Anisotropy governed competition of magnetic phases in the honeycomb quantum magnet Na3_3Ni2_2SbO6_6 studied by dilatometry and high-frequency ESR

Thermodynamic properties as well as low-energy magnon excitations of $S=1$ honeycomb-layered Na$_3$Ni$_2$SbO$_6$ have been investigated by high-resolution dilatometry, static magnetisation, and high-frequency electron spin resonance studies in magnetic fields up to 16 T. At $T_{\rm N}$ = 16.5 K, there is a tricritical point separating two distinct antiferromagnetic phases AF1 and AF2 from the paramagnetic regime. In addition, our data imply short-range antiferromagnetic correlations at least up to $\sim 5\cdot T_{\rm N}$. Well below $T_{\rm N}$, the magnetic field $B_{\rm C1}\approx$ 9.5 T is needed to stabilize AF2 against AF1. The thermal expansion and magnetostriction anomalies at $T_{\rm N}$ and $B_{\rm C1}$ imply significant magnetoelastic coupling, both of which associated with a sign change of $\partial L/\partial B$. The transition at $B_{\rm C1}$ is associated with softening of the antiferromagnetic resonance modes observed in the electron spin resonance spectra. The anisotropy gap $\Delta = 360$ GHz implies considerable uniaxial anisotropy. We conclude the crucial role of axial anisotropy favoring the AF1 spin structure over the AF2 one. While the magnetostriction data disprove a simple spin-flop scenario at $B_{\rm C1}$, the nature of a second transition at $B_{\rm C2}\approx$ 13 T remains unclear. Both the sign of the magnetostriction and Gr\"uneisen analysis suggest the short-range correlations at high temperatures to be of AF2-type

Forecasting age-specific breast cancer mortality using functional data models

Accurate estimates of future age-specific incidence and mortality are critical for allocation of resources to breast cancer control programs and evaluation of screening programs. The purpose of this study is to apply functional data analysis techniques to model age-specific breast cancer mortality time trends, and forecast entire age-specific mortality function using a state-space approach. We use yearly unadjusted breast cancer mortality rates in Australia, from 1921 to 2001 in 5 year age groups (45 to 85+). We use functional data analysis techniques where mortality and incidence are modeled as curves with age as a functional covariate varying by time. Data is smoothed using nonparametric smoothing methods then decomposed (using principal components analysis) to estimate basis functions that represent the functional curve. Period effects from the fitted functions are forecast then multiplied by the basis functions, resulting in a forecast mortality curve with prediction intervals. To forecast, we adopt a state-space approach and an extension of the Pegels modeling framework for selecting among exponential smoothing methods. Overall, breast cancer mortality rates in Australia remained relatively stable from 1960 to the late 1990's but declined over the last few years. A set of K=4 basis functions minimized the mean integrated squared forecasting error (MISFE) and accounts for 99.3% of variation around the mean mortality curve. 20 year forecast suggest a continual decline at a slower rate and stabilize beyond 2010 and by age, forecasts show a decline in all age groups with the greatest decline in older women. We illustrate the utility of a new modelling and forecasting approach to model breast cancer mortality rates using a functional model of age. The methods have the potential to incorporate important covariates such as Hormone Replacement Therapy (HRT) and interventions to represent mammographic screening. This would be particularly useful for evaluating the impact of screening on mortality and incidence from breast cancer.Mortality, Breast Cancer, Forecasting, Functional Data Analysis, Exponential Smoothing

Expenditure and resource utilisation for cervical screening in Australia

BACKGROUND The National Cervical Screening Program in Australia currently recommends that women aged 18-69 years are screened with conventional cytology every 2 years. Publicly funded HPV vaccination was introduced in 2007, and partly as a consequence, a renewal of the screening program that includes a review of screening recommendations has recently been announced. This study aimed to provide a baseline for such a review by quantifying screening program resource utilisation and costs in 2010. METHODS A detailed model of current cervical screening practice in Australia was constructed and we used data from the Victorian Cervical Cytology Registry to model age-specific compliance with screening and follow-up. We applied model-derived rate estimates to the 2010 Australian female population to calculate costs and numbers of colposcopies, biopsies, treatments for precancer and cervical cancers in that year, assuming that the numbers of these procedures were not yet substantially impacted by vaccination. RESULTS The total cost of the screening program in 2010 (excluding administrative program overheads) was estimated to be A$194.8M. We estimated that a total of 1.7 million primary screening smears costing$96.7M were conducted, a further 188,900 smears costing $10.9M were conducted to follow-up low grade abnormalities, 70,900 colposcopy and 34,100 histological evaluations together costing$21.2M were conducted, and about 18,900 treatments for precancerous lesions were performed (including retreatments), associated with a cost of $45.5M for treatment and post-treatment follow-up. We also estimated that$20.5M was spent on work-up and treatment for approximately 761 women diagnosed with invasive cervical cancer. Overall, an estimated $23 was spent in 2010 for each adult woman in Australia on cervical screening program-related activities. CONCLUSIONS Approximately half of the total cost of the screening program is spent on delivery of primary screening tests; but the introduction of HPV vaccination, new technologies, increasing the interval and changing the age range of screening is expected to have a substantial impact on this expenditure, as well as having some impact on follow-up and management costs. These estimates provide a benchmark for future assessment of the impact of changes to screening program recommendations to the costs of cervical screening in Australia

Cervical abnormalities are more common among Indigenous than other Australian women: a retrospective record-linkage study, 2000-2011

Indigenous Australian women have much higher incidence of cervical cancer compared to non-Indigenous women. Despite an organised cervical screening program introduced 25 years ago, a paucity of Indigenous-identified data in Pap Smear Registers remains. Prevalence of cervical abnormalities detected among the screened Indigenous population has not previously been reported. We conducted a retrospective cohort study of population-based linked health records for 1,334,795 female Queensland residents aged 20–69 years who had one or more Pap smears during 2000–2011; from linked hospital records 23,483 were identified as Indigenous. Prevalence was calculated separately for Indigenous and non-Indigenous women, for cytology-detected low-grade (cLGA) and high-grade abnormalities (cHGA), and histologically confirmed high-grade abnormalities (hHGA). Odds ratios (OR) were estimated from logistic regression analysis. In 2010–2011 the prevalence of hHGA among Indigenous women (16.6 per 1000 women screened, 95% confidence interval [CI] 14.6–18.9) was twice that of non-Indigenous women (7.5 per 1000 women screened, CI 7.3–7.7). Adjusted for age, area-level disadvantage and place of residence, Indigenous women had higher prevalence of cLGA (OR 1.4, CI 1.3–1.4), cHGA (OR 2.2, CI 2.1–2.3) and hHGA (OR 2.0, CI 1.9–2.1). Our findings show that Indigenous women recorded on the Pap Smear Register have much higher prevalence for cLGA, cHGA and hHGA compared to non-Indigenous women. The renewed cervical screening program, to be implemented in 2017, offers opportunities to reduce the burden of abnormalities and invasive cancer among Indigenous women and address long-standing data deficiencies.Lisa J. Whop, Peter Baade, Gail Garvey, Joan Cunningham, Julia M. L. Brotherton, Kamalini Lokuge, Patricia C. Valery, Dianne L. O, Connell, Karen Canfell, Abbey Diaz, David Roder, Dorota M. Gertig, Suzanne P. Moore, John R. Condo

The first comprehensive report on Indigenous Australian women's inequalities in cervical screening: a retrospective registry cohort study in Queensland, Australia (2000-2011)

BACKGROUND: The Australian National Cervical Screening Program, introduced more than 20 years ago, does not record the Indigenous status of screening participants. This article reports the first population-based estimates of participation in cervical screening for Indigenous and non-Indigenous Australian women. METHODS: This was a retrospective, population-based study of 1,334,795 female Queensland residents, aged 20 to 69 years, who participated in cervical screening from 2000 to 2011; 26,829 were identified as Indigenous through linkage to hospitalization records. Participation rates were calculated as the number of women screened divided by the average estimated resident population, with adjustments made for hysterectomies, for each 2-, 3-, and 5-year screening period. Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), which were adjusted for age group, place of residence, and socioeconomic disadvantage. RESULTS: In 2010-2011, the 2-year participation rate was 55.7% (95% CI, 55.6%-55.9%) for non-Indigenous women and 33.5% (95% CI, 32.9%-34.1%) for Indigenous women; this represented a decrease from 2000-2001 (57.7% [95% CI, 57.6%-57.9%] and 35.3% [95% CI, 34.5%-36.1%], respectively). The difference between Indigenous and non-Indigenous women was greatest for those aged 45 to 49 years. The 3- and 5-year participation rates were higher within both groups, and the absolute differences between the 2 groups were larger. Significant interactions between the Indigenous status and the place of residence and socioeconomic disadvantage highlight that the Indigenous/non-Indigenous differential was evident in all places of residence except for very remote areas (OR, 0.99; 95% CI, 0.95-1.02) and was greatest in the most affluent areas (OR, 0.26; 95% CI, 0.24-0.27). CONCLUSIONS: Indigenous Australian women participate less than non-Indigenous women, and this gap has not closed. These results provide important benchmarks for the new Australian cervical screening program commencing in 2017, which will provide opportunities to reduce inequities for Indigenous women and address longstanding data deficiencies in the collection of the Indigenous status. Cancer 2016;122:1560-9. VC 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.Lisa J. Whop, Gail Garvey, Peter Baade, Joan Cunningham, Kamalini Lokuge, Julia M. L. Brotherton, Patricia C. Valery, Dianne L. O, Connell, Karen Canfell, Abbey Diaz, David Roder, Dorota Gertig, Suzanne P. Moore and John R. Condo

The time-evolution of DCIS size distributions with applications to breast cancer growth and progression

Ductal carcinoma {\em in situ} (DCIS) lesions are non-invasive tumours of the breast which are thought to precede most invasive breast cancers (IBC). As individual DCIS lesions are initiated, grow and invade (i.e. become IBC) the size distribution of the DCIS lesions present in a given human population will evolve. We derive a differential equation governing this evolution and show, for given assumptions about growth and invasion, that there is a unique distribution which does not vary with time. Further, we show that any initial distribution converges to this stationary distribution exponentially quickly. It is therefore reasonable to assume that the stationary distribution is equal to the true DCIS size distribution, at least for human populations which are relatively stable with respect to the determinants of breast cancer. Based on this assumption and the size data of 110 DCIS lesions detected in a mammographic screening program between 1993 and 2000, we produce maximum likelihood estimates for certain growth and invasion parameters. Assuming that DCIS size is proportional to a positive power $p$ of the time since tumour initiation we estimate $p$ to be 0.50 with a 95% confidence interval of $(0.35, 0.71)$. Therefore we estimate that DCIS lesions follow a square-root growth law and hence that they grow rapidly when small and relatively slowly when large. Our approach and results should be useful for other mathematical studies of cancer, especially those investigating biological mechanisms of invasion.Comment: 12 pages, 2 figures and 1 table. To appear in Mathematical Medicine and Biolog