Baseline PET radiomics outperforms the IPI risk score for prediction of outcome in diffuse large B-cell lymphoma

The objective of this study is to externally validate the clinical positron emission tomography (PET) model developed in the HOVON-84 trial and to compare the model performance of our clinical PET model using the international prognostic index (IPI). In total, 1195 patients with diffuse large B-cell lymphoma (DLBCL) were included in the study. Data of 887 patients from 6 studies were used as external validation data sets. The primary outcomes were 2-year progression-free survival (PFS) and 2-year time to progression (TTP). The metabolic tumor volume (MTV), maximum distance between the largest lesion and another lesion (Dmaxbulk), and peak standardized uptake value (SUVpeak) were extracted. The predictive values of the IPI and clinical PET model (MTV, Dmaxbulk, SUVpeak, performance status, and age) were tested. Model performance was assessed using the area under the curve (AUC), and diagnostic performance, using the positive predictive value (PPV). The IPI yielded an AUC of 0.62. The clinical PET model yielded a significantly higher AUC of 0.71 (P < .001). Patients with high-risk IPI had a 2-year PFS of 61.4% vs 51.9% for those with high-risk clinical PET, with an increase in PPV from 35.5% to 49.1%, respectively. A total of 66.4% of patients with high-risk IPI were free from progression or relapse vs 55.5% of patients with high-risk clinical PET scores, with an increased PPV from 33.7% to 44.6%, respectively. The clinical PET model remained predictive of outcome in 6 independent first-line DLBCL studies, and had higher model performance than the currently used IPI in all studies.

Cost-Effectiveness of Shortening Treatment Duration Based on Interim PET Outcome in Patients With Diffuse Large B-cell Lymphoma

BACKGROUND

Guideline recommendations for diffuse large-B-cell lymphoma (DLBCL) treatment are shifting from long to short treatment duration, although it is still unclear whether shortening treatment duration does not cause any harm. As interim PET (I-PET) has high negative predictive value for progression, we evaluated the cost-effectiveness of shortening treatment duration dependent on I-PET result.

MATERIALS AND METHODS

We developed a Markov cohort model using the PET Re-Analysis (PETRA) database to evaluate a long treatment duration (LTD) strategy, ie 8x R-CHOP or 6x R-CHOP plus 2 R, and a short treatment duration (STD) strategy, ie 6x R-CHOP. Strategies were evaluated separately in I-PET2 positive and I-PET2 negative patients. Outcomes included total costs and quality-adjusted life-years (QALYs) per patient (pp) from a societal perspective. Net monetary benefit (NMB) per strategy was calculated using a willingness-to-pay threshold of €50,000/QALY. Robustness of model predictions was assessed in sensitivity analyses.

RESULTS

In I-PET2 positive patients, shortening treatment duration led to 50.4 additional deaths per 1000 patients. The STD strategy was less effective (-0.161 [95%CI: -0.343;0.028] QALYs pp) and less costly (-€2768 [95%CI: -€8420;€1105] pp). Shortening treatment duration was not cost-effective (incremental NMB -€5281). In I-PET2 negative patients, shortening treatment duration led to 5.0 additional deaths per 1000 patients and a minor difference in effectiveness (-0.007 [95%CI: -0.136;0.140] QALY pp). The STD strategy was less costly (-€5807 [95%CI: -€10,724;-€2685] pp) and led to an incremental NMB of €5449, indicating that it is cost-effective to shorten treatment duration. Robustness of these findings was underpinned by deterministic and probabilistic sensitivity analyses.

CONCLUSION

Treatment duration should not be shortened in I-PET2 positive patients whereas it is cost-effective to shorten treatment duration in I-PET2 negative patients.

Towards a qAOP framework for predictive toxicology - Linking data to decisions

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Chemical toxicity assessment depends on the quantification of kinetics and dynamics.

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Quantitative AOPs (qAOPs) are toxicodynamic models based on Adverse Outcome Pathways.

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Existing e-resources could form the basis of an e-infrastructure for qAOP modelling.

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Best practices for qAOP development, assessment and application are needed.

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Three qAOP case studies are presented to illustrate a modelling workflow.

The adverse outcome pathway (AOP) is a conceptual construct that facilitates organisation and interpretation of mechanistic data representing multiple biological levels and deriving from a range of methodological approaches including in silico, in vitro and in vivo assays. AOPs are playing an increasingly important role in the chemical safety assessment paradigm and quantification of AOPs is an important step towards a more reliable prediction of chemically induced adverse effects. Modelling methodologies require the identification, extraction and use of reliable data and information to support the inclusion of quantitative considerations in AOP development. An extensive and growing range of digital resources are available to support the modelling of quantitative AOPs, providing a wide range of information, but also requiring guidance for their practical application. A framework for qAOP development is proposed based on feedback from a group of experts and three qAOP case studies. The proposed framework provides a harmonised approach for both regulators and scientists working in this area.

In Silico Approaches In Carcinogenicity Hazard Assessment: Current Status and Future Needs

Historically, identifying carcinogens has relied primarily on tumor studies in rodents, which require enormous resources in both money and time. In silico models have been developed for predicting rodent carcinogens but have not yet found general regulatory acceptance, in part due to the lack of a generally accepted protocol for performing such an assessment as well as limitations in predictive performance and scope. There remains a need for additional, improved in silico carcinogenicity models, especially ones that are more human-relevant, for use in research and regulatory decision-making. As part of an international effort to develop in silico toxicological protocols, a consortium of toxicologists, computational scientists, and regulatory scientists across several industries and governmental agencies evaluated the extent to which in silico models exist for each of the recently defined 10 key characteristics (KCs) of carcinogens. This position paper summarizes the current status of in silico tools for the assessment of each KC and identifies the data gaps that need to be addressed before a comprehensive in silico carcinogenicity protocol can be developed for regulatory use.

EFSA's OpenFoodTox: An open source toxicological database on chemicals in food and feed and its future developments

Since its creation in 2002, the European Food Safety Authority (EFSA) has produced risk assessments for over 5000 substances in >2000 Scientific Opinions, Statements and Conclusions through the work of its Scientific Panels, Units and Scientific Committee. OpenFoodTox is an open source toxicological database, available both for download and data visualisation which provides data for all substances evaluated by EFSA including substance characterisation, links to EFSA's outputs, applicable legislations regulations, and a summary of hazard identification and hazard characterisation data for human health, animal health and ecological assessments. The database has been structured using OECD harmonised templates for reporting chemical test summaries (OHTs) to facilitate data sharing with stakeholders with an interest in chemical risk assessment, such as sister agencies, international scientific advisory bodies, and others. This manuscript provides a description of OpenFoodTox including data model, content and tools to download and search the database. Examples of applications of OpenFoodTox in chemical risk assessment are discussed including new quantitative structure-activity relationship (QSAR) models, integration into tools (OECD QSAR Toolbox and AMBIT-2.0), assessment of environmental footprints and testing of threshold of toxicological concern (TTC) values for food related compounds. Finally, future developments for OpenFoodTox 2.0 include the integration of new properties, such as physico-chemical properties, exposure data, toxicokinetic information; and the future integration within in silico modelling platforms such as QSAR models and physiologically-based kinetic models. Such structured in vivo, in vitro and in silico hazard data provide different lines of evidence which can be assembled, weighed and integrated using harmonised Weight of Evidence approaches to support the use of New Approach Methodologies (NAMs) in chemical risk assessment and the reduction of animal testing.

FNA indication according to ACR-TIRADS, EU-TIRADS and K-TIRADS in thyroid incidentalomas at 18F-FDG PET/CT

OBJECTIVE

Focal thyroid incidentaloma (TI) occurs in a 2% of ¹⁸F-FDG PET/CT and about one-third of TIs is cancer. Due to the lack of evidence on the optimal management of TI, current guidelines suggest performing fine-needle aspiration cytology (FNA). The study aim was to evaluate the reliability of ACR-TIRADS, EU-TIRADS, and K-TIRADS in indicating FNA in TIs.

DESIGN

We retrospectively reviewed ¹⁸F-FDG PET/CT TIs recorded during the period 2016-2019. Enrolled were TIs with histologic outcome and autonomous nodules. Cases with uncertain matching between ¹⁸F-FDG PET/CT, US/scintiscan and histology were excluded.

RESULTS

Eighty TIs at ¹⁸F-FDG PET/CT (median size 17 mm, median SUVmax 7.85) were included; a 26.2% was cancer. The percentage of nodules classified as high risk according to ACR-TIRADS, EU-TIRADS, and K-TIRADS was 20%, 30%, and 29.8%, respectively. The cancer prevalence in high-risk class was 56.2%, 66.7%, and 65.2% in ACR-TIRADS, EU-TIRADS, and K-TIRADS, respectively. ACR-TIRADS had the lowest number of cases with FNA indication (48%) and the K-TIRADS, the highest one (75%). Evaluating the reliability of the three systems in indicating FNA, we found a 100% sensitivity and NPV for EU-TIRADS and K-TIRADS; while all the three systems showed poor specificity and PPV.

CONCLUSION

All TIRADSs were reliable to stratify the risk of cancer in focal TI. Comparing their reliability in indicating FNA, we found a good performance of EU-TIRADS and K-TIRADS. Considering the high cancer percentage expected in this setting of patients, those TIRADS with higher propensity to indicate FNA should be preferred.

Filling Data Gaps by Read-across: A Mini Review on its Application, Developments and Challenges

Read-across is a non-testing data gap filling technique which provides information for toxicological assessments by inferring from known toxicity data of compound(s) with a "similar" property or chemical profile. The increased usage of read-across was driven by monetary, timing and ethical costs associated with in vivo testing, as well as promoted by regulatory frameworks to minimize new animal testing (e. g., EU-REACH). Several guidance documents have been published by ECHA and OECD providing guidelines on how to perform, assess and document a read-across study. In parallel, much effort was invested by the scientific community to provide good read-across practices and structured frameworks to enhance validity of read-across justifications. Nevertheless, read-across is an evolving method with several open issues and opportunities. A brief review is here provided on key developments on the use of read-across, regulatory and scientific expectations, practical hurdles and open challenges.

Immunoassay of Neuron-Specific Enolase (Nse) and Serum Fragments of Cytokeratin 19 (Cyfra 21.1) as Tumor Markers in Small Cell Lung Cancer: Clinical Evaluation and Biological Hypothesis

NSE is a biochemical marker for small cell lung cancer (SCLC) diagnosis and management. CYFRA 21.1 is a newly developed immunoassay to detect the serum fragments of cytokeratin 19 which are also expressed in SCLC with or without neurofilaments. The aim of this study was to evaluate the diagnostic performance and prognostic role of the two markers in SCLC and their contribution to chemotherapy monitoring and patient follow-up. We studied 62 patients with pathologically proven SCLC: 28 with limited disease (LD) and 34 with extensive disease (ED), and 100 patients with non-malignant pulmonary disease. Immunoradiometric assays (IRMA) were employed to test NSE and CYFRA 21.1 in patients and control subjects. For each patient subset results were expressed as median and interquartile distribution range. NSE and CYFRA 21.1 sensitivity was 0.52 (33/62) and 0.56 (35/62), respectively. In the group of patients with LD, NSE and CYFRA 21.1 sensitivity was 0.42 (12/28) and 0.54 (15/28) and in patients with ED, NSE and CYFRA 21.1 were positive in 0.62 (21/34) and 0.59 (20/34) of cases, respectively. Combining the two markers, a sensitivity of 0.78 (22/28) in LD, 0.82 (28/34) in ED and a global sensitivity of 0.80 (50/62) was obtained. Only NSE was significantly linked to the extension of disease (Mann-Whitney U test p = 0.002) while CYFRA 21.1 did not correlate. The analysis of survival and the evaluation of the two markers at diagnosis showed CYFRA 21.1 to be strongly linked to the patients’ outcome, independently of both clinical prognostic factors and NSE levels (log rank and Cox's model). The markers’ performance during chemotherapy was tested in a group of 33 patients with at least one marker above cut-off. NSE can be considered a reliable marker of tumor mass modifications under chemotherapy, while CYFRA 21.1 expression seems to be relatively independent of tumor volume modifications. An applicable model of biomarkers in SCLC could be the concurrent assay of NSE and CYFRA 21.1 in pre-therapeutic assessment and therapy planning. CYFRA 21.1 does not play an important role during therapy monitoring and follow-up; in these phases NSE alone may be employed.

Tissue Polypeptide-Specific Antigen (Tps) Immunoassay in the Diagnosis and Clinical Staging of Prostatic Carcinoma. Comparison with Prostate-Specific Antigen (Psa)

This experimental study investigated the potential role of Tissue Polypeptide-Specific Antigen (TPS) in comparison with Prostate-Specific Antigen (PSA) in the diagnosis and the clinical and pathological staging of prostate cancer. Serum TPS and PSA levels were determined in 128 patients (pts) with benign prostatic hypertrophy (BPH; Group 1) and in 92 pts with prostate cancer (Group 2). TPS was also measured in a control group of 100 healthy subjects. Normal cutoff values of 85 U/l for TPS and 4 ng/ml for PSA were determined on the basis of ROC curve analysis. The sensitivity, specificity and accuracy in the diagnosis of prostate cancer were 49%, 95% and 76% for TPS, and 84%, 90% and 87% for PSA. The combination of the two markers provided a higher accuracy (88%), improving the sensitivity of PSA, since 47% of patients with normal PSA had pathological levels of TPS. TPS showed an increase in sensitivity from low to higher stages of disease and, in patients with skeletal involvement, from small to larger numbers of bone metastases (Kruskal Wallis p < 0.0001). Nevertheless, TPS serum levels are not useful in the clinical staging of prostate cancer as they have a poorer performance than PSA. TPS was ineffective (ROC curve area=0.68) in predicting extraprostatic disease and demonstrated a reduced ability (area = 0.78) to identify skeletal involvement. Moreover, the combination of the two markers did not significantly improve the performance of PSA alone. The serum concentration of TPS in patients with localized tumors was not related to the degree of tumor cell differentiation evaluated by the Gleason score.

Conclusion

Our preliminary experience suggests that TPS in association with PSA may be useful at the time of diagnosis of prostate cancer. However, these preliminary data have to be confirmed by larger clinical trials and the role of this association in the clinical setting needs to be analyzed with an adequate evaluation of the cost-effectiveness ratio.

Evaluation of the serum markers CEA, NSE, TPS and CYFRA 21.1 in lung cancer

We investigated the role of tumor markers CEA, NSE, TPS and CYFRA 21.1 in lung cancer diagnosis and staging in 169 patients with histologically confirmed lung cancer (43 SCLC and 126 NSCLC). In SCLC patients NSE and CYFRA 21.1 showed the highest senstitivity and their combination improve significantly the diagnostic sensitivity and accuracy. In NSCLC patients CYFRA 21.1 showed the highest sensitivity and global accuracy and no markers association was as effective as CYFRA 21.1 alone. Based on data from our study it can be concluded that in patients with suspected lung cancer the serum NSE and CYFRA 21.1 assay is a suitable association to confirm the clinical hypothesis. NSE in SCLC and CYFRA 21.1 in NSCLC are useful in the evaluation of disease extent and successive treatment planning.

Evaluation of Chromogranin a Expression in Serum and Tissues of Breast Cancer Patients

Human chromogranin A (CgA) is a member of the granin family and is widely distributed in large dense core granules of endocrine and neuroendocrine cells. A variety of non-neuroendocrine carcinomas arising in various tissues show patterns of neuroendocrine differentiation. Expression of CgA has been documented in epithelial cells of normal mammary gland as well as in breast cancers, and elevation of serum CgA has been detected in patients with breast cancer. Our study was undertaken to evaluate the relationship between serum CgA levels and neuroendocrine features in breast cancer. In addition, we evaluated the expression of serum CgA in patients affected by breast cancer compared to controls and the relationship between serum CgA and tumor histology, extent of disease, lymph node status, tumor stage and serum CA 15.3 levels. We enrolled 266 patients with infiltrating ductal or lobular breast carcinoma and a group of 100 age-matched healthy women serving as controls. Serum CgA and CA 15.3 were assayed by specific immunoradiometric methods. The overall sensitivity of CgA and CA 15.3 was 0.06 and 0.34, respectively (χ219.1, p<0.0005). No relationship was found between serum levels of CgA and tumor histology, extent of disease, lymph node status or tumor stage while serum levels of CA 15.3 were strongly correlated with all these variables but tumor histology. No relationship was found between serum levels of CgA and CA 15.3. Immunostaining against CgA, CgB, NSE and synaptophysin was performed on primary tumor tissue of 14 serum CgA-positive and 24 serum CgA-negative patients and was negative in all cases. We also evaluated eight cases of pathologically-proven neuroendocrine breast cancer: only four and two of these showed positive CgA immunostaining and increased serum CgA concentration, respectively. In conclusion, serum CgA assay offers no additional information regarding the presence, the extent and the histology of breast cancer compared to the CA 15.3 assay. Moreover, serum CgA was not an accurate marker to identify or exclude the rare neuroendocrine differentiation of breast cancer. We therefore conclude that CgA is not useful as a serum marker in breast cancer.

Immunoradiometric Assay of Chromogranin a in the Diagnosis of Small Cell Lung Cancer: Comparative Evaluation with Neuron-Specific Enolase

The aims of our work were 1) to determine the diagnostic performance of an immunoradiometric assay of chromogranin A (CgA) in smal cell lung cancer and 2) to compare its discriminatory power with that of neuron-specific enolase (NSE), the marker currently used for SCLC. We selected 166 cases of small cell (64) and non-small cell (102) lung cancer and 106 cases of non-malignant lung diseases as controls. Both CgA and NSE were assayed by immunoradiometric methods and cutoff values were established on the basis of a pre-fixed specificity of 95% in non-malignant lung diseases. The CgA assay showed better diagnostic sensitivity than NSE in SCLC (61% versus 57%), especially in limited disease, and a low positivity rate in NSCLC with respect to NSE (14% versus 22%). By contrast, NSE reflected disease extent more accurately than CgA (U test: CgA p<0.05, NSE p<0.001). Finally, we found that the CgA assay was not affected by hemolysis whereas NSE serum levels greatly increased in hemolyzed sera. In conclusion, CgA assaying by an IRMA method is a reliable procedure in the diagnosis of SCLC. NSE remains the marker of choice in staging and monitoring of the disease. Further studies are needed to evaluate the prognostic significance of the marker and its role in therapy monitoring and patient follow-up.

Chromogranin-A as a Serum Marker for Neuroendocrine Tumors: Comparison with Neuron-Specific Enolase and Correlation with Immunohistochemical Findings

Background

Chromogranin-A (Cg-A) is a 439-amino-acid protein contained in secretory granules of neuroendocrine cells, in addition to specific hormone peptides or neuropeptides. Since Cg-A is co-released with peptide hormones its serum concentration can be used as a marker of neuroendocrine tumors.

Aim

Evaluation of the analytical performance of a new IRMA method for Cg-A assay and of the clinical value of serum Cg-A and neuron-specific enolase (NSE) in neuroendocrine tumors. In addition, we compared the diagnostic usefulness of both Cg-A and NSE serum levels and their relationship to tissue expression.

Patients and methods

Initially we evaluated the analytical performance (intra- and interassay imprecision, dilution test and detection limit) of the Cg-A RIACT method (CIS Bio-International, Gifsur-Yvette, France). We selected 50 patients affected by various histologically confirmed neuroendocrine tumors (NETs): 111In-pentetreotide scan and helical computed tomography were employed to assess tumor extent. Cg-A and NSE were measured before surgery in serum samples of patients and 50 age-matched controls by IRMA methods. After surgery immunohistochemical stains for Cg-A and NSE were performed on surgical specimens of tumor tissue.

Results

Cg-A levels were significantly higher (p<0.0001) in patients with NETs than in healthy controls and we found a positive correlation between serum and tissue expression (p<0.05). Serum levels of Cg-A were also related to tumor extent (p<0.05) but in some cases we observed significant elevation of serum Cg-A in small, intensely immunoreactive NETs. ROC curve analysis showed better accuracy for serum Cg-A compared to NSE in the diagnosis of NETs, while no significant relationship was found between serum expression and immunostaining for NSE.

Discussion

Our results confirmed the biological and clinical significance of circulating Cg-A as an expression of granular content in neuroendocrine tissues and supported the complementary usefulness of serum Cg-A in the diagnosis and evaluation of NETs together with imaging modalities.

Serum Calcitonin-Negative Medullary Thyroid Carcinoma: Role of CgA and CEA as Complementary Markers

The biochemical activity of medullary thyroid carcinoma (MTC) includes production of calcitonin (CT), chromogranin A (CgA) and carcinoembryonic antigen (CEA). Routine CT measurement has been proposed as part of the initial evaluation of thyroid nodules and its use could ultimately decrease the morbidity and mortality of MTC. We report on a 43-year-old female patient with a large MTC expressing CT, CgA and CEA on immunostains but with negative preoperative CT and CgA results. Serum CEA was slightly increased and its rapid disappearance predicted radical cure by surgery as confirmed by 2-year follow-up. Our report illustrates that a diagnosis of MTC cannot always be excluded by negative preoperative CT. Fine-needle aspiration with cytomorphological analysis and complementary immunocytochemistry remains an essential diagnostic tool. Finally, serum aliquots must be stored before thyroid surgery in order to measure circulating forms of complementary markers found by tissue immunostaining (CEA and CgA)

Focal thyroid incidental uptake detected by 18F-fluorodeoxyglucose positron emission tomography

Aim: To perform a meta-analysis of published data on the prevalence and risk of malignancy of focal thyroid incidental uptake (FTIs) detected by Fluorine-18-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) or PET/CT. Methods: A comprehensive literature search of studies published up to and including December 2012 was performed. Pooled prevalence and malignancy risk of FTIs were calculated, including a sub-analysis for the geographic areas of origin of the studies. Results: 34 studies including 215 057 patients were selected. Pooled prevalence of FTIs was 1.92% (95% confidence interval [95%CI]: 1.87–1.99%). Overall, 1522 FTIs underwent histopathology evaluation. Pooled risk of malignancy was 36.2% (95%CI: 33.8–38.6%), without significant differences among various geographic areas. Conclusions: FTIs are observed in about 2% of 18F-FDG-PET or PET/CT scans and carry a significant risk of malignancy. Therefore, further investigation is warranted whenever FTIs are detected by 18F-FDG-PET or PET/CT.

High-sensitive basal serum thyroglobulin 6-12 months after thyroid ablation is strongly associated with early response to therapy and event-free survival in patients with low-to-intermediate risk differentiated thyroid carcinomas

OBJECTIVE

High-sensitive thyroglobulin assays (hsTg) has decreased the need for stimulated Tg measurements in patients with differentiated thyroid carcinoma (DTC). However, multiple assays analyzing the same samples may report different values. Accordingly, appropriate assay-specific cut-off levels should be selected in representative patient series. Here, we evaluate the role of a new hsTg assay in low-to-intermediate risk DTC patients and select appropriate assay-specific clinical cut-off limits.

DESIGN

This was a retrospective study. The response to treatment was assessed according to ATA.

METHODS

Patients with low-to-intermediate risk DTC treated and regularly followed-up in our thyroid center. Tg was measured on the Kryptor Compact Plus Instrument (BRAHMS Thermo Fisher Scientific).

RESULTS

The study series comprised 201 DTC patients and excellent response (ER) was demonstrated in 184 (91.5%). Optimized threshold of basal Tg (onT4-Tg) measured 6-12 months after initial treatment was set by ROC curves analysis at 0.28 ng/mL. Having onT4-Tg <0.28 ng/mL at 6-12 months after treatment was associated with longer disease-free survival of Kaplan-Meier (P < 0.001), ER at early follow-up (odds ratio (OR): 165, P < 0.001) and absence of relapse during follow-up (OR: 328, P = 0.0001).

CONCLUSIONS

Patients with low- and intermediate-risk DTC could be considered cured when they have onT4-Tg levels <0.28 ng/mL coupled with negative imaging at their first post-ablation visit.

Modeling ready biodegradability of fragrance materials

In the present study, quantitative structure activity relationships were developed for predicting ready biodegradability of approximately 200 heterogeneous fragrance materials. Two classification methods, classification and regression tree (CART) and k-nearest neighbors (kNN), were applied to perform the modeling. The models were validated with multiple external prediction sets, and the structural applicability domain was verified by the leverage approach. The best models had good sensitivity (internal ≥80%; external ≥68%), specificity (internal ≥80%; external 73%), and overall accuracy (≥75%). Results from the comparison with BIOWIN global models, based on group contribution method, show that specific models developed in the present study perform better in prediction than BIOWIN6, in particular for the correct classification of not readily biodegradable fragrance materials.