Aspartate-ß-hydroxylase and hypoxia marker expression in head and neck carcinomas: implications for HPV-associated tumors.

BACKGROUND: A proportion of head and neck carcinomas (HNSCCs) are induced by high-risk human papillomaviruses (HPVs) and are associated with better patient outcomes compared to patients with HNSCCs related to tobacco and alcohol abuse. In the microenvironment of solid tumors, including HNSCCs, oxygen levels are often reduced, and a hypoxic state is induced. This can lead to a poor treatment response and a worse patient prognosis. One of the hypoxia-responsive genes is aspartate-ß-hydroxylase (ASPH), whose activity promotes the growth, invasiveness, and metastasis of many types of solid tumors. METHODS: In our study, HNSCC samples were analyzed for the expression of ASPH and selected endogenous hypoxia markers by real-time PCR and/or multiplex fluorescence immunohistochemistry. RESULTS: Except for the EPAS1 gene, which had higher mRNA expression in the HPV-negative group of HNSCC (p < 0.05), we found no other differences in the expression of the tested genes that were related to HPV status. On the contrary, a statistically significantly higher number of cells producing ASPH (p < 0.0001), HIF1A (p < 0.0001), GLUT1 (p < 0.0001), and MMP13 (p < 0.05) proteins were detected in the HPV-positive tumor group than in the HPV-negative sample group. All the evaluated markers, except for MMP9/13, were more abundant in the tumor parenchyma than in the tumor stroma. The Cox proportional hazard models showed that increased numbers of cells with GLUT1 and HIF1A protein expression were positive prognostic markers for overall and disease-specific survival in patients independent of HPV tumor status. CONCLUSION: The study examined HNSCC samples and found that elevated ASPH and hypoxia marker proteins, typically associated with poor prognosis, may actually indicate active HPV infection, the strongest prognostic factor in HNSCC patients. In cases where HPV status is uncertain, increased expression of HIF1A and GLUT1 can serve as positive prognostic factors.

Multiparametric analysis of the specific immune response against SARS-CoV-2.

BACKGROUND: SARS-CoV-2, which causes COVID-19, has killed more than 7 million people worldwide. Understanding the development of postinfectious and postvaccination immune responses is necessary for effective treatment and the introduction of appropriate antipandemic measures. OBJECTIVES: We analysed humoral and cell-mediated anti-SARS-CoV-2 immune responses to spike (S), nucleocapsid (N), membrane (M), and open reading frame (O) proteins in individuals collected up to 1.5 years after COVID-19 onset and evaluated immune memory. METHODS: Peripheral blood mononuclear cells and serum were collected from patients after COVID-19. Sampling was performed in two rounds: 3-6 months after infection and after another year. Most of the patients were vaccinated between samplings. SARS-CoV-2-seronegative donors served as controls. ELISpot assays were used to detect SARS-CoV-2-specific T and B cells using peptide pools (S, NMO) or recombinant proteins (rS, rN), respectively. A CEF peptide pool consisting of selected viral epitopes was applied to assess the antiviral T-cell response. SARS-CoV-2-specific antibodies were detected via ELISA and a surrogate virus neutralisation assay. RESULTS: We confirmed that SARS-CoV-2 infection induces the establishment of long-term memory IgG+ B cells and memory T cells. We also found that vaccination enhanced the levels of anti-S memory B and T cells. Multivariate comparison also revealed the benefit of repeated vaccination. Interestingly, the T-cell response to CEF was lower in patients than in controls. CONCLUSION: This study supports the importance of repeated vaccination for enhancing immunity and suggests a possible long-term perturbation of the overall antiviral immune response caused by SARS-CoV-2 infection.

A 24-h activity profile and adiposity among children and adolescents: Does the difference between school and weekend days matter?

BACKGROUND: Twenty-four-hour movement behaviours are gaining attention in the research community. However, no study has addressed how 24-h activity profiles vary between structured and less structured days and whether an unfavourable activity profile is associated with childhood obesity. We aimed to analyse differences between school day and weekend day 24-h activity profiles and their associations with adiposity indicators among children and adolescents. METHODS: Participants were 382 children and 338 adolescents who wore wrist accelerometers for 24 hours a day for seven consecutive days. The 24-h activity profile expressed by the average acceleration (AvAcc) and intensity gradient (IG) were estimated from multi-day raw accelerometer data. Adiposity indicators included body mass index (BMI) z-score, fat mass percentage (FM%), fat mass index (FMI), and visceral adipose tissue (VAT). Multiple linear regression of activity profile metrics and adiposity indicators was performed separately for school and weekend days. RESULTS: Weekend days AvAcc and IG were lower compared to school days in both age groups (p <0.001 for all). Specifically, AvAcc was lower by 9.4% and 11.3% in children and adolescents, respectively. IG on weekend days was lower (more negative) by 3.4% in children and 3.1% in adolescents. Among children, on school days AvAcc and IG were negatively associated with FM%, FMI, and VAT, whilst on weekend days AvAcc was positively associated with BMI z-score, FMI, and VAT (p < 0.05 for all). Among adolescents, negative associations were found between weekend day AvAcc and IG and FM% and FMI (p < 0.05 for all), respectively. CONCLUSIONS: This study confirms the importance of 24-h activity profile as a potentially protective factor against excess adiposity. The variability of movement behaviours during structured and less structured days should be considered when optimizing the 24-h movement behaviours to prevent childhood obesity.

PD1+CD8+ Cells Are an Independent Prognostic Marker in Patients with Head and Neck Cancer.

Head and neck squamous cell carcinomas (HNSCCs) belong to a group of diverse tumors, which can be induced by infection with human papillomavirus (HPV) or tobacco and alcohol consumption. The viral etiology of HNSCC relates to better clinical outcomes reflecting a different immune system response. Here, we retrospectively analyzed 97 tissue samples from oral and oropharyngeal carcinomas associated and non-associated with HPV infection using multispectral fluorescent immunohistochemistry. To evaluate the immune cell infiltration in tumor and stroma compartments, we designed four panels of four to five antibodies. We detected more T lymphocytes in the stroma, compared to the tumor parenchyma. In HPV positive (HPV+) in comparison to HPV negative (HPV-) tumors, higher counts of CD3+CD4+, CD3+CD8+, PD1+CD4+, PD1+CD8+ T cells, and ICOS- Treg cells were detected while more ICOS+ Treg cells and CTLA4+CD4+ T cells were observed in HPV- than in HPV+ tumors. The results of the univariate and multivariate analyses confirmed the predominant impact of HPV status on prognosis. More importantly, the number of CD8+PD-1+ T cells was identified as an independent factor, influencing the overall and/or disease-specific survival of patients with oral cavity or oropharyngeal carcinomas.

Outcomes After Human Papillomavirus Vaccination in Patients With Recurrent Respiratory Papillomatosis: A Nonrandomized Clinical Trial.

Importance: Recurrent respiratory papillomatosis (RRP) is a rare benign chronic disease of the larynx etiologically linked with the infection of low-risk human papillomavirus (HPV). Combination of surgical and immunomodulatory therapy has limited success. Possible use of prophylactic HPV vaccine that includes HPV-6 and HPV-11 antigens has been studied. Objective: To evaluate if the HPV vaccination is associated with a lower number of recurrences requiring surgical intervention in patients with new and recurrent RRP. Design, Setting, and Participants: This was a non-placebo-controlled intervention study. Enrollment data were collected from October 2011 to August 2013. The patients were followed up at 1 month, 12 months, and 5 years after the third dose of the vaccine and clinically monitored until December 31, 2018. Data were analyzed from 2019 to 2021. Altogether, 50 adults with active RRP were enrolled and followed up in referral centers. For the final outcome, follow-up data for 42 patients were available. Eight patients who did not fulfill the protocol were excluded. Interventions: All patients received HPV vaccine as an adjuvant treatment and were clinically followed up. When RRP progression or a significant recurrent lesion was detected, surgical removal via direct laryngoscopy was indicated. No adjuvant therapy with antiviral or biological agents was used. Main Outcomes and Measures: This study compared the prevaccination and postvaccination positivity for HPV-specific antibodies. The main outcome was the difference in the frequency of RRP recurrences in the prevaccination and postvaccination period. Results: A total of 50 patients with RRP were enrolled (median [SD] age, 41.5 [12.3] years [range, 21-73 years]; 39 [78%] men and 11 [22%] women). After HPV vaccination, patients with previously no HPV-specific antibodies showed seroconversion, and all patients developed 100-fold higher levels of HPV vaccine type-specific antibodies compared with the prevaccination period. In patients with recurrent RRP, decreased frequency of recurrences requiring surgical treatment was present after vaccination (from 0.85 to 0.36 recurrences/y). No difference in postvaccination recurrences was found between patients with newly diagnosed and recurrent RRP. Conclusions and Relevance: In this nonrandomized clinical trial, the frequency of RRP recurrences was significantly lower after HPV vaccination, and patients with RRP thus had a reduced burden of disease. Because no difference was detected in the frequency of recurrent postvaccination lesions in patients with new and recurrent disease, it appears that both groups showed equal benefit following HPV vaccination. These findings suggest that the earlier that patients with RRP receive HPV vaccine, the sooner they may show reduced burden of disease. Trial Registration: EudraCT Identifier: 2011-002667-14; ClinicalTrials.gov Identifier: NCT01375868.

ARG1 mRNA Level Is a Promising Prognostic Marker in Head and Neck Squamous Cell Carcinomas.

Head and neck squamous cell carcinomas (HNSCC) can be induced by smoking or alcohol consumption, but a growing part of cases relate to a persistent high-risk papillomavirus (HPV) infection. Viral etiology has a beneficial impact on the prognosis, which may be explained by a specific immune response. Tumor associated macrophages (TAMs) represent the main immune population of the tumor microenvironment with a controversial influence on the prognosis. In this study, the level, phenotype, and spatial distribution of TAMs were evaluated, and the expression of TAM-associated markers was compared in HPV positive (HPV+) and HPV negative (HPV-) tumors. Seventy-three formalin and embedded in paraffin (FFPE) tumor specimens were examined using multispectral immunohistochemistry for the detection of TAM subpopulations in the tumor parenchyma and stroma. Moreover, the mRNA expression of TAM markers was evaluated using RT-qPCR. Results were compared with respect to tumor etiology, and the prognostic significance was evaluated. In HPV- tumors, we observed more pro-tumorigenic M2 in the stroma and a non-macrophage arginase 1 (ARG1)-expressing population in both compartments. Moreover, higher mRNA expression of M2 markers-cluster of differentiation 163 (CD163), ARG1, and prostaglandin-endoperoxide synthase 2 (PTGS2)-was detected in HPV- patients, and of M1 marker nitric oxide synthase 2 (NOS2) in HPV+ group. The expression of ARG1 mRNA was revealed as a negative prognostic factor for overall survival of HNSCC patients.

Exploratory drilling: how to set up, carry out, and evaluate a seroprevalence study.

Seroprevalence studies represent a very important tool to find out what fraction of population has already met with the new type of coronavirus (e.g. SARS-CoV-2). Without these data, it is almost impossible for the state authorities to manage the epidemic and adopt rational measures. This article brings the results of a medium-sized seroprevalence study which was carried out in the spring of 2020 in South Bohemia. In the Strakonice and Písek regions, the ELISA method was used to test the prevalence of IgA and IgG antibodies in 2011 subjects, volunteers from general public and selected professions working in areas with a higher exposure to the infection. The study showed that already in May 2020, 2.9% of inhabitants of the Strakonice region and 1.9% of inhabitants of the Písek region had antibodies against the coronavirus. These numbers imply that for each PCR positive person, there were at least fifty others who had probably already undergone the infection. The article points out three types of problems that might occur in such a study. First, the study must be planned correctly, and possible outcomes must be pre-assessed. Second, an appropriate test must be selected with known parameters. This enables us to correctly estimate the share of false positive and false negative results. Third, the data must be evaluated in a reasonable way and correct inference must be performed. We offer a set of recommendations how to manage these issues and how to solve problems that inevitably arise in such a large-scale testing.

Prevalence and correlates of adherence to the combined movement guidelines among Czech children and adolescents.

BACKGROUND: There are limited studies on the prevalence of adherence to the combined guidelines for physical activity (PA), sedentary behavior, and sleep in children and adolescents. Moreover, little is known about correlates of adherence to the guidelines. Therefore, the main aim of this study is to examine the prevalence and identify the correlates of adherence to the combined movement guidelines among children and adolescents. METHODS: A total of 355 children aged 8-13 years (44% boys) and 324 adolescents aged 14-18 years (43% boys) from the Czech Republic participated in this study. PA and sleep duration were estimated using multi-day 24-h raw data from wrist-worn accelerometers. Recreational screen time was parent proxy-reported in children and self-reported in adolescents. Seventeen potential correlates were grouped into three homogenous categories for biological and cognitive, behavioral, and family correlates. The multi-level multivariable logistic regression was applied to identify correlates of adherence to combined movement guidelines and to specific combinations of any of two recommendations. RESULTS: Approximately 6.5% of children and 2.2% of adolescents met all recommendations of the combined movement guidelines. In children, girls (OR = 0.4; 95% CI = 0.1-0.9) and participants with overweight or obese fathers (OR = 0.3; 95% CI = 0.1-0.7) had significantly lower odds of adherence to the combined movement guidelines. Additionally, children had higher odds of meeting specific combinations of two recommendations if they reported regular fruit and vegetable intake, participated in organized PA, or if their fathers had a university degree. Meanwhile, paternal overweight and obesity, and high sleep efficiency were associated with lower odds of meeting specific combinations of recommendations. In adolescents, sex, fruit and vegetable intake, organized PA, and active play were correlates of meeting specific combinations of any two recommendations. CONCLUSIONS: A low proportion of children and adolescents met the combined movement guidelines and several correlates related to family were identified. Family is a key source of influence for healthy movement behaviors during childhood and adolescence.

Bayesian approach for analysis of time-to-event data in plant biology.

BACKGROUND: Plants, like all living organisms, metamorphose their bodies during their lifetime. All the developmental and growth events in a plant's life are connected to specific points in time, be it seed germination, seedling emergence, the appearance of the first leaf, heading, flowering, fruit ripening, wilting, or death. The onset of automated phenotyping methods has brought an explosion of such time-to-event data. Unfortunately, it has not been matched by an explosion of adequate data analysis methods. RESULTS AND DISCUSSION: In this paper, we introduce the Bayesian approach towards time-to-event data in plant biology. As a model example, we use seedling emergence data of maize under control and stress conditions but the Bayesian approach is suitable for any time-to-event data (see the examples above). In the proposed framework, we are able to answer key questions regarding plant emergence such as these: (1) Do seedlings treated with compound A emerge earlier than the control seedlings? (2) What is the probability of compound A increasing seedling emergence by at least 5 percent? CONCLUSION: Proper data analysis is a fundamental task of general interest in life sciences. Here, we present a novel method for the analysis of time-to-event data which is applicable to many plant developmental parameters measured in field or in laboratory conditions. In contrast to recent and classical approaches, our Bayesian computational method properly handles uncertainty in time-to-event data and it is capable to reliably answer questions that are difficult to address by classical methods.

Bayesian multiple hypotheses testing in compositional analysis of untargeted metabolomic data.

Clinical metabolomics aims at finding statistically significant differences in metabolic statuses of patient and control groups with the intention of understanding pathobiochemical processes and identification of clinically useful biomarkers of particular diseases. After the raw measurements are integrated and pre-processed as intensities of chromatographic peaks, the differences between controls and patients are evaluated by both univariate and multivariate statistical methods. The traditional univariate approach relies on t-tests (or their nonparametric alternatives) and the results from multiple testing are misleadingly compared merely by p-values using the so-called volcano plot. This paper proposes a Bayesian counterpart to the widespread univariate analysis, taking into account the compositional character of a metabolome. Since each metabolome is a collection of some small-molecule metabolites in a biological material, the relative structure of metabolomic data, which is inherently contained in ratios between metabolites, is of the main interest. Therefore, a proper choice of logratio coordinates is an essential step for any statistical analysis of such data. In addition, a concept of b-values is introduced together with a Bayesian version of the volcano plot incorporating distance levels of the posterior highest density intervals from zero. The theoretical background of the contribution is illustrated using two data sets containing samples of patients suffering from 3-hydroxy-3-methylglutaryl-CoA lyase deficiency and medium-chain acyl-CoA dehydrogenase deficiency. To evaluate the stability of the proposed method as well as the benefits of the compositional approach, two simulations designed to mimic a loss of samples and a systematical measurement error, respectively, are added.

Prognostic value of posttreatment HPV-specific antibodies in patients with oropharyngeal tumors.

BACKGROUND: The presence of human papillomavirus (HPV)-specific antibodies in patients with head and neck cancer at enrollment has prognostic significance. In cervical carcinoma patients, the decrease of HPV E6/E7-specific antibodies appears to be associated with a better prognosis. METHODS: This prospective study with follow-up focused on the persistence and prognostic value of antibodies specific for HR HPV-derived VLPs and HPV16 E6/E7 oncoproteins in patients with oropharyngeal cancers. In this study, we analyzed sera of 93 patients taken a year after the end of treatment and sera from 58 of these patients taken up to 14 years after treatment. RESULTS: The level of HPV-specific antibodies decreased on the 1-year follow-up and the decrease during the long follow-up was statistically significant. For HPV16 E7 antibodies the decrease was steeper in nonrecurrent patients. While the level of antibodies at enrollment was not predictive of recurrences, the decrease of HPV16 E6 antibodies at 1-year follow up was associated with better overall as well as disease-specific survival of patients. CONCLUSIONS: The data suggest that the pretreatment level of HPV-specific antibodies is not predictive of the occurrence of recurrences but the decrease HPV16 E6 antibodies on the 1-year follow-up is predictive of better survival of HN patients.

Analysis of the seasonal incidence of acute respiratory infections including influenza (ARI) in the Czech Republic - possible contribution of the functional data boxplot in epidemiology.

AIMS: The detection of an epidemic outbreak is possible only if the baseline incidence level of a given disease is well defined. The determination of the baseline is complicated by the presence of epidemic outbreaks in historical data. The aim of the paper is to provide a new way of determining the baseline. METHODS: The analyzed data containing weekly records on the incidence of acute respiratory infections including influenza (ARI) in the Czech Republic and its regions are taken from the nationwide surveillance system; data on 15 seasons from 2001/02 to 2015/16 are included. Functional boxplots of the data are constructed and five distinct methods (componentwise mean, componentwise median, median, trimmed mean, and adjusted mean) were used for the computation of the baseline level function. RESULTS: It was shown that the methods based on functional data analysis could successfully overcome the problems that arise when the conventional methods are used for the determination of the baseline function. CONCLUSION: The functional boxplot - a new statistical tool - can bring not only a transparent visualisation of comprehensive data, but can also help epidemiologists and other public health experts to determine the baseline incidence level of a given disease as well as to detect unusual epidemic seasons.

Specific and combined subjective responses to noise and their association with cardiovascular diseases.

INTRODUCTION: Noise is one of the most extensive environmental factors affecting the general population. The present study is focused on the association between discomfort caused by noise and the incidence of certain diseases (ischaemic heart disease, stroke and hypertension). MATERIALS AND METHODS: This cross-sectional questionnaire study, conducted in 10 cities in the Czech Republic, comprises two stages with 3592 obtained questionnaires in the first phase and 762 in the second phase. Twelve variables describe subjective responses to noise from different sources at different times of day. The intensity of the associations between variables was measured by correlation coefficient. Logistic regression was used for fitting models of morbidity, and confounders such as age and socio-economic status were included. The hypotheses from the first phase were independently validated using data from the second phase. RESULTS: The general rates of noise annoyance/sleep disturbance had greater correlation with traffic noise variables than with neighbourhood noise variables. Factors significantly associated with diseases are: for hypertension - annoyance by traffic noise (the elderly, odds ratio (OR) 1.4) and sleep disturbance by traffic and neighbourhood noise (the elderly, OR 1.6); for ischaemic heart disease - the general rate of noise annoyance (all respondents, OR 1.5 and the adults 30-60 years, OR 1.8) and the general rate of annoyance and sleep disturbance (all respondents, OR 1.3); for stroke - annoyance and sleep disturbance by traffic and neighbourhood noise (all respondents, OR 1.8). CONCLUSION: Factors that include multiple sources of noise or non-specific noise are associated with the studied diseases more frequently than the source-specific factors.

Can renal ultrasonography and DMSA scintigraphy be used for the prediction of irreversible histological lesions of the upper pole in duplex system with ureteroceles or ectopic ureters?

AIM: To assess of the role of renal ultrasonography (US) and DMSA renal scintigraphy in the prediction of irreversible histological lesions of the upper pole in duplex system. METHODS: A prospective cohort study based on data collected between 2005 and 2012 at our institution. The cohort consisted of 23 patients with ureteroceles and 28 patients with ectopic ureters who underwent upper pole nephrectomy. Preoperative recordings from ultrasound and nuclear renal scans were compared with the histological findings. Histological irreversible lesions were defined as the presence of dysplasia and/or severe chronic interstitial nephritis (CIN) in ≥ 90% of the specimen. ROC (Receiver Operating Characteristic) curves were used to investigate thresholds in order to identify irreversible lesions using various differential functions. The histology was correlated with the results of imaging. RESULTS: Pathological findings were found in all histological samples. Histological lesions were irreversible in 20/23 patients (87.0%) with ureteroceles and in 14/28 patients (50.0%) with ectopic ureters. The model is able to predict irreversible lesions if an upper pole differential function is ≤ 3% in patients with ureteroceles, and ≤ 2% in the presence of ectopic ureters. Weak association between parenchymal thinning on ultrasonography and irreversible lesions was found in patients with ectopic ureters. CONCLUSION: DMSA renal scintigraphy provides a useful tool for the prediction of irreversible lesions in the upper pole. Low differential function (≤ 3% and ≤ 2%, respectively) indicates irreversible lesions, favoring heminephrectomy. Higher differential function indicates greater remaining biological potential of the parenchyma, favoring reconstruction of the upper pole.

Development of 5' LTR DNA methylation of latent HIV-1 provirus in cell line models and in long-term-infected individuals.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) latency represents the major barrier to virus eradication in infected individuals because cells harboring latent HIV-1 provirus are not affected by current antiretroviral therapy (ART). We previously demonstrated that DNA methylation of HIV-1 long terminal repeat (5' LTR) restricts HIV-1 reactivation and, together with chromatin conformation, represents an important mechanism of HIV-1 latency maintenance. Here, we explored the new issue of temporal development of DNA methylation in latent HIV-1 5' LTR. RESULTS: In the Jurkat CD4(+) T cell model of latency, we showed that the stimulation of host cells contributed to de novo DNA methylation of the latent HIV-1 5' LTR sequences. Consecutive stimulations of model CD4(+) T cell line with TNF-α and PMA or with SAHA contributed to the progressive accumulation of 5' LTR DNA methylation. Further, we showed that once established, the high DNA methylation level of the latent 5' LTR in the cell line model was a stable epigenetic mark. Finally, we explored the development of 5' LTR DNA methylation in the latent reservoir of HIV-1-infected individuals who were treated with ART. We detected low levels of 5' LTR DNA methylation in the resting CD4(+) T cells of the group of patients who were treated for up to 3 years. However, after long-term ART, we observed an accumulation of 5' LTR DNA methylation in the latent reservoir. Importantly, within the latent reservoir of some long-term-treated individuals, we uncovered populations of proviral molecules with a high density of 5' LTR CpG methylation. CONCLUSIONS: Our data showed the presence of 5' LTR DNA methylation in the long-term reservoir of HIV-1-infected individuals and implied that the transient stimulation of cells harboring latent proviruses may contribute, at least in part, to the methylation of the HIV-1 promoter.

Analysis of the integration of human papillomaviruses in head and neck tumours in relation to patients' prognosis.

Integration, which leads to the disruption of the circular HPV genome, is considered as a critical, albeit not obligatory, step in carcinogenic progression. Although cervical carcinomas with extrachromosomal HPV plasmid genomes have been described, the virus is integrated in 70% of HPV16-positive cervical tumours. Limited information is available about HPV integration in head and neck tumours (HNC). In this study, we have characterised the physical status of HPV in a set of tonsillar tumour samples using different methods--the mapping of E2 integration breakpoint at the mRNA level, the 3' RACE based Amplification of Papillomavirus Oncogene Transcripts (APOT) assay and Southern blot. Furthermore, the impact of HPV integration on patients' prognosis has been evaluated in a larger set of 186 patients with head and neck cancer. Based on the analysis of E2 mRNA, HPV was integrated in the host genome in 43% of the HPV-positive samples. Extrachromosomal or mixed form was present in 57%. In fresh frozen samples, the APOT and E2 mapping results were in agreement. The results were confirmed using Southern blotting. Furthermore, the type and exact site of integration were determined. The survival analysis of 186 patients revealed HPV positivity, tumour size and lymph node positivity as factors that influence disease specific survival. However, no statistically significant difference was found in disease specific survival between patients with HPV-positive integrated vs. extrachromosomal/mixed forms of the virus.

When less is more: a simple predictive model for repeated prostate biopsy outcomes.

OBJECTIVES: To present a new predictive model for repeated prostate biopsy outcomes. Several practical problems are described that arise when searching for a proper model among those that already exist. A new model is developed with only two explanatory variables and a simple graphical output. METHODS: This is a retrospective cohort study based on data collected from December 2006 to June 2011 at the Clinic of Urology of the University Hospital in Olomouc, Czech Republic. The cohort consists of 221 patients who underwent the first repeated biopsy after an initial biopsy with a negative outcome. All patients had prostate-specific antigen (PSA) levels between 1.5 and 16.5 ng/mL and a prostate volume not greater than 100mL. A logistic regression model was fitted. RESULTS: Of the 221 patients, 29 (13%) were diagnosed with prostate cancer on the repeated biopsy. The final model includes the PSA level and the transitory zone volume as predictors. Its accuracy is 76.4%. The cut-off point of 0.0687 in the predicted positive repeated biopsy outcome assures 95% sensitivity and prevents 42% of unnecessary biopsies. CONCLUSIONS: The accuracy of the model is comparable to that of more complex models (with more than two predictors) published in the literature. The model includes only two routinely measured variables, and hence it is accessible for a wide range of practitioners. The simple graphical outcome makes the model even more attractive.