A unified framework for estimating country-specific cumulative incidence for 18 diseases stratified by polygenic risk

Polygenic scores (PGSs) offer the ability to predict genetic risk for complex diseases across the life course; a key benefit over short-term prediction models. To produce risk estimates relevant to clinical and public health decision-making, it is important to account for varying effects due to age and sex. Here, we develop a novel framework to estimate country-, age-, and sex-specific estimates of cumulative incidence stratified by PGS for 18 high-burden diseases. We integrate PGS associations from seven studies in four countries (N = 1,197,129) with disease incidences from the Global Burden of Disease. PGS has a significant sex-specific effect for asthma, hip osteoarthritis, gout, coronary heart disease and type 2 diabetes (T2D), with all but T2D exhibiting a larger effect in men. PGS has a larger effect in younger individuals for 13 diseases, with effects decreasing linearly with age. We show for breast cancer that, relative to individuals in the bottom 20% of polygenic risk, the top 5% attain an absolute risk for screening eligibility 16.3 years earlier. Our framework increases the generalizability of results from biobank studies and the accuracy of absolute risk estimates by appropriately accounting for age- and sex-specific PGS effects. Our results highlight the potential of PGS as a screening tool which may assist in the early prevention of common diseases.

Factors associated with advanced-stage diagnosis of cervical cancer in Estonia: a population-based study

OBJECTIVES

Cervical cancer (CC) remains a crucial public health issue in Estonia, with high incidence and late diagnosis. The aim of this study was to examine time trends of stage-specific CC incidence in Estonia and factors associated with advanced-stage diagnosis of CC.

STUDY DESIGN

This was a nationwide population-based retrospective study.

METHODS

Data on CC cases diagnosed in Estonia in 2007-2018 were obtained from the Estonian Cancer Registry, including tumour, nodes, metastases stage at diagnosis. Sociodemographic data were obtained from the Population Registry. To estimate the risk of advanced-stage diagnosis (stages II-IV vs stage I) associated with sociodemographic factors, Poisson regression with robust variance was used to calculate univariate and multivariate prevalence ratios (PR) with 95% confidence intervals (CIs). Time trends of stage-specific CC incidence for 2005-2019 were examined with joinpoint analysis.

RESULTS

Incidence of stage I CC showed a significant decline of 4.9% per year since 2007, whereas no change was seen for other stages. Of the 2046 women diagnosed in 2007-2018, 1137 (55.6%) were diagnosed at an advanced stage; this proportion increased from 51% in 2007-2009 to 58% in 2015-2018 (P = 0.004). Multivariate regression analysis showed that advanced-stage diagnosis was associated with age (PR 2.16, 95% CI 1.87-2.49 for women aged ≥75 years compared with those aged 30-44 years), educational level (PR 1.32, 95% CI 1.15-1.51 for women with basic/primary education compared to university education) and marital status (PR 1.14, 95% CI 1.01-1.29 for single women compared to married/cohabiting women). No associations were observed by region of residence or nationality.

CONCLUSIONS

To reduce CC mortality, it is crucial to improve prevention and early diagnosis of CC in Estonia through human papillomavirus vaccination and effective and quality-assured screening particularly targeting high-risk groups as well as encouraging symptom awareness and regular check-ups among older women.

The impact of sociodemographic factors on the utilization of radiation therapy in breast cancer patients in Estonia: a register-based study

Background

Radiation therapy is an important part of multimodal breast cancer treatment. The aim was to examine the impact of sociodemographic factors on radiation therapy use in breast cancer (BC) patients in Estonia, linking cancer registry data to administrative databases.

Methods

Estonian Cancer Registry provided data on women diagnosed with BC in Estonia in 2007–2018, including TNM stage at diagnosis. Use of radiation therapy within 12 months of diagnosis was determined from Estonian Health Insurance Funds claims, and sociodemographic characteristics from population registry. Receipt of radiation therapy was evaluated over time and by clinical and sociodemographic factors. Poisson regression with robust variance was used to calculate univariate and multivariate prevalence rate ratios (PRR) with 95 % confidence intervals (CI) for receipt of radiation therapy among stage I–III BC patients age < 70 years who underwent primary surgery.

Results

Overall, of 8637 women included in the study, 4310 (50 %) received radiation therapy within 12 months of diagnosis. This proportion increased from 39 to 58 % from 2007 to 2009 to 2016–2018 (p < 0.001). Multivariate regression analysis showed that compared to women with stage I BC, those with more advanced stage were less likely to receive radiation therapy. Receipt of radiation therapy increased significantly over time and was nearly 40 % higher in 2016–2018 than in 2007–2009. Use of radiation therapy was significantly lower for women with the lowest level of education compared to those with a university degree (PRR 0.88, 95 % CI 0.80–0.97), and for divorced/widowed women (PRR 0.95, 95 % CI 0.91–0.99) and single women (PRR 0.92, 95 % CI 0.86–0.99), compared to married women. Age at diagnosis, nationality and place of residence were not associated with receipt of radiation therapy.

Conclusions

The study showed considerable increase in the use of radiation therapy in Estonia over the study period, which is in line with increases in available equipment. The lack of geographic variations suggests equal access to therapy for patients living in remote regions. However, educational level and marital status were significantly associated with receipt of radiation therapy, highlighting the importance of psychosocial support in ensuring equal access to care.

Cancer Incidence Trends in the Oil Shale Industrial Region in Estonia

Large oil shale resources are found in Eastern Estonia, where the mineral resource is mined, excavated, and used for electricity generation and shale oil extraction. During industrial activities in the last 100 years, pollutants have been emitted in large amounts, some of which are toxic and carcinogenic. The current study aims to analyse time trends in cancer incidence in the oil shale industry-affected areas and compare them with overall cancer incidence rates and trends in Estonia. We analysed Estonian Cancer Registry data on selected cancer sites that have been previously indicated to have relationships with industrial activities like oil shale extraction. We included lung cancer, kidney cancer, urinary bladder cancer, leukaemia, breast cancer, and non-Hodgkin's lymphoma. A statistically significantly higher lung cancer age-standardized incidence rate (ASIR) was found during the study period (1992-2015) only in males in the oil shale areas as compared to males in Estonia overall: 133.6 and 95.5 per 100,000, respectively. However, there appeared to be a statistically significant (p < 0.05) decrease in the lung cancer ASIR in males in the oil shale areas (overall decrease 28.9%), whereas at the same time, there was a significant increase (p < 0.05) in non-oil shale areas (13.3%) and in Estonia overall (1.5%). Other cancer sites did not show higher ASIRs in the oil shale industrial areas compared to other areas in Estonia. Possible explanations could be improved environmental quality, socio-economic factors, and other morbidities.

Recent changes in breast cancer incidence and mortality in Estonia: Transition to the west

Background The aim of this study was to examine breast cancer (BC) incidence and mortality trends in Estonia during recent decades and to compare the pattern of these trends with other selected European countries and regions. We attempt to explain the findings in relation to changes in Estonian society and healthcare system. Methods BC incidence (1985-2012) and mortality (1985-2013) data for Estonia were obtained from the Estonian Cancer Registry and Statistics Estonia. Data for selected European countries were obtained from the EUREG database. Joinpoint regression was used to analyze age-standardized rates in Estonia by age. For international comparison of incidence and mortality rates, we used scatterplot with 95% confidence ellipses and the mortality to incidence ratio. Results The overall BC incidence continues to increase in Estonia, while mortality has been in decline since 2000. Both incidence and mortality trends varied considerably across age groups. Among women aged 60 years and older, BC incidence increased at a rate of nearly 3% per year. Significant decrease in mortality was seen only among women aged 50-59 years. Comparison of scatterplots between countries and regions revealed two clusters in Europe separated along the incidence axis. The correlation between incidence and mortality in Estonia changed its direction in the mid-1990s. Conclusion In recent years, the dynamics of BC burden in Estonia has transitioned towards the high incidence-low mortality type model, which is characteristic to Western, Northern and Southern Europe. Although overall BC incidence is much lower in Estonia than in more affluent European countries, mortality from BC is still relatively high, particularly among elderly women.

Disparity in Breast Cancer Late Stage at Diagnosis in Missouri: Does Rural Versus Urban Residence Matter?

INTRODUCTION

Despite the fact that black women have a lower incidence of breast cancer compared to white women, black women experience higher death rates than any other group. We examined the stage of breast cancer presentation by race and geographic region using population-based breast cancer incidence in all 115 counties in the state of Missouri.

METHODS

We used 2003-2008 breast cancer incidence data from Missouri Cancer Registry and Research Center. County of residence was categorized as urban or rural using the rural-urban continuum code. We computed the conditional proportion of stage at diagnosis by race and metropolitan status and also used Pearson's chi-squared test with Yates' continuity correction to determine statistical significance of association.

RESULTS

Results of the study indicate that a greater proportion of black women (38.8 %) compared to white women (30.2 %) were diagnosed with more advanced breast metastasis. Our results further suggest that stage at diagnosis depended on county of residence or metropolitan status (p = .04). Women living in non-metropolitan counties were slightly more likely to have late-stage breast cancer than their metropolitan counterparts (32.0 vs 30.7 %). Overall, black women had 1.5-fold increased odds of late-stage breast cancer diagnosis compared to their white counterparts (OR = 1.50; 95 % CI, 1.39, 1.63; p < 0.0001). While the odds of late diagnosis among women living in non-metropolitan or rural counties was over 11 % higher compared with their metropolitan or urban counterpart.

CONCLUSION

The current study corroborates previous findings that the risk of late-stage breast cancer diagnosis was higher among women residing in non-metropolitan rural counties.

Identifying women at risk for delayed presentation of breast cancer: a cross-sectional study in Estonia

BACKGROUND

Survival from breast cancer remains lower in Estonia than in most other European countries. More advanced stage and larger tumors that have impact on survival may be a result of delay in seeking help for breast cancer symptoms. The aim of this study was to identify determinants of delayed presentation among breast cancer patients in Estonia.

METHODS

The study population included women with primary breast cancer diagnosed in Estonia in 2008-2010. All data were collected using structured personal interviews carried out by trained nurses in the hospital setting. Only patients with self-discovered symptoms were included in this analysis. Patient delay was measured as time elapsing from symptom self-discovery to first medical consultation. The effect of different factors on the likelihood of prolonged delay (>90 days) was evaluated using logistic regression.

RESULTS

Among 703 eligible patients, median patient delay was 16 days (interquartile range 5-54 days). Seventeen percent of the patients had their first medical consultation more than three months after self-detection of symptoms. In multivariate analysis, the risk of prolonged delay was significantly associated with age 65 years and over (OR 2.27, 95% CI 1.23-4.20), current smoking (OR 2.09, 95% CI 1.21-3.61), symptoms other than painless breast lump or breast pain (OR 1.84, 95% CI 1.08-3.16), no history of mammograms (OR 1.83, 95% CI 1.13-2.95), having received no information on breast cancer during past year (OR 1.77, 95% CI 1.05-2.99), and previous benign breast problems (OR 1.65, 95% CI 1.01-2.67). Non-significant risk increase was seen with lower education.

CONCLUSIONS

This study provides evidence that factors associated with delayed presentation of breast cancer in Eastern Europe are similar to those observed in Western countries. The results suggest that educational messages to general population should aim at increasing awareness of "non-lump" symptoms of breast cancer and encouraging women of all ages to present in a timely manner. Women at risk for delayed presentation such as smokers and women with no history of mammograms could be identified in the primary care setting.

Breast cancer screening utilization among Eastern European immigrant women worldwide: a systematic literature review and a focus on psychosocial barriers

OBJECTIVE

Many countries host growing Eastern European immigrant communities whose breast cancer preventive behaviors are largely unknown. Thus, we aimed to synthesize current evidence regarding secondary prevention via breast cancer screening utilized by that population.

METHODS

All observational, general population studies on breast cancer screening with Eastern European immigrant women and without any country, language, or age restrictions were identified. Screening modalities included breast self-examination, clinical breast examination, and mammography.

RESULTS

The selected 30 studies were published between 1996 and 2013 and came from Australia, Canada, Denmark, Germany, Israel, the Netherlands, Spain, Switzerland, the UK, and the USA. The reported prevalence of monthly breast self-examination was 0-48%; for yearly clinical breast examination 27-54%; and for biennial mammography 0-71%. The substantial methodologic heterogeneity prevented a meta-analysis. Nonetheless, irrespective of host country, healthcare access, or educational level, the findings consistently indicated that Eastern European immigrant women underutilize breast cancer screening largely because of insufficient knowledge about early detection and an external locus of control regarding decision making in health matters.

CONCLUSIONS

This is a vulnerable population for whom the implementation of culturally tailored breast cancer screening programs is needed. As with other underscreened immigrant/minority groups, Eastern European women's inadequate engagement in prevention is troublesome as it points to susceptibility not only to cancer but also to other serious conditions for which personal action and responsibility are critical.

Avoidable mortality in Estonia: exploring the differences in life expectancy between Estonians and non-Estonians in 2005-2007

OBJECTIVES

A considerable increase in social inequalities in mortality was observed in Eastern Europe during the post-communist transition. This study evaluated the contribution of avoidable causes of death to the difference in life expectancy between Estonians and non-Estonians in Estonia.

STUDY DESIGN

Descriptive study.

METHODS

Temporary life expectancy (TLE) was calculated for Estonian and non-Estonian men and women aged 0-74 years in 2005-2007. The ethnic TLE gap was decomposed by age and cause of death (classified as preventable or treatable).

RESULTS

The TLE of non-Estonian men was 3.53 years less than that of Estonian men, and the TLE of non-Estonian women was 1.36 years less than that of Estonian women. Preventable causes of death contributed 2.19 years to the gap for men and 0.78 years to the gap for women, while treatable causes contributed 0.67 and 0.33 years, respectively. Cardiorespiratory conditions were the major treatable causes of death, with ischaemic heart disease alone contributing 0.29 and 0.08 years to the gap for men and women, respectively. Conditions related to alcohol and substance use represented the largest proportion of preventable causes of death.

CONCLUSIONS

Inequalities in health behaviours underlie the ethnic TLE gap in Estonia, rather than inequalities in access to health care or the quality of health care. Public health interventions should prioritize primary prevention aimed at alcohol and substance use, and should be implemented in conjunction with wider social policy measures.

Preventing breast cancer in women with schizophrenia

OBJECTIVE

To record risk factors for breast cancer in women with schizophrenia and recommend preventive actions.

METHOD

A PubMed literature search (from 2005 to 2010) was conducted, using the search terms 'schizophrenia', 'antipsychotics', 'breast cancer' and 'risk factors'.

RESULTS

Several risk factors of relevance to schizophrenia were identified: obesity, elevated prolactin levels, low participation in mammography screening, high prevalence of diabetes, comparatively low parity, low incidence of breastfeeding, social disadvantage, high levels of smoking and alcohol consumption, low activity levels.

CONCLUSION

Awareness of breast cancer risk should lead to more accurate risk ascertainment, stronger linkage with primary care, regular monitoring and screening, judicious choice and low dose of antipsychotic treatment, concomitant use of adjunctive cognitive and psychosocial therapies, referral to diet and exercise programmes as well as smoking and drinking cessation programmes, avoidance of hormonal treatment and discussion with patient and family about the pros and cons of preventive measures in high-risk women. Psychiatrists are in a position to reverse many of the identified risk factors.