Importance sampling method of correction for multiple testing in affected sib-pair linkage analysis

Using the Genetic Analysis Workshop 13 simulated data set, we compared the technique of importance sampling to several other methods designed to adjust p-values for multiple testing: the Bonferroni correction, the method proposed by Feingold et al., and naïve Monte Carlo simulation. We performed affected sib-pair linkage analysis for each of the 100 replicates for each of five binary traits and adjusted the derived p-values using each of the correction methods. The type I error rates for each correction method and the ability of each of the methods to detect loci known to influence trait values were compared. All of the methods considered were conservative with respect to type I error, especially the Bonferroni method. The ability of these methods to detect trait loci was also low. However, this may be partially due to a limitation inherent in our binary trait definitions

Meta-Analysis of Local Invasive Breast Cancer Recurrence After Electron Intraoperative Radiotherapy.

BACKGROUND: Electron intraoperative radiotherapy (IORT) can be used during breast conserving surgery to treat early-stage invasive breast cancer. Using data from current clinical and observational studies, this study aimed to assess the impact of single-fraction electron IORT on local recurrence rates. METHODS: Studies on single-fraction electron IORT during breast conserving surgery were identified through a search of PubMed and Google Scholar, as well as through secondary referencing. Local recurrence rate was the main outcome of interest. A meta-analysis of proportions using a binomial distribution to model the within-study variability and a random effects model was conducted to estimate a pooled local recurrence rate. To estimate a 5-year recurrence rate, a single-sample Poisson-normal model was applied to model the probability of events occurring during a fixed period (60 months). RESULTS: The study identified 13 publications. The analysis demonstrated a pooled monthly local recurrence rate of 0.02% per person-month (95% confidence interval CI 0.00-0.06%) for the studies with a follow-up period shorter than 5 years, 0.03% per person-month (95% CI 0.02-0.06%) for studies with a follow-up period of 5 years or longer, and 0.02% per person-month (95% CI 0.01-0.04%) overall. Based on this model, the predicted 5-year local recurrence rate was 2.7% (range 1.9-3.7%). CONCLUSIONS: According to the published literature, the rate of breast cancer local recurrence after electron IORT was 0.02% per person-month, with an adjusted 5-year recurrence rate of 2.7%. These findings support the recent guidelines from the American Society for Radiation Oncology (ASTRO) supporting the use of electron IORT for low-risk patients

Importance sampling method of correction for multiple testing in affected sib-pair linkage analysis.

Using the Genetic Analysis Workshop 13 simulated data set, we compared the technique of importance sampling to several other methods designed to adjust p-values for multiple testing: the Bonferroni correction, the method proposed by Feingold et al., and naïve Monte Carlo simulation. We performed affected sib-pair linkage analysis for each of the 100 replicates for each of five binary traits and adjusted the derived p-values using each of the correction methods. The type I error rates for each correction method and the ability of each of the methods to detect loci known to influence trait values were compared. All of the methods considered were conservative with respect to type I error, especially the Bonferroni method. The ability of these methods to detect trait loci was also low. However, this may be partially due to a limitation inherent in our binary trait definitions