Binge drinking and alcohol prices: a systematic review of age-related results from econometric studies, natural experiments and field studies

Background: Heavy episodic (“binge”) drinking of alcohol has serious public health implications, especially for youth and young adults. Previous summaries and surveys have failed to address in a comprehensive manner the effects of alcohol prices on binge drinking by gender or age group. Methods: A qualitative systematic review is performed for effects of alcohol prices (or tax surrogates) on binge drinking for three age groups: youth, young adults, and adults. Outcomes examined include binge participation, intensity and frequency. Criteria for data collection and potential sources of bias are discussed, including adequacy of price data. Price-binge relationships are judged using a 95% confidence interval (p ≤ 0.05) for statistical significance. Results: Fifty-six relevant econometric studies were found, with studies and results distributed equally among three age groups. Also found were five natural experiments for tax reductions and six field studies. Null results or mixed results are found in more than half of the studies. The body of evidence indicates that binge drinkers are not highly-responsive to increased prices. Non-responsiveness holds generally for younger and older drinkers and for male and female binge drinkers alike. A limitation of the current literature is that results are only available for higher-income countries. Conclusions: Increased alcohol taxes or prices are unlikely to be effective as a means to reduce binge drinking, regardless of gender or age group

Methods for Cancer Epigenome Analysis

Accurate detection of epimutations in tumor cells is crucial for understanding the molecular pathogenesis of cancer. Alterations in DNA methylation in cancer are functionally important and clinically relevant, but even this well-studied area is continually re-evaluated in light of unanticipated results, including a strong connection between aberrant DNA methylation in adult tumors and polycomb group profiles in embryonic stem cells, cancer-associated genetic mutations in epigenetic regulators such as DNMT3A and TET family genes, and the discovery of abundant 5-hydroxymethylcytosine, a product of TET proteins acting on 5-methylcytosine, in human tissues. The abundance and distribution of covalent histone modifications in primary cancer tissues relative to normal cells is a largely uncharted area, although there is good evidence for a mechanistic role of cancer-specific alterations in epigenetic marks in tumor etiology, drug response and tumor progression. Meanwhile, the discovery of new epigenetic marks continues, and there are many useful methods for epigenome analysis applicable to primary tumor samples, in addition to cancer cell lines. For DNA methylation and hydroxymethylation, next-generation sequencing allows increasingly inexpensive and quantitative whole-genome profiling. Similarly, the refinement and maturation of chromatin immunoprecipitation with next-generation sequencing (ChIP-seq) has made possible genome-wide mapping of histone modifications, open chromatin and transcription factor binding sites. Computational tools have been developed apace with these epigenome methods to better enable the accuracy and interpretation of the data from the profiling methods