Factors contributing to differences in cervical cancer screening in rural and urban community health centers.

INTRODUCTION: Community health centers (CHCs) provide historically marginalized populations with primary care, including cancer screening. Previous studies have reported that women living in rural areas are less likely to be up to date with cervical cancer screening than women living in urban areas. However, little is known about rural-urban differences in cervical cancer screening in CHCs and the contributing factors, and whether such differences changed during the COVID-19 pandemic. METHODS: Using 8-year pooled Uniform Data System (2014-2021) data and Oaxaca-Blinder decomposition, the extent to which CHC- and catchment area-level characteristics explained rural-urban differences in up-to-date cervical cancer screening was estimated. RESULTS: Up-to-date cervical cancer screening was lower in rural CHCs than urban CHCs (38.2% vs 43.0% during 2014-2019), and this difference increased during the pandemic (43.5% vs 49.0%). The rural-urban difference in cervical cancer screening in 2014-2019 was mostly explained by differences in CHC-level proportions of patients with limited English proficiency (55.9%) or income below the poverty level (12.3%) and females aged 21 to 64 years (9.8%), and catchment area-level's unemployment (3.4%) and primary care physician density (3.2%). However, Medicaid (-48.5%) or no insurance (-19.6%) counterbalanced the differences between rural-urban CHCs. The contribution of these factors to rural-urban differences in cervical cancer screening generally increased in 2020-2021. CONCLUSIONS: Rural-urban differences in cervical cancer screening were mostly explained by multiple CHC-level and catchment area-level characteristics. The findings call for tailored interventions, such as providing resources and language services, to improve cancer screening utilization among uninsured, Medicaid, and patients with limited English proficiency in rural CHCs.

Government Housing Assistance and Cancer Screening Among Adults With Low Income.

INTRODUCTION: Access to affordable housing may support cancer control for adults with low income by alleviating financial barriers to preventive care. This study examines relationships between cancer screening and receipt of government housing assistance among adults with low income. METHODS: Data are from the 2019 and 2021 National Health Interview Survey. Eligible respondents were classified as up-to-date or not with breast cancer (BC), cervical cancer (CVC) and colorectal cancer (CRC) screening guidelines. Multivariable logistic regression was used to model guideline-concordant screening by receipt of government housing assistance, overall and stratified by urban-rural status, race/ethnicity, and age. Analyses were performed in 2023. RESULTS: Analyses for BC, CVC and CRC screening included 2,258, 3,132, and 3,233 respondents, respectively. There was no difference in CVC screening by housing assistance status, but screening for BC and CRC was higher among those who received assistance compared to those who did not (59.7% vs. 50.8%, p<0.01 for BC; 57.1% vs. 44.1%, p<0.01 for CRC). In models adjusted for sociodemographic characteristics, health status and insurance, these differences were not statistically significant for either BC or CRC screening. In stratified adjusted models, housing assistance was statistically significantly associated with increased BC screening in urban areas (aOR=1.35, 95% CI=1.00-1.82) and among Hispanic women (aOR=2.20, 95% CI=1.01-4.78) and women 45-54 years of age (aOR=2.10, 95% CI=1.17-3.75). CONCLUSIONS: Policies that address housing affordability may enhance access to BC screening for some subgroups, including women in urban areas, Hispanic women, and younger women. More research on the mechanisms that link housing assistance to BC screening is needed.

Genome-wide Association Study of Bladder Cancer Reveals New Biological and Translational Insights.

BACKGROUND: Genomic regions identified by genome-wide association studies (GWAS) for bladder cancer risk provide new insights into etiology. OBJECTIVE: To identify new susceptibility variants for bladder cancer in a meta-analysis of new and existing genome-wide genotype data. DESIGN, SETTING, AND PARTICIPANTS: Data from 32 studies that includes 13,790 bladder cancer cases and 343,502 controls of European ancestry were used for meta-analysis. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES: Log-additive associations of genetic variants were assessed using logistic regression models. A fixed-effects model was used for meta-analysis of the results. Stratified analyses were conducted to evaluate effect modification by sex and smoking status. A polygenic risk score (PRS) was generated on the basis of known and novel susceptibility variants and tested for interaction with smoking. RESULTS AND LIMITATIONS: Multiple novel bladder cancer susceptibility loci (6p.22.3, 7q36.3, 8q21.13, 9p21.3, 10q22.1, 19q13.33) as well as improved signals in three known regions (4p16.3, 5p15.33, 11p15.5) were identified, bringing the number of independent markers at genome-wide significance (p < 5 × 10-8) to 24. The 4p16.3 (FGFR3/TACC3) locus was associated with a stronger risk for women than for men (p-interaction = 0.002). Bladder cancer risk was increased by interactions between smoking status and genetic variants at 8p22 (NAT2; multiplicative p value for interaction [pM-I] = 0.004), 8q21.13 (PAG1; pM-I = 0.01), and 9p21.3 (LOC107987026/MTAP/CDKN2A; pM-I = 0.02). The PRS based on the 24 independent GWAS markers (odds ratio per standard deviation increase 1.49, 95% confidence interval 1.44-1.53), which also showed comparable results in two prospective cohorts (UK Biobank, PLCO trial), revealed an approximately fourfold difference in the lifetime risk of bladder cancer according to the PRS (e.g., 1st vs 10th decile) for both smokers and nonsmokers. CONCLUSIONS: We report novel loci associated with risk of bladder cancer that provide clues to its biological underpinnings. Using 24 independent markers, we constructed a PRS to stratify lifetime risk. The PRS combined with smoking history, and other established risk factors, has the potential to inform future screening efforts for bladder cancer. PATIENT SUMMARY: We identified new genetic markers that provide biological insights into the genetic causes of bladder cancer. These genetic risk factors combined with lifestyle risk factors, such as smoking, may inform future preventive and screening strategies for bladder cancer.

Prospective evaluation of a breast-cancer risk model integrating classical risk factors and polygenic risk in 15 cohorts from six countries.

BACKGROUND: Rigorous evaluation of the calibration and discrimination of breast-cancer risk-prediction models in prospective cohorts is critical for applications under clinical guidelines. We comprehensively evaluated an integrated model incorporating classical risk factors and a 313-variant polygenic risk score (PRS) to predict breast-cancer risk. METHODS: Fifteen prospective cohorts from six countries with 239 340 women (7646 incident breast-cancer cases) of European ancestry aged 19-75 years were included. Calibration of 5-year risk was assessed by comparing expected and observed proportions of cases overall and within risk categories. Risk stratification for women of European ancestry aged 50-70 years in those countries was evaluated by the proportion of women and future cases crossing clinically relevant risk thresholds. RESULTS: Among women <50 years old, the median (range) expected-to-observed ratio for the integrated model across 15 cohorts was 0.9 (0.7-1.0) overall and 0.9 (0.7-1.4) at the highest-risk decile; among women ≥50 years old, these were 1.0 (0.7-1.3) and 1.2 (0.7-1.6), respectively. The proportion of women identified above a 3% 5-year risk threshold (used for recommending risk-reducing medications in the USA) ranged from 7.0% in Germany (∼841 000 of 12 million) to 17.7% in the USA (∼5.3 of 30 million). At this threshold, 14.7% of US women were reclassified by adding the PRS to classical risk factors, with identification of 12.2% of additional future cases. CONCLUSION: Integrating a 313-variant PRS with classical risk factors can improve the identification of European-ancestry women at elevated risk who could benefit from targeted risk-reducing strategies under current clinical guidelines.

Comparative validation of the BOADICEA and Tyrer-Cuzick breast cancer risk models incorporating classical risk factors and polygenic risk in a population-based prospective cohort of women of European ancestry.

BACKGROUND: The Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) and the Tyrer-Cuzick breast cancer risk prediction models are commonly used in clinical practice and have recently been extended to include polygenic risk scores (PRS). In addition, BOADICEA has also been extended to include reproductive and lifestyle factors, which were already part of Tyrer-Cuzick model. We conducted a comparative prospective validation of these models after incorporating the recently developed 313-variant PRS. METHODS: Calibration and discrimination of 5-year absolute risk was assessed in a nested case-control sample of 1337 women of European ancestry (619 incident breast cancer cases) aged 23-75 years from the Generations Study. RESULTS: The extended BOADICEA model with reproductive/lifestyle factors and PRS was well calibrated across risk deciles; expected-to-observed ratio (E/O) at the highest risk decile :0.97 (95 % CI 0.51 - 1.86) for women younger than 50 years and 1.09 (0.66 - 1.80) for women 50 years or older. Adding reproductive/lifestyle factors and PRS to the BOADICEA model improved discrimination modestly in younger women (area under the curve (AUC) 69.7 % vs. 69.1%) and substantially in older women (AUC 64.6 % vs. 56.8%). The Tyrer-Cuzick model with PRS showed evidence of overestimation at the highest risk decile: E/O = 1.54(0.81 - 2.92) for younger and 1.73 (1.03 - 2.90) for older women. CONCLUSION: The extended BOADICEA model identified women in a European-ancestry population at elevated breast cancer risk more accurately than the Tyrer-Cuzick model with PRS. With the increasing availability of PRS, these analyses can inform choice of risk models incorporating PRS for risk stratified breast cancer prevention among women of European ancestry.

Evaluating Discrimination of a Lung Cancer Risk Prediction Model Using Partial Risk-Score in a Two-Phase Study.

BACKGROUND: Independent validation of risk prediction models in prospective cohorts is required for risk-stratified cancer prevention. Such studies often have a two-phase design, where information on expensive biomarkers are ascertained in a nested substudy of the original cohort. METHODS: We propose a simple approach for evaluating model discrimination that accounts for incomplete follow-up and gains efficiency by using data from all individuals in the cohort irrespective of whether they were sampled in the substudy. For evaluating the AUC, we estimated probabilities of risk-scores for cases being larger than those in controls conditional on partial risk-scores, computed using partial covariate information. The proposed method was compared with an inverse probability weighted (IPW) approach that used information only from the subjects in the substudy. We evaluated age-stratified AUC of a model including questionnaire-based risk factors and inflammation biomarkers to predict 10-year risk of lung cancer using data from the Prostate, Lung, Colorectal, and Ovarian Cancer (1993-2009) trial (30,297 ever-smokers, 1,253 patients with lung cancer). RESULTS: For estimating age-stratified AUC of the combined lung cancer risk model, the proposed method was 3.8 to 5.3 times more efficient compared with the IPW approach across the different age groups. Extensive simulation studies also demonstrated substantial efficiency gain compared with the IPW approach. CONCLUSIONS: Incorporating information from all individuals in a two-phase cohort study can substantially improve precision of discrimination measures of lung cancer risk models. IMPACT: Novel, simple, and practically useful methods are proposed for evaluating risk models, a critical step toward risk-stratified cancer prevention.

iCARE: An R package to build, validate and apply absolute risk models.

This report describes an R package, called the Individualized Coherent Absolute Risk Estimator (iCARE) tool, that allows researchers to build and evaluate models for absolute risk and apply them to estimate an individual's risk of developing disease during a specified time interval based on a set of user defined input parameters. An attractive feature of the software is that it gives users flexibility to update models rapidly based on new knowledge on risk factors and tailor models to different populations by specifying three input arguments: a model for relative risk, an age-specific disease incidence rate and the distribution of risk factors for the population of interest. The tool can handle missing information on risk factors for individuals for whom risks are to be predicted using a coherent approach where all estimates are derived from a single model after appropriate model averaging. The software allows single nucleotide polymorphisms (SNPs) to be incorporated into the model using published odds ratios and allele frequencies. The validation component of the software implements the methods for evaluation of model calibration, discrimination and risk-stratification based on independent validation datasets. We provide an illustration of the utility of iCARE for building, validating and applying absolute risk models using breast cancer as an example.

Comparative Validation of Breast Cancer Risk Prediction Models and Projections for Future Risk Stratification.

BACKGROUND: External validation of risk models is critical for risk-stratified breast cancer prevention. We used the Individualized Coherent Absolute Risk Estimation (iCARE) as a flexible tool for risk model development and comparative model validation and to make projections for population risk stratification. METHODS: Performance of two recently developed models, one based on the Breast and Prostate Cancer Cohort Consortium analysis (iCARE-BPC3) and another based on a literature review (iCARE-Lit), were compared with two established models (Breast Cancer Risk Assessment Tool and International Breast Cancer Intervention Study Model) based on classical risk factors in a UK-based cohort of 64 874 white non-Hispanic women (863 patients) age 35-74 years. Risk projections in a target population of US white non-Hispanic women age 50-70 years assessed potential improvements in risk stratification by adding mammographic breast density (MD) and polygenic risk score (PRS). RESULTS: The best calibrated models were iCARE-Lit (expected to observed number of cases [E/O] = 0.98, 95% confidence interval [CI] = 0.87 to 1.11) for women younger than 50 years, and iCARE-BPC3 (E/O = 1.00, 95% CI = 0.93 to 1.09) for women 50 years or older. Risk projections using iCARE-BPC3 indicated classical risk factors can identify approximately 500 000 women at moderate to high risk (>3% 5-year risk) in the target population. Addition of MD and a 313-variant PRS is expected to increase this number to approximately 3.5 million women, and among them, approximately 153 000 are expected to develop invasive breast cancer within 5 years. CONCLUSIONS: iCARE models based on classical risk factors perform similarly to or better than BCRAT or IBIS in white non-Hispanic women. Addition of MD and PRS can lead to substantial improvements in risk stratification. However, these integrated models require independent prospective validation before broad clinical applications.