Biochemical control in intermediate- and high-risk prostate cancer after EBRT with and without brachytherapy boost.

PURPOSE: External beam radiotherapy (EBRT) with or without brachytherapy boost (BTB) has not been compared in prospective studies using guideline-recommended radiation dose and recommended androgen-deprivation therapy (ADT). In this multicenter retrospective analysis, we compared modern-day EBRT with BTB in terms of biochemical control (BC) for intermediate-risk (IR) and high-risk (HR) prostate cancer. METHODS: Patients were treated for primary IR or HR prostate cancer during 1999-2019 at three high-volume centers. Inclusion criteria were prescribed ≥ 76 Gy EQD2 (α/ß = 1.5 Gy) for IR and ≥ 78 Gy EQD2 (α/ß = 1.5 Gy) for HR as EBRT alone or with BTB. All HR patients received ADT and pelvic irradiation, which were optional in IR cases. BC between therapies was compared in survival analyses. RESULTS: Of 2769 initial patients, 1176 met inclusion criteria: 468 HR (260 EBRT, 208 BTB) and 708 IR (539 EBRT, 169 BTB). Median follow-up was 49 and 51 months for HR and IR, respectively. BTB patients with ≥ 113 Gy EQD2Gy experienced a stable, good BC outcome compared with BTB at lower doses. Patients treated with ≥ 113 Gy EQD2Gy also experienced significantly improved BC compared with EBRT (10-year BC failure rates after ≥ 113 Gy BTB and EBRT: respectively 20.4 and 41.8% for HR and 7.5 and 20.8% for IR). CONCLUSIONS: In patients with IR and HR prostate cancer, BTB with ≥ 113 Gy EQD2Gy offered a BC advantage compared with dose-escalated EBRT and lower BTB doses.

Prognosis of patients with hepatocellular carcinoma treated with immunotherapy - development and validation of the CRAFITY score.

BACKGROUND & AIMS: Immunotherapy with atezolizumab plus bevacizumab represents the new standard of care in systemic front-line treatment of hepatocellular carcinoma (HCC). However, biomarkers that predict treatment success and survival remain an unmet need. METHODS: Patients with HCC put on PD-(L)1-based immunotherapy were included in a training set (n = 190; 6 European centers) and a validation set (n = 102; 8 European centers). We investigated the prognostic value of baseline variables on overall survival using a Cox model in the training set and developed the easily applicable CRAFITY (CRP and AFP in ImmunoTherapY) score. The score was validated in the independent, external cohort, and evaluated in a cohort of patients treated with sorafenib (n = 204). RESULTS: Baseline serum alpha-fetoprotein ≥100 ng/ml (hazard ratio [HR] 1.7; p = 0.007) and C-reactive protein ≥1 mg/dl (HR, 1.7; p = 0.007) were identified as independent prognostic factors in multivariable analysis and were used to develop the CRAFITY score. Patients who fulfilled no criterion (0 points; CRAFITY-low) had the longest median overall survival (27.6 (95% CI 19.5-35.8) months), followed by those fulfilling 1 criterion (1 point; CRAFITY-intermediate; 11.3 (95% CI 8.0-14.6) months), and patients meeting both criteria (2 points; CRAFITY-high; 6.4 (95% CI 4.8-8.1) months; p <0.001). Additionally, best radiological response (complete response/partial response/stable disease/progressive disease) was significantly better in patients with lower CRAFITY score (CRAFITY-low: 9%/20%/52%/20% vs. CRAFITY-intermediate: 3%/25%/36%/36% vs. CRAFITY-high: 2%/15%/22%/61%; p = 0.003). These results were confirmed in the independent validation set and in different subgroups, including Child-Pugh A and B, performance status 0 and ≥1, and first-line and later lines. In the sorafenib cohort, CRAFITY was associated with survival, but not radiological response. CONCLUSIONS: The CRAFITY score is associated with survival and radiological response in patients receiving PD-(L)1 immunotherapy. The score may help with patient counseling but requires prospective validation. LAY SUMMARY: The immunotherapy-based regimen of atezolizumab plus bevacizumab represents the new standard of care in systemic first-line therapy of hepatocellular carcinoma (HCC). Biomarkers to predict treatment outcome are an unmet need in patients undergoing immunotherapy for HCC. We developed and externally validated a score that predicts outcome in patients with HCC undergoing immunotherapy with immune checkpoint blockers.

Assessing the effect of a partly unobserved, exogenous, binary time-dependent covariate on survival probabilities using generalised pseudo-values.

BACKGROUND: Investigating the impact of a time-dependent intervention on the probability of long-term survival is statistically challenging. A typical example is stem-cell transplantation performed after successful donor identification from registered donors. Here, a suggested simple analysis based on the exogenous donor availability status according to registered donors would allow the estimation and comparison of survival probabilities. As donor search is usually ceased after a patient's event, donor availability status is incompletely observed, so that this simple comparison is not possible and the waiting time to donor identification needs to be addressed in the analysis to avoid bias. It is methodologically unclear, how to directly address cumulative long-term treatment effects without relying on proportional hazards while avoiding waiting time bias. METHODS: The pseudo-value regression technique is able to handle the first two issues; a novel generalisation of this technique also avoids waiting time bias. Inverse-probability-of-censoring weighting is used to account for the partly unobserved exogenous covariate donor availability. RESULTS: Simulation studies demonstrate unbiasedness and satisfying coverage probabilities of the new method. A real data example demonstrates that study results based on generalised pseudo-values have a clear medical interpretation which supports the clinical decision making process. CONCLUSIONS: The proposed generalisation of the pseudo-value regression technique enables to compare survival probabilities between two independent groups where group membership becomes known over time and remains partly unknown. Hence, cumulative long-term treatment effects are directly addressed without relying on proportional hazards while avoiding waiting time bias.

Clinical Neuropathology practice guide 5-2015: MGMT methylation pyrosequencing in glioblastoma: unresolved issues and open questions.

O6-methylguanine-methyltransferase (MGMT) promoter methylation status has prognostic and, in the subpopulation of elderly patients, predictive value in newly diagnosed glioblastoma. Therefore, knowledge of the MGMT promoter methylation status is important for clinical decision-making. So far, MGMT testing has been limited by the lack of a robust test with sufficiently high analytical performance. Recently, one of several available pyrosequencing protocols has been shown to be an accurate and robust method for MGMT testing in an intra- and interlaboratory ring trial. However, some uncertainties remain with regard to methodological issues, cut-off definitions, and optimal use in the clinical setting. In this article, we highlight and discuss several of these open questions. The main unresolved issues are the definition of the most relevant CpG sites to analyze for clinical purposes and the determination of a cut-off value for dichotomization of quantitative MGMT pyrosequencing results into "MGMT methylated" and "MGMT unmethylated" patient subgroups as a basis for further treatment decisions.

The ART-strategy: sequential assessment of the ART score predicts outcome of patients with hepatocellular carcinoma re-treated with TACE.

BACKGROUND & AIMS: Recently, we developed the ART score (assessment for re-treatment with TACE) to guide the decision for a second transarterial chemoembolization (TACE-2) in patients with hepatocellular carcinoma (HCC). Patients with an ART score of 0-1.5 points gained benefit from a second TACE session, while patients with an ART score ≥2.5 points did not. Here, we investigated (1) the prognostic significance of the ART score prior to the third (TACE-3) and fourth TACE (TACE-4), and (2) the feasibility of an ART score guided re-treatment strategy by sequential assessment of the ART score in HCC patients treated with multiple TACE sessions. METHODS: 109 patients, diagnosed with intermediate stage HCC and treated with ≥3 TACE sessions between January 1999 and December 2009 at the Medical Universities of Vienna and Innsbruck, were included. The ART score prior to each TACE session was assessed in comparison to the TACE naïve liver. The prognostic performance of the ART score before TACE-3 and 4 was evaluated with and without stratification based on the ART score prior to the respective last intervention. RESULTS: The pre-TACE-3 ART score discriminated two groups with different prognosis and remained a valid predictor of OS independent of Child-Pugh score (5-7 points), CRP-levels and tumor characteristics. Even in patients with an initially beneficial ART score (0-1.5 points) before TACE-2, repeated ART score assessment before TACE-3 identified a subgroup of patients with dismal prognosis (median OS: 27.8 vs. 10.8 months, p<0.001). Similar results were observed when the ART score was applied before TACE-4. CONCLUSIONS: The sequential assessment of the ART score identifies patients with dismal prognosis prior to each TACE session.

How to STATE suitability and START transarterial chemoembolization in patients with intermediate stage hepatocellular carcinoma.

BACKGROUND & AIMS: We aimed to establish an objective point score to guide the decision for the first treatment with transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). METHODS: 277 patients diagnosed with HCC and treated with transarterial treatments between 1/2002 and 12/2011 at the Medical Universities of Vienna (training cohort) and Innsbruck (validation cohort) were included. We investigated the impact of baseline liver function and tumour load on overall survival (OS, log-rank test) and developed a point score (STATE-score: Selection for TrAnsarterial chemoembolisation TrEatment) in the training-cohort (n=131, Vienna) by using a stepwise Cox regression model. The STATE-score was externally validated in an independent validation cohort (n=146, Innsbruck) and thereafter combined with the Assessment for Retreatment with TACE (ART)-score to identify patients who are (un)suitable for TACE. RESULTS: The STATE-score starts with the serum-albumin level (g/L), which is reduced by 12 points each, if the tumour load exceeds the up-to-7 criteria and/or C-reactive protein (CRP) levels are ⩾1 mg/dl (maximum reduction: 24 points). The STATE-score differentiated 2 groups (<18, ⩾18 points) with distinct prognosis (median OS: 5.3 vs. 19.5 months; p<0.001) and a lower STATE-score was associated with short-term harm and increased mortality after TACE-1 (39% vs. 14% p<0.001). Sequential use of the STATE and the ART-score (START-strategy) identified the most (un)suitable patients for TACE. Results were confirmed in the external validation-cohort and were independent from recently proposed baseline selection tools. CONCLUSION: The STATE-score identifies patients who are (un)suitable for the first TACE. The START-strategy identified the best candidates for multiple TACE sessions.

Evidence-based detection of pulmonary arterial hypertension in systemic sclerosis: the DETECT study.

OBJECTIVE: Earlier detection of pulmonary arterial hypertension (PAH), a leading cause of death in systemic sclerosis (SSc), facilitates earlier treatment. The objective of this study was to develop the first evidence-based detection algorithm for PAH in SSc. METHODS: In this cross-sectional, international study conducted in 62 experienced centres from North America, Europe and Asia, adults with SSc at increased risk of PAH (SSc for >3 years and predicted pulmonary diffusing capacity for carbon monoxide <60%) underwent a broad panel of non-invasive assessments followed by diagnostic right heart catheterisation (RHC). Univariable and multivariable analyses selected the best discriminatory variables for identifying PAH. After assessment for clinical plausibility and feasibility, these were incorporated into a two-step, internally validated detection algorithm. Nomograms for clinical practice use were developed. RESULTS: Of 466 SSc patients at increased risk of PAH, 87 (19%) had RHC-confirmed PAH. PAH was mild (64% in WHO functional class I/II). Six simple assessments in Step 1 of the algorithm determined referral to echocardiography. In Step 2, the Step 1 prediction score and two echocardiographic variables determined referral to RHC. The DETECT algorithm recommended RHC in 62% of patients (referral rate) and missed 4% of PAH patients (false negatives). By comparison, applying European Society of Cardiology/European Respiratory Society guidelines to these patients, 29% of diagnoses were missed while requiring an RHC referral rate of 40%. CONCLUSIONS: The novel, evidence-based DETECT algorithm for PAH detection in SSc is a sensitive, non-invasive tool which minimises missed diagnoses, identifies milder disease and addresses resource usage.

The ART of decision making: retreatment with transarterial chemoembolization in patients with hepatocellular carcinoma.

UNLABELLED: We aimed to establish an objective point score to guide the decision for retreatment with transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). In all, 222 patients diagnosed with HCC and treated with multiple TACE cycles between January 1999 and December 2009 at the Departments of Gastroenterology/Hepatology of the Medical Universities of Vienna (training cohort) and Innsbruck (validation cohort) were included. We investigated the effect of the first TACE on parameters of liver function and tumor response and their impact on overall survival (OS, log rank test) and developed a point score (ART score: Assessment for Retreatment with TACE) in the training cohort (n = 107, Vienna) by using a stepwise Cox regression model. The ART score was externally validated in an independent validation cohort (n = 115, Innsbruck). The increase of aspartate aminotransferase (AST) by >25% (hazard ratio [HR] 8.4; P < 0.001), an increase of Child-Pugh score of 1 (HR 2.0) or ≥2 points (HR 4.4) (P < 0.001) from baseline, and the absence of radiologic tumor response (HR 1.7; P = 0.026) remained independent negative prognostic factors for OS and were used to create the ART score. The ART score differentiated two groups (0-1.5 points; ≥2.5 points) with distinct prognosis (median OS: 23.7 versus 6.6 months; P < 0.001) and a higher ART score was associated with major adverse events after the second TACE (P = 0.011). These results were confirmed in the external validation cohort and remained significant irrespective of Child-Pugh stage and the presence of ascites prior the second TACE. CONCLUSION: An ART score of ≥2.5 prior the second TACE identifies patients with a dismal prognosis who may not profit from further TACE sessions. (HEPATOLOGY 2013;57:2261-2273).

Methods for non-proportional hazards in clinical trials: A systematic review.

For the analysis of time-to-event data, frequently used methods such as the log-rank test or the Cox proportional hazards model are based on the proportional hazards assumption, which is often debatable. Although a wide range of parametric and non-parametric methods for non-proportional hazards has been proposed, there is no consensus on the best approaches. To close this gap, we conducted a systematic literature search to identify statistical methods and software appropriate under non-proportional hazard. Our literature search identified 907 abstracts, out of which we included 211 articles, mostly methodological ones. Review articles and applications were less frequently identified. The articles discuss effect measures, effect estimation and regression approaches, hypothesis tests, and sample size calculation approaches, which are often tailored to specific non-proportional hazard situations. Using a unified notation, we provide an overview of methods available. Furthermore, we derive some guidance from the identified articles.

Non-Alzheimer neurodegenerative pathologies and their combinations are more frequent than commonly believed in the elderly brain: a community-based autopsy series.

Neurodegenerative diseases are characterised by neuronal loss and cerebral deposition of proteins with altered physicochemical properties. The major proteins are amyloid-ß (Aß), tau, α-synuclein, and TDP-43. Although neuropathological studies on elderly individuals have emphasised the importance of mixed pathologies, there have been few observations on the full spectrum of proteinopathies in the ageing brain. During a community-based study we performed comprehensive mapping of neurodegeneration-related proteins and vascular pathology in the brains of 233 individuals (age at death 77-87; 73 examined clinically in detail). While all brains (from individuals with and without dementia) showed some degree of neurofibrillary degeneration, Aß deposits were observed only in 160 (68.7 %). Further pathologies included α-synucleinopathies (24.9 %), non-Alzheimer tauopathies (23.2 %; including novel forms), TDP-43 proteinopathy (13.3 %), vascular lesions (48.9 %), and others (15.1 %; inflammation, metabolic encephalopathy, and tumours). TDP-43 proteinopathy correlated with hippocampal sclerosis (p < 0.001) and Alzheimer-related pathology (CERAD score and Braak and Braak stages, p = 0.001). The presence of one specific variable (cerebral amyloid angiopathy, Aß parenchymal deposits, TDP-43 proteinopathy, α-synucleinopathy, vascular lesions, non-Alzheimer type tauopathy) did not increase the probability of the co-occurrence of others (p = 0.24). The number of observed pathologies correlated with AD-neuropathologic change (p < 0.0001). In addition to AD-neuropathologic change, tauopathies associated well with dementia, while TDP-43 pathology and α-synucleinopathy showed strong effects but lost significance when evaluated together with AD-neuropathologic change. Non-AD neurodegenerative pathologies and their combinations have been underestimated, but are frequent in reality as demonstrated here. This should be considered in diagnostic evaluation of biomarkers, and for better clinical stratification of patients.

Clinical neuropathology practice guide 3-2013: levels of evidence and clinical utility of prognostic and predictive candidate brain tumor biomarkers.

A large number of potential tissue biomarkers has been proposed for brain tumors. However, hardly any have been adopted for routine clinical use, so far. For most candidate biomarkers substantial controversy exists with regard to their usefulness in clinical practice. The multidisciplinary neurooncology taskforce of the Vienna Comprehensive Cancer Center Central Nervous System Unit (CCC-CNS) addressed this issue and elaborated a four-tiered levels-of-evidence system for assessing analytical performance (reliability of test result) and clinical performance (prognostic or predictive) based on consensually defined criteria. The taskforce also consensually agreed that only biomarker candidates should be considered as ready for clinical use, which meet defined quality standards for both, analytical and clinical performance. Applying this levels-of-evidence system to MGMT, IDH1, 1p19q, Ki67, MYCC, MYCN and ß-catenin, only immunohistochemical IDH1 mutation testing in patients with diffuse gliomas is supported by sufficient evidence in order to be unequivocally qualified for clinical use. For the other candidate biomarkers lack of published evidence of sufficiently high analytical test performance and, in some cases, also of clinical performance limits evidence-based confirmation of their clinical utility. For most of the markers, no common standard of laboratory testing exists. We conclude that, at present, there is a strong need for studies that specifically address the analytical performance of candidate brain tumor biomarkers. In addition, standardization of laboratory testing is needed. We aim to regularly challenge and update the present classification in order to systematically clarify the current translational status of candidate brain tumor biomarkers and to identify specific research needs for accelerating the translational pace.

Exploratory investigation of eight circulating plasma markers in brain tumor patients.

Several blood biomarkers have been established for the early diagnosis, screening and follow-up of non central nervous system cancers. However, there is lack of knowledge on biochemical blood alterations in brain tumor patients. In this study, we prospectively collected blood plasma samples of 105 adult brain tumor patients with diffuse low-grade glioma (World Health Organization (WHO) II, n = 7), anaplastic glioma (WHO III, n = 10), glioblastoma multiforme (WHO IV, glioblastoma multiforme (GBM)) (n = 34), meningioma (WHO I, n = 8), atypical meningioma (WHO II, n = 5), and intracerebral metastasis (ICM; n = 41). In each case, we measured plasma concentrations of neuropeptide Y, brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, placental growth factor (PlGF), S100B, secretagogin, interleukin 8, and glial fibrillary acidic protein (GFAP) using enzyme-linked immunosorbent assay. Plasma marker concentrations were correlated to patient parameters including neuropathological diagnosis and neuroradiological features. Most of the markers were detectable in all diagnostic categories in variable concentrations. GFAP plasma detectability was strongly associated with a diagnosis of GBM (p < 0.001). Plasma GFAP and plasma placental growth factor showed promising moderate potential in the differential diagnosis of unifocal GBM versus unifocal supratentorial ICM (area under the curve = 0.73, p < 0.05). To summarize, our data show that none of the investigated markers is suitable to substitute histological diagnosis. However, measurement of circulating GFAP and PlGF may support neuroradiological differential diagnosis of GBM versus ICM.

Influence of the American ODAC statement on Austrian bevacizumab prescribing practice for metastatic breast cancer.

BACKGROUND: Results of trial E2100 led to the accelerated approval of bevacizumab as first-line therapy for patients with metastatic breast cancer (MBC) in the U.S. in February 2008. Based on results from subsequent trials, the U.S. Food and Drug Administration Oncologic Drugs Advisory Committee (ODAC) issued a statement proposing to withdraw the license for bevacizumab in July 2010, whereas bevacizumab approval for MBC was not withdrawn in Europe. In this nationwide survey, we investigated the influence of the discrepancy between the ODAC and European Medicines Agency (EMA) positions on the prescription practice of bevacizumab for MBC in Austria during the period January 2006 to June 2011. METHODS: The absolute number of bevacizumab administrations for MBC patients per month in all Austrian hospitals within the mentioned time frame was retrieved from a comprehensive national database. Bevacizumab prescription numbers for other malignancies were retrieved in order to rule out that a change in bevacizumab prescribing practice might reflect general changes in Austrian health care policy. RESULTS: A steady increase in bevacizumab use was seen from January 2006 to June 2010 (42 versus 1,357 administrations per month) for MBC. Thereafter, a significant decline in bevacizumab prescriptions for MBC became evident, with numbers dropping to 842 in March 2011 and 662 in June 2011. Bevacizumab prescriptions showed only minor variations in control cohorts. CONCLUSIONS: The Austrian bevacizumab prescribing practice in MBC patients was significantly influenced by the ODAC statement issued in July 2010, whereas the EMA position was accepted to a lesser degree.

Podoplanin-expressing cancer-associated fibroblasts are associated with poor prognosis in invasive breast cancer.

While cancer research has been focused on tumor cells for many years, evidence is growing that the tumor stroma and in particular cancer-associated fibroblasts (CAFs) in particular play essential roles in the progression of human malignant disease. In human lung cancer, CAFs expressing the transmembrane protein podoplanin were shown to have significant influence on the patients' prognosis. In this study, we investigated the presence and prognostic role of podoplanin-expressing CAFs in a large series of patients with invasive breast cancer. Podoplanin expression was evaluated immunohistochemically in 367 breast cancers. Tumors with ≥10% distinct podoplanin staining were considered as positive (CAF+). Cytoplasmic podoplanin expression of tumor cells was considered as positive when ≥5% of tumor cells showed a distinct podoplanin expression. In normal breast tissue, no podoplanin-expressing fibrocytes were found. Thirty-three patients (9%) with breast cancer showed podoplanin expression in CAFs. In 28 patients (8%), a podoplanin expression in tumor cells was observed. A strong negative correlation of CAF+ with estrogen receptor status (p<0.001), and a significant association with higher histological grading (p<0.001) was seen. In multivariable analysis, CAFs+ was an independent prognostic factor for disease free (1.78 Hazard ratio; p=0.026) and overall survival (2.304 Hazard ratio; p=0.002) in patients with breast cancer. Podoplanin-expressing CAFs contribute to the prognosis of invasive breast cancer, indicating a highly aggressive subgroup. CAFs may present a highly selective target for anti-cancer therapies in patients with invasive breast cancer.

Prognostic value of Ki67 index in anaplastic oligodendroglial tumours--a translational study of the European Organization for Research and Treatment of Cancer Brain Tumor Group.

AIMS: To evaluate the prognostic value and clinical utility of Ki67 tumour cell proliferation index in anaplastic oligodendroglial tumours (AOT). METHODS AND RESULTS: We performed anti-Ki67 immunostaining (MIB-1 antibody) of formalin-fixed and paraffin-embedded tumour tissue specimens of 128 patients with newly diagnosed AOT that were treated in a randomized Phase III trial. Ki67 index was assessed by three independent observers and was correlated to clinical, histopathological and molecular features (including 1p/19q co-deletion, epithelial growth factor receptor gene (EGFR) amplification, isocitrate dehydrogenase (IDH1) mutations, O6-methylguanine-DNA methyltransferase gene (MGMT) promoter methylation, and patient survival times. Intra- and inter-observer agreement of Ki67 index assessment was excellent. Univariable analysis (n = 79) showed that patients with a low Ki67 index had significantly more favourable progression-free survival (PFS) (P-value = 0.004, log-rank test) and overall survival (OS) (P-value = 0.003, log-rank test) than patients with a high Ki67 index, respectively. On multivariable analysis (n = 43), Ki67 index showed no independent association with PFS or OS. CONCLUSIONS: In AOT the Ki67 index has a strong prognostic impact on univariable analysis, but no independent influence on multivariable analysis. However, further prospective studies including larger numbers of cases and standardized evaluation of Ki67 index in conjunction with other relevant prognostic parameters are needed to draw definitive conclusions.

Relevance of the type III error in epidemiological maps.

BACKGROUND: A type III error arises from a two-sided test, when one side is erroneously favoured although the true effect actually resides on the other side. The relevance of this grave error in decision-making is studied for epidemiological maps. RESULTS: Theoretical considerations confirm that a type III error may be large for regions with small numbers of expected cases even when no spatial smoothing has been performed. A simulation study based on infant mortality data in Austria reveals that spatial smoothing may additionally increase the risk of type III errors. CONCLUSIONS: The occurrence of a type III error should be taken into account when interpreting results presented in epidemiological maps, particularly with regard to sparsely populated regions and spatial smoothing.

Clinical Neuropathology Practice News 4-2012: levels of evidence for brain tumor biomarkers.

The National Comprehensive Cancer Network (NCCN) recently published a task force report on the evaluation of the clinical utility of tumor biomarkers in oncology. In this report, common terminology and the use of levels of evidence scores to aid the evaluation of biomarker tests in oncology were proposed. Furthermore, the task force applied a level of evidence system to selected biomarkers of several cancer types. According to this system, the highest level of evidence, IA, is granted to a biomarker only if it has been evaluated in at least one adequately powered and specifically designed prospective controlled trial. For gliomas, only 1p/19q testing in oligodendroglial tumors was classified as IA by the NCCN task force. For all of the following biomarkers the present evidence level for clinical utility was regarded as lower than that of 1p/19q status: MGMT gene promoter methylation testing (glioblastoma), IDH mutation testing (diffusely growing gliomas), BRAF fusion testing (pilocytic astrocytoma) and CIMP testing (diffusely growing gliomas). The task force acknowledged that the exact application of levels of evidence needs further refinement. To our mind, the implementation of a brain tumor expert panel seems vital to evaluate the evidence levels of neurooncological biomarkers according to generally accepted criteria on a regular basis. Systematic identification of current research needs and widely accepted up-to-date recommendations for efficient biomarker application in everyday practice could be gained.

Weighted pseudo-values for partly unobserved group membership in paediatric stem cell transplantation studies.

Generalised pseudo-values have been suggested to evaluate the impact of allogeneic stem cell transplantation on childhood leukaemia. The approach compares long-term survival of two cohorts defined by the availability or non-availability of suitable donors for stem cell transplantation. A patient's cohort membership becomes known only after completed donor search with or without an identified donor. If a patient suffers an event during donor search, stem cell transplantation will no longer be indicated. In such a case, donor search will be ceased and cohort membership will remain unknown. The generalised pseudo-values approach considers donor identification as binary time-dependent covariate and uses inverse-probability-of-censoring weighting to adjust for non-identified donors. The approach leads to time-consuming computations due to multiple redefinitions of the risk set for pseudo-value calculation and an explicit adjustment for waiting-time bias. Here, the problem is looked at from a different angle. By considering the probability that a donor would have been identified after ceasing of donor search, weights for common pseudo-values are defined. This leads to a faster alternative approach as only a single risk set is necessary. Extensive computer simulations show that both, the generalised and the new weighted pseudo-values approach, provide approximately unbiased estimates. Confidence interval coverage is satisfactory for typical clinical scenarios. In situations, where donor identification takes considerably longer than usual, the weighted pseudo-values approach is preferable. Both approaches complement each other as they have different potential in addressing further aspects of the underlying medical question.