Evaluation of the benefits, harms and cost‐effectiveness of potential alternatives to iFOBT testing for colorectal cancer screening in Australia

The Australian National Bowel Cancer Screening Program (NBCSP) will fully roll‐out 2‐yearly screening using the immunochemical Faecal Occult Blood Testing (iFOBT) in people aged 50 to 74 years by 2020. In this study, we aimed to estimate the comparative health benefits, harms, and cost‐effectiveness of screening with iFOBT, versus other potential alternative or adjunctive technologies. A comprehensive validated microsimulation model, Policy1‐Bowel, was used to simulate a total of 13 screening approaches involving use of iFOBT, colonoscopy, sigmoidoscopy, computed tomographic colonography (CTC), faecal DNA (fDNA) and plasma DNA (pDNA), in people aged 50 to 74 years. All strategies were evaluated in three scenarios: (i) perfect adherence, (ii) high (but imperfect) adherence, and (iii) low adherence. When assuming perfect adherence, the most effective strategies involved using iFOBT (annually, or biennially with/without adjunct sigmoidoscopy either at 50, or at 54, 64 and 74 years for individuals with negative iFOBT), or colonoscopy (10‐yearly, or once‐off at 50 years combined with biennial iFOBT). Colorectal cancer incidence (mortality) reductions for these strategies were 51–67(74–80)% in comparison with no screening; 2‐yearly iFOBT screening (i.e. the NBCSP) would be associated with reductions of 51(74)%. Only 2‐yearly iFOBT screening was found to be cost‐effective in all scenarios in context of an indicative willingness‐to‐pay threshold of A$50,000/life‐year saved (LYS); this strategy was associated with an incremental cost‐effectiveness ratio of A$2,984/LYS–A$5,981/LYS (depending on adherence). The fully rolled‐out NBCSP is highly cost‐effective, and is also one of the most effective approaches for bowel cancer screening in Australia

Calculation of the relative metastabilities of proteins in subcellular compartments of Saccharomyces cerevisiae

[abridged] Background: The distribution of chemical species in an open system at metastable equilibrium can be expressed as a function of environmental variables which can include temperature, oxidation-reduction potential and others. Calculations of metastable equilibrium for various model systems were used to characterize chemical transformations among proteins and groups of proteins found in different compartments of yeast cells. Results: With increasing oxygen fugacity, the relative metastability fields of model proteins for major subcellular compartments go as mitochondrion, endoplasmic reticulum, cytoplasm, nucleus. In a metastable equilibrium setting at relatively high oxygen fugacity, proteins making up actin are predominant, but those constituting the microtubule occur with a low chemical activity. A reaction sequence involving the microtubule and spindle pole proteins was predicted by combining the known intercompartmental interactions with a hypothetical program of oxygen fugacity changes in the local environment. In further calculations, the most-abundant proteins within compartments generally occur in relative abundances that only weakly correspond to a metastable equilibrium distribution. However, physiological populations of proteins that form complexes often show an overall positive or negative correlation with the relative abundances of proteins in metastable assemblages. Conclusions: This study explored the outlines of a thermodynamic description of chemical transformations among interacting proteins in yeast cells. The results suggest that these methods can be used to measure the degree of departure of a natural biochemical process or population from a local minimum in Gibbs energy.Comment: 32 pages, 7 figures; supporting information is available at http://www.chnosz.net/yeas

Will cervical screening remain cost-effective in women offered the next generation nonavalent HPV vaccine? Results for four developed countries

A next generation nonavalent human papillomavirus (HPV) vaccine ("HPV9 vaccine") is being introduced in several countries. The aims of this study were to evaluate whether cervical screening will remain cost-effective in cohorts offered nonavalent vaccines and if so, to characterize the optimal number of screening tests. We used a dynamic model of HPV vaccination and cervical screening to evaluate the cost-effectiveness of strategies involving varying numbers of primary HPV tests per lifetime for cohorts offered the nonavalent vaccine as 12 year-olds. For each of four countries-the USA, New Zealand (NZ), Australia and England-we considered local factors including vaccine uptake rates (USA/NZ uptake ∼50%; Australia/England uptake >70%), attributable fractions of HPV9-included types, demographic factors, costs and indicative willingness-to-pay (WTP) thresholds. Extensive probabilistic sensitivity analysis was performed. We found that, in the USA, four screens per lifetime was the most likely scenario, with 34% probability of being optimal at WTP US$50,000/LYS, increasing to 84$100,000/LYS. In New Zealand, five screens per lifetime was the most likely scenario, with 100% probability of being optimal at NZ$42,000/LYS, given the assumptions used. In Australia, two screens per lifetime was the most likely scenario, with 62$50,000/LYS. In England, four screens per lifetime was the most likely scenario, with 32% probability of being optimal at GB£20,000/LYS, increasing to 96% probability at GB£30,000/LYS. We conclude that some cervical screening will remain cost-effective, even in countries with high vaccination coverage. However, the optimal number of screens may vary between countries