous associations, we identified seven new prostate cancer susceptibility loci on chromosomes 2, 4, 8, 11 and 22 (with P = 1.6 x 10(-8) to P = 2.7 x 10(-33)).

Students' Reactions to a Problem-based Student-centred Course

An eight-week course based on a non-traditional instructional format was offered to 136 first-year medical and dental students. The course was problem-based, student-centred and took place in a small tutorial setting. During and at the end of the course students evaluated their own performance, as well as the course itself. Analysis of the results showed that students reacted favourably to this mode of instruction and requested that more courses should be offered utilizing this approach. The performance of students surpassed the expectation of members of the faculty.