Log-epsilon-skew normal: A generalization of the log-normal distribution.

The log-normal distribution is widely used to model non-negative data in many areas of applied research. In this paper, we introduce and study a family of distributions with non-negative reals as support and termed the log-epsilon-skew normal (LESN) which includes the log-normal distributions as a special case. It is related to the epsilon-skew normal developed in Mudholkar and Hutson (2000) the way the log-normal is related to the normal distribution. We study its main properties, hazard function, moments, skewness and kurtosis coefficients, and discuss maximum likelihood estimation of model parameters. We summarize the results of a simulation study to examine the behavior of the maximum likelihood estimates, and we illustrate the maximum likelihood estimation of the LESN distribution parameters to two real world data sets.

Factors Associated With Problems for Adolescents Returning to the Classroom After Sport-Related Concussion.

The primary objective of this study was to determine factors in the clinic setting associated with concussion-related problems in the school setting. A total of 91 student athletes, 13 to 19 years old, completed the SCAT2 and computerized testing during their initial visit to the clinic. During a follow-up telephone interview, one-third reported problems with return to school. The presence of problems reported in school was associated with severity of concussion as represented by recovery time and the overall number of symptoms at the first clinic visit. Gender, age, and previous concussions were not associated with school problems. Athletes with computerized test scores below the ninth percentile were more likely to report school problems. The current study offers some descriptive information for clinicians and ideas for future research related to adolescent athletes with concussion and problems with return to the classroom.

Measures of biomarker dependence using a copula-based multivariate epsilon-skew-normal family of distributions.

In this note we develop a new multivariate copula model based on epsilon-skew-normal marginal densities for the purpose of examining biomarker dependency structures. We illustrate the flexibility and utility of this model via a variety of graphical tools and a data analysis example pertaining to salivary biomarker. The multivariate normal model is a sub-model of the multivariate epsilon-skew-normal distribution.

Breast cancer resistance protein (BCRP) and excision repair cross complement-1 (ERCC1) expression in esophageal cancers and response to cisplatin and irinotecan based chemotherapy.

BACKGROUND: Esophageal cancer patients face a dismal outcome despite tri-modality management and median survival remains 15-18 months. Breast cancer resistance protein (BCRP) is an ATP-dependent efflux protein associated with chemotherapy resistance. The role of BCRP expression in esophageal cancer and normal esophageal cells is not known. Excision repair cross complement-1 (ERCC1) overexpression has been correlated with poorer response to cisplatin based chemotherapy. We examined the expression of BCRP and ERCC1 in patients with esophageal cancer and correlated it with survival in patients receiving irinotecan and cisplatin based chemotherapy. METHODS: With IRB approval, 40 cases of esophageal cancer diagnosed from 2004-2008, were stained for BCRP and ERCC1 expression by immunohistochemistry and scored by a pathologist blinded to clinical data. Baseline demographics, therapy given and survival data were collected and correlated with BCRP and ERCC1 expression. Fisher's exact test was used to determine association between BCRP and ERCC1 expression and demographics. Cox proportional hazards model was used for association of BCRP and ERCC1 with survival. RESULTS: On immunohistochemistry, 30/40 cancers (75%) expressed BCRP. Interestingly, down-regulation of BCRP expression in tumor compared with normal cells was seen in 40% of patients. ERCC1 positivity was seen in 15/30 cases (50%). Median overall survival (OS) was 19 months with no difference in survival between BCRP positive and negative patients (P=0.13) or ERCC1 positive and negative patients (P=0.85). Estimated hazard ratio (HR) of death for BRCP positive patients was 2.29 (95% CI: 0.79-6.64) and for ERCC1 positive patients was 1.09 (95% CI: 0.46-2.56). There was no association of BCRP and ERCC1 expression with disease stage, age, gender or histology. For patients who received cisplatin and irinotecan as first line chemotherapy, there was no difference in survival based on BCRP or ERCC1 status. CONCLUSIONS: BCRP expression is seen in a majority of esophageal cancers and normal esophageal mucosa. ERCC1 expression is seen in about half of the patients with esophageal cancer. Irinotecan based studies with esophageal and gastric cancer suggest response rates of 14-65%. Whether the 40% of tumors in our study found with down regulation of BCRP expression, constitute a majority of these responders needs to be prospectively validated in a larger data set. It should include markers such as ERCC1 predicting response to 5-fluorouracil and platinum based chemotherapy, to enable individualizing therapy for this cancer.

Regional myocardial sympathetic denervation predicts the risk of sudden cardiac arrest in ischemic cardiomyopathy.

OBJECTIVES: The PAREPET (Prediction of ARrhythmic Events with Positron Emission Tomography) study sought to test the hypothesis that quantifying inhomogeneity in myocardial sympathetic innervation could identify patients at highest risk for sudden cardiac arrest (SCA). BACKGROUND: Left ventricular ejection fraction (LVEF) is the only parameter identifying patients at risk of SCA who benefit from an implantable cardiac defibrillator (ICD). METHODS: We prospectively enrolled 204 subjects with ischemic cardiomyopathy (LVEF ≤35%) eligible for primary prevention ICDs. Positron emission tomography (PET) was used to quantify myocardial sympathetic denervation ((11)C-meta-hydroxyephedrine [(11)C-HED]), perfusion ((13)N-ammonia) and viability (insulin-stimulated (18)F-2-deoxyglucose). The primary endpoint was SCA defined as arrhythmic death or ICD discharge for ventricular fibrillation or ventricular tachycardia >240 beats/min. RESULTS: After 4.1 years follow-up, cause-specific SCA was 16.2%. Infarct volume (22 ± 7% vs. 19 ± 9% of left ventricle [LV]) and LVEF (24 ± 8% vs. 28 ± 9%) were not predictors of SCA. In contrast, patients developing SCA had greater amounts of sympathetic denervation (33 ± 10% vs. 26 ± 11% of LV; p = 0.001) reflecting viable, denervated myocardium. The lower tertiles of sympathetic denervation had SCA rates of 1.2%/year and 2.2%/year, whereas the highest tertile had a rate of 6.7%/year. Multivariate predictors of SCA were PET sympathetic denervation, left ventricular end-diastolic volume index, creatinine, and no angiotensin inhibition. With optimized cut-points, the absence of all 4 risk factors identified low risk (44% of cohort; SCA <1%/year); whereas ≥2 factors identified high risk (20% of cohort; SCA ∼12%/year). CONCLUSIONS: In ischemic cardiomyopathy, sympathetic denervation assessed using (11)C-HED PET predicts cause-specific mortality from SCA independently of LVEF and infarct volume. This may provide an improved approach for the identification of patients most likely to benefit from an ICD. (Prediction of ARrhythmic Events With Positron Emission Tomography [PAREPET]; NCT01400334).

Computed tomography scans as an objective measure of disease severity in chronic rhinosinusitis.

OBJECTIVES: A truly objective method of measuring disease severity in chronic rhinosinusitis (CRS) has only recently existed. We evaluated computed tomography (CT) scans of CRS patients using this novel objective 3D computerized system and compared results with a novel 2D computerized analysis of a single coronal slice through the osteomeatal complex (OMC) and subjective methods including Lund-Mackay and Zinreich's modified Lund-Mackay. STUDY DESIGN: Prospective multicenter study. SETTING: Two academic tertiary referral centers. SUBJECTS AND METHODS: Forty-six adults with a diagnosis of CRS underwent CT examination and received an intramuscular triamcinolone injection, dosage weight dependent, followed by CT scan 4 to 5 weeks later. Recruitment lasted 21 months. Scans were evaluated with all 4 scoring methods over 5 months. RESULTS: The Lin's concordance class correlation (CCC) of the OMC method revealed the best correlation to the 3D volumetric computerized values (0.915), followed by the Zinreich (0.904) and Lund-Mackay methods (0.824). Posttreatment results demonstrated that both the OMC (0.824) and Zinreich's (0.778) methods had strong agreement with the 3D volumetric methods and were very sensitive to change, whereas the Lund-Mackay (0.545) had only moderate agreement. CONCLUSION: Computerized CT analysis provides the most comprehensive, objective, and reproducible method of measuring disease severity and is very sensitive to change induced by treatment intervention. A 2D coronal image through the OMC provides a valid, user-friendly method of assessing CRS and is representative of CRS severity in all sinuses. Zinreich's subjective method correlated well overall, but the Lund-Mackay method lagged behind in disease representation and sensitivity to change.

A combined inspiratory and expiratory muscle training program improves respiratory muscle strength and fatigue in multiple sclerosis.

OBJECTIVE: To determine the effects of a short-duration, combined (inspiratory and expiratory), progressive resistance respiratory muscle training (RMT) protocol on respiratory muscle strength, fatigue, health-related quality of life, and functional performance in individuals with mild-to-moderate multiple sclerosis (MS). DESIGN: Quasi-experimental before-after trial. SETTING: University rehabilitation research laboratory. PARTICIPANTS: Volunteers with MS (N=21) were divided into 2 groups: RMT (n=11; 9 women, 2 men; mean age ± SD, 50.9 ± 5.7y, mean Expanded Disability Status Scale score ± SD, 3.2 ± 1.9) and a control group that did not train (n=10; 7 women, 3 men; mean age ± SD, 56.2 ± 8.8y, mean Expanded Disability Status Scale score ± SD, 4.4 ± 2.1). Expanded Disability Status Scale scores ranged from 1 to ≤6.5. No patients withdrew from the study. INTERVENTION: Training was a 5-week combined progressive resistance RMT program, 3d/wk, 30 minutes per session. MAIN OUTCOME MEASURES: The primary outcome measures were maximal inspiratory pressure and expiratory pressure and the Modified Fatigue Impact Scale. All subjects completed secondary measures of pulmonary function, the six-minute walk test, the timed stair climb, the Multiple Sclerosis Self-Efficacy Scale, the Medical Outcomes Study 36-Item Short-Form Health Survey, and the Physical Activity Disability Scale. RESULTS: Maximal inspiratory pressure and expiratory pressure (mean ± SD) increased 35% ± 22% (P<.001) and 26% ± 17% (P<.001), respectively, whereas no changes were noted in the control group (12% ± 23% and -4% ± 17%, respectively). RMT improved fatigue (Modified Fatigue Impact Scale, P<.029), with no change or worsening in the control group. No changes were noted in the six-minute walk test, stair climb, Multiple Sclerosis Self-Efficacy Scale, or Physical Activity Disability Scale in the RMT group. The control group had decreases in emotional well-being and general health (Medical Outcomes Study 36-Item Short-Form Health Survey). CONCLUSIONS: A short-duration, combined RMT program improved inspiratory and expiratory muscle strength and reduced fatigue in patients with mild to moderate MS.

Biological effects and clinical significance of lenalidomide-induced tumour flare reaction in patients with chronic lymphocytic leukaemia: in vivo evidence of immune activation and antitumour response.

Lenalidomide has demonstrated impressive antileukaemic effects in patients with chronic lymphocytic leukaemia (CLL). The mechanism(s) by which it mediates these effects remain unclear. Clinically, CLL patients treated with lenalidomide demonstrate an acute inflammatory reaction, the tumour flare reaction that is suggestive of an immune activation phenomenon. Samples from CLL patients treated with lenalidomide were used to evaluate its effect on the tumour cell and components of its microenvironment (immune cellular and cytokine). Lenalidomide was unable to directly induce apoptosis in CLL cells in vitro, however it modulated costimulatory (CD80, CD83, CD86) surface molecules on CLL cells in vitro and in vivo. Concurrently, we demonstrated that NK cell proliferation was induced by lenalidomide treatment in patients and correlated with clinical response. Cytokine analysis showed increase in levels of TNF-α post-lenalidomide treatment, consistent with acute inflammatory reaction. Furthermore, the basal cytokine profile (high IL-8, MIG, IP-10 and IL-4 levels and low IL-5, MIP1a, MIP1b, IL12/p70) was predictive of clinical response to lenalidomide. Collectively, our correlative studies provide further evidence that the antileukaemic effect of lenalidomide in CLL is mediated not only through modulation of the leukaemic clone but also through elements of the tumour microenvironment.

Improved survival following surgery and radiation therapy for olfactory neuroblastoma: analysis of the SEER database.

BACKGROUND: Olfactory Neuroblastoma is a rare malignant tumor of the olfactory tract. Reports in the literature comparing treatment modalities for this tumor are limited. METHODS: The SEER database (1973-2006) was queried by diagnosis code to identify patients with Olfactory Neuroblastoma. Kaplan-Meier was used to estimate survival distributions based on treatment modality. Differences in survival distributions were determined by the log-rank test. A Cox multiple regression analysis was then performed using treatment, race, SEER historic stage, sex, age at diagnosis, year at diagnosis and SEER geographic registry. RESULTS: A total of 511 Olfactory Neuroblastoma cases were reported. Five year overall survival, stratified by treatment modality was: 73% for surgery with radiotherapy, 68% for surgery only, 35% for radiotherapy only, and 26% for neither surgery nor radiotherapy. There was a significant difference in overall survival between the four treatment groups (p < 0.01). At ten years, overall survival stratified by treatment modality and stage, there was no significant improvement in survival with the addition of radiation to surgery. CONCLUSIONS: Best survival results were obtained for surgery with radiotherapy.

Increasing age and treatment modality are predictors for subsequent diagnosis of bladder cancer following prostate cancer diagnosis.

PURPOSE: To determine the effect of prostate cancer therapy (surgery or external beam irradiation, or both or none) on the actuarial incidence of subsequent bladder cancer. METHODS AND MATERIALS: The Surveillance, Epidemiology, and End Results registry from 1973 to 2005 was analyzed. Treatment was stratified as radiotherapy, surgery, both surgery and adjuvant radiation, and neither modality. Brachytherapy was excluded. RESULTS: In all, 555,337 prostate carcinoma patients were identified; 124,141 patients were irradiated; 235,341 patients were treated surgically; 32,744 patients had both surgery and radiation; and 163,111 patients received neither modality. Bladder cancers were diagnosed in: 1,836 (1.48%) men who were irradiated (mean age, 69.4 years), 2,753 (1.09%) men who were treated surgically (mean age, 66.9 years); 683 (2.09%) men who received both modalities (mean age, 67.4 years), and 1,603 (0.98%) men who were treated with neither modality (mean age, 71.8 years). In each treatment cohort, Kaplan-Meier analyses showed that increasing age (by decade) was a significant predictor of developing bladder cancer (p < 0.0001). Incidence of bladder cancer was significantly different for either radiation or surgery alone versus no treatment, radiation versus surgery alone, and both surgery and radiation versus either modality alone (p < 0.0001). On multivariate analysis, age and irradiation were highly significant predictors of being diagnosed with bladder cancer. CONCLUSIONS: Following prostate cancer, increasing age and irradiation were highly significant predictors of being diagnosed with bladder cancer. While use of radiation increased the risk of bladder cancer compared to surgery alone or no treatment, the overall incidence of subsequent bladder cancer remained low. Routine bladder cancer surveillance is not warranted.

Extent of disease burden determined with magnetic resonance imaging of the bone marrow is predictive of survival outcome in patients with multiple myeloma.

BACKGROUND: Multiple myeloma (MM) remains an incurable cancer. Treatment often is initiated at the time patients experience a progressive increase in tumor burden. The authors of this report investigated magnetic resonance imaging of the bone marrow (BM-MRI) as a novel approach to quantify disease burden and validated a staging system by correlating BM-MRI with common clinical and laboratory parameters. METHODS: The extent of bone marrow involvement was evaluated by BM-MRI. Clinical and laboratory parameters were assessed in patients with active MM, and correlations between variables were assessed statistically. Bone marrow involvement by BM-MRI was defined as stage A (0%), stage B (<10%), stage C (10%-50%), and stage D (>50%). RESULTS: In total, 170 consecutive patients were evaluated (77 women and 93 men), including 144 patients who had active MM. The median age was 61 years (age range, 35-83 years). Advance stage disease (stage >I) based on Durie-Salmon (DS) staging or International Staging System (ISS) criteria was observed in 122 patients (84%) and 77 patients (53%), respectively. Lytic bone disease was noted in 120 patients (83%). There was a significant association between BM-MRI involvement and DS stage (P = .0006), ISS stage (P = .0001), the presence of lytic bone disease (P < .0001) and mean beta-2 microglobulin levels (P < .0001). Among the patients with previously untreated MM, there was a significant association between BM-MRI stage and overall survival (OS) (univariate P = .013; multivariate P = .045). Plasmacytosis on bone marrow biopsy at diagnosis was not predictive of OS (P = .91). CONCLUSIONS: BM-MRI is a novel approach for quantifying disease burden in patients with MM. The current investigation in a large cohort of nontransplantion MM patients demonstrated that the extent of bone marrow involvement determined by BM-MRI correlates accurately with other conventional parameters of disease burden and can independently predict survival in patients with MM at the time of initial diagnosis.

Treatment of early-stage uterine papillary serous carcinoma at Roswell Park Cancer Institute, 1992-2006.

OBJECTIVE: Optimal management of early-stage uterine papillary serous carcinoma (UPSC) remains controversial. We reviewed our outcomes in this patient population. METHODS: The Roswell Park Cancer Institute (RPCI) tumor registry identified all patients with Stages I and IIA UPSC treated between January 1992 and June 2006. The Fisher's exact test was used to compare recurrence rates by adjuvant therapy received. Overall survival (OS) estimates were made using the Kaplan-Meier method. RESULTS: Fifty-eight patients with Stage I or IIA UPSC underwent surgery. Thirty-four patients (59%) were surgically staged. Among 21 patients with Stage IA disease, 15 received adjuvant therapy. With a median follow-up of 44.7 months, only one recurrence was observed in a patient who received adjuvant brachytherapy. The 5-year OS was 66%. Among 37 patients with Stages IB-IIA, 30 patients received adjuvant therapy. With a median follow-up of 29 months, there were 7 recurrences. The 5-year OS was 60%. Although there were no significant differences in recurrence by adjuvant therapy received, a significant OS benefit was found in those who received radiation. There was no significant difference in OS distributions of those patients who received Carboplatin/Paclitaxel chemotherapy. CONCLUSIONS: Despite the limitations of our retrospective study, we have shown that even comprehensively staged early-stage UPSC patients are still at risk for recurrence despite adjuvant therapy received. Hence, all patients with this histologic diagnosis should be considered at high risk for recurrence and counseled appropriately regarding the risks and benefits of adjuvant therapy.

Radiation treatment interruptions greater than one week and low hemoglobin levels (12 g/dL) are predictors of local regional failure after definitive concurrent chemotherapy and intensity-modulated radiation therapy for squamous cell carcinoma of the head and neck.

PURPOSE: To determine whether baseline hemoglobin level and radiation treatment interruptions predict for loco-regional failure after intensity-modulated radiation therapy (IMRT) with concurrent chemotherapy for definitive treatment of squamous cell carcinoma of the head and neck (SCCHN). METHODS: This retrospective review identified 78 consecutive patients treated with definitive concurrent chemoradiation for SCCHN. Patients were treated with IMRT to 70 Gy in 35 daily fractions to the high-dose target volume and 56 Gy to the elective target volume. RESULTS: Median age of the cohort was 62 (37-81). Median follow-up was 12 months. Tumor sites included: oropharynx (54%), larynx (36%), oral cavity (5%), and hypopharynx (5%). Fifteen of 78 patients (19%) experienced loco-regional failure. These included: 6 primary site failures, 5 regional failures, and 4 failures in both the primary site and regional lymph nodes. All but one failure occurred in the high-dose target volume. Only duration of radiation treatment and baseline hemoglobin levels were significant predictors of local control. Loco-regional failure occurred in 6 of 13 patients (46%) with radiation treatment interruptions (>1 week) versus 9 of 65 patients (14%) completing radiation therapy without interruption (P = 0.0148). Loco-regional failure occurred in 7 of 19 patients (37%) whose pretreatment hemoglobin level was <12 g/dL compared with 8 of 59 patients (14%) with hemoglobin levels > or = 12 (P = 0.042). CONCLUSION: Overall radiation treatment time and pretreatment hemoglobin level were significant predictors for loco-regional failure after definitive concurrent chemotherapy and IMRT for SCCHN.