Kai Kammers

Adjuvant radiotherapy of regional lymph nodes in breast cancer - a meta-analysis of randomized trials.

BackgroundRadiotherapy (RT) improves overall survival (OS) of breast cancer patients after breast conserving surgery and after mastectomy in patients with involved lymph nodes (LN). The contribution of RT to the regional LN to this survival benefit was poorly understood. Recently, the results of three large randomized trials addressing this question have become available.Material and methodsThe published abstracts (full publication pending) of the MA.20 (n=1832) and the EORTC 22922–10925 (EORTC) (n=4004) trial and the full publication of the French trial (n=1334) were basis of the meta-analysis. Main eligibility criteria were positive axillary LN (all trials), LN negative disease with high risk for recurrence (MA.20), and medial/central tumor location (French, EORTC). The MA.20 and the EORTC trial tested the effect of additional regional RT to the internal mammary (IM) LN and medial supraclavicular (MS) LN, whereas in the French trial all patients received RT to the MS-LN and solely RT to the IM-LN was randomized. Primary endpoint was OS. Secondary endpoints were disease-free survival (DFS) and distant metastasis free survival (DMFS).ResultsRegional RT of the MS-LN and the IM-LN (MA.20 and EORTC) resulted in a significant improvement of OS (Hazard Ratio (HR) 0.85 (95% CL 0.75 - 0.96)). Adding the results of the French trial and using the random effects model to respect the different design of the French trial, the effect on OS of regional radiotherapy was still significant (HR 0.88 (95% CL 0.80 - 0.97)). The absolute benefits in OS were 1.6% in the MA.20 trial at 5 years, 1.6% in the EORTC trial at 10 years, and 3.3% in the French trial at 10 years (not significant in single trials). Regional radiotherapy of the MS-LN and the IM-LN (MA.20 and EORTC) was associated with a significant improvement of DFS (HR 0.85 (95% CL 0.77 - 0.94)) and DMFS (HR 0.82 (95% CL 0.73 - 0.92)). The effect sizes were not significantly different between trials for any end point.ConclusionAdditional regional radiotherapy to the internal mammary and medial supraclavicular lymph nodes statistically significantly improves DFS, DMFS, and overall survival in stage I-III breast cancer.

Reproducible RNA-seq analysis using recount2

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Molecular biological determinations of meningioma progression and recurrence.

Meningiomas are tumors that arise from the coverings of the brain or spinal cord. 5% of the cases turn into malignant forms with aggressive clinical behavior and increased risk of tumor recurrence. One hundred and five patients with meningiomas were operated by open surgery. To investigate predictors of meningioma recurrence in total 124 samples of 105 patients were investigated by iFISH. Dual-probe hybridization was performed to access chromosomal alterations of chromosomes 1p-, 9p- and 22q. Additionally, methylation of TIMP3 and p16 was analyzed with MS-PCR. Of the 105 investigated tumors 59.1% (62/105) were WHO grade I, 33.3% (35/105) were WHO grade II and 7.7% (8/105) were anaplastic meningiomas (grade III), respectively. The histopathological data correlates with the recurrence rate of the investigated meningiomas. Hypermethylation of TIMP3 was detected in 13.3% of all meningiomas: 10.9% in WHO grade I meningiomas, 25.0% in grade II and 14.3% in grade III meningiomas, respectively. No correlation of TIMP3 hypermethylation with tumor recurrence or WHO grade (p = 0.2) was observed. Interestingly, deletion of 1p36 emerged as a significant predictor of shorter overall survival (log rank test, p<0.001), whereas TIMP3 promoter methylation had no significant effect on overall survival (log rank test, p = 0.799). The results of the current study support the finding that the deletion of chromosome 1p is an independent marker of meningioma recurrence and progression (p = 0.0097). Therefore the measurement of genetic aberrations in meningiomas allows in a combined histological approach a more precise assessment of the prognosis of meningiomas than histopathology alone.

Approach to family screening in arrhythmogenic right ventricular dysplasia/cardiomyopathy

AIMS A combination of variable expression, age-related penetrance, and unpredictable arrhythmic events complicates management of relatives of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) patients. We aimed to (i) determine predictors of ARVD/C diagnosis and (ii) optimize arrhythmic risk stratification among first-degree relatives of ARVD/C patients. METHODS AND RESULTS Detailed phenotypic and outcome data of 274 first-degree relatives (46% male; 36.5 ± 18.9 years) of 138 ARVD/C probands were obtained. Ninety-six (35%) relatives were diagnosed with ARVD/C according to 2010 Task Force Criteria (TFC). Siblings had a three-fold-increased risk of ARVD/C diagnosis compared with parents and children (odds ratio 3.11, P < 0.001). Multivariable logistic regression identified symptoms (P < 0.001), being a sibling (P < 0.001), the presence of a pathogenic mutation (P < 0.001), and female sex (P = 0.010) as predictors of ARVD/C diagnosis. During 6.7 ± 3.8 years of follow-up, 21 (8%) relatives experienced a sustained ventricular arrhythmia (cycle length 271 ± 48 ms). While being a sibling was a predictor of ARVD/C diagnosis, neither relatedness to the proband (P = 0.185) nor malignant family history (P = 0.347) was significantly associated with arrhythmic events. Meeting TFC independent of family history criteria had higher prognostic value for arrhythmic events than conventional 2010 TFC, which include family history [area under the receiver operating characteristic curve 0.95 (95% CI 0.93-0.97) vs. 0.85 (95% CI 0.82-0.88), P < 0.001]. CONCLUSION One-third of first-degree relatives develop manifest ARVD/C. Siblings have highest risk of disease, even after correcting for age and sex. Fulfilment of TFC independent of family history is superior to conventional TFC for arrhythmic risk stratification of relatives.

Survival models with preclustered gene groups as covariates

BackgroundAn important application of high dimensional gene expression measurements is the risk prediction and the interpretation of the variables in the resulting survival models. A major problem in this context is the typically large number of genes compared to the number of observations (individuals). Feature selection procedures can generate predictive models with high prediction accuracy and at the same time low model complexity. However, interpretability of the resulting models is still limited due to little knowledge on many of the remaining selected genes. Thus, we summarize genes as gene groups defined by the hierarchically structured Gene Ontology (GO) and include these gene groups as covariates in the hazard regression models. Since expression profiles within GO groups are often heterogeneous, we present a new method to obtain subgroups with coherent patterns. We apply preclustering to genes within GO groups according to the correlation of their gene expression measurements.ResultsWe compare Cox models for modeling disease free survival times of breast cancer patients. Besides classical clinical covariates we consider genes, GO groups and preclustered GO groups as additional genomic covariates. Survival models with preclustered gene groups as covariates have similar prediction accuracy as models built only with single genes or GO groups.ConclusionsThe preclustering information enables a more detailed analysis of the biological meaning of covariates selected in the final models. Compared to models built only with single genes there is additional functional information contained in the GO annotation, and compared to models using GO groups as covariates the preclustering yields coherent representative gene expression profiles.

Induction chemotherapy followed by concurrent radio-chemotherapy versus concurrent radio-chemotherapy alone as treatment of locally advanced squamous cell carcinoma of the head and neck (HNSCC): A meta-analysis of randomized trials

BACKGROUND Induction chemotherapy with docetaxel, cisplatin and 5 FU (TPF) before radiotherapy (RT) or radio-chemotherapy (RT-CHX) has been shown to improve overall survival (OS) compared to induction chemotherapy with cisplatin and 5 FU in locally advanced squamous cell carcinoma of the head and neck (HNSCC). Whether TPF induction before RT-CHX improves clinical outcome in comparison with RT-CHX alone is still a matter of debate. Recently, the results of 5 randomized trials addressing this question have become available. METHODS In the 5 trials of interest, in total 1022 patients with locally advanced HNSCC were randomly assigned to receive either TPF induction CHX followed by concurrent RT-CHX or concurrent RT-CHX alone. Platin or taxane based CHX was used during RT. 51.3% of the patients had oropharyngeal, 7.3% hypoharyngeal, 18.7% laryngeal, 19.4% oral cavity and 3.5% had other HNSCC. Published hazard ratios and hazard ratios extracted from available survival curves for OS and progression free survival (PFS) were basis of the meta-analysis. Meta-analysis of the effect sizes on OS and PFS was performed using a random effects model based on parameter estimates of log hazard ratios in Cox models and their standard errors. RESULTS Additional induction CHX with TPF before RT-CHX did neither result in a significant improvement of OS (Hazard Ratio: 1.010, 95% confidence limits (CL) 0.84-1.21, p=0.92), nor in a statistically significant benefit of PFS (Hazard Ratio: 0.91, 95% CL 0.75-1.1, p=0.32). CONCLUSION Additional induction CHX with TPF before RT-CHX does not improve OS and PFS in locally advanced HNSCC compared to definite RT-CHX.

RNA helicase DDX3: a novel therapeutic target in Ewing sarcoma

RNA helicase DDX3 has oncogenic activity in breast and lung cancers and is required for translation of complex mRNA transcripts, including those encoding key cell-cycle regulatory proteins. We sought to determine the expression and function of DDX3 in sarcoma cells, and to investigate the antitumor activity of a novel small molecule DDX3 inhibitor, RK-33. Utilizing various sarcoma cell lines, xenografts and human tissue microarrays, we measured DDX3 expression at the mRNA and protein levels, and evaluated cytotoxicity of RK-33 in sarcoma cell lines. To study the role of DDX3 in Ewing sarcoma, we generated stable DDX3-knockdown Ewing sarcoma cell lines using DDX3-specific small hairpin RNA (shRNA), and assessed oncogenic activity. DDX3-knockdown and RK-33-treated Ewing sarcoma cells were compared with wild-type cells using an isobaric mass-tag quantitative proteomics approach to identify target proteins impacted by DDX3 inhibition. Overall, we found high expression of DDX3 in numerous human sarcoma subtypes compared with non-malignant mesenchymal cells, and knockdown of DDX3 by RNA interference inhibited oncogenic activity in Ewing sarcoma cells. Treatment with RK-33 was preferentially cytotoxic to sarcoma cells, including chemotherapy-resistant Ewing sarcoma stem cells, while sparing non-malignant cells. Sensitivity to RK-33 correlated with DDX3 protein expression. Growth of human Ewing sarcoma xenografts expressing high DDX3 was inhibited by RK-33 treatment in mice, without overt toxicity. DDX3 inhibition altered the Ewing sarcoma cellular proteome, especially proteins involved in DNA replication, mRNA translation and proteasome function. These data support further investigation of the role of DDX3 in sarcomas, advancement of RK-33 to Ewing sarcoma clinical trials and development of RNA helicase inhibition as a novel anti-neoplastic strategy.

Integrated Omic Analysis of a Guinea Pig Model of Heart Failure and Sudden Cardiac Death.

Here, we examine key regulatory pathways underlying the transition from compensated hypertrophy (HYP) to decompensated heart failure (HF) and sudden cardiac death (SCD) in a guinea pig pressure-overload model by integrated multiome analysis. Relative protein abundances from sham-operated HYP and HF hearts were assessed by iTRAQ LC-MS/MS. Metabolites were quantified by LC-MS/MS or GC-MS. Transcriptome profiles were obtained using mRNA microarrays. The guinea pig HF proteome exhibited classic biosignatures of cardiac HYP, left ventricular dysfunction, fibrosis, inflammation, and extravasation. Fatty acid metabolism, mitochondrial transcription/translation factors, antioxidant enzymes, and other mitochondrial procsses, were downregulated in HF but not HYP. Proteins upregulated in HF implicate extracellular matrix remodeling, cytoskeletal remodeling, and acute phase inflammation markers. Among metabolites, acylcarnitines were downregulated in HYP and fatty acids accumulated in HF. The correlation of transcript and protein changes in HF was weak (R(2) = 0.23), suggesting post-transcriptional gene regulation in HF. Proteome/metabolome integration indicated metabolic bottlenecks in fatty acyl-CoA processing by carnitine palmitoyl transferase (CPT1B) as well as TCA cycle inhibition. On the basis of these findings, we present a model of cardiac decompensation involving impaired nuclear integration of Ca(2+) and cyclic nucleotide signals that are coupled to mitochondrial metabolic and antioxidant defects through the CREB/PGC1α transcriptional axis.

Do insulin-like growth factor associated proteins qualify as a tumor marker? Results of a prospective study in 163 cancer patients

ObjectiveInsulin-like growth factor (IGF)-1, -2 and Insulin like growth factor binding proteins (IGFBP) are involved in the proliferation and differentiation of cells. It has never been evaluated, if the IGF-system can serve as a tumor marker in neoplasms.MethodsIn our prospective study 163 patients with colorectal cancer (22), prostate cancer (21), head and neck tumors (17), lymphomas (20), lung cancer (34) and other entities (49) were analysed for their IGF and IGFBP serum levels at the beginning and the end of radiotherapy and compared to 13 healthy people. Subgroups of patients with local tumor disease versus metastatic disease, primary and recurrent therapy and curative versus palliative therapy were compared.ResultsThe serum levels of IGF-2 were significantly elevated in patients with prostate and colorectal cancer. However, sensitivity and specificity were only 70%. IGFBP-2 serum levels were elevated in patients with head and neck tumors. Again sensitivity and specificity were only 73%. A difference between local disease and metastatic disease could not be found. A difference between IGF serum levels before and after radiotherapy could not be detected.ConclusionThe IGF-system cannot serve as a new tumor marker. The detected differences are very small, sensitivity and specificity are too low. IGF measurement is not useful for the evaluation of the success of radiotherapy in malignancies.

Influence of dosimetric and clinical criteria on the requirement of artificial nutrition during radiotherapy of head and neck cancer patients

PURPOSE/OBJECTIVE(S) Intensification of radiotherapy and chemotherapy for head-and-neck cancer (HNC) may lead to increased rates of long term dysphagia as a severe side effect. Mucositis and consequent swallowing problems require artificial nutrition in many HNC patients undergoing radiotherapy or chemoradiation. It is unknown, which predict factors for prophylactic PEG tube insertion appear useful. MATERIALS/METHODS From an institutional database, 101 patients (72 male, 29 female, mean age 59.5years) were identified who underwent radiotherapy or chemoradiation for HNC. Primary end point of the investigation was the need for artificial nutrition for more than 4days during radiotherapy. Dose volume parameters of defined normal tissue structures potentially of relevance for swallowing ability as well as clinical factors were used to develop a predictive model using a binary multiple logistic regression model. RESULTS Whereas several dosimetric and clinical factors were significant predictors for the need of artificial nutrition on univariate analysis, on multivariate analysis only three factors remained independently significant: mean dose to the oropharynx+1cm circumferential margin, ECOG performance state (0-1 vs. 2-4), and the use of chemotherapy (yes vs. no). CONCLUSIONS Using a 3 parameter model we could distinguish HNC-patients with different risks for the need of artificial nutrition during radiotherapy. After independent validation, the model could be helpful to decision on prophylactic PEG tube insertion.