Search

Background and Purpose: Randomized studies have shown that adding hyperthermia (HT) to re-irradiation (re-RT) improves treatment outcome for patients with breast cancer recurrences. We evaluated the efficacy and side effects in patients treated with re-RT and HT for irresectable locoregional breast cancer recurrences., Material and Methods: From September 1996 to December 2011, 248 patients with a macroscopic breast cancer recurrence were treated with re-RT and HT. Radiotherapy (RT) was applied to a dose of 32 Gy in 4 Gy fractions, twice weekly. HT was prescribed once weekly after RT. Primary endpoints for this analysis were complete response (CR) and local control (LC). Secondary endpoints were overall survival (OS), and toxicity. Patient-, tumor-, and treatment-related characteristics predictive for the endpoints were identified in univariate and multivariate analyses., Results: The median follow-up period was 32 months. The CR rate was 70%. At 1, 3, and 5 years LC was 53%, 40% and 39%, and OS was 66%, 32%, and 18%, respectively. OS after 10 years was 10%. Thermal burns developed in 23% patients, healing with conservative measures. The incidence of 5 years late grade 3 toxicity was 1%. A few patients survived more than 10 years without evidence of disease., Conclusions: The combination of re-RT and HT results in a high rate of long-term LC with acceptable late toxicity, and many patients remained locally controlled for the rest of their survival period., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Purpose: Evaluation of efficacy and side effects of combined re-irradiation and hyperthermia electively or for subclinical disease in the management of locoregional recurrent breast cancer., Methods and Materials: Records of 198 patients with recurrent breast cancer treated with re-irradiation and hyperthermia from 1993 to 2010 were reviewed. Prior treatments included surgery (100%), radiotherapy (100%), chemotherapy (42%), and hormonal therapy (57%). Ninety-one patients were treated for microscopic residual disease following resection or systemic therapy and 107 patients were treated electively for areas at high risk for local recurrences. All patients were re-irradiated to 28-36Gy (median 32) and treated with 3-8 hyperthermia treatments (mean 4.36). Forty percent of the patients received concurrent hormonal therapy. Patient and tumor characteristics predictive for actuarial local control (LC) and toxicity were studied in univariate and multivariate analysis., Results: The median follow-up was 42months. Three and 5year LC-rates were 83% and 78%. Mean of T90 (tenth percentile of temperature distribution), maximum and average temperatures were 39.8°C, 43.6°C, and 41.2°C, respectively. Mean of the cumulative equivalent minutes (CEM43) at T90 was 4.58min. Number of previous chemotherapy and surgical procedures were most predictive for LC. Cumulative incidence of grade 3 and 4 late toxicity at 5years was 11.9%. The number of thermometry sensors and depth of treatment volume were associated with acute hyperthermia toxicity., Conclusions: The combination of re-irradiation and hyperthermia results in a high LC-rate with acceptable toxicity., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

In our randomized trial on hyperbaric oxygen (HBO), it was shown that HBO could reduce dysphagia and xerostomia, which are frequently encountered after (chemo-) radiotherapy (RT) and/or surgery for head and neck cancer (HNC). A risk model and nomogram are developed to select those patients who most likely will respond to HBO treatment. A total of 434 HNC patients treated from 2000 to 2008 were analyzed and filled out the EORTC QLQC-30 and H&N35 questionnaires. Age, gender, chemotherapy, T and N stages, site, radiotherapy technique, RT boost, surgery of the primary tumor and neck, bilateral RT, and dose were analyzed in a statistical model. The discriminative value of the model was evaluated based on receiver operating characteristics (ROC), the area under the curve (AUC), sensitivity, specificity, and proportion of correctly classified measures. Significant factors in predicting swallowing problems are age, follow-up duration, tumor site, chemotherapy, surgery of the primary tumor and neck, and dose. For dry mouth, the significant factors are age, gender, tumor site, N stage, chemotherapy, and bilateral irradiation. For dysphagia and xerostomia, the area under the ROC curve is 0.7034 and 0.7224, respectively, with a specificity of 89/77%, sensitivity of 27/58%, and a positive predictive value of 83/67% for dysphagia and xerostomia, respectively. The developed predictive risk model could be used to select patients for costly hyperbaric oxygen treatment to prevent or reduce severe late side effects of HNC treatment. Our model serves as a guideline for the Department of Radiation Oncology to reduce costs by excluding patients not amenable to hyperbaric oxygen protocols. The nomogram presented is a useful tool for clinicians in assessing patient risks when deciding on follow-up strategies (e.g., hyperbaric oxygen treatment) after RT or surgery for HNC.

In meta-analysis of clinical trials, investigating the relationship between the baseline risk and the treatment benefit is often of interest in order to explain the between trials heterogeneity with respect to treatment effect. The relationship is commonly described with a linear model taking into account the fact that the latent baseline risk is estimated from a finite sample and thus subjected to measurement error. Depending on the specific assumption about the latent baseline risks, two different classes of methods can be pursued. In the literature, it is commonly assumed that the latent baseline risks are sampled from a (normal) distribution. Such methods are often criticised for needing a distribution. Here, we propose the use of methods that require no distributional assumption on the baseline risks. A number of alternative methods are reviewed and are illustrated via simulation and by application to a published meta-analysis data.

Background: Breast cancer recurrences in previously irradiated areas are treated with reirradiation (reRT) and hyperthermia (HT). The aim of this retrospective study is to quantify the toxicity of HT in breast cancer patients with reconstruction., Methods: Between 1992 and 2009, 36 patients were treated with reRT with a scheme of 8 fractions of 4.0 Gy in 4 weeks, and HT on a total of 37 tissue reconstructions. The types of reconstructions were: split-thickness skin graft (15), transverse rectus abdominis myocutaneous flap (1), latissimus dorsi flap (14), rhomboid flap (1) or a combination of grafts and flaps (6). Toxicities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. Patient, tumour, and treatment characteristics predictive for the endpoints were identified in univariate and multivariate analyses. The primary endpoint was HT toxicity. Secondary endpoints were acute and late radiotherapy (RT) toxicity, complete response (CR), local control (LC) and overall survival (OS)., Results: The median follow-up time was 64 months. Grade 2 HT toxicity occurred in four patients and grade 3 in three. The three patients with grade 3 HT toxicity required reoperation. None of the evaluated parameters showed a significant relationship with HT toxicity. The CR rate in 15 patients with macroscopic disease was 80%. The 3 and 5 year LC rates were 74% and 69%; the median OS was 55 months., Conclusions: Combined reRT and HT in breast cancer patients with reconstruction is safe and effective.

Objective: Recent data suggest that a gene-environment interaction between smoking and the HLA shared epitope alleles plays a role in shaping the autoimmune reaction to specific citrullinated antigens. This study was undertaken to determine the effects of HLA shared epitope alleles and tobacco exposure on the immune response against various citrullinated antigens. These associations were analyzed in the anti-citrullinated protein antibody (ACPA)-positive stratum to control for the possibility that the associations found are explained by the known interaction between HLA shared epitope alleles and tobacco exposure on ACPA status., Methods: In 661 patients with rheumatoid arthritis, reactivity against several citrullinated antigens from vimentin, fibrinogen, enolase, and myelin basic protein was determined by enzyme-linked immunosorbent assay. The effects of the HLA shared epitope alleles and tobacco exposure were assessed by logistic regression analysis. Biologic interaction was analyzed by investigating whether the effects of the risk factors combined exhibited departure from additivity., Results: A significant interaction between tobacco exposure and HLA shared epitope alleles was found for the presence of ACPA as reported previously. When these interaction effects were studied for several ACPA "fine specificities," significant interactions were noted for several citrullinated peptides. However, these interactions were not present after stratification for ACPA status, indicating that the interaction between tobacco exposure and HLA shared epitope alleles influences autoimmunity not to specific citrullinated antigens, but rather to ACPA development., Conclusion: Our data indicate that the gene-environment interaction between HLA shared epitope alleles and smoking does not appear to shape the reactivity of the ACPA response. These data suggest that smoking promotes nonspecific citrullination rather than citrullination of specific antigens., (Copyright © 2011 by the American College of Rheumatology.)

This article reviews various recently suggested approaches to estimate the random effects distribution in a linear mixed model, i.e. (1) the smoothing by roughening approach of Shen and Louis,(1) (2) the semi-non-parametric approach of Zhang and Davidian,(2) (3) the heterogeneity model of Verbeke and Lesaffre( 3) and (4) a flexible approach of Ghidey et al. (4) These four approaches are compared via an extensive simulation study. We conclude that for the considered cases, the approach of Ghidey et al. (4) often shows to have the smallest integrated mean squared error for estimating the random effects distribution. An analysis of a longitudinal dental data set illustrates the performance of the methods in a practical example.

A linear mixed model with a smooth random effects density is proposed. A similar approach to P-spline smoothing of Eilers and Marx (1996, Statistical Science 11, 89-121) is applied to yield a more flexible estimate of the random effects density. Our approach differs from theirs in that the B-spline basis functions are replaced by approximating Gaussian densities. Fitting the model involves maximizing a penalized marginal likelihood. The best penalty parameters minimize Akaike's Information Criterion employing Gray's (1992, Journal of the American Statistical Association 87, 942-951) results. Although our method is applicable to any dimensions of the random effects structure, in this article the two-dimensional case is explored. Our methodology is conceptually simple, and it is relatively easy to fit in practice and is applied to the cholesterol data first analyzed by Zhang and Davidian (2001, Biometrics 57, 795-802). A simulation study shows that our approach yields almost unbiased estimates of the regression and the smoothing parameters in small sample settings. Consistency of the estimates is shown in a particular case.