Time Of First Screening Research Articles

OA06.02 The Role of Simulation Modeling in Shaping Lung Cancer Screening Policies in the US and Elsewhere

Models of the natural history of cancer have played an important role in shaping cancer prevention and control policies across the world. Notably, the US National Cancer institute (NCI) Cancer Intervention and Surveillance Modeling Network (CISNET) consortium has developed multiple such models and a modeling infrastructure that has supported the development of guidelines and policies for cancer screening and tobacco control in the US and elsewhere. The CISNET Lung models incorporate and synthetize smoking and lung cancer data from clinical trials, epidemiological studies and surveillance systems. These models have informed US screening guidelines. But important questions remain as screening programs are being implemented, such as the relative effectiveness of risk-based versus pack-year eligibility strategies or the potential of cessation programs within the context of lung screening. Simulation of the US 1950 and 1960 birth-cohorts show that for a given number of screens, risk-based screening programs lead in general to higher mortality reductions than pack-year based strategies. This is also true for LYG, but the difference is less pronounced. Independently of the program, adding cessation interventions at the point of screening leads to considerable gains in LYG, and to a lesser effect on deaths prevented. E.g., under current guidelines and a 40% screening uptake scenario, adding a cessation intervention at the time of first screen with a 15% success probability, could increase LYG by 140% and lung cancer deaths prevented by 28% (fig). But the actual gains would greatly depend on coverage and the cessation probability (fig). Simulation modeling provides a framework to extrapolate findings from clinical trials and epidemiological studies into population outcomes. This has shown to be key to be able to refine and identify lung cancer prevention optimal strategies for a given setting. And to gather support among stakeholders to adopt and implement such strategies.

Biennial lung cancer screening in Canada with smoking cessation—outcomes and cost-effectiveness

BackgroundGuidelines recommend low-dose CT (LDCT) screening to detect lung cancer among eligible at-risk individuals. We used the OncoSim model (formerly Cancer Risk Management Model) to compare outcomes and costs between annual and biennial LDCT screening. MethodsOncoSim incorporates vital statistics, cancer registry data, health survey and utility data, cost, and other data, and simulates individual lives, aggregating outcomes over millions of individuals. Using OncoSim and National Lung Screening Trial eligibility criteria (age 55–74, minimum 30 pack-year smoking history, smoking cessation less than 15 years from time of first screen) and data, we have modeled screening parameters, cancer stage distribution, and mortality shifts for screen diagnosed cancer. Costs (in 2008 Canadian dollars) and quality of life years gained are discounted at 3% annually. ResultsCompared with annual LDCT screening, biennial screening used fewer resources, gained fewer life-years (61,000 vs. 77,000), but resulted in very similar quality-adjusted life-years (QALYs) (24,000 vs. 23,000) over 20 years. The incremental cost-effectiveness ratio (ICER) of annual compared with biennial screening was $54,000–$4.8 million/QALY gained. Average incremental CT scan use in biennial screening was 52% of that in annual screening. A smoking cessation intervention decreased the average cost-effectiveness ratio in most scenarios by half. ConclusionsOver 20 years, biennial LDCT screening for lung cancer appears to provide similar benefit in terms of QALYs gained to annual screening and is more cost-effective. Further study of biennial screening should be undertaken in population screening programs. A smoking cessation program should be integrated into either screening strategy.

Screening attendance, age group and diabetic retinopathy level at first screen.

AimsTo report on the relationships between age at diagnosis of diabetes, time from registration with the screening programme to first diabetic eye screening and severity of diabetic retinopathy.MethodsData were extracted from four English screening programmes and from the Scottish, Welsh and Northern Irish programmes. Time from diagnosis of diabetes to first screening and age at diagnosis were calculated.ResultsTime from registration with the screening programme to first screening episode is strongly related to age at registration. Within 18 months of registration 89% of 3958 young people under 18 years of age and 81% of 391 293 people over 35 years of age were seen. In 19 058 people between 18 and 34 years of age, 80% coverage was not reached until 2 years and 9 months. The time from diagnosis of diabetes to first screening is positively associated with severity of disease (P < 0.0001).ConclusionsThis report is the first that to demonstrate that those in the 18–34 year age group are least likely to attend promptly for screening after registration with a higher risk of referable diabetic retinopathy being present at the time of first screen. Date of diagnosis should be recorded and prodigious efforts made to screen all people promptly after diagnosis. Screening programmes should collect data on those who have not attended within one year of registration.

Mid-term Body Mass Index increase among obese and non-obese individuals in middle life and deprivation status: A cohort study

BackgroundIn the UK, obesity is associated with a clear socioeconomic gradient, with individuals of lower socioeconomic status being more likely to be obese. Several previous studies, using individual measures of soecioeconomic status, have shown a more rapid increase in Body Mass Index (BMI) over time among adults of lower socioeconomic status. We conducted a study to further examine whether ecologically defined deprivation status influences within-individual BMI change during middle life, as the answer to this question can help determine optimal preventive strategies both for obesity per se, and its' associated socioeconomic disparities.MethodsAnonymised records of participants to the Stockport population-based cardiovascular disease risk factor screening programme were analysed. Individuals aged 35–55 who had a first screening episode between 1989 and 1993, and a subsequent screening episode were included in the study. Deprivation status was defined using quintiles of the Townsend score. Mean annual BMI change by deprivation group was calculated using linear regression. Subsequently, deprivation group was included in the model as an ordinal variable, to test for trend. The modelling was repeated separately for individuals who were obese (BMI < 30) and non-obese at the time of first screening. In supplementary analysis, regression models were also adjusted for baseline BMI.ResultsOf 21,976 women and 19,158 men initially screened, final analysis included just over half of all individuals [11,158 (50.8%) women and 9,831 (51.3%) men], due to the combined effect of loss to follow-up and incomplete BMI ascertainment. In both sexes BMI increased by 0.19 kg/m2 annually (95% Confidence Intervals 0.15–0.24 for women and 0.16–0.23 for men). All deprivation groups had similar mean annual change, and there was no evidence of a significant deprivation trend (p = 0.801, women and 0.892, men). Restricting the analysis to individuals who were non-obese at baseline did not alter the results in relation to the lack of a deprivation effect. When restricting the analysis to individuals who were obese at baseline however, the findings were suggestive of an association of BMI increase with higher deprivation group, which was further supported by a significant association when adjusting for baseline BMI.ConclusionIn the study setting, the BMI of non-obese individuals aged 35–55 was increasing over time independently of deprivation status; among obese individuals a positive association with higher deprivation was found. The findings support that socioeconomic differences in mean BMI and obesity status are principally attained prior to 35 years of age. Efforts to tackle inequalities in mean BMI and obesity status should principally concentrate in earlier life periods, although there may still be scope for focusing inequality reduction efforts on obese individuals even in middle life.

Severe retinopathy of prematurity: longitudinal observation of disease and screening implications.

To test the effectiveness of our Canadian retinopathy of prematurity (ROP) screening guidelines as applied to high-risk premature infants. Retrospective longitudinal cohort study. A total of 969 infants were examined longitudinally between 1991 and 2000 and 46 of these infants screened were treated for severe ROP. Data from weekly ROP screening examination results were collected from a geographical area and analysed. The average incidence of severe ROP requiring treatment in the population of premature infants eligible for screening was 48.3 per 1000. In all, 46 infants were treated in this cohort. The mean gestational age (GA) was 25.5 weeks of age and the mean birth weight was 750 g. The mean chronological age (CA) and postmenstrual age (PMA) at the time of first screening was 36 days and 30.7 weeks, respectively. The first identification of any ROP in this group was at a mean CA 60 days and PMA of 34.1 weeks. The mean CA and PMA of the first observation of stage 3 were 74 days and 36.3 weeks. The mean CA and PMA at the time of treatment were 86 days and 37.7 week. Our observations and analysis indicate the following ROP screening recommendations: infants of 28 weeks of GA or less, infants with a GA between 28 weeks and 30 weeks should have a single 'spot examination' at approximately 37 weeks of PMA (or prior to discharge from hospital) to include possible outliers; infants born with a birth weight of 1250 g or less; initial screening examination should be at 31 weeks of PMA or 4 weeks of CA, whichever is later; in the presence of any active ROP, the infant should be followed every 1-2 weeks; and stage 3 should be followed at least every 7 days.

Predictors of non-attendance for second round mammography in an Australian mammographic screening programme.

To determine the socioeconomic, cultural, and clinical predictors of non-attendance for second round mammography. Retrospective cohort study of 121 889 women aged 50-69 years who attended for first mammography screening in the BreastScreen Victoria programme in 1995/1996 and who were recommended to be invited for routine biennial mammography. Women were considered to be non-attenders if they had not attended for rescreening within 27 months of their initial screening. Relative risk (RR) was used to compare categories for non-attendance for second screening, and a multivariate model was fitted to adjust for possible confounding. BreastScreen Victoria, a population based mammographic screening programme, which offers free biennial mammography to all women 40 years and older. The programme specifically targets women aged 50-69 years. In the multivariate analysis, women from non-English speaking backgrounds were more likely not to attend for second round screening (RR ranged from 1.18 to 1.77). Indigenous women (RR 2.02, 95% confidence interval (CI) 1.61 to 2.54) and women who reported either significant symptoms (RR 1.90, 95% CI 1.76 to 2.05) or other breast symptoms (RR 2.25, 95% CI 2.15 to 2.36) at the time of first round screening were also more likely not to attend for second round screening. Women from non-English speaking backgrounds, indigenous women, and women who report symptoms at the time of first screening are more likely to not attend for second round screening. It is important to investigate why these women do not attend for second round screening so that services can be more appropriately tailored to their needs.

An unusually severe phenotype for familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a dominantly inherited predisposition to the development of many hundreds to thousands of adenomatous polyps of the colon. The mean age of onset is around...

Effectiveness of screening for breast cancer in women under 50 years at entry: The Kotka pilot project in Finland

It is still uncertain whether mammography is beneficial to women under 50 years of age. We report a follow-up of 4 1-year birth cohorts in 13 Finnish municipalities subjected to service screening. The women in these cohorts were born in even calendar years and they were 40-47 years old at the time of first screening, which was repeated every other year. At the beginning, 4,163 women were invited and 86% attended. Women were screened with mammography, physical breast examination and information on detection and early diagnosis of breast cancer by breast self-examination (BSE) was given. Incident cases of breast cancer and breast-cancer deaths were recorded. The expected numbers of incident breast-cancer cases and deaths from breast cancer were derived from control women who were residents of the same municipalities but who were born in adjacent calendar years (odd years) to those screened. In the screened cohorts 13 cancers were screen-detected, 32 cancers were interval cases and 8 cases were diagnosed among the non-attenders, while in the controls 85 cancers were detected during a 9-year follow-up from 1982 to 1990. One death from breast cancer occurred in the screened cohorts among cases diagnosed between 1982 and 1990, against 10 expected breast-cancer deaths during a 10-year follow-up from 1982 to 1991 of women initially free of breast cancer. Breast-cancer mortality in the screened cohorts was significantly lower than in the controls (Rate Ratio 0.11), but it is not clear how much of the reduction in mortality could be accounted for by the mammography itself and how much to other activities included in the screening programme (especially training in BSE) or to chance variation. It is unlikely that a programme sensitivity of 25% (13/53) would have resulted in 89% (100-11) effectiveness or reduction in the risk of death from breast cancer.

Breast Cancer Risk Associated With Reproductive Factors and Breast Parenchymal Patterns

In a population-based study of 23,511 women 50-67 years of age at the time of first screening, a striking relationship was found between parity and age at first childbirth, on the one hand, and two radiologic aspects of breast parenchymal pattern (dysplasia and prominent duct pattern), on the other. These relationships appeared to be causal.