Optimizing Screening for Intrastriatal Interventions in Huntington's Disease Using Predictive Models.

BACKGROUND: Intrastriatal delivery of potential therapeutics in Huntington's disease (HD) requires sufficient caudate and putamen volumes. Currently, volumetric magnetic resonance imaging is rarely done in clinical practice, and these data are not available in large research cohorts such as Enroll-HD. OBJECTIVE: The objective of this study was to investigate whether predictive models can accurately classify HD patients who exceed caudate and putamen volume thresholds required for intrastriatal therapeutic interventions. METHODS: We obtained and merged data for 1374 individuals across three HD cohorts: IMAGE-HD, PREDICT-HD, and TRACK-HD/TRACK-ON. We imputed missing data for clinical variables with >72% non-missing values and used the model-building algorithm BORUTA to identify the 10 most important variables. A random forest algorithm was applied to build a predictive model for putamen volume >2500 mm3 and caudate volume >2000 mm3 bilaterally. Using the same 10 predictors, we constructed a logistic regression model with predictors significant at P < 0.05. RESULTS: The random forest model with 1000 trees and minimal terminal node size of 5 resulted in 83% area under the curve (AUC). The logistic regression model retaining age, CAG repeat size, and symbol digit modalities test-correct had 85.1% AUC. A probability cutoff of 0.8 resulted in 5.4% false positive and 66.7% false negative rates. CONCLUSIONS: Using easily obtainable clinical data and machine learning-identified initial predictor variables, random forest, and logistic regression models can successfully identify people with sufficient striatal volumes for inclusion cutoffs. Adopting these models in prescreening could accelerate clinical trial enrollment in HD and other neurodegenerative disorders when volume cutoffs are necessary enrollment criteria. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Melatonin Supplementation for Cancer-Related Fatigue in Patients With Early Stage Breast Cancer Receiving Radiotherapy: A Double-Blind Placebo-Controlled Trial.

BACKGROUND: Fatigue is common in patients undergoing radiotherapy (RT) and can significantly impact quality of life. Melatonin, a safe inexpensive natural supplement, may improve symptoms and attenuate the side effects of RT. The purpose of this randomized double-blind placebo-controlled phase III trial was to assess the effects of melatonin for preventing fatigue and other symptoms in patients with breast cancer undergoing RT. METHODS: Female early stage or Ductal carcinoma in situ patients with breast cancer ≥18 years of age with Eastern Cooperative Oncology Group (ECOG) performance status <3, hemoglobin ≥9 g/dL, planned for outpatient RT treatment with curative intent, were randomized 1:1 to melatonin 20 mg or placebo, orally, starting the night before RT initiation until 2 weeks post-RT. Randomization was stratified according to treatment duration (<3 weeks, ≥3 weeks) and prior chemotherapy. The primary endpoint was the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue scale), and secondary endpoints were FACIT-F subscales, Edmonton Symptom Assessment Scale (ESAS), and Patient-Reported Outcomes Measurement Information System (PROMIS) scores obtained at baseline, and 2 and 8 weeks post-RT. A 2-sided ANOVA F-test at a 4.5% significance level for the primary endpoint was used. Secondary analyses were reported using an F-test at a 5% significance level. The goal was to recruit approximately 140 patients with interim analysis planned mid-recruitment. RESULTS: Eighty-five patients were screened for eligibility; 79 patients were randomized: 40 to melatonin and 39 to placebo; 78 patients were treated and included in the interim analysis at the mid-recruitment point. Baseline patient characteristics of age, race, and ECOG performance status were similar in both arms. The treatment effect was studied using a longitudinal mixed effects model with the effect of treatment over time (treatment × time) as the primary outcome parameter. The treatment × time for FACIT-Fatigue did not demonstrate statistical significance (P-value .83) in the melatonin group compared to placebo. In addition, secondary analyses of FACIT physical, social, emotional, and functional well-being scores did not demonstrate statistical significance (P-values of .35, .06, .62, and .71, respectively). Total PROMIS scores, collected as secondary outcome reported by patients, did not demonstrate statistically significant change over time either (P-value is .34). The other secondary scale, ESAS, was analyzed for each individual item and found to be nonsignificant, anxiety (P = .56), well-being (.82), drowsiness (.83), lack of appetite (.35), nausea (.79), pain (.50), shortness of breath (.77), sleep (.45), and tiredness (.56). Depression was the only item demonstrating statistical significance with a decrease of 0.01 unit in the placebo group, a change not considered clinically significant. Melatonin was well-tolerated with no grade 3 or 4 adverse events reported. The most common side effects were headache, somnolence, and abdominal pain. No patients died while participating in this study. Two patients died within a year of study completion from breast cancer recurrence. Sixteen patients withdrew prior to study completion for various reasons including adverse events, hospitalizations unrelated to study drug, RT discontinuation, and COVID-19 precautions. CONCLUSIONS: In this double-blind placebo-controlled phase III trial, melatonin did not prevent or significantly improve fatigue and other symptoms in patients with early stage breast cancer undergoing RT. The analysis, showing little evidence of an effect, at mid-recruitment, assured early termination of the trial.

Heterogeneity of weight loss and transcriptomic signatures in pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is highly associated with cachexia and weight loss, which is driven by the tumour's effect on the body. Data are lacking on differences in these metrics based on PDAC anatomic location. We hypothesize that the primary tumour's anatomic region influences the prevalence and severity of unintentional weight loss. METHODS: Treatment naïve patients with PDAC who underwent pancreatectomy at a single institution between 2012 and 2020 were identified retrospectively. Patients with pancreatic head or distal tumours were matched by sex, age, N and T stage. Serologic and anthropometric variables were obtained at the time of diagnosis. Skeletal muscle index (SMI), muscle radiation attenuation (MRA) and adiposity were measured. The primary outcome was presence of significant weight loss [>5% body weight (BW) loss in past 6 months]. Signed rank tests, Cochran Mantel Haenszel tests and Kaplan-Meier survival analysis are presented. RNA-seq of tumours was performed to explore enriched pathways related to cachexia and weight loss. RESULTS: Pancreatic head tumours (n = 24) were associated with higher prevalence (70.8% vs. 41.7%, P = 0.081) and degree of weight loss (7.9% vs. 2.5%, P = 0.014) compared to distal tumours (n = 24). BMI (P = 0.642), SMI (P = 0.738) and MRA (P = 0.478) were similar between groups. Combining BW loss, SMI and MRA into a composite score, patients with pancreatic head cancers met more criteria associated with poor prognosis (P = 0.142). Serum albumin (3.9 vs. 4.4 g/dL, P = 0.002) was lower and bilirubin (4.5 vs. 0.4 mg/dL, P < 0.001) were higher with pancreatic head tumours. Survival differed by tumour location (P = 0.014) with numerically higher median overall survival with distal tumours (11.1 vs. 21.8 months; P = 0.066). Transcriptomic analysis revealed inactivation of appetite stimulation, weight regulation and nutrient digestion/metabolism pathways in pancreatic head tumours. CONCLUSIONS: Resectable pancreatic head PDAC is associated with higher prevalence of significant weight loss and more poor prognosis features. Pancreaticobiliary obstruction and hypoalbuminemia in patients with head tumours suggests compounding effects of nutrient malabsorption and systemic inflammation on molecular drivers of cachexia, possibly contributing to shorter survival. Therefore, PDAC-associated cachexia is a heterogenous syndrome, which may be influenced by the primary tumour location. Select patients with resectable pancreatic head tumours may benefit from nutritional rehabilitation to improve outcomes.

MDA-9/Syntenin in the tumor and microenvironment defines prostate cancer bone metastasis.

Bone metastasis is a frequent and incurable consequence of advanced prostate cancer (PC). An interplay between disseminated tumor cells and heterogeneous bone resident cells in the metastatic niche initiates this process. Melanoma differentiation associated gene-9 (mda-9/Syntenin/syndecan binding protein) is a prometastatic gene expressed in multiple organs, including bone marrow-derived mesenchymal stromal cells (BM-MSCs), under both physiological and pathological conditions. We demonstrate that PDGF-AA secreted by tumor cells induces CXCL5 expression in BM-MSCs by suppressing MDA-9-dependent YAP/MST signaling. CXCL5-derived tumor cell proliferation and immune suppression are consequences of the MDA-9/CXCL5 signaling axis, promoting PC disease progression. mda-9 knockout tumor cells express less PDGF-AA and do not develop bone metastases. Our data document a previously undefined role of MDA-9/Syntenin in the tumor and microenvironment in regulating PC bone metastasis. This study provides a framework for translational strategies to ameliorate health complications and morbidity associated with advanced PC.

Dual Targeting of the PDZ1 and PDZ2 Domains of MDA-9/Syntenin Inhibits Melanoma Metastasis.

Genome-wide gene expression analysis and animal modeling indicate that melanoma differentiation associated gene-9 (mda-9, Syntenin, Syndecan binding protein, referred to as MDA-9/Syntenin) positively regulates melanoma metastasis. The MDA-9/Syntenin protein contains two tandem PDZ domains serving as a nexus for interactions with multiple proteins that initiate transcription of metastasis-associated genes. Although targeting either PDZ domain abrogates signaling and prometastatic phenotypes, the integrity of both domains is critical for full biological function. Fragment-based drug discovery and NMR identified PDZ1i, an inhibitor of the PDZ1 domain that effectively blocks cancer invasion in vitro and in vivo in multiple experimental animal models. To maximize disruption of MDA-9/Syntenin signaling, an inhibitor has now been developed that simultaneously binds and blocks activity of both PDZ domains. PDZ1i was joined to the second PDZ binding peptide (TNYYFV) with a PEG linker, resulting in PDZ1i/2i (IVMT-Rx-3) that engages both PDZ domains of MDA-9/Syntenin. IVMT-Rx-3 blocks MDA-9/Syntenin interaction with Src, reduces NF-κB activation, and inhibits MMP-2/MMP-9 expression, culminating in repression of melanoma metastasis. The in vivo antimetastatic properties of IVMT-Rx-3 are enhanced when combined with an immune-checkpoint inhibitor. Collectively, our results support the feasibility of engineering MDA-9 dual-PDZ inhibitors with enhanced antimetastatic activities and applications of IVMT-Rx-3 for developing novel therapeutic strategies effectively targeting melanoma and in principle, a broad spectrum of human cancers that also overexpress MDA-9/Syntenin.

Bilateral transversus abdominis plane and rectus sheath blocks with liposomal bupivacaine for patients undergoing robotic prostatectomy.

As robotic prostatectomy surgery becomes more prevalent, it is important to identify any regional techniques to optimize patient's recovery. We evaluated the effectiveness of bilateral transversus abdominis plane (TAP) and rectus sheath (RS) blocks with liposomal bupivacaine. We hypothesized that these blocks would reduce perioperative opioid use and pain scores. A retrospective cohort of patients from May 2018 and May 2021 at a single large VA hospital were studied. We compared those not receiving a nerve block against those receiving the TAP and RS as part of an Enhanced Recovery After Surgery (ERAS) pathway starting in May 2019. The primary outcome was post-operative opioid use. Secondary outcomes were post-operative pain scores and hospital length of stay. One hundred and thirty-four patients were included in the final analysis. Eighty-one patients did not receive a block and fifty-three patients did receive a block. No difference existed between the groups in regard to median oral morphine equivalents (mg) used in PACU or any post-operative day. No difference existed in median opioid usage (mg) or pain scores between the two groups on any post-operative day. There was no difference in temporal association of median pain scores or narcotic usage between the two groups. Bilateral TAP and RS with liposomal bupivacaine did not significantly decrease post-operative opioid use, improve pain scores, or decrease hospital length of stay for patients undergoing robotic prostatectomy. Further studies need to be done to evaluate the effect of these blocks with liposomal bupivacaine.

Cholinergic Nucleus 4 Degeneration and Cognitive Impairment in Isolated Rapid Eye Movement Sleep Behavior Disorder.

BACKGROUND: Cholinergic nucleus 4 (Ch4) degeneration is associated with cognitive impairment in Parkinson's disease and dementia with Lewy bodies, but it is unknown if Ch4 degeneration is also present in isolated rapid eye movement sleep behavior disorder (iRBD). OBJECTIVE: The aim was to determine if there is evidence of Ch4 degeneration in patients with iRBD and if it is associated with cognitive impairment. METHODS: We analyzed the clinical and neuropsychological data of 35 iRBD patients and 35 age- and sex-matched healthy controls. Regional gray matter density (GMD) was calculated for Ch4 using probabilistic maps applied to brain magnetic resonance imaging (MRI). RESULTS: Ch4 GMD was significantly lower in the iRBD group compared to controls (0.417 vs. 0.441, P = 0.02). Ch4 GMD was also found to be a significant predictor of letter number sequencing (ß-coefficient = 58.31, P = 0.026, 95% confidence interval [7.47, 109.15]), a measure of working memory. CONCLUSIONS: iRBD is associated with Ch4 degeneration, and Ch4 degeneration in iRBD is associated with impairment in working memory. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

One Minute of EEG Data Provides Sufficient and Reliable Data for Identifying Lewy Body Dementia.

OBJECTIVE: To determine the minimum duration of electroencephalography (EEG) data necessary to differentiate EEG features of Lewy body dementia (LBD), that is, dementia with Lewy bodies and Parkinson disease dementia, from non-LBD patients, that is, Alzheimer disease and Parkinson disease. METHODS: We performed quantitative EEG analysis for 16 LBD and 14 non-LBD patients. After artifact removal, a fast Fourier transform was performed on 90, 60, and thirty 2-second epochs to derive dominant frequency; dominant frequency variability; and dominant frequency prevalence. RESULTS: In LBD patients, there were no significant differences in EEG features derived from 90, 60, and thirty 2-second epochs (all P >0.05). There were no significant differences in EEG features derived from 3 different groups of thirty 2-second epochs (all P >0.05). When analyzing EEG features derived from ninety 2-second epochs, we found that LBD had significantly reduced dominant frequency, reduced dominant frequency variability, and reduced dominant frequency prevalence alpha compared with the non-LBD group (all P <0.05). These same differences were observed between the LBD and non-LBD groups when analyzing thirty 2-second epochs. CONCLUSIONS: There were no differences in EEG features derived from 1 minute versus 3 minutes of EEG data, and both durations of EEG data equally differentiated LBD from non-LBD.

Melanoma differentiation associated gene-9/syndecan binding protein promotes hepatocellular carcinoma.

BACKGROUND AND AIMS: The oncogene Melanoma differentiation associated gene-9/syndecan binding protein (MDA-9/SDCBP) is overexpressed in many cancers, promoting aggressive, metastatic disease. However, the role of MDA-9 in regulating hepatocellular carcinoma (HCC) has not been well studied. APPROACH AND RESULTS: To unravel the function of MDA-9 in HCC, we generated and characterized a transgenic mouse with hepatocyte-specific overexpression of MDA-9 (Alb/MDA-9). Compared with wild-type (WT) littermates, Alb/MDA-9 mice demonstrated significantly higher incidence of N-nitrosodiethylamine/phenobarbital-induced HCC, with marked activation and infiltration of macrophages. RNA sequencing (RNA-seq) in naive WT and Alb/MDA-9 hepatocytes identified activation of signaling pathways associated with invasion, angiogenesis, and inflammation, especially NF-κB and integrin-linked kinase signaling pathways. In nonparenchymal cells purified from naive livers, single-cell RNA-seq showed activation of Kupffer cells and macrophages in Alb/MDA-9 mice versus WT mice. A robust increase in the expression of Secreted phosphoprotein 1 (Spp1/osteopontin) was observed upon overexpression of MDA-9. Inhibition of NF-κB pathway blocked MDA-9-induced Spp1 induction, and knock down of Spp1 resulted in inhibition of MDA-9-induced macrophage migration, as well as angiogenesis. CONCLUSIONS: Alb/MDA-9 is a mouse model with MDA-9 overexpression in any tissue type. Our findings unravel an HCC-promoting role of MDA-9 mediated by NF-κB and Spp1 and support the rationale of using MDA-9 inhibitors as a potential treatment for aggressive HCC.

Patient Survival With and Without Radiation Therapy for Early-Stage Diffuse Large B-Cell Lymphoma in the Era of PET and Rituximab.

Purpose: The benefit of radiation therapy (RT) becomes uncertain in the treatment of early stage diffuse large B-cell lymphoma (DLBCL) in the era of rituximab, positron emission topography (PET), and computed tomography (CT). We sought to retrospectively review modern patients with early stage I-II DLBCL treated with rituximab and staged by PET-CT to better define which patients benefit from consolidative RT. Methods and Materials: Patients with early stage I-II DLBCL from 1998 to 2017 were reviewed coinciding with our institutional utilization of rituximab with the standard regimen of cyclophosphamide, doxorubicin, vincristine, and prednisone and PET-CT. Relevant clinical information was used to calculate National Comprehensive Cancer Network international prognostic index (IPI) scores. Kaplan-Meier survival analysis and a Cox proportional hazards model were used for overall survival (OS). Results: Seventy-seven patients received chemoimmunotherapy alone, and 41 received chemoimmunotherapy plus RT. Median follow-up time was 9.5 years. On univariate analysis, extranodal disease (P = .04) and National Comprehensive Cancer Network IPI (P < .001) were significantly correlated with OS. Five-year OS was 87% versus 67%, and 10-year OS was 67% versus 58%, numerically higher favoring RT (P = .16). On multivariate Cox regression analysis of OS controlling for IPI and extranodal disease, the addition of RT was associated with improved OS (hazard ratio of 0.4, P = .01). Conclusions: The current analysis supports the use of consolidative RT in early stage DLBCL given an OS benefit on multivariate analysis. Further prospective randomized data are needed to confirm these findings.

Eligibility Criteria Perpetuate Disparities in Enrollment and Participation of Black Patients in Pancreatic Cancer Clinical Trials.

PURPOSE: Clinical trials determine safety and efficacy of cancer therapeutics and establish standards of care. Minority patient participation in cancer clinical trials is dismal. We aimed to determine the impact of eligibility criteria on disparities in pancreatic ductal adenocarcinoma (PDAC) clinical trial candidacy. METHODS: Traditional PDAC trial eligibility criteria were obtained from ClinicalTrials.gov. Patients with PDAC who sought care at Virginia Commonwealth University Health from 2010 to 2019 were included. Clinical data were obtained from billing codes and discrete values in the electronic medical record. Eligibility criteria differences between racial groups were determined using chi-squared tests and unconditional maximum likelihood-based odds ratios. RESULTS: Among 676 patients, most identified as Black or White race (42.5% and 51.6%, respectively). Using traditional criteria, Black patients were more likely to be ineligible for participation compared with White patients (42.4% v 33.2%, P = .023) secondary to hypoalbuminemia (14.1% v 7.9%, P = .023), HIV (3.1% v 0.3%, P = .010), hepatitis B (1.7% v 0%, P = .043), and hepatitis C (9.1% v 3.4%, P = .005). Black patients were also numerically more likely to be ineligible because of renal dysfunction, recent coronary stenting, and uncontrolled diabetes mellitus. Prior cancer treatment excluded fewer Black than White patients (9.1% v 14.0%, P = .072), most attributable to lower rates of neoadjuvant chemotherapy received. Strategic eligibility criteria revisions could equalize ineligibility rates between Black and White patients (26.8% v 24.8%, P = .581). CONCLUSION: Traditional eligibility criteria differentially exclude Black patients from participating in PDAC clinical trials. These criteria perpetuate disparities, limit generalizability, and are often not medically justifiable. Revised criteria may improve participant diversity, without compromising safety or study results.

Early termination in single-parameter model phase II clinical trial designs using decreasingly informative priors.

Background: To exchange the type of subjective Bayesian prior selection for assumptions more directly related to statistical decision making in clinician studies and trials, the decreasingly informative prior (DIP) is considered. We expand standard Bayesian early termination methods in one-parameter statistical models for Phase II clinical trials to include decreasingly informative priors (DIP). These priors are designed to reduce the chance of erroneously adapting trials too early by parameterize skepticism in an amount always equal to the unobserved sample size. Method: We show how to parameterize these priors based on effective prior sample size and provide examples for common single-parameter models, include Bernoulli, Poisson, and Gaussian distributions. We use a simulation study to search through possible values of total sample sizes and termination thresholds to find the smallest total sample size (N) under admissible designs, which we define as having at least 80% power and no greater than 5% type I error rate. Results: For Bernoulli, Poisson, and Gaussian distributions, the DIP approach requires fewer patients when admissible designs are achieved. In situations where type I error or power are not admissible, the DIP approach yields similar power and better-controlled type I error with comparable or fewer patients than other Bayesian priors by Thall and Simon. Conclusions: The DIP helps control type I error rates with comparable or fewer patients, especially for those instances when increased type I error rates arise from erroneous termination early in a trial.

Anticholinergic Medication Burden in Parkinson's Disease Outpatients.

BACKGROUND: Individuals with Parkinson's disease (PD) may be especially vulnerable to future cognitive decline from anticholinergic medications. OBJECTIVE: To characterize anticholinergic medication burden, determine the co-occurrence of anticholinergic and cholinesterase inhibitors, and to assess the correlations among anticholinergic burden scales in PD outpatients. METHODS: We studied 670 PD outpatients enrolled in a clinic registry between 2012 and 2020. Anticholinergic burden was measured with the Anticholinergic Cognitive Burden Scale (ACB), Anticholinergic Drug Scale (ADS), Anticholinergic Risk Scale (ARS), and Drug Burden Index-Anticholinergic component (DBI-Ach). Correlations between scales were assessed with weighted kappa coefficients. RESULTS: Between 31.5 to 46.3% of PD patients were taking medications with anticholinergic properties. Among the scales applied, the ACB produced the highest prevalence of medications with anticholinergic properties (46.3%). Considering only medications with definite anticholinergic activity (scores of 2 or 3 on ACB, ADS, or ARS), the most common anticholinergic drug classes were antiparkinsonian (8.2%), antipsychotic (6.4%), and urological (3.3%) medications. Cholinesterase inhibitors and medications with anticholinergic properties were co-prescribed to 5.4% of the total cohort. The most highly correlated scales were ACB and ADS (κ= 0.71), ACB and ARS (κ= 0.67), and ADS and ARS (κ= 0.55). CONCLUSION: A high proportion of PD patients (20%) were either taking antiparkinsonian, urological, or antipsychotic anticholinergic medications or were co-prescribed anticholinergic medications and cholinesterase inhibitors. By virtue of its detection of a high prevalence of anticholinergic medication usage and its high correlation with other scales, our data support use of the ACB scale to assess anticholinergic burden in PD patients.

Interprofessional Image Verification Workshop for Physician and Physics Residents: A Multi-Institutional Experience.

PURPOSE: Verification of patient position through pretreatment setup imaging is crucial in modern radiation therapy. As treatment complexity increases and technology evolves, physicist-physician collaboration becomes imperative for safe and successful radiation delivery. Despite the importance of both, residency programs lack formal interprofessional education (IPE) activities or structured training for image verification. Here we show the impact of an interprofessional image verification workshop for residents in a multi-institutional setting. METHODS: The workshop included a lecture by the attending physicist and physician, and hands-on image registration practice by learners (medical physics residents, MP; and radiation oncology residents, RO). All participants filled out pre- and postactivity surveys and rated their comfort from 1 to 10 in (A) selecting what type of imaging to order for a given case and (B) independently assessing the setup quality based on imaging. A paired 1-tailed t test (α = 0.05) was used to evaluate significance; Spearman rank correlation coefficient was used to assess correlation of ratings and RO postgraduate year (PGY). Surveys had free-response questions about IPE and image verification activities in residency. RESULTS: A total of 71 residents from 7 institutions participated between 2018 and 2020. Pre- and postsurveys were completed by 50 residents (38RO, 12MP) and showed an increase in (A) from 5.5 ± 2.2 to 7.1 ± 1.6 (P < .001) and in (B) from 5.1 ± 2.3 to 6.8 ± 1.5 (P < .001), with significant increases per subgroup (AΔ, RO = 1.8 ± 1.7, P < .001; BΔ, RO = 1.9 ± 1.8, P <. 001; AΔ, MP = 1.1 ± 1.4, P = .012; BΔ, MP = 1.2 ± 1.6, P = .016). RO confidence scores moderately correlated with PGY. Survey responses indicated that image verification training is mostly unstructured, with extent of exposure varying by program and attending; most with little-to-no training. Time constraints were identified as the main barrier. IPE was noted as a useful way to incorporate different perspectives into the process. CONCLUSIONS: Formal image verification training increases resident comfort with setup imaging review and provides opportunities for interprofessional collaboration in radiation oncology residency programs.

Statistical Modeling of Longitudinal Data with Non-ignorable Non-monotone Missingness with Semiparametric Bayesian and Machine Learning Components.

In longitudinal studies, outcomes are measured repeatedly over time and it is common that not all the patients will be measured throughout the study. For example patients can be lost to follow-up (monotone missingness) or miss one or more visits (non-monotone missingness); hence there are missing outcomes. In the longitudinal setting, we often assume the missingness is related to the unobserved data, which is non-ignorable. Pattern-mixture models (PMM) analyze the joint distribution of outcome and patterns of missingness in longitudinal data with non-ignorable nonmonotone missingness. Existing methods employ PMM and impute the unobserved outcomes using the distribution of observed outcomes, conditioned on missing patterns. We extend the existing methods using latent class analysis (LCA) and a shared-parameter PMM. The LCA groups patterns of missingness with similar features and the shared-parameter PMM allows a subset of parameters to be different between latent classes when fitting a model. We also propose a method for imputation using distribution of observed data conditioning on latent class. Our model improves existing methods by accommodating data with small sample size. In a simulation study our estimator had smaller mean squared error than existing methods. Our methodology is applied to data from a phase II clinical trial that studies quality of life of patients with prostate cancer receiving radiation therapy.

PLK1 Induces Chromosomal Instability and Overrides Cell-Cycle Checkpoints to Drive Tumorigenesis.

Polo-like kinase 1 (PLK1) is an essential cell-cycle regulator that is frequently overexpressed in various human cancers. To determine whether Plk1 overexpression drives tumorigenesis, we established transgenic mouse lines that ubiquitously express increased levels of Plk1. High Plk1 levels were a driving force for different types of spontaneous tumors. Increased Plk1 levels resulted in multiple defects in mitosis and cytokinesis, supernumerary centrosomes, and compromised cell-cycle checkpoints, allowing accumulation of chromosomal instability (CIN), which resulted in aneuploidy and tumor formation. Clinically, higher expression of PLK1 positively associated with an increase in genome-wide copy-number alterations in multiple human cancers. This study provides in vivo evidence that aberrant expression of PLK1 triggers CIN and tumorigenesis and highlights potential therapeutic opportunities for CIN-positive cancers. SIGNIFICANCE: These findings establish roles for PLK1 as a potent proto-oncogene and a CIN gene and provide insights for the development of effective treatment regimens across PLK1-overexpressing and CIN-positive cancers.

Target volume definition for staple line recurrences of non-small cell lung cancer.

BACKGROUND: Staple line (SL) recurrences of non-small cell lung cancer (NSCLC) are commonly treated with radiotherapy (RT), but the target volume definition - whole SL versus focused on recurrence - is unclear. The aim of the study was to determine the appropriate target volume for RT of SL recurrences. MATERIALS AND METHODS: Twenty-two consecutive patients (20 stage I, 2 stage II) treated with salvage RT for SL recurrences were retrospectively analyzed. Imaging features at the time of SL recurrence were evaluated to guide target volume definition. RESULTS: Surgery: All patients had complete tumor resection (wedge resection in 10 (45%) and lobectomy in 12 (55%) patients). 14 (64%) patients had risk factors for recurrence, including surgical margins ≤ 2 cm, angiolymphatic and visceral pleural invasion.Salvage RT: After a median 26 months (9-67), all 22 patients developed SL recurrence which was metabolically active on PET in all and biopsy-confirmed in 18/22 (82%) patients. All patients underwent RT targeting the location of the SL recurrence only. 13/22 (59%) patients had additional PE T-negative nodular or linear SL changes that were not included in the irradiated volume.Recurrence after RT: After a median 17 months (9-34) 10/22 (45%) patients recurred either regionally 6/10 (60%), in the lungs 4/10 (40%) or distally 3/10 (30%). No patient recurred at the SL. Two-year overall and disease-free survival rates after RT were 71% and 65%, respectively. CONCLUSION: RT to SL recurrences alone results in excellent local control. Additional treatment to reduce regional and distant recurrences should be considered.

Moderately Hypofractionated Intensity Modulated Radiation Therapy With Simultaneous Integrated Boost for Prostate Cancer: Five-Year Toxicity Results From a Prospective Phase I/II Trial.

BACKGROUND: In this phase I/II trial, 5-year physician-assessed toxicity and patient reported quality of life data is reported for patients undergoing moderately hypofractionated intensity modulated radiation therapy (IMRT) for prostate cancer using a simultaneous integrated boost (SIB) and pelvic lymph node (LN) coverage. MATERIALS AND METHODS: Patients with T1-T2 localized prostate cancer were prospectively enrolled, receiving risk group based coverage of prostate ± seminal vesicles (SVs) ± pelvic lymph nodes (LNs). Low risk (LR) received 69.6 Gy/29 fractions to the prostate, while intermediate risk (IR) and high risk (HR) patients received 72 Gy/30fx to the prostate and 54Gy/30fx to the SVs. If predicted risk of LN involvement >15%, 50.4 Gy/30fx was delivered to pelvic LNs. Androgen deprivation therapy was given to IR and HR patients. RESULTS: There were 55 patients enrolled and 49 patients evaluable at a median follow up of 60 months. Included were 11 (20%) LR, 23 (41.8%) IR, and 21 (38.2%) HR patients. Pelvic LN treatment was given in 25 patients (51%). Prevalence rates of late grade 2 GI toxicity at 1, 3, and 5 years was 5.8, 3.9, and 5.8%, respectively, with no permanent grade 3 events. Prevalence rates of late grade 2 GU toxicity at 1, 3, and 5 years rates were 15.4, 7.7, and 13.5%, respectively, with three grade 3 events (5.8%). The biochemical relapse free survival at 5 years was 88.3%. There were no local, regional, or distant failures, with all patients still alive at last follow up. CONCLUSION: Moderate hypofractionation of localized prostate cancer utilizing a SIB technique and LN coverage produces tolerable acute/late toxicity. Given equivalent efficacy between moderate hypofractionation schedules, the optimal regimen will be determined by long-term toxicity reported from both the physician and patient perspective. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier NCT01117935, Date of Registration: 5/6/2010.

Utilization of Multiparametric MRI of Prostate in Patients under Consideration for or Already in Active Surveillance: Correlation with Imaging Guided Target Biopsy.

This study sought to assess the value of multiparametric magnetic resonance image (mp-MRI) in patients with a prostate cancer (PCa) Gleason score of 6 or less under consideration for or already in active surveillance and to determine the rate of upgrading by target biopsy. Three hundred and fifty-four consecutive men with an initial transrectal ultrasound-guided (TRUS) biopsy-confirmed PCa Gleason score of 6 or less under clinical consideration for or already in active surveillance underwent mp-MRI and were retrospectively reviewed. One hundred and nineteen of 354 patients had cancer-suspicious regions (CSRs) at mp-MRI. Each CSR was assigned a Prostate Imaging Reporting and Data System (PI-RADS) score based on PI-RADS v2. One hundred and eight of 119 patients underwent confirmatory imaging-guided biopsy for CSRs. Pathology results including Gleason score (GS) and percentage of specimens positive for PCa were recorded. Associations between PI-RADS scores and findings at target biopsy were evaluated using logistic regression. At target biopsy, 81 of 108 patients had PCa (75%). Among them, 77 patients had upgrading (22%, 77 of 354 patients). One hundred and forty-six CSRs in 108 patients had PI-RADS 3 n = 28, 4 n = 66, and 5 n = 52. The upgraded rate for each category of CSR was for PI-RADS 3 (5 of 28, 18%), 4 (47 of 66, 71%) and 5 (49 of 52, 94%). Using logistic regression analysis, differences in PI-RADS scores from 3 to 5 are significantly associated with the probability of disease upgrade (20%, 73%, and 96% for PI-RADS score of 3, 4, and 5, respectively). Adding mp-MRI to patients under consideration for or already in active surveillance helps to identify undiagnosed PCa of a higher GS or higher volume resulting in upgrading in 22%.