Similar effectiveness with primary HPV and cytology screening - Long-term follow-up of randomized cervical cancer screening trial.

BACKGROUND: Long-term effects of primary human papillomavirus (HPV) screening on cervical cancer incidence and mortality are still missing. We conducted a long-term follow-up of the Finnish randomized HPV screening trial, the first HPV screening trial run within the routine screening program, to assess these measures. METHODS: During 2003-2008, over 236,000 individuals were randomized (1:1) to HPV and cytology screening arms in Southern Finland. To compare the study arms, we calculated the cervical cancer incidence and mortality rate ratios using Poisson regression. RESULTS: During a total of 3.5 million person-years of follow-up, we observed 129 cervical cancers and 32 cervical cancer deaths in the cytology arm, 139 cervical cancers and 32 cervical cancer deaths in the HPV arm. Compared to the cytology arm, in the HPV arm, the incidence rate ratio was 1.08 (95% CI 0.85-1.37), and the mortality rate ratio was 1.01 (95% CI 0.61-1.64). CONCLUSIONS: We studied the effects of HPV screening on both cervical cancer incidence and mortality for the first time in a setting with an already well-established, high-quality cytology screening program. In this kind of setting with a low incidence of cervical cancer, HPV and cytology screening showed similar effectiveness. HPV screening provides, however, an objective, validated test system and enables self-sampling which can improve screening coverage. More attention is needed yet to ensure the balance between the harms and benefits of HPV screening.

Lower incidence of vaginal cancer after cervical human papillomavirus screening - long-term follow-up of Finnish randomized screening trial.

OBJECTIVE: Around 70% of vaginal cancers and 40-50% of vulvar cancers are attributable to human papillomavirus (HPV). Globally the burden of these diseases is estimated to grow due to the increasing HPV prevalence and rapidly aging global population. We aimed to examine if HPV screening for cervical cancer has an additional beneficial effect in preventing vaginal and vulvar cancers. To assess this, we used long-term follow-up data from the Finnish randomized HPV screening trial. METHODS: Between 2003 and 2008, over 236,000 women were individually randomized (1:1) to primary HPV or cytology screening in Southern Finland. We followed this cohort up to the year 2020. To compare the study arms, we calculated site-specific and pooled incidence rate ratios (IRRs) and mortality rate ratios (MRRs) for vaginal and vulvar cancers using Poisson regression. RESULTS: During 3,5 million person-years of follow-up, the IRR for vaginal cancer in the HPV arm compared to the cytology arm was 0.40 (95% CI 0.17-0.88) and the corresponding MRR was 0.74 (95% 0.21-2.24). The corresponding IRR for vulvar cancer was 0.73 (95% 0.50-1.08) and the MRR was 0.64 (95% 0.23-1.62). The pooled IRR was 0.67 (95% 0.47 ̶ 0.95) and MRR 0.67 (95% 0.31 ̶ 1.37). CONCLUSION: We found lower incidence of vaginal cancers with HPV screening compared to cytology screening. To validate our results, we recommend analyzing data on vaginal and vulvar cancers also from other HPV screening studies.

A population-based cohort study on changes in breast, lung and colorectal cancer incidence and mortality among non-Western immigrant women.

BACKGROUND: Cancer risk varies geographically, and migrants are influenced by different risk factors before, during and after migration. Increased migration from non-Western countries to the Nordic countries calls for a better understanding of the migrants' cancer risk and the change in risk patterns over time. The aim of this study was to compare the incidence and mortality of breast, colorectal and lung cancer between non-Western immigrant and the native female population in Denmark, Finland, Iceland, and Norway. MATERIAL AND METHODS: Data from national registries were processed and pre-analysed in each country. Multivariate Poisson regression models were used to model the relative differences in incidence and mortality as rate ratios (RR). The country-specific estimates and summary statistics were pooled together using a random effects model. RESULTS: Non-Western immigrant women had significantly lower breast (RR 0.71, 0.65-0.78), colorectal (RR 0.72, 0.57-0.92) and lung (RR 0.55, 0.42-0.72) cancer incidence rates than native women, and the risk of these cancers among immigrant women increased with duration of residence. Differences were parallel in breast, colorectal and lung cancer mortality (RR 0.64, 0.55-0.74; RR 0.66, 0.48-0.92; RR 0.51, 0.34-0.79). Among immigrant women, higher education increased the risk for breast cancer and decreased it for lung cancer. CONCLUSION: The results significantly complement and add to the previous findings of cancer burden and cancer burden transition among migrants and provide evidence of a prolonged cancer risk advantage among non-Western immigrant women. However, the findings show an increasing risk of lifestyle-related cancers with increasing duration of residence in the host country. Further studies are needed to discover underlying reasons for this phenomenon.

Cervical, liver and stomach cancer incidence and mortality in non-Western immigrant women: a retrospective cohort study from four Nordic countries.

BACKGROUND: Cervical, liver and stomach cancers are the most common infection-associated malignancies and the leading cause of morbidity in non-Western regions. We compared the incidence and mortality of these cancers between non-Western immigrant and non-immigrant Nordic female populations. We also analysed the effect of age at immigration, duration of residence and education on cancer burden. MATERIAL AND METHODS: Study population consisted of women residents in Denmark, Finland, Iceland and Norway in 1973-2020. Non-Western women contributed 3.1% of the total 260 million person-years at risk. All women were followed from their 20th birthday, or from the date of immigration if after, until the date of their first primary cancer diagnosis, death, emigration, or the end of the country-specific study period. All data were adjusted for 10-year age groups and calendar periods, and immigrant data was further broken down by region of birth, age at immigration and education level. Country-specific estimates were produced by multivariable Poisson regression and pooled in Finland with a random effects model. RESULTS: Altogether, there were 60 982 cases of cervical, liver and stomach cancer in the study population, causing 36 582 deaths. The immigrant women had significantly higher liver (rate ratio [RR] 1.78, 95% confidence interval (CI) 1.03-3.06) and stomach cancer incidence (RR 1.68, CI 1.29-2.18), and stomach cancer mortality (RR 1.49, CI 1.17-1.92) than non-immigrant women. In the immigrant population, high education was related to lower incidence and mortality of studied cancers. The rate ratio of cervical cancer decreased with duration of residence and increased with rising age at immigration. CONCLUSION: Due to the increased incidence and mortality of infection-related cancers and changes in cancer patterns by age at immigration and duration of residence, attention should be paid to targeted health care services for immigrants. Special efforts should be given to women who have spent their youth in high-risk areas.

Alternative cytology triage strategies for primary HPV screening.

OBJECTIVE: Primary HPV screening programmes for cervical cancer have been implemented in many European countries using a cytology triage. Nonetheless, the optimal cytology triage strategy for minimizing the harms and maximizing the benefits is yet unclear. We identified key characteristics of different algorithms for HPV screening with cytology triage. METHODS: Using the Finnish randomized HPV screening trial data, we formulated five post-hoc algorithms for HPV screening with a cytology triage, one for HPV screening without a triage and one for cytology screening. Sensitivity, specificity, positive predictive value, colposcopy referral rate and cumulative sensitivity for CIN II + s detected during the first and second screening rounds of the trial were calculated for all algorithms. RESULTS: In the first screening round, direct referral of HPV positives to colposcopy led to the highest sensitivity (94%) accompanied by the lowest specificity (93%). Following HPV positives up with one repeat screen showed 86% sensitivity and 97% specificity. The corresponding figures with two repeat screens were 84% and 98%. In HPV algorithms, where cytology negative HPV positive individuals had no follow-up, the sensitivities were 65-82% and the specificities 98-99%. The Cytology algorithm had a low sensitivity (69%) with a high specificity (99%). Compared to the first round, the second-round sensitivities were lower and specificities similar or higher. CONCLUSIONS: The best balance between sensitivity and specificity was achieved by an HPV algorithm with two repeated follow-up tests. However, all HPV algorithms with cytology triage increased colposcopy volume more than the cytology algorithm and thus provoked overdiagnosis.

What can We Learn From High-Performing Screening Programs to Increase Bowel Cancer Screening Participation in Australia?

BACKGROUND: Colorectal cancer (CRC) is the second most diagnosed cancer in men and women and second most common cause of cancer death in Australia; Australia's CRC incidence and mortality are among the world's highest. The Australian National Bowel Cancer Screening Program began in 2006; however, only 33% of those approached for the first time by the Program between 2018 and 2019 returned the kit. Of the 5.7 million kits sent during this period, only 44% were returned. Our aim was to identify practices and features of national bowel cancer screening programs in countries with similar programs but higher screening participation, to identify potential interventions for optimising Australian CRC screening participation. METHODS: We searched published and grey literature for CRC screening programs reporting at least 50% screening participation using postal invitation and free return of iFOBT home kits. Interviews were conducted with cancer registry staff and academic researchers, focused on participant and practitioner engagement in screening. RESULTS: National programs in Netherlands, Scotland, Denmark, and Finland reported over 50% screening participation rates for all invitation rounds. Shared characteristics include small populations within small geographic areas relative to Australia; relatively high literacy; a one-sample iFOBT kit; national registration systems for population cancer screening research; and screening program research including randomised trials of program features. CONCLUSIONS: Apart from the one-sample kit, we identified no single solution to persistent Australian low uptake of screening. Research including randomised trials within the program promises to increase participation. IMPACT: This screening program comparison suggests that within-program intervention trials will lead to increased Australian screening participation.

Optimizing screening with faecal immunochemical test for both sexes - Cost-effectiveness analysis from Finland.

A faecal immunochemical test (FIT) screening pilot was introduced in Finland in 2019 with sex-specific screening strategies. This study aims to model cost-effectiveness of sex-specific strategies for the whole population, and to assess whether the current strategies are optimal. We developed separate MISCAN-Colon models, including different FIT performances, for the Finnish men and women using the first-year data of the FIT screening pilot. We evaluated 180 FIT strategies varying in FIT cut-off, screening interval, age to start, and age to stop screening, and compared them to no-screening by sex. We used incremental cost-effectiveness ratios (ICERs) to identify the optimal strategy after combining all male and female strategies and restricting the analysis by costs and referral rate to diagnostic colonoscopies. Offering annual FIT screening with a cut-off of 25 µg/g at 50-79 years in men and with a cut-off of 10 µg/g at 55-69 years in women was optimal. This combined strategy prevented 28% of colorectal cancer (CRC) cases and 55% of CRC deaths with acceptable costs (ICER = 9000€/life-years gained). Screening at the current target age of 60-74 years was suboptimal for both sexes. Among strategies with the same target age and interval for both sexes, expected benefits from optimal screening were lower but still reasonable. Our results support a wider age range of screening in men, and a lower cut-off for a positive test in women when restrictions on colonoscopy capacity and costs are in place. National FIT screening program should start at younger age.

Cervical testing beyond the screening target age - A register-based cohort study from Finland.

OBJECTIVE: It has been proposed that cervical cancer screening should be continued in women with previous abnormal results or irregular attendance. We examined the coverage and factors that might influence cervical testing beyond the age range of the organized cervical screening programme in Finland. The national programme invites women in every five years least until the age of 60. After the stopping age, only opportunistic service is available. METHODS: Data on cervical testing were collected from the Mass Screening Registry and providers of opportunistic Pap/HPV-testing and were linked with information on socio-economic variables. The study included 373,353 women who had at least one invitation to the national screening programme between ages 50-60 years, and who were aged 65-74 years in the follow-up period 2006-2016. Multivariable binomial regression models were conducted to determine associations. RESULTS: Altogether 33% of the study population had been tested at least once at ages 65-74 years. Previous regular screening attendance (adjRR 1.70; 95% CI 1.67-1.73) and earlier abnormal results (adjRR 2.08; 95% CI 2.04-2.12) were most clearly related to higher testing adherence at older age. Other factors related to higher testing adherence were urban area of residence, domestic mother tongue, high education level, and high socio-economic status. CONCLUSION: Testing at older age was frequent with normal results, whereas only a small proportion of women with earlier abnormal results or irregular attendance were tested. The upper age limit of the national programme should be raised to 65 years, and the invitations thereafter should be targeted to selected high-risk groups.

Sociodemographic features and patterns of non-participation in colorectal cancer screening in Finland.

BACKGROUND: Colorectal cancer (CRC) screening was run as a randomized health services programme in Finland between 2004 and 2016. This study evaluates sociodemographic features and patterns of non-participation among men and women invited to be screened. METHODS: The study population in this register-based study includes 233 211 men and women invited to guaiac faecal occult blood test screening on consecutive screening rounds (n = 708 621 invitations). A generalized estimating equation (GEE) was used to estimate incidence rate ratios (IRR) between sociodemographic features and non-participation. RESULTS: The overall proportion of non-participation was 31.6% and was higher in men (38.8%) than in women (24.6%). Birth cohort, education, marital status and country of birth were associated with non-participation. The birth cohort of 1950-54 was less likely to participate than the birth cohort of 1940-44. Men and women with primary education were more likely non-participants (IRR 1.26, CI 1.23-1.29 and IRR 1.22, CI 1.18-1.26, respectively) than men or women with tertiary education. Further, unmarried persons and immigrants had an increased risk of non-participation. Initial non-participation predicted subsequent behaviour, since, e.g. ∼80% of first-round non-participants also remained non-participants in the second round. CONCLUSION: Education, gender and marital status had a significant effect on non-participation in the CRC screening programme. As high and comprehensive participation is essential for a successful screening programme, attention should be paid in ensuring participation of all sociodemographic groups. Special efforts should be invested in those not participating in the first invitational round, since initial non-participation predicts non-participation to subsequent invitations.

Differences in cervical test coverage by age, socioeconomic status, ethnic origin and municipality type - A nationwide register-based study.

An invitational organized cervical cancer screening together with widely spread opportunistic testing has coexisted for decades in Finland. The aim of this study was to examine the coverage of cervical tests by age, socioeconomic status, ethnicity and municipality type within and outside the organized screening program. We had a cohort of women of whom 1,2 million were in the target age range of screening and residing in Finland in 2010-2014. Data on Pap and/or HPV -tests within and outside the screening program were collected from the Mass Screening Registry, the pathology laboratories and the health insurance reimbursement registry and five-year population coverages of tests were reported. The total test coverage was 86.0%; 95% CI, (85.8-86.1), and was notably lower for those with an unknown socioeconomic status and pensioners (68.8%; 95% CI, (67.9-69.6) and 77.1%; 95% CI, (76.5-77.6), respectively) compared to upper-level employers (89.8%; 95% CI, (89.5-90.2)). Coverage was also lower for non-native speaking women (72.4%; 95% CI, (71.8-73.0)) compared to native speakers (86.9%; 95% CI, (86.7-87.0)) and for women living in urban municipalities (85.5%; 95% CI, (85.3-85.7)) compared to semi-urban (87.4%; 95% CI, (87.0-87.8)). Although overall coverage was high, tests within and outside the program seemed to concentrate on women with presumably good access to health services. Tests outside the program were especially common among young women who are at a low risk of invasive cervical cancer. Efforts should be made to reduce excessive opportunistic testing and to increase attendance at the program among hard-to-reach populations.

NordScreen - an interactive tool for presenting cervical cancer screening indicators in the Nordic countries.

Introduction: Quality assurance and improvement of cancer screening programs require up-to-date monitoring systems and evidence-based indicators. National quality reports exist but the definition and calculation of indicators vary making comparisons between countries difficult. The aim is to stimulate collaborative research and quality improvements in screening through freely available, comparable and regularly updated quality indicators. The project currently includes data on cervical cancer screening but population-based screening programs for breast cancer and colorectal cancer may be included in the future. Material and methods: Through a network of Nordic and Baltic screening managers, population-based individual screening data from each country were converted to standard format in each collaborative center, aggregated by the same R program script and then uploaded to the NordScreen online platform. Registry data included all cervical tests except for Finland where only tests based on invitation are included. Results: The NordScreen collaboration has so far collated standardized indicators based on 32.8 million screening tests from four Nordic countries and Estonia. Interactive comparison of test coverage and distribution of women by number of tests are currently possible online. In 2016, the test coverage within a time interval of 5.5 years in the age group 30-64 year-olds was between 78 and 84% in Iceland, Norway and Sweden whereas 70% in Finland. The application allows users to choose indicator specifications interactively. Conclusions: NordScreen is a pilot model for comparable, reliable and accessible cross-country comparisons of cancer screening. Comparability between countries is enhanced by a uniform data structure and standardized calculations. The comparison of coverage rates to national figures shows that the methods used nationally and in the NordScreen project produce similar results.

The effect of colorectal cancer screening on health status in a survey study.

BACKGROUND: Colorectal cancer (CRC) screening has been found to reduce mortality from CRC but it may have adverse effects on other aspects of health. Our aim was to evaluate the effect of CRC screening on overall health status among men and women within a randomized health-services study in Finland. MATERIAL AND METHODS: A random sample of 10,648 men and women born in 1951 received a questionnaire on health and lifestyle. They were randomized for CRC screening or controls (1:1) in 2011 (N = 10,271). The current study population consisted of those who responded to the questionnaire both before and after screening (n = 4895). Self-rated health (SRH), perceived healthiness of diet and perceived physical fitness were used to determine health status, and assessed with logistic and ordered logistic models using calendar time (2010, 2012), screening randomization and demographic characteristics as covariates. RESULTS: SRH, healthiness of diet and physical fitness improved over time (OR 1.32, CI 1.17-1.48, OR 1.23, CI 1.08-1.41 and OR 1.44, CI 1.28-1.60, respectively). Compared to non-invited controls, CRC screening invitation had no effect on these measures (OR 0.91, CI 0.74-1.12, OR 0.95, CI 0.75-1.20, and OR 1.09, CI 0.87-1.37, respectively). Women reported better health status than men. However, among those who attended screening, women reported weaker, and men better health status than the respective controls. CONCLUSIONS: CRC screening did not have any effect on health status measured using self-rated health, healthiness of diet, and physical fitness. Thus, screening for colorectal cancer can be recommended as a health policy.

Improved diagnostics and change of tumour characteristics in breast cancer: a retrospective study over two decades.

BACKGROUND: Generally, screen-detected cancers have more favourable tumour characteristics than clinically detected or symptomatic cancers. Less is known, whether the tumour characteristics of breast cancer have changed over time into more favourable in general and whether the changes have been similar in all ages. MATERIAL AND METHODS: The aim of this study was to explore the change of breast cancer characteristics in parallel to the implementation of modern diagnostic methods in three age groups over four 5-year time periods between 1992 and 2011. The data from 942 primary breast cancers in one university hospital district in Finland were combined with data from the Finnish Cancer Registry and the Mass Screening Registry. The association of favourable tumour characteristics with time period, age group and diagnostic methods was explored. RESULTS: The most discernible secular change was the increase in oestrogen (ER)-positive cancers in every consecutive time period. The risk for ER positivity in the second, third and fourth period was 2- to 2.71-fold compared to the first period. An increase in small tumours and node-negative tumours was detected during the most recent years of data collection. The secular changes were observed in all age groups; however, overall ER positivity was most frequent among women beyond screening age and small tumours among screening-aged women. The increase in small and node-negative tumours could partly be explained by the implementation of new radiological methods. CONCLUSIONS: This study detected a secular change of tumour characteristics into more favourable irrespective of age group. If the trend continues, it seems that we are going to have a breast cancer population of mainly small ER-positive breast cancers in the future forcing to rethink the therapeutic approach.

Lifestyle in population-based colorectal cancer screening over 2-year follow-up.

Background: Colorectal cancer (CRC) screening may cause changes in health-related lifestyle. In 2010, Finnish Mass Screening Registry began a study on psychosocial effects of CRC screening. This article examines whether there are differential developments in self-reported lifestyle at ages 59-61 years among CRC screening invitees and non-contacted controls. Methods: A population-based random sample of 10 648 Finnish adults born in 1951 and living in the municipalities voluntary involved in the CRC screening programme were sent a lifestyle questionnaire in 2010. In 2011, the cohort was randomised (1 : 1) for their first ever CRC screening at age 60 or for controls. The questionnaires were repeated in 2012 for all. From both survey rounds, 2508 pairs of completed questionnaires were available for analysis from the screening group and 2387 from the control group. The outcome was 2-year change in total lifestyle index of CRC risk factors (diet, physical activity, body mass index, alcohol consumption and smoking). Results: Total lifestyle index decreased throughout the follow-up in both the screening group [odds ratio (OR) = 0.80, 95% confidence interval (CI) 0.72-0.90] and in the control group (OR = 0.80, CI 0.71-0.90) indicating no difference in lifestyle changes between groups. There was also no significant difference by screening participation: the change in score was similar in those participating screening (OR 0.81, CI 0.72-0.92) and in those invited, but not participating (OR 0.75, CI 0.55-1.03). Conclusion: Present study found no unfavourable changes in total lifestyle in the studied age group due to CRC screening. Results are reassuring from the point of view of CRC screening evaluation.

Impact of organized and opportunistic Pap testing on the risk of cervical cancer in young women - A case-control study from Finland.

OBJECTIVE: Effectiveness of organized cervical cancer screening has been shown in several studies. However, screening among women aged <25years has been suggested to have little or no impact on the risk of cervical cancer. Also the significance of opportunistic testing in preventing cervical cancer is unclear. The aim of this study was to clarify the effect of opportunistic testing and organized screening on the risk of cervical cancer among young Finnish women. METHODS: In the Finnish Cancer Registry there were 284 cervical cancer cases diagnosed and tested below the age of 40 in 2004-2009. Screening histories and data on opportunistic testing for these women and their 1698 age-matched controls were derived from databases of the Mass Screening Registry and The National Institute for Health and Welfare from 1997 onward. OR's and 95% CI's for the association of cervical cancer diagnosis and participation in organized screening and opportunistic testing were estimated using unconditional logistic regression. Results were corrected for self-selection bias and attendance rate. RESULTS: Among women aged under 25, OR of cervical cancer for any Pap test taken 0.5-5.5years before diagnosis was 1.25 (95% CI 0.46-3.43). Attending only organized screening at age 25-39 resulted in OR 0.52 (0.36-0.77), attending only opportunistic testing in OR 0.86 (0.60-1.25) and attending both in OR 0.48 (0.29-0.79). CONCLUSION: Opportunistic testing showed no clear additional benefit on preventing cervical cancer. The study also supports findings on a smaller effect of screening in younger age groups.

Impact of organised mammography screening on breast cancer mortality in a case-control and cohort study.

BACKGROUND: The usefulness of case-control studies has been questioned. Our aim was to evaluate the long-term effect of screening on breast cancer mortality within the population-based mammography programme in Finland using a case-control design, and to compare the analyses with the earlier cohort study. METHODS: The cases were women invited to screening, diagnosed and died from breast cancer in 1992-2011 while being 50-84 years at death. We chose 10 controls for each case with non-restrictive eligibility criteria. Our data included 1907 cases and 18 978 matched controls. We analysed associations between the screening participation and the risk of breast cancer death using the conditional Cox proportional hazards model. The effect estimates were corrected for self-selection bias. RESULTS: An overall effect of screening was 0.67 (95% confidence interval (CI): 0.49-0.90), and that remained unchanged over time. Analyses with matching criteria comparable to the cohort study yielded an effect (0.70, 95% CI: 0.49-1.00) in 1992-2003 similar to that of the previous cohort analysis (0.72, 95% CI: 0.56-0.88). CONCLUSIONS: Organised mammography screening decreases mortality from breast cancer by 33% among the participants. If made comparable, a case-cohort study can yield effect estimates similar to a cohort study.

Use of exogenous hormones and the risk of breast cancer: results from self-reported survey data with validity assessment.

PURPOSE: Main aim was to estimate the association between use of exogenous hormones and breast cancer (BC) risk in a large population-based survey, and to assess the representativeness and overall validity of the data. METHODS: The survey 'Women's Health and Use of Hormones' was conducted in Finland in 2009, including 7,000 BC cases and 20,000 matched population controls. Conditional logistic regression was used to estimate odds ratios and their 95 % confidence interval. For validation, exposure prevalences were compared with population data from Statistics Finland and two large population-based surveys. RESULTS: We found positive associations with BC risk and exclusive use of hormone-releasing intrauterine device (HR IUD) in postmenopausal women (1.48, 95 % CI 1.10-1.99), when compared to never-users of any hormonal contraceptive and considering only prediagnostic use in cases. Regarding use of other hormonal contraceptives (HC), a positive association between long HC use (≥2 years) and BC was observed in both groups, OR being 1.37 (95 % CI 1.12-1.68) for premenopausal and 1.11 (95 % CI 1.03-1.20) for postmenopausal women, when compared to never-users of other HC. CONCLUSIONS: Observed association between HR IUD use and risk of BC in postmenopausal women is worrying and deserves further attention. Selection bias seemed not to explain this result. Considering the increasing popularity of HR IUD use in, e.g., USA, impact of possible adverse effects in public health could be significant.

Proportion of women with self-reported opportunistic mammography before organized screening.

BACKGROUND: In Finland, organized nationwide breast cancer (BC) screening is biennially offered for women aged 50-69 years. The aim was to estimate, for the first time in Finland, the proportion of women having opportunistic mammography at age less than 50 years and to investigate the role of BC family history and educational level for having opportunistic mammography. MATERIAL AND METHODS: The study material comprises two self-administered, population-based questionnaires from altogether 9845 healthy women; 4666 women in Women's Health and Use of Hormone-study (WHH survey), and 5179 in Breast Cancer Screening, Lifestyle and Quality of Life-study (EET survey). We report the estimated proportions of women with self-reported opportunistic mammography at age <50 years in percentages. RESULTS: The response percentages were 53% in the WHH survey and 52% in the EET survey. The percentage of women with self-reported opportunistic mammography was 66.7% and 60.4% in the two questionnaires, respectively. Regarding family history of BC, 76.5% and 68.5% of women with BC family history in a first degree relative reported having had a mammography, in contrast to that of 65.5% and 59.4% of women without BC family history. Opportunistic mammography was also more common in women with >12 years of education than women with ≤12 years of education. DISCUSSION AND CONCLUSIONS: Overall, some two thirds of the women reports of having had a mammography before organized screening started. Opportunistic mammography was more likely among women with a positive family history of BC in a first degree relative as well as more than 12 years of education. Regardless of low response activity, the observed popularity of opportunistic mammography before organized screening gives ground for further evaluation of the related health care practices. Screening activity before organized screening also influences the evaluation of the screening program, as women have different, indeterminate histories of pre-organized screening.

Design and respondent selection of a population-based study on associations between breast cancer screening, lifestyle and quality of life.

BACKGROUND: Only few studies have integrated breast cancer screening, lifestyle, and quality of life. Potential bias due to selective non-response may disrupt associations being investigated. We describe the design of a Finnish population-based study on associations between breast cancer screening and various indicators for lifestyle and quality of life, and evaluate the level of bias among the respondents from the first study rounds over 2 years. METHODS: The study target population of 10,000, 49-year-old women was randomly drawn from the Finnish National Population Registry. The data included birth year, marital status, municipality, and primary language. Data on education were retrieved from Statistics Finland. Questionnaires focusing on lifestyle-related risk factors and quality of life were sent to the target population in 2012-13, 1 year before the first invitation to organized breast cancer screening. We evaluated associations between willingness to respond and demographic characteristics in the eligible study population. Additionally, we examined associations between the demographic characteristics and the Satisfaction With Life Scale (SWLS), and evaluated the impact of non-response using inverse probability weighting and multiple imputation. RESULTS: The questionnaire response proportion was 52.4%. Compared to non-respondents, respondents were more often married, academically educated, and native speakers of Finnish or Swedish. Nevertheless, the estimates of the SWLS among the respondents were in line with those corrected by non-response in the eligible study population. CONCLUSIONS: Based on the SWLS, the respondents are representative of women in the entire eligible study population.

Effect of Test History at Ages 50-64 on Later Cervical Cancer Risk: A Population-based Case-control Study.

As life expectancy increases, the effectiveness of cervical cancer screening programs needs to be reassessed for the older population. We addressed the effect of test history in and outside organized screening at age 50-64 years on later cervical cancer risk. A case-control study was conducted by deriving 229 cases of 65-79 years old women with invasive cervical cancer in 2010-2019 from the Finnish Cancer Registry. Ten controls were matched for each case by birth year and hospital district. The effect of test uptake and abnormal results in 50-64 year olds on cancer risk was investigated using conditional logistic regression and adjusted for self-selection. Test uptake within the 50-64 years age group showed 75% lower odds of cervical cancer [adjusted OR (aOR) = 0.25; 95% confidence interval (95% CI), 0.18-0.35]. Untested women had 4.9 times higher odds than those tested with normal results (aOR = 4.86; 95% CI, 3.42-6.92). Having at least one abnormal test result increased the odds by 2.5 when compared with only normal results but showed lower odds when compared with untested women. The importance of testing is exhibited by the result showing a reduction of odds of cancer to one-fourth for those tested compared with untested. Similarly, receiving abnormal results was protective of cancer compared with having no tests highlighting the importance of proper follow-up. Therefore, screening history should be considered when further developing cervical cancer screening programs with special interest in non-attenders and those receiving abnormal results at older ages. Significance: To our knowledge, this is the first study from Finnish data describing the effect of test history on later cervical cancer at older ages. Focusing on the cervical tests taken within the Finnish national screening program and outside it highlights the overall importance of having cervical tests and adds this study into the slowly increasing number of studies considering all cervical testing in Finland.