Kaire Innos

Correcting uterine cancer mortality in Estonia using linkage of causes of death and cancer registry data, 2000–2021

Cervical and corpus uteri cancer mortality may be underestimated due to a proportion of deaths attributed to unspecified uterine cancer. The aim was to estimate corrected mortality rates and trends for cervical and corpus uteri cancer in Estonia after reallocation of underlying cause of death using individual linkage of death records and cancer registry records. Deaths in Estonian female population in 2000-2021 with the underlying cause of cervical cancer (ICD-10 code C53), corpus uteri cancer (C54) or cancer of uterus not otherwise specified (C55) were individually linked to Estonian Cancer Registry to identify any cancers diagnosed in these persons. Underlying cause of death was reallocated if applicable. Original and corrected age-standardized (world) mortality trends were modelled using joinpoint regression. During 2000-2021, the corrected number of deaths was 1409 cervical cancer deaths (originally 1388, 1.5 % increase), 1146 corpus uteri cancer deaths (902, 27 % increase), and 50 unspecified uterine cancer deaths (368, 86 % decrease). Proportion of unspecified deaths decreased from 26 % (2000-2004) to 4 % (2016-2021) (p < 0.001). After correction, cervical cancer mortality trend steepened slightly from 0.8 % decrease per year to 1.1 % decrease (both significant). Corpus uteri cancer mortality trend changed direction from significant increase of 1.9 % per year to significant decrease of 1.4 % per year. Routine linkage of causes of death records with cancer registry is warranted for validating underlying cause of death. The results emphasize the importance of the availability of medical documentation for physicians assigning cause of death as well as relevant training.

HPV self-sampling in organized cervical cancer screening program: A randomized pilot study in Estonia in 2021

Background Cervical cancer incidence in Estonia ranks among the highest in Europe, but screening attendance has remained low. This randomized study aimed to evaluate the impact of opt-in and opt-out human papillomavirus (HPV) self-sampling options on participation in organized screening. Methods A random sample of 25,591 women were drawn from the cervical cancer screening target population who were due to receive a reminder in autumn 2021 and thereafter randomly allocated to two equally sized intervention arms (opt-out and opt-in) receiving a choice between HPV self-sampling or clinician sampling. In the opt-out arm, a self-sampler was sent to home address by regular mail; the opt-in arm received an e-mail containing a link to order a self-sampler online. The remaining 30,102 women in the control group received a standard reminder for conventional screening. Participation by intervention arm, age and region of residence was calculated; a questionnaire was used to assess self-sampling user experience. Results A significant difference in participation was seen between opt-out (41.7%) (19.8% chose self-sampling and 21.9% clinician sampling), opt-in (34.1%) (7.9% self-sampling, 26.2% clinician sampling) and control group (29.0%, clinician sampling only). All age groups and regions in the intervention arms showed higher participation compared to the control group, but the size of the effect varied. Among self-sampling users, 99% agreed that the device was easy to use and only 3.5% preferred future testing at the clinic. Conclusion Providing women with a choice between self-sampling and clinician sampling significantly increased participation in cervical cancer screening. Opt-in and opt-out options had a different effect across age groups, suggesting the need to adapt strategies.

Quality Assessment of Cervical Cytology Practices in Estonia From 2007 to 2018

Background Cervical cancer incidence and mortality in Estonia are among the highest in Europe, although the overall coverage with cervical cytology is high. This indicates potential issues with the quality of collection and/or laboratory evaluation of cervical cytology. Objectives The aim of the retrospective observational study was to assess the quality of cervical cytology specimen collection, evaluation, and reporting using laboratory reports in Estonia. Methods The study included women with a cervical cancer diagnosis in 2017−2018. Cervical cytology and histology reports for these women in 2007−2018 were obtained from ten laboratories. We described the quality of cytology specimen collection and reporting of cytology results. Multivariate logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) to identify factors associated with NILM as the last cervical cytology result within 5 or 2 years before the cervical cancer diagnosis. Also, we calculated cytology-histology correlation (CHC). Results We identified 503 cytology and 100 histology reports from 138 women. The laboratories differed greatly regarding human resources, work capacity and volume. Differences between local and regional laboratories were observed in reporting specimen adequacy (P &lt; .001). We found that local laboratories had 3 times higher odds (OR = 2.95, 95% CI: 1.05−8.33) of reporting normal results 2 years before cancer diagnosis than regional laboratories. According to the CHC, 58.9% of pairs were in agreement. Conclusions The study showed considerable heterogeneity and suboptimal performance of cervical cytology practices in Estonia, particularly at local laboratories. Efforts to improve laboratory quality assurance are crucial.

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

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. This was a nationwide population-based retrospective study. 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. 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. 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.