P15.14.B Radionecrosis versus progression in brain tumors: results of a promising MRI tools

Background

Distinguish between radiation necrosis (RN) and tumor progression, in patients with irradiated primary or metastatic brain tumors, is a diagnostic challenge. Also the use of new MRI sequences, like diffusion, perfusion-weighted and spectroscopy, or PET with new amino acid tracers, is not always able to differentiate these two entities.To overcome this crucial problem, encouraging results have been obtained using the analysis of delayed contrast extravasation MRI to calculate high resolution maps, called “treatment response assessment maps” (TRAMs). Aim of this exploratory analysis is to assess TRAM ability in differentiate between radiation effect and tumor progression in a small cohort of brain tumor patients treated with radiation therapy (RT).

Material and Methods

Thirty-four patients irradiated for primary and metastatic brain tumors were evaluated. 12 patients have primary brain tumors, 22 patients have brain metastases from different solid tumors. Distinguish by histological subtypes and type of treatment, the 12 patients with primary brain tumors were: 8 glioblastoma, 2 anaplastic astrocitoma, 1 pleomorphic xanthoastrocytoma WHO grade II, and 1 anaplastic xanthoastrocytoma WHO grade III, treated with surgery followed by RT and concomitant and\or adjuvant chemotherapy with temozolomide. Among brain metastatic patients, primary tumor was: 18 non-small cell lung cancer, 2 malignant melanoma, 1 breast cancer and 1 renal cell carcinoma. All of them were treated with stereotactic radiosurgery at the dose of 20-24Gy in 1fraction, or with hypofractionated stereotactic radiotherapy at the dose of 27-30Gy in 3fractions. All images were uploaded and elaborate into the image workstation ([Brainlab AG, Olof-Palme-Straße 9, 81829 Munich]). TRAMs were calculated by subtracting T1 MRI images acquired 5 minutes after contrast injection from the T1 MRI images acquired 60-105 minutes later. On TRAMs, radiation effects appeared as red areas whereas persistent tumoral lesion appeared as blue areas.

Results

From February 2021, 34 patients have been evaluated, in a prospective study, with this novel MRI modality. During their follow-up, 13patients (38%) showed a clinicoradiologic suspicion of a persistent tumoral lesion or progressive disease, and 21 (62%) a suspicion of RN. For 14patients a brain MET-PET has been performed. TRAMs analysis have shown a fair agreement with clinicoradiologic diagnosis, perfusion-weighted MRI, and PET imaging. Moreover, 7 patients underwent surgical resection, with histopathological confirm of persistent disease in 4 and radionecrosis in 3.

Conclusion

These preliminary results show the ability of TRAMs evaluation in distinguish between RN and progressive disease. The recruitment of new patients continues, and further evaluations are ongoing to evaluate sensitivity and positive predictive value of TRAMs analysis.

In Silico Models for Developmental Toxicity

Modeling developmental toxicity has been a challenge for (Q)SAR model developers due to the complexity of the endpoint. Recently, some new in silico methods have been developed introducing the possibility to evaluate the integration of existing methods by taking advantage of various modeling perspectives. It is important that the model user is aware of the underlying basis of the different models in general, as well as the considerations and assumptions relative to the specific predictions that are obtained from these different models for the same chemical. The evaluation on the predictions needs to be done on a case-by-case basis, checking the analogues (possibly using structural, physicochemical, and toxicological information); for this purpose, the assessment of the applicability domain of the models provides further confidence in the model prediction. In this chapter, we present some examples illustrating an approach to combine human-based rules and statistical methods to support the prediction of developmental toxicity; we also discuss assumptions and uncertainties of the methodology.

Quantitative Structure-Activity Relationship Modeling of the Amplex Ultrared Assay to Predict Thyroperoxidase Inhibitory Activity

The thyroid system plays a major role in the regulation of several physiological processes. The dysregulation of the thyroid system caused by the interference of xenobiotics and contaminants may bring to pathologies like hyper- and hypothyroidism and it has been recently correlated with adverse outcomes leading to cancer, obesity, diabetes and neurodevelopmental disorders. Thyroid disruption can occur at several levels. For example, the inhibition of thyroperoxidase (TPO) enzyme, which catalyses the synthesis of thyroid hormones, may cause dysfunctions related to hypothyroidism. The inhibition of the TPO enzyme can occur as a consequence of prolonged exposure to chemical compounds, for this reason it is of utmost importance to identify alternative methods to evaluate the large amount of pollutants and other chemicals that may pose a potential hazard to the human health. In this work, quantitative structure-activity relationship (QSAR) models to predict the TPO inhibitory potential of chemicals are presented. Models are developed by means of several machine learning and data selection approaches, and are based on data obtained in vitro with the Amplex UltraRed-thyroperoxidase (AUR-TPO) assay. Balancing methods and feature selection are applied during model development. Models are rigorously evaluated through internal and external validation. Based on validation results, two models based on Balanced Random Forest (BRF) and K-Nearest Neighbours (KNN) algorithms were selected for a further validation phase, that leads predictive performance (BA = 0.76-0.78 on external data) that is comparable with the reported experimental variability of the AUR-TPO assay (BA ∼0.70). Finally, a consensus between the two models was proposed (BA = 0.82). Based on the predictive performance, these models can be considered suitable for toxicity screening of environmental chemicals.

QSAR Models for Human Carcinogenicity: An Assessment Based on Oral and Inhalation Slope Factors

Carcinogenicity is a crucial endpoint for the safety assessment of chemicals and products. During the last few decades, the development of quantitative structure-activity relationship ((Q)SAR) models has gained importance for regulatory use, in combination with in vitro testing or expert-based reasoning. Several classification models can now predict both human and rat carcinogenicity, but there are few models to quantitatively assess carcinogenicity in humans. To our knowledge, slope factor (SF), a parameter describing carcinogenicity potential used especially for human risk assessment of contaminated sites, has never been modeled for both inhalation and oral exposures. In this study, we developed classification and regression models for inhalation and oral SFs using data from the Risk Assessment Information System (RAIS) and different machine learning approaches. The models performed well in classification, with accuracies for the external set of 0.76 and 0.74 for oral and inhalation exposure, respectively, and r2 values of 0.57 and 0.65 in the regression models for oral and inhalation SFs in external validation. These models might therefore support regulators in (de)prioritizing substances for regulatory action and in weighing evidence in the context of chemical safety assessments. Moreover, these models are implemented on the VEGA platform and are now freely downloadable online.

Salvage radiotherapy for oligo-progressive malignant pleural mesothelioma

OBJECTIVES

No standard treatment option is available for patients with unresectable malignant pleural mesothelioma (MPM) progressing after upfront chemotherapy. We aimed to explore the role of focal radiotherapy (FRT) as a treatment modality for oligo-progressive MPM.

MATERIALS AND METHODS

In this retrospective study, consecutive patients pretreated with ≥1 lines of chemotherapy were included. Oligo-progressive MPM was defined as an unresectable disease with radiological progression at ≤3 sites according to a chest-abdominal contrast-enhanced computed tomography. Patients were treated with either stereotactic body radiotherapy (SBRT, ≥5 Gy per fraction) or hypo-fractionated radiotherapy (hypoRT, <5 Gy per fraction). Time to further systemic therapy (TFST) and local control (LC) after FRT were the primary endpoints. Biologically effective dose (BED) was calculated using three different alpha/beta models (1.5 Gy, 3 Gy and 10 Gy).

RESULTS

From April 2006 to March 2019, 37 patients were treated on 43 pleural lesions; 16/37 (43 %) had undergone upfront multimodality treatment (MMT) including surgery. FRT was given in 22/37 (59.5 %) after one line of chemotherapy. SBRT was delivered for 26/43 lesions (60.5 %), hypoRT for 17/43 (39.5 %). Median TFST was 6 months (95 % CI 4.9-7.1). LC at 6 months and 1 year was 84 % and 76 %, respectively. Median TFST was longer in patients treated after 1 vs >1 line of chemotherapy (9 vs 4 months, p = 0.001) and in patients pretreated with MMT (6 vs 3 months, p = 0.021). Six-month LC was better in patients treated with a BED > 100 using alpha/beta 1.5 and 3. No ≥ G3 acute or late toxicities were reported.

CONCLUSION

FRT was feasible in selected patients with oligo-progressive MPM, allowing delay of further systemic therapies, with no severe toxicity. FRT was more effective when performed at progression after one line of systemic therapy. Our results suggest a radio-resistant behavior of MPM.

Zebrafish AC50 modelling: (Q)SAR models to predict developmental toxicity in zebrafish embryo

Developmental toxicity refers to the occurrence of adverse effects on a developing organism as a consequence of exposure to hazardous chemicals. The assessment of developmental toxicity has become relevant to the safety assessment process of chemicals. The zebrafish embryo developmental toxicology assay is an emerging test used to screen the teratogenic potential of chemicals and it is proposed as a promising test to replace teratogenic assays with animals. Supported by the increased availability of data from this test, the developmental toxicity assay with zebrafish has become an interesting endpoint for the in silico modelling. The purpose of this study was to build up quantitative structure-activity relationship (QSAR) models. In this work, new in silico models for the evaluation of developmental toxicity were built using a well-defined set of data from the ToxCast^TM Phase I chemical library on the zebrafish embryo. Categorical and continuous QSAR models were built by gradient boosting machine learning and the Monte Carlo technique respectively, in accordance with Organization for Economic Co-operation and Development principles and their statistical quality was satisfactory. The classification model reached balanced accuracy 0.89 and Matthews correlation coefficient 0.77 on the test set. The regression model reached correlation coefficient R² 0.70 in external validation and leave-one-out cross-validated Q² 0.73 in internal validation.

Preliminary Results of a Randomized Study on Postmenopausal Women With Early Stage Breast Cancer: Adjuvant Hypofractionated Whole Breast Irradiation Versus Accelerated Partial Breast Irradiation (HYPAB Trial)

BACKGROUND

The purpose of this study was to report preliminary data of a randomized phase III trial comparing hypofractionated whole breast irradiation (HWBI) and accelerated partial breast irradiation (APBI) using volumetric modulated arc therapy (VMAT).

MATERIAL AND METHODS

The HYPAB trial enrolled postmenopausal women with biopsy-proven infiltrating breast cancer, clinically negative axilla, single T1 to T2 tumors, who were treated with breast-conserving surgery. Patients were randomized 1:1 after surgery to HWBI (40.5 Gy whole breast, 48.0 Gy to surgical bed, 15 fractions over 3 weeks) or APBI (30 Gy delivered in 5 fractions of 6 Gy given on alternate days on the surgical bed). Cosmetic outcome was the primary end point of the study.

RESULTS

A total of 172 patients were enrolled. After a median follow-up of 36 months, 5 local failures and 3 locoregional failures were recorded, with no difference between the 2 treatment arms. Use of HWBI as compared with APBI was significantly correlated with increased incidence of overall (62% vs. 14%; P < .001) and grade 2 (18% vs. 1%; P < .001) acute skin toxicity. APBI was correlated with a lower incidence of overall late toxicity as compared with HWBI (18% vs. 41%; P = .001), but no significant difference was found in term of occurrence of grade 2 events (1% vs. 4%; P = NS). At comparative assessment between baseline and post-radiotherapy evaluation, impairment in cosmetic outcome was reported in 19 (11%) patients. Owing to premature closure of the study, no per-protocol comparison between the treatment arms was performed.

CONCLUSION

APBI with the VMAT technique is safe and feasible, with lower acute toxicity when compared with HWBI.

Integrated In Silico Models for the Prediction of No-Observed-(Adverse)-Effect Levels and Lowest-Observed-(Adverse)-Effect Levels in Rats for Sub-chronic Repeated-Dose Toxicity

Repeated-dose toxicity (RDT) is a critical endpoint for hazard characterization of chemicals and is assessed to derive safe levels of exposure for human health. Here we present the first attempt to model simultaneously no-observed-(adverse)-effect level (NO(A)EL) and lowest-observed-(adverse)-effect level (LO(A)EL). Classification and regression models were derived based on rat sub-chronic repeated dose toxicity data for 327 compounds from the Fraunhofer RepDose database. Multi-category classification models were built for both NO(A)EL and LO(A)EL though a consensus of statistics- and fragment-based algorithms, while regression models were based on quantitative relationships between the endpoints and SMILES-based attributes. NO(A)EL and LO(A)EL models were integrated, and predictions were compared to exclude inconsistent values. This strategy improved the performance of single models, leading to R² greater than 0.70, root-mean-square error (RMSE) lower than 0.60 (for regression models), and accuracy of 0.61-0.73 (for classification models) on the validation set, based on the endpoint and the threshold applied for selecting predictions. This study confirms the effectiveness of the modeling strategy presented here for assessing RDT of chemicals using in silico models.

Pesticides, cosmetics, drugs: identical and opposite influences of various molecular features as measures of endpoints similarity and dissimilarity

The similarity is an important category in natural sciences. A measure of similarity for a group of various biochemical endpoints is suggested. The list of examined endpoints contains (1) toxicity of pesticides towards rainbow trout; (2) human skin sensitization; (3) mutagenicity; (4) toxicity of psychotropic drugs; and (5) anti HIV activity. Further applying and evolution of the suggested approach is discussed. In particular, the conception of the similarity (dissimilarity) of endpoints can play the role of a "useful bridge" between quantitative structure property/activity relationships (QSPRs/QSARs) and read-across technique.

QSAR models for biocides: The example of the prediction of Daphnia magna acute toxicity

Biocides are multi-component products used to control undesired and harmful organisms able to affect human or animal health or to damage natural and manufactured products. Because of their widespread use, aquatic and terrestrial ecosystems could be contaminated by biocides. The environmental impact of biocides is evaluated through eco-toxicological studies with model organisms of terrestrial and aquatic ecosystems. We focused on the development of in silico models for the evaluation of the acute toxicity (EC₅₀) of a set of biocides collected from different sources on the freshwater crustacean Daphnia magna, one of the most widely used model organisms in aquatic toxicology. Toxicological data specific for biocides are limited, so we developed three models for daphnid toxicity using different strategies (linear regression, random forest, Monte Carlo (CORAL)) to overcome this limitation. All models gave satisfactory results in our datasets: the random forest model showed the best results with a determination coefficient r² = 0.97 and 0.89, respectively, for the training (TS) and the validation sets (VS) while linear regression model and the CORAL model had similar but lower performance (r² = 0.83 and 0.75, respectively, for TS and VS in the linear regression model and r² = 0.74 and 0.75 for the CORAL model).

QSAR modeling of Daphnia magna and fish toxicities of biocides using 2D descriptors

In the recent years, ecotoxicological hazard potential of biocidal products has been receiving increasing attention in the industries and regulatory agencies. Biocides/pesticides are currently one of the most studied groups of compounds, and their registration cannot be done without the empirical toxicity information. In view of limited experimental data available for these compounds, we have developed Quantitative Structure-Activity Relationship (QSAR) models for the toxicity of biocides to fish and Daphnia magna following principles of QSAR modeling recommended by the OECD (Organization for Economic Cooperation and Development). The models were developed using simple and interpretable 2D descriptors and validated using stringent tests. Both models showed encouraging statistical quality in terms of determination coefficient R² (0.800 and 0.648), cross-validated leave-one-out Q² (0.760 and 0.602) and predictive R²_pred or Q²_ext (0.875 and 0.817) for fish (n_Training = 66, n_Test = 22) and Daphnia magna (n_Training = 100, n_Test = 33) toxicity datasets, respectively. These models should be applicable for data gap filling in case of new or untested biocidal compounds falling within the applicability domain of the models. In general, the models indicate that the toxicity increases with lipophilicity and decreases with polarity, branching and unsaturation. We have also developed interspecies toxicity models for biocides using the daphnia and fish toxicity data and used the models for data gap filling.

QSAR Development for Plasma Protein Binding: Influence of the Ionization State

Purpose

This study explored several strategies to improve the performance of literature QSAR models for plasma protein binding (PPB), such as a suitable endpoint transformation, a correct representation of chemicals, more consistency in the dataset, and a reliable definition of the applicability domain.

Methods

We retrieved human fraction unbound (Fu) data for 670 compounds from the literature and carefully checked them for consistency. Descriptors were calculated taking account of the ionization state of molecules at physiological pH (7.4), in order to better estimate the affinity of molecules to blood proteins. We used different algorithms and chemical descriptors to explore the most suitable strategy for modeling the endpoint. SMILES (simplified molecular input line entry system)-based string descriptors were also tested with the CORAL software (CORelation And Logic). We did an outlier analysis to establish the models to use (or not to use) in case of well recognized families.

Results

Internal validation of the selected models returned Q² values close to 0.60. External validation also gave r² values always greater than 0.60. The CORAL descriptor based model for √fu was the best, with r² 0.74 in external validation.

Conclusions

Performance in prediction confirmed the robustness of all the derived models and their suitability for real-life purposes, i.e. screening chemicals for their ADMET profiling. Optimization of descriptors can be useful in order to obtain the correct results with a ionized molecule.

Electronic supplementary material

The online version of this article (10.1007/s11095-018-2561-8) contains supplementary material, which is available to authorized users.

Impact of REACH legislation on the production and importation of CMR (carcinogen, mutagen and reproductive) and explosive chemicals in Italy from 2011 to 2015

On 1 June 2007, the European Commission issued the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) to protect both the environment and human health. We analyzed the impact of REACH in the Italian market considering the presence of chemicals, their diversity, importation and production during the period 2011-2015, with particular attention to products with toxic or explosive properties. There was a reduction of the chemicals on the market, in terms of tons but also the absolute numbers of types of compounds. The production reduction was particularly noticeable for explosive chemicals: -14.7%. CMR products did not show any statistically significant reduction in term of tons: -2.3%.

(Eco)toxicological maps: A new risk assessment method integrating traditional and in silico tools and its application in the Ledra River (Italy)

Contaminants giving rise to emerging concern like pharmaceuticals, personal care products, pesticides and Endocrine Disrupting Chemicals (EDCs) have been detected in wastewaters, as reported in the literature, but little is known about their (eco)toxicological effects and consequent human health impact. The present study aimed at overcoming this lack of information through the use of in silico methods integrated with traditional toxicological risk analysis. This is part of a pilot project involving the management of wastewater treatment plants in the Ledra River basin (Italy). We obtained data to work up a global risk assessment method combining the evaluations of health risks to humans and ecological receptors from chemical contaminants found in this specific area. The (eco)toxicological risk is expressed by a single numerical value, permitting the comparison of different sampling sites and the evaluation of future environmental and technical interventions.

Induction chemotherapy followed by neoadjuvant chemoradiotherapy and surgery in locally advanced rectal cancer: preliminary results of a phase II study

Background and purpose

To report preliminary results of induction chemotherapy (IC) followed by neoadjuvant chemoradiotherapy (CRT) and surgery in locally advanced rectal cancer (LARC) patients.

Materials and methods

This is the preliminary evaluation of a phase II study. Patients with histologically proven rectal adenocarcinoma, stage II-III disease, who met the inclusion criteria, received induction FOLFOXIRI (5-FU, leucovorin, oxaliplatin and irinotecan) regimen in combination with targeted agents followed by CRT and surgery. Analysis of the first 8 patients was required to confirm the treatment feasibility before the accrual of 20 additional patients.

Results

The first 8 patients were evaluated. The median follow-up time was 23 months. There were no treatment-related deaths. Trimodality strategy was well tolerated with high compliance and a good level of toxicity. There were no evidence of febrile neutropenia and any grade 4 adverse events were recorded. Three patients had pathologic complete response (pCR) and 1 patient had a nearly pCR (ypT1 ypN0).

Conclusion

Preliminary results are encouraging. FOLFOXIRI regimen plus targeted agents followed by CRT and surgery seems a safe approach. Longer follow-up and higher number of patients are mandatory to confirm such findings.

Classification of a Naïve Bayesian Fingerprint model to predict reproductive toxicity$

Using data from the Leadscope database and Procter and Gamble researchers (1172 compounds after data curation) a new classification model to predict reproductive toxicity was developed. The model is based on Naïve Bayesian methods that use the fingerprint "extended connectivity fingerprint 2". Bits generated by the fingerprint are used from the models as descriptors to discriminate between the two classes. This technique permits the creation of a model without the use of descriptors. After a study on the probability scores, the Naïve Bayesian Fingerprint model shows a good performance on reproductive toxicity. The Matthews Correlation Coefficient value was ≥0.4 in validation. The development of new models to predict complex endpoints such as reproductive toxicity is increasingly requested, with reference also to the REACH legislation in Europe or TSCA in the USA.

QSAR models for predicting acute toxicity of pesticides in rainbow trout using the CORAL software and EFSA's OpenFoodTox database

Optimal (flexible) descriptors were used to establish quantitative structure - activity relationships (QSAR) for toxicity of pesticides (n=116) towards rainbow trout. A heterogeneous set of hundreds of pesticides has been used, taken from the EFSA's chemical Hazards Database: OpenFoodTox. Optimal descriptors are preparing from simplified molecular input-line entry system (SMILES). So-called, correlation weights of different fragments of SMILES are calculating by the Monte Carlo optimization procedure where correlation coefficient between endpoint and optimal descriptor plays role of the target function. Having maximum of the correlation coefficient for the training set, one can suggest that the optimal descriptor calculated with these correlation weights can correlate with endpoint for external validation set. This approach was checked up with three different distributions into the training (≈85%) set and external validation (≈15%) set. The statistical characteristics of these models are (i) for training set correlation coefficient (r²) ranges 0.72-0.81, and root mean squared error (RMSE) ranges 0.54-1.25; (ii) for external (validation) set r² ranges 0.74-0.84; and RMSE ranges 0.64-0.75. Computational experiments have shown that presence of chlorine, fluorine, sulfur, and aromatic fragments is promoter of increase for the toxicity.

The application of new HARD-descriptor available from the CORAL software to building up NOAEL models

Continuous QSAR models have been developed and validated for the prediction of no-observed-adverse-effect (NOAEL) in rats, using training and test sets from the Fraunhofer RepDose® database and EFSA's Chemical Hazards Database: OpenFoodTox. This paper demonstrates that the HARD index, as an integrated attribute of SMILES, improves the prediction power of NOAEL values using the continuous QSAR models and Monte Carlo simulations. The HARD-index is a line of eleven symbols, which represents the presence, or absence of eight chemical elements (nitrogen, oxygen, sulfur, phosphorus, fluorine, chlorine, bromine, and iodine) and different kinds of chemical bonds (double bond, triple bond, and stereo chemical bond). Optimal molecular descriptors calculated with the Monte Carlo technique (maximization of correlation coefficient between the descriptor and endpoint) give satisfactory predictive models for NOAEL. Optimal molecular descriptors calculated in this way with the Monte Carlo technique (maximization of correlation coefficient between the descriptor and endpoint) give amongst the best results available in the literature. The models are built up in accordance with OECD principles.

Procedures and recommended times in the care process of the patient with pancreatic cancer: PAN-TIME consensus between scientific societies

PURPOSE

Pancreatic cancer (PC) is a disease with bad prognosis. It is usually diagnosed at advanced stages and its treatment is complex. The aim of this consensus document was to provide recommendations by experts that would ameliorate PC diagnosis, reduce the time to treatment, and optimize PC management by interdisciplinary teams.

METHODS

As a consensus method, we followed the modified Delphi methodology. A scientific committee of experts provided 40 statements that were submitted in two rounds to a panel of 87 specialists of 12 scientific societies.

RESULTS

Agreement was reached for 39 of the 40 proposed statements (97.5%).

CONCLUSIONS

Although a screening of the asymptomatic population is not a feasible option, special attention to potential symptoms during primary care could ameliorate early diagnostic. It is especially important to decrease the period until diagnostic tests are performed. This consensus could improve survival in PC patients by decreasing the time to diagnose and time to treatment and by the implementation of multidisciplinary teams.

Synergic development of pharmacokinetics and bioanalytical methods as support of pharmaceutical research

The development of pharmacokinetics led this science to achieve a relevant role in the investigation of new chemical entities for therapeutic application, and has allowed a series of new useful realizations of out of patent drugs like prolonged release and delayed release formulations, therapeutic delivery system (TDS) for drugs to be active in systemic circulation avoiding the first pass effect, orodispersible and effervescent formulations, intramuscular and subcutaneous depot formulations acting over a long period, oral inhalatory systems, and drug association at fixed dose. The above applications had pharmacokinetics as protagonist and have required the support from bioanalytical methods to assay drug concentrations, even in pg·mL(-1) of plasma, that really have paralleled the synergic development of pharmacokinetics.The complexity of the above realizations required specific guidelines from the regulatory authorities, mainly the US FDA and EU EMA, which have normalized and, in most cases, simplified the above applications admitting some waivers of in vivo bioequivalence.However, this review highlights some critical points, not yet focused on by operating guidelines, which need to be clarified by regulatory authorities. One of the most relevant issues is about the planning and conducting bioavailability and bioequivalence trials with endogenous substances, that possess own homeostatic equilibria with fluctuations, in some cases with specific rhythms, like melatonin and female sex hormones. The baseline subtraction required by guidelines to define the net contribute to the exogenous absorbed drug in most cases is a non-solvable problem.

In Silico Model for Developmental Toxicity: How to Use QSAR Models and Interpret Their Results

Modeling developmental toxicity has been a challenge for (Q)SAR model developers due to the complexity of the endpoint. Recently, some new in silico methods have been developed introducing the possibility to evaluate the integration of existing methods by taking advantage of various modeling perspectives. It is important that the model user is aware of the underlying basis of the different models in general, as well as the considerations and assumptions relative to the specific predictions that are obtained from these different models for the same chemical. The evaluation on the predictions needs to be done on a case-by-case basis, checking the analogs (possibly using structural, physicochemical, and toxicological information); for this purpose, the assessment of the applicability domain of the models provides further confidence in the model prediction. In this chapter, we present some examples illustrating an approach to combine human-based rules and statistical methods to support the prediction of developmental toxicity; we also discuss assumptions and uncertainties of the methodology.

Paradoxical psoriasis in a large cohort of patients with inflammatory bowel disease receiving treatment with anti-TNF alpha: 5-year follow-up study

BACKGROUND

Psoriasis is an emerging paradoxical side effect in patients with inflammatory bowel disease (IBD) when treated with anti-TNF alpha. Patients with severe skin lesions unresponsive to topical therapy need to withdraw from treatment.

AIM

To estimate the incidence of paradoxical psoriasis in a large cohort of IBD patients treated with anti-TNF alpha and to analyse its clinical correlates.

METHODS

A retrospective cohort study on all IBD patients who started anti-TNF alpha at our IBD Centre from January 2008 to December 2013 was performed. Proportional hazards regression models were used to estimate the association between each predictor and time to the development of psoriasis. Time-dependent predictors were updated at each available time point.

RESULTS

Four hundred and two patients were included. Participants contributed a total of 839 person-years of follow-up, during which 42 incident cases of psoriasis were recorded, with an incidence rate of five per 100 person-years. Cox-regression survival analysis revealed smoking as independent predictor of psoriasis (HR: 2.37, 95% CI: 1.36-4.48; P = 0.008). Conversely, concomitant immunosuppressive therapy was inversely related to psoriasis (HR: 0.33, 95% CI: 0.12-0.92; P = 0.03).

CONCLUSIONS

Paradoxical psoriasis is a relevant side effect of anti-TNF alpha therapy, with an incidence rate of five per 100 person-years. Smoking is confirmed as the main risk factor for developing lesions. The combination therapy with anti-TNF alpha plus immunosuppressants is associated with a reduced risk of paradoxical psoriasis.

Development of psoriasis scalp with alopecia during treatment of Crohn's disease with infliximab and rapid response to both diseases to ustekinumab

Anti tumor necrosis factor antibodies are used to treat both psoriasis and inflammatory bowel disease. Several paradoxical cases of psoriatic skin lesions induced by tumor necrosis factor antagonist therapy have been described in IBD patients in the recent years. Ustekinumab, a fully human anti-interleukin-12/-23 monoclonal antibody, is the first drug of a new class of biologic therapy approved for the treatment of moderate to severe plaque psoriasis. Data on the efficacy of ustekinumab in patients with moderate-to-severe Crohn's disease, especially in patients previously treated with infliximab, have been recently published. We report about the effectiveness of ustekinumab in the treatment of both severe scalp psoriasis lesions with alopecia and active Crohn's disease.

New biological agents for the treatment of the "high risk" IBD patients

BACKGROUND

Several new biological drugs have been introduced in the last decade or are under investigation for the treatment of IBD. They include anti TNFalpha agents, anti adhesion molecules, anti IL-12/23, anti IL-6R and others. Their role in IBD therapy will be discussed in regard of the association of chronic inflammation and cancer in the gut. The risk of colorectal cancer is increased in ulcerative colitis (UC) and, to some extent, in Crohn's disease (CD). This association is well known from many years. However, the mechanisms linking chronic inflammation and carcinogenesis are beginning to be elucidated only recently.

RESULTS AND CONCLUSIONS

Experimental data indicate that several cytokines could play a role in promoting tumour development. In this perspective, the anti cytokine agents could be not only powerful tools in treating inflammation but also efficacious in preventing the onset of inflammation associated colorectal cancer.

Combined therapy with infliximab and seton drainage for perianal fistulizing Crohn's disease with anal endosonographic monitoring: a single-centre experience

During infliximab treatment of perianal Crohn's disease (CD), the healing of the skin opening precedes fistula tract healing and this contributes to abscess formation and fistula recurrence. The aims of this study were to evaluate the efficacy of combined treatment with infliximab and setons for complex perianal fistulas in CD and to define the optimal time for seton removal by anal endosonography (AE). Nine consecutive patients with CD were studied. Perianal sepsis was eradicated when necessary and setons were placed before infliximab therapy. Setons were removed after AE evidence of fistulous tracts healing. Patients received a mean of 10+/-2.3 infliximab infusions. At week 6 all patients showed a reduction in mean CD activity index (p<0.005) and perianal disease activity index (p<0.0001). Complete fistula response was achieved in eight of nine patients. In six patients after a mean of 9.2 infusions, infliximab treatment was discontinued. Clinical and AE response persisted at 19.4+/-8.8 months (range 3-28 months) in five of these patients. One patient had fistula recurrence 20 weeks after infliximab discontinuation and responded rapidly to retreatment. At the time of this report, two patients were still on infliximab and in remission after a mean follow-up of 25+/-5 months. Combined therapy with infliximab and setons with AE monitoring of the response showed high efficacy in the management of patients with CD with complex perianal fistulas.

Length of follow-up after fistulotomy and fistulectomy associated with endorectal advancement flap repair for fistula in ano

BACKGROUND

The length of follow-up required after surgical repair of cryptoglandular fistula in ano has not been established. This prospective study determined the follow-up time needed to establish that an anal fistula has been cured after elective fistulotomy or fistulectomy associated with endorectal advancement flap (ERAF) repair.

METHODS

Between January 2001 and June 2004, consecutive patients with anal fistula of cryptoglandular aetiology were included provided that they lived within the catchment area of the hospital and agreed to participate in a follow-up programme, which comprised scheduled visits every month until complete wound healing and annually thereafter.

RESULTS

Some 206 of 219 eligible patients were evaluable; fistulotomy was performed in 115 and ERAF repair in 91. Median follow-up was 42 (range 24-65) months. Eighteen patients had recurrence of the fistula during follow-up, with a median time to relapse of 5.0 (range 1.0-11.7) months. There were no recurrences after 1 year.

CONCLUSION

Recurrence of fistula in ano of cryptoglandular origin treated by means of fistulotomy or ERAF repair occurs within the first year of operation.

Single agent versus combination chemotherapy for metastatic breast cancer

BACKGROUND

It is commonly thought that combining chemotherapy agents for treating women with metastatic breast cancer will result in regimens that are more active, offer superior tumour response rates with more time before progression and improve overall survival. However, it is not known whether giving patients more intensive chemotherapy regimens (judged according to some measure eg dose, dose intensity, response rate, or toxicity) results in better health outcomes. One way to investigate the effect of more versus less-intensive chemotherapy is to compare regimens containing a single drug (and hence possibly less active treatment) with regimens containing a greater number of drugs (and hence possibly more active but more toxic), even when adjustments are made to dosages or schedules to account for toxicity.

OBJECTIVES

To compare use of single chemotherapy agents with regimens containing a combination of agents for the treatment of metastatic breast cancer.

SEARCH STRATEGY

The Specialised Register maintained by the Editorial Base of the Cochrane Breast Cancer Group was searched on 2nd May 2003 using the codes for "advanced breast cancer", "chemotherapy". Details of the search strategy applied by the group to create the register, and the procedure used to code references, are described in the group's module on The Cochrane Library.

SELECTION CRITERIA

Randomised trials comparing single agent chemotherapy with combination therapy in women with metastatic breast cancer.

DATA COLLECTION AND ANALYSIS

Data were collected from published trials. Studies were assessed for eligibility and quality, and data were extracted by two independent reviewers. Hazard ratios were derived for time-to-event outcomes where possible, and a fixed effect model was used for meta-analysis. Response rates were analysed as dichotomous variables. Toxicity and quality of life data were extracted where present.

MAIN RESULTS

Thirty seven eligible trials were identified of which 28 had published time-to-event data. The quality of randomisation was generally not described. Data, based on an estimated 4220 deaths in 5707 women, show a modest advantage for combination chemotherapy regimens compared with single agents with a hazard ratio (HR) for overall survival of 0.88 (95% CI=0.83-0.94, P<0.0001) and no evident heterogeneity. Results are similar if the analysis is limited to trials in women receiving first-line chemotherapy. Combination regimens are favourably associated with time to progression (overall HR of 0.78 (95% CI=0.73-0.83, P<0.00001) and tumour response rates (OR 1.28, CI=1.15-1.42, P<0.00001) although significant heterogeneity was observed (P=0.002 and P<0.00001 respectively). This probably reflects the varying efficacy of the comparator regimens used in the trials. Women receiving combination regimens experienced a higher toxicity level for leukopenia, hair loss and nausea and vomiting compared with those receiving a single agent, which was statistically significant.

AUTHORS' CONCLUSIONS

Compared with single-chemotherapy agents, combination regimens show a statistically significant advantage for tumor response and time to progression in women with metastatic breast cancer, a modest improvement in overall survival and significantly worse toxicities.

Strategies for increasing women participation in community breast cancer screening

BACKGROUND

Strategies for reducing breast cancer mortality in western countries have focused on screening, at least for women aged 50 to 69 years. One of the requirements of any community screening program is to achieve a high participation rate, which is related to methods of invitation. Therefore, it was decided to systematically review the scientific evidence on the different strategies aimed at improving women's participation in breast cancer screening programs and activities.

OBJECTIVES

To assess the effectiveness of different strategies for increasing the participation rate of women invited to community (population-based) breast cancer screening activities or mammography programs.

SEARCH STRATEGY

MEDLINE (1966-2000), CENTRAL (2000), and EMBASE (1998-1999) searches for 1966 to 1999 were supplemented by reports and letters to the European Screening Breast Cancer Programs (Euref Network).

SELECTION CRITERIA

Both published and unpublished trials were eligible for inclusion, provided the women had been invited to a community breast screening activity or program and had been randomised to an intervention group or a control group with no active intervention.

DATA COLLECTION AND ANALYSIS

We identified 151 articles, which were reviewed independently by two people. The discrepancies were resolved by a third reviewer in order to reach consensus. Thirty-four studies were excluded because they lacked a control group; 58 of the other 117 articles were considered as opportunistic and not community-based; 59 articles, which reported 70 community-based randomised controlled trials or clinical controlled trials, were accepted. In 24 of these, the control group had not been exposed to any active intervention, but 8 of the 24 had to be excluded because the denominator for estimating attendance was unknown. At the end, 16 studies constituted the material for this review, although two studies were further excluded because their groups were not comparable at baseline. Data from all but one study were based on or converted to an intention-to-treat analysis. Attendance in response to the mammogram invitation was the main outcome measure.

MAIN RESULTS

The evidence favoured five active strategies for inviting women into community breast cancer screening services: letter of invitation (OR 1.66, 95% CI 1.43 to 1.92), mailed educational material (OR 2.81, 95% CI 1.96 to 4.02), letter of invitation plus phone call (OR 2.53, 95% CI 2.02 to 3.18), phone call (OR 1.94, 95% CI 1.70 to 2.23), and training activities plus direct reminders for the women (OR 2.46, 95% CI 1.72 to 3.50). Home visits did not prove to be effective (OR 1.06, 95 % CI 0.80 to 1.40) and letters of invitation to multiple examinations plus educational material favoured the control group (OR 0.62, 95 % CI 0.32 to 1.20).

REVIEWER'S CONCLUSIONS

Most active recruitment strategies for breast cancer screening programs examined in this review were more effective than no intervention. Combinations of effective interventions can have an important effect. Some costly strategies, as a home visit and a letter of invitation to multiple screening examinations plus educational material, were not effective. Further reviews comparing the effective interventions and studies that include cost-effectiveness, women's satisfaction and equity issues are needed.

[Adenocarcinoma of the ceruminous glands: report of three cases]

We report three cases of ceruminoma seen in our department over a 1-year period and review the neoplasms of the ceruminous glands. According to the Welti classification, our three cases were ceruminous adenocarcinomas. Based on existing literature, ceruminous adenocarcinoma is the least frequent neoplasm of the ceruminous glands.

[An epidemic outbreak of measles in a rural area]

OBJECTIVE

Analysis of an outbreak of measles among a partially vaccinated school population: the epidemiology, the effectiveness of the control measures and the efficacy of the vaccine (EV).

DESIGN

A descriptive study and cohorts study.

SETTING

Primary Care in the borough of Sant Andreu de la Barca.

PATIENTS AND OTHERS PARTICIPANTS

The school population of Sant Andreu de la Barca.

MEASUREMENTS AND MAIN RESULTS

The outbreak lasted three months and twenty days, with 95 cases overall. The most affected age group was form 4 to 10. 8.4% presented complications. Children were infected at school in 87% of the cases. The overall infection rate of the population between 0 and 15 was 2.4%. 36% of the cases had been correctly immunized and 43% were preventable cases. Vaccine coverage contacts was 67%. 84% of the susceptible contacts were vaccinated. Immunization status and immunization age of 323 out of 500 pupils was studied for the EX analysis. Global EV was 66% (42-80), 58% (13-80) for those immunized, between 12-14 month of age and 71% (43-85) for those immunized after the 15 month of age.

CONCLUSIONS

In order to eradicate the autoctonous measles an increase in immunization coverage, an improvement in the epidemiologic surveillance, and in the outbreak control measures are needed.

[The optimization of the data base of a voluntary health care cooperative for the study of postoperative morbidity in benign prostatic hypertrophy]

BACKGROUND

Investigation in health care services by data bases (DB) is undergoing an important increase in numerous countries. Several of the most relevant epidemiologic studies on the postsurgical morbidity and mortality of benign hypertrophy of the prostate (BHP) have used DB. The aim of this study was to prepare and optimize the DB of a health cooperative (Asistencia Sanitaria Colegial).

METHODS

Since 1981 the DB contains sociodemographic variables, data concerning visits to general practitioners and specialists, complementary examinations and hospitalizations. The coding system was specifically developed by the cooperative. The study base was made up of all the policies of the members between January 1981 and December 1988 (101,400 males). To identify the policies 14 codes potentially related with BHP were initially chosen and all the policies containing any of these codes were selected, with the manual analysis of 204 policies being thereby performed.

RESULTS

The total number of policies initially selected for the study was 3,157. Manual revision discarded the use of 9 of the 14 codes used in the first selection. In agreement with the 5 codes able to define diseases of prostatic gland and to the file in which they appeared the policies were classified as probable diseases of prostatic gland (n = 1,007, 31.9%), possible (n = 805, 25.5%) and improbable (n = 1,345, 42.5%). Likewise, the strategy to follow for the selection of a cohort of BHP cases was defined.

CONCLUSIONS

The manual analysis of policies evidenced a remarkable coherence and exhaustiveness of the information registered. The principal difficulties found with the data base used were the lack of a sole diagnosis and the coding system used in addition to the impossibility of automatically controlling the assistance received by the patients outside the cooperative system. The availability of a data base such as that herein described with a well defined large population and with accessible sociodemographic and health care information justifies collaborative efforts among health care administrators, clinicians, computer scientists and epidemiologists.

Chemical modification studies of beef-heart mitochondrial b-c1 complex. Effect of modification by ethoxyformic anhydride

The effect of the histidine-modifier ethoxyformic anhydride (EFA) on the enzymatic properties of the mitochondrial b-c1 complex (ubiquinol-cytochrome c reductase) has been investigated. Chemical modification by EFA inhibited to the same extent the reductase and the proton translocating activity of the complex. In particular EFA modification of the complex resulted in: strong inhibition of the antimycin-insensitive reduction of b cytochromes; inhibition of the antimycin-promoted oxidant-induced reduction of b cytochromes and inhibition of oxidation of pre-reduced b cytochromes. Analysis of the absorbance at 238 nm, indicative of N-(ethoxyformyl)histidine derivative, of the various polypeptide subunits separated by high-pressure liquid chromatography procedure, showed that EFA modified residues in core proteins and in the low-molecular-mass proteins. Both the inhibition of the redox and the protonmotive activity of the complex and the absorbance increase at 238 nm of the core protein fraction were readily reversed by hydroxylamine, indicating that modification of histidine residue(s) in core protein(s) is critical for the activity of the complex. This was supported by the finding that modification of the reductase with EFA prevented binding of fluorescein isothiocyanate to histidine residue(s) in core protein II. EFA modification of the reductase was without effect on the binding of N-(7-dimethylamino-4-methylcoumarinyl)maleimide to the various polypeptides of the complex except for the binding to the Fe-S protein which was greatly potentiated. Thus primary chemical modification of histidine residue(s) in core protein (II) appears to cause, in turn, a conformational change in the Rieske Fe-S protein.