http://repub.eur.nl/res/aut/25373/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/37348/ 2012-10-01T00:00:00Z Background: The focal primary torsion dystonias (FPTDs) form a group of clinical heterogeneous syndromes and can be considered a genetic complex disease; it is thought to be primed by genetic variants with variable impact and triggered by non-genetic factors. Thorough clinical description of FPTDs cohorts is sparse but essential for further progress in genetic research. Objective: To establish suggested relations between age at onset (AaO), site and family history in a large focal dystonias cohort and gain more insight into familial clustering for genetic research. Patients and methods: A prospective cohort study between March 2008 and March 2011, including 676 FPTD patients attending the botulinum toxin outpatient clinics of six Dutch movement disorder centres. Results and conclusions: Of all of the FPTD patients, 25% had a familial predisposition; in 2.4% a Mendelian inheritance pattern was noted. With a stronger family history, a significantly lower AaO was seen in all focal dystonias. In both the sporadic and familial focal dystonia groups, AaO had an effect on the distribution of dystonia, with a caudal to cranial tendency. In all focal dystonia forms, women were more frequently affected, except for writer's cramp. Careful clinical characterisation will allow the formation of phenotype subgroups. We suggest that genetic research into FPTDs will benefit from this approach and discuss genetic research strategies to decipher the complex background of focal dystonias. http://repub.eur.nl/res/pub/34854/ 2012-01-01T00:00:00Z Background. In general, the estimated prognosis of patients with cancer is based on patient characteristics known at the time of diagnosis and presented as if a lifetime verdict. However, the prognosis of patients with cancer who survive the first critical years changes, along with the prognosis for those with local or regional recurrences or distant metastases. Methods. This study concerns 2927 patients with a primary head and neck squamous cell carcinoma (HNSCC). We developed prognostic models after initial treatment and at different time points during follow-up. Results. The developed models show the effects of survival time, recurrences, and distant metastasis during follow-up. The C-statistics ranged from 0.76 to 0.69. Conclusion. Prognosis is dynamic: the passage of time and the occurrence of life events change the predicted probabilities of survival. The models enhance our insight in the effect of recurrences and metastasis during follow-up and could be used for better patient counseling. http://repub.eur.nl/res/pub/37218/ 2012-01-01T00:00:00Z Background. Electronic patient files generate an enormous amount of medical data. These data can be used for research, such as prognostic modeling. Automatization of statistical prognostication processes allows automatic updating of models when new data is gathered. The increase of power behind an automated prognostic model makes its predictive capability more reliable. Cox proportional hazard regression is most frequently used in prognostication. Automatization of a Cox model is possible, but we expect the updating process to be time-consuming. A possible solution lies in an alternative modeling technique called random survival forests (RSFs). RSF is easily automated and is known to handle the proportionality assumption coherently and automatically. Performance of RSF has not yet been tested on a large head and neck oncological dataset. This study investigates performance of head and neck overall survival of RSF models. Performances are compared to a Cox model as the "gold standard." RSF might be an interesting alternative modeling approach for automatization when performances are similar. Methods. RSF models were created in R (Cox also in SPSS). Four RSF splitting rules were used: log-rank, conservation of events, log-rank score, and log-rank approximation. Models were based on historical data of 1371 patients with primary head-and-neck cancer, diagnosed between 1981 and 1998. Models contain 8 covariates: tumor site, T classification, N classification, M classification, age, sex, prior malignancies, and comorbidity. Model performances were determined by Harrell's concordance error rate, in which 33% of the original data served as a validation sample. Results. RSF and Cox models delivered similar error rates. The Cox model performed slightly better (error rate, 0.2826). The log-rank splitting approach gave the best RSF performance (error rate, 0.2873). In accord with Cox and RSF models, high T classification, high N classification, and severe comorbidity are very important covariates in the model, whereas sex, mild comorbidity, and a supraglottic larynx tumor are less important. A discrepancy arose regarding the importance of M1 classification (see Discussion). Conclusion. Both approaches delivered similar error rates. The Cox model gives a clinically understandable output on covariate impact, whereas RSF becomes more of a "black box." RSF complements the Cox model by giving more insight and confidence toward relative importance of model covariates. RSF can be recommended as the approach of choice in automating survival analyses. http://repub.eur.nl/res/pub/28275/ 2010-12-01T00:00:00Z Background: Dynamic predictions on head and neck cancer survival could offer, besides improved patient counseling, insight into long-term effects of tumor- and patient-based characteristics on survival. Theoretically, there could be a certain time period after diagnosis after which the patient returns to a population risk on survival. Methods. In all, 7255 patients with a primary head and neck squamous cell carcinoma (HNSCC) aged 25 to 90 years, diagnosed between January 1980 and January 2004 in The Netherlands, were included. Conditional 5-year relative survival for every additional year survived was computed. Results. The overall conditional relative prognosis reached a plateau after approximately 4 years; a permanent 20% to 25% excess mortality for long-term HNSCC survivors remained. Conclusions. Conditional 5-year relative survival for patients with HNSCC remains poorer compared to age- and sex-matched counterparts in the general population, even when alive at 15 years after diagnosis. We assume that this is caused by an excess comorbidity in these patients, mainly due to smoking and alcohol abuse. http://repub.eur.nl/res/pub/20846/ 2010-09-01T00:00:00Z Dedicated software packages incorporating prognostic models are meant to aid physicians in making accurate predictions of prognosis. This study concerns 742 predictions of 5-year survival on consecutive newly diagnosed patients with head- and neck squamous cell carcinoma. The 5-year survival predictions made by the physicians are not compared with actual survival, but with a prediction made by OncologIQ, a dedicated software package. We used a linear regression and a linear mixed-effects model to look at absolute differences between both predictions and possible learning effects. Predictions made by the physicians were optimistic and inaccurate. Using the linear regression and linear mixed-effects models, the physicians' learning effect showed little improvement per successive prediction. We conclude that prognostic predictions in general are imprecise. When given feedback on the model's predicted survival, the accuracy increases, but only very modestly. http://repub.eur.nl/res/pub/28170/ 2010-09-01T00:00:00Z Goals of work: This paper presents an observational study of the longitudinal effects of cancer treatment on quality of life (QoL) in patients treated for head and neck squamous cell carcinoma (HNSCC), and evaluated the contribution of patients' baseline illness cognitions to the prediction of QoL 2 years after diagnosis. Patients and methods: One hundred seventy-seven patients eligible for primary treatment for HNSCC completed the Illness Perception Questionnaire-Revised at baseline and the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire-30 at baseline, at 1-year and 2-year follow-ups. Main results Compared to baseline, patients reported better emotional functioning at both follow-ups (p<0.001), worse social functioning at 12 months (p<0.05), and better global health status at 24 months (p<0.05). Patients' own implicit common sense beliefs about their illness added small but significant amounts of variance to the prediction of QoL after 2 years. Less belief in own behavior causing the illness predicted better functioning and better global health. Strong illness identity beliefs predicted worse functioning and worse global health. Negative perceptions about the duration of the illness (chronic timeline beliefs) and more negative perceived consequences also predicted worse QoL. Conclusions: Our results on the negative perceptions about the duration of the illness, perceived consequences, and high symptom awareness predicting worse QoL illustrate the detrimental effects of uncertainty and negative expectations about the future course of the illness. The identification of these cognitive factors provides possible targets for counseling strategies to assist patients in long-term adjustment to HNSCC. http://repub.eur.nl/res/pub/24088/ 2009-11-01T00:00:00Z Background. Can a "typical" voice in terms of auditory perception be defined after type I or II chordectomy? Do other parameters in a multidimensional voice protocol correlate to this perceptual profile? Methods. Voice evaluation using a multidimensional voice protocol including perceptual (GRBAS; grade, roughness, breathiness, asthenia, strain scale), acoustic, aerodynamic, stroboscopic analyses, and self-assessment (Voice Handicap Index [VHI]) in a cohort of 37 consecutive patients with T1a midcord glottic carcinoma. Results. Sixty-five percent of patients had dysphonia, dominated by mild breathiness (mean grade 1.4). Voice Handicap was minimal (mean VHI 19). Acoustic and aerodynamic parameters were only mildly deviant. The correlations between perceptual analysis and the other parameters were weak. Conclusion. The typical laser treated voice (type I or II resections) is characterized by mild breathiness in perceptual analysis. Correlations with other parameters, including patients' self assessment, are weak. Therefore, these outcomes do not form 1 integrated voice profile. This may have consequences for clinical decision-making. http://repub.eur.nl/res/pub/32437/ 2008-09-01T00:00:00Z Objective: To compare voice quality after radiotherapy or endoscopic laser surgery in patients with similar T1a midcord glottic carcinomas according to a validated multidimensional protocol. Design: Retrospective cohort study. Setting: University cancer referral center. Patients: Two cohorts of consecutive patients willing to participate after treatment for primary Tla midcord glottic carcinoma with laser surgery (18 of 23 eligible) or radiotherapy (16 of 18 eligible). Main Outcome Measures: Posttreatment voice quality was evaluated according to a multidimensional voice protocol based on validated European Laryngological Society recommendations, including perceptual, acoustic, aerodynamic, and stroboscopic analyses, together with patient self-assessment using the Voice Handicap Index. Results: Approximately half of the patients had mild to moderate voice dysfunction in the perceptual analysis (53% [8 of 15] in the radiotherapy group and 61% [11 of 18] in the laser surgery group) and on the Voice Handicap Index (44% [7 of 16] in the radiotherapy group and 56% [10 of 18] in the laser surgery group). The voice profile in the laser surgery group was mainly breathy; in the radiotherapy group, it was equally breathy and rough, with a trend for more jitter in the acoustic analysis. There was no statistical difference in the severity of voice dysfunction between the groups in any of the variables. Conclusions: Endoscopic laser surgery offers overall voice quality equivalent to that of radiotherapy for patients with Tla midcord glottic carcinoma, although specific voice profiles may ultimately be different for the 2 modalities. We believe that endoscopic laser surgery is the preferred treatment in these patients because it provides oncologic control similar to that of radiotherapy and the additional benefits of lower costs, shorter treatment time, and the possibility of successive procedures. http://repub.eur.nl/res/pub/30200/ 2008-09-01T00:00:00Z Background. Since the introduction of endoscopic laser surgery at our institution in 1996, 189 patients have been treated for T1 glottic carcinoma. Methods. Treatment allocation (radiotherapy vs laser surgery) and outcome were evaluated. Results. Fifty-one percent of T1a lesions were considered suitable for laser surgery. Sixteen percent of T1 a patients treated with laser surgery needed additional treatment because of positive resection margins. Overall local control and larynx preservation were 89% and 96%. Both were poorer in T1a patients with larger lesions treated with radiotherapy (local control 75% versus 89%, p = .05, larynx preservation 83% vs 100%, p = .001). Conclusion. Outcome for T1a patients selected for laser surgery is excellent. In patients with larger lesions treated with radiotherapy, outcome is inferior to patients selected for laser surgery, but also to that reported for (unselected) T1a carcinomas treated with radiotherapy in literature. Strategies to improve treatment results in patients deemed unsuitable for laser surgery should be designed.