Recent work in the literature had evaluated the energy-momentum tensor of a Casimir apparatus in a weak gravitational field, for an electromagnetic field subject to perfect conductor boundary conditions on parallel plates. The Casimir apparatus was then predicted to experience a tiny push in the upwards direction, and the regularized energy-momentum tensor was found to have a trace anomaly. The latter, unexpected property made it compelling to assess what happens in a simpler case. For this purpose, the present paper studies a free, real massless scalar field subject to homogeneous Dirichlet conditions on the parallel plates. Working to first order in the constant gravity acceleration, the resulting regularized and renormalized energy-momentum tensor is found to be covariantly conserved, while the trace anomaly vanishes if the massless scalar field is conformally coupled to gravity. Conformal coupling also ensures a finite Casimir energy and finite values of the pressure upon parallel plates.

Objective Assess the progression, persistence, and regression of cervical intraepithelial neoplasia grade 2 (CIN2) after new guidelines on conservative treatment, compared with previous practice. Design Nationwide register‐based cohort study. Setting Denmark. Population Women aged 18–44 years diagnosed with CIN2 on biopsy: 6721 in 2008–2011 and 6399 in 2014–2017. Methods Register data were retrieved from before (2008–2011) and after (2014–2017) the introduction of new guidelines. Histology diagnoses at second visit were used to assess progression (CIN3+), persistence (CIN2), or regression (CIN1/normal). Main outcome measures Proportion of CIN2 by type of management. Relative risk (RR) and corresponding 95% confidence intervals (95% CIs) for progression, persistence, and regression at second visit in 2014–2017, versus 2008–2011. Results The proportion of CIN2 managed conservatively increased from 29.6% in 2008–2011 to 53.3% in 2014–2017 (RR 1.81, 95% CI 1.73–1.89). Time to second visit increased by 2 months. Regression increased from 23.5 to 30.2% (RR 1.29, 95% CI 1.22–1.36), whereas persistence and progression decreased, from 42.6 to 34.9% (RR 0.82, 95% CI 0.78–0.86) and from 28.0 to 22.8% (RR 0.81, 95% CI 0.77–0.86), respectively. In 2008–2011, women managed conservatively had a regression rate of 41.8%, persistence rate of 40.9%, and progression rate of 16.6%. In 2014–2017, these rates were 46.7, 35.5, and 17.1%, respectively. Conclusion After implementation of the new guidelines, conservative management became more frequent, and is now used for more than half of women with CIN2. Lesion regression became more frequent, now experienced by 47% of women managed conservatively. Similar regression rates were seen in women younger and older than 30 years, suggesting that conservative management is justifiable for women of childbearing age. Tweetable abstract In Denmark, more than half of women with CIN2 are managed conservatively, and half of these women experience lesion regression.

PurposeThe currently recommended double reading of all screening mammography examinations is an economic burden for screening programs. The sensitivity of screening is higher for women with low breast density than for women with high density. One may therefore ask whether single reading could replace double reading at least for women with low density. We addressed this question using data from a screening program where the radiologists coded their readings independently.MethodsData include all screening mammography examinations in the Capital Region of Denmark from 1 November 2012 to 31 December 2013. Outcome of screening was assessed by linkage to the Danish Pathology Register. We calculated sensitivity, specificity, number of interval cancers, and false positive-tests per 1000 screened women by both single reader and consensus BI-RADS density code.ResultsIn total 54,808 women were included. The overall sensitivity of double reading was 72%, specificity was 97.6%, 3 women per 1000 screened experienced an interval cancer, and 24 a false-positive test. Across all BI-RADS density codes, single reading consistently decreased sensitivity as compared with consensus reading. The same was true for specificity, apart from results across BI-RADS density codes set by reader 2.ConclusionsSingle reading decreased sensitivity as compared with double reading across all BI-RADS density codes. This included results based on consensus BI-RADS density codes. This means that replacement of double with single reading would have negative consequences for the screened women, even if density could be assessed automatically calibrated to the usual consensus level.

4vHPV vaccination has been tested in randomized controlled trials under almost ideal conditions, and studies of real‐life use have compared outcome between vaccinated and unvaccinated women from the same birth cohort and mostly before screening age. Here we present the first—to our knowledge—evaluation of the impact of the 4vHPV vaccination in real life without selection bias in the reported data. The study has been carried out by comparing the results after first cervical screening between an HPV‐vaccinated and an unvaccinated birth cohort, consisting of women born in Denmark in 1993 and 1983, respectively. Cytology data covering an 8‐year period, from the age of 15 (age of HPV‐vaccination) to age 23 (age of invitation to first cervical screening), were retrieved from the Danish National Pathology Register. Abnormal cytology, defined as atypical squamous cell of undetermined significance and worse (ASCUS+) was detected in 9.4% of women born in 1993 as compared with 9.0% of women born in 1983; RR = 1.04 (95% CI 0.96–1.12), p = .29. Detection of high‐grade squamous intraepithelial lesion (HSIL) was statistically significantly lower in the 1993 than in the 1983 cohort, RR = 0.6 (95% CI 0.5–0.7), p < .0001, while the opposite pattern was seen for ASCUS RR = 1.4 (95% CI 1.2–1.6), p < .0001. The decrease in HSIL means that more women can be spared referral for colposcopy and biopsy. The increase of ASCUS could be explained by transition from conventional to liquid‐based cytology, but this observation requires further monitoring.

Background: Attention in the 2000s on the importance of mammographic density led us to study screening sensitivity, breast cancer incidence, and associations with risk factors by mammographic density in Danish breast cancer screening programs. Here, we summarise our approaches and findings. Methods: Dichotomized density codes: fatty, equal to BI-RADS density code 1 and part of 2, and other mixed/dense data from the 1990s—were available from two counties, and BI-RADS density codes from one region were available from 2012/13. Density data were linked with data on vital status, incident breast cancer, and potential risk factors. We calculated screening sensitivity by combining data on screen-detected and interval cancers. We used cohorts to study high density as a predictor of breast cancer risk; cross-sectional data to study the association between life style factors and density, adjusting for age and body mass index (BMI); and time trends to study the prevalence of high density across birth cohorts. Results: Sensitivity decreased with increasing density from 78% in women with BI-RADS 1 to 47% in those with BI-RADS 4. For women with mixed/dense compared with those with fatty breasts, the rate ratio of incident breast cancer was 2.45 (95% CI 2.14–2.81). The percentage of women with mixed/dense breasts decreased with age, but at a higher rate the later the women were born. Among users of postmenopausal hormone therapy, the percentage of women with mixed/dense breasts was higher than in non-users, but the patterns across birth cohorts were similar. The occurrence of mixed/dense breast at screening age decreased by a z-score unit of BMI at age 13—odds ratio (OR) 0.56 (95% CI 0.53–0.58)—and so did breast cancer risk and hazard ratio (HR) 0.92 (95% CI 0.84–1.00), but it changed to HR 1.01 (95% CI 0.93–1.11) when controlled for density. Age and BMI adjusted associations between life style factors and density were largely close to unity; physical activity OR 1.06 (95% CI 0.93–1.21); alcohol consumption OR 1.01 (95% CI 0.81–1.27); air pollution OR 0.96 (95% 0.93–1.01) per 20 μg/m3; and traffic noise OR 0.94 (95% CI 0.86–1.03) per 10 dB. Weak negative associations were seen for diabetes OR 0.61 (95% CI 0.40–0.92) and cigarette smoking OR 0.86 (95% CI 0.75–0.99), and a positive association was found with hormone therapy OR 1.24 (95% 1.14–1.35). Conclusion: Our data indicate that breast tissue in middle-aged women is highly dependent on childhood body constitution while adult life-style plays a modest role, underlying the need for a long-term perspective in primary prevention of breast cancer.