Sociodemographic characteristics of women with invasive cervical cancer in British Columbia, 2004-2013: a descriptive study

Strategies to accelerate the elimination of cervical cancer in British Columbia, Canada: a modelling study

BACKGROUND

To eliminate cervical cancer in Canada by 2040, defined as an annual age-standardized incidence rate (ASIR) lower than 4.0 per 100 000 women, the Canadian Partnership Against Cancer (CPAC) identified 3 priorities for action: increasing human papillomavirus (HPV) vaccine coverage, implementing HPV-based screening and increasing screening participation, and improving follow-up after abnormal screen results. Our objective was to explore the impact of these priorities on the projected time to elimination of cervical cancer in British Columbia.

METHODS

We used OncoSim-Cervical, a microsimulation model led and supported by CPAC and developed by Statistics Canada that simulates HPV transmission and the natural history of cervical cancer for the Canadian population. We updated model parameters to reflect BC's historical participation rates and program design. We simulated the transition to HPV-based screening and developed scenarios to explore the additional impact of achieving 90% vaccination coverage, 95% screening recruitment, 90% ontime screening, and 95% follow-up compliance. We projected cervical cancer incidence, ASIR, and year of elimination for the population of BC for 2023-2050.

RESULTS

HPV-based screening at current vaccination, participation, and follow-up rates can eliminate cervical cancer by 2034. Increasing on-time screening and follow-up compliance could achieve this target by 2031. Increasing vaccination coverage has a small impact over this time horizon.

INTERPRETATION

With the implementation of HPV-based screening, cervical cancer can be eliminated in BC before 2040. Efforts to increase screening participation and follow-up through this transition could potentially accelerate this timeline, but the transition from cytology- to HPV-based screening is fundamental to achieving this goal.

Addressing the burden of cervical cancer for Indigenous women in Latin America and the Caribbean: a call for action

Cervical cancer, primarily caused by human papillomavirus (HPV) infection, poses a significant global health challenge. Due to higher levels of poverty and health inequities, Indigenous women worldwide are more vulnerable to cervical cancer than their non-Indigenous counterparts. However, despite constituting nearly 10% of the population in Latin America and the Caribbean (LAC), the true extent of the burden of cervical cancer among Indigenous people in this region remains largely unknown. This article reviews the available information on cervical cancer incidence and mortality, as well as HPV infection prevalence, among Indigenous women in LAC. The limited existing data suggest that Indigenous women in this region face a heightened risk of cervical cancer incidence and mortality compared to non-Indigenous women. Nevertheless, a substantial knowledge gap persists that must be addressed to comprehensively assess the burden of cervical cancer among Indigenous populations, especially through enhancing cancer surveillance across LAC countries. Numerous structural, social and cultural barriers hindering Indigenous women's access to HPV vaccination and cervical cancer screening worldwide have been identified and are reviewed in this article. The discussion highlights the critical role of culturally sensitive education, community engagement, and empowerment strategies in overcoming those barriers. Drawing insights from the success of targeted strategies in certain high-income countries, the present article advocates for research, policies and healthcare interventions tailored to the unique context of LAC countries.

Individual and Geospatial Determinants of Health Associated With School-Based Human Papillomavirus Immunization in Alberta: Population-Based Cohort Study

BACKGROUND

Human papillomavirus (HPV) infection causes nearly all cervical cancer cases and is a cause of anogenital and oropharyngeal cancers. The incidence of HPV-associated cancers is inequitable, with an increased burden on marginalized groups in high-income countries. Understanding how immunization status varies by material and social deprivation, health system, and geospatial factors is valuable for prioritizing and planning HPV immunization interventions.

OBJECTIVE

The objective of this study was to describe school-based HPV immunization rates by individual and geospatial determinants of health in Alberta, Canada.

METHODS

Health administrative data for male and female individuals born in 2004 in Alberta were used to determine HPV immunization status based on age and the number of doses administered in schools during the 2014/2015-2018/2019 school years. Immunization status and its relationship with material and social deprivation and health system factors were assessed by a logistic regression model. Geospatial clustering was assessed using Getis-Ord Gi* hot spot analysis. Mean scores of material and social deprivation and health system factors were compared between hot and cold spots without full HPV immunization using independent samples t tests. A multidisciplinary team comprising researchers and knowledge users formed a co-design team to design the study protocol and review the study results.

RESULTS

The cohort consisted of 45,207 youths. In the adjusted model, the odds of those who did not see their general practitioner (GP) within 3 years before turning 10 years old and not being fully immunized were 1.965 times higher (95% CI 1.855-2.080) than those who did see their GP. The odds of health system users with health conditions and health system nonusers not being fully immunized were 1.092 (95% CI 1.006-1.185) and 1.831 (95% CI 1.678-1.998) times higher, respectively, than health system users without health conditions. The odds of those who lived in areas with the most material and social deprivation not being fully immunized were 1.287 (95% CI 1.200-1.381) and 1.099 (95% CI 1.029-1.174) times higher, respectively, than those who lived in areas with the least deprivation. The odds of those who lived in rural areas not being fully immunized were 1.428 times higher (95% CI 1.359-1.501) than those who lived in urban areas. Significant hot spot clusters of individuals without full HPV immunization exist in rural locations on the northern and eastern regions of Alberta. Hot spots had significantly worse mean material deprivation scores (P=.008) and fewer GP visits (P=.001) than cold spots.

CONCLUSIONS

Findings suggest that material and social deprivation, health system access, and rural residency impact HPV immunization. Such factors should be considered by public health professionals in other jurisdictions and will be used by the Alberta co-design team when tailoring programs to increase HPV vaccine uptake in priority populations and regions.

Sociodemographic characteristics and their association with survival in women with cervical cancer

BACKGROUND

In 2020, the highest incidence and mortality from cervical cancer (CC) were detected in low and middle-income countries. CC remains a health problem for women living in them. In Mexico, CC ranks second in cancer incidence and mortality in women. The main characteristics of this population are low income, low educational level, and inadequate medical coverage. The present study characterized the Mexican population by CC, and the sociodemographic variables that impacted overall survival (OS) were identified.

METHODS

A retrospective study that included a cohort of patients with a confirmed diagnosis of CC at the Instituto Nacional de Cancerologia between 2003 and 2016. Information was collected on sociodemographic variables related to the disease and OS.

RESULTS

Four thousand six hundred thirty-one patients were included. The median age was 51 years, 78.5% were unemployed, 44.4% lived in a rural/suburban area, 50.8% had a partner when collecting this information, and 74.3% were classified as having low socioeconomic status. Age, living in a rural/suburban area, more advanced stages of the disease, and not receiving cancer treatment were associated with lower OS.

CONCLUSION

CC continues to affect mainly women with minimal resources, low educational levels, and living in marginalized areas. These characteristics influence the OS. Prevention and timely detection programs, education, and training focused on this population and with broader coverage are required to identify patients with CC at earlier stages.

Small area disease mapping of cancer incidence in British Columbia using Bayesian spatial models and the smallareamapp R Package

INTRODUCTION

There is an increasing interest in small area analyses in cancer surveillance; however, technical capacity is limited and accessible analytical approaches remain to be determined. This study demonstrates an accessible approach for small area cancer risk estimation using Bayesian hierarchical models and data visualization through the smallareamapp R package.

MATERIALS AND METHODS

Incident lung (N = 26,448), female breast (N = 28,466), cervical (N = 1,478), and colorectal (N = 25,457) cancers diagnosed among British Columbia (BC) residents between 2011 and 2018 were obtained from the BC Cancer Registry. Indirect age-standardization was used to derive age-adjusted expected counts and standardized incidence ratios (SIRs) relative to provincial rates. Moran's I was used to assess the strength and direction of spatial autocorrelation. A modified Besag, York and Mollie model (BYM2) was used for model incidence counts to calculate posterior median relative risks (RR) by Community Health Service Areas (CHSA; N = 218), adjusting for spatial dependencies. Integrated Nested Laplace Approximation (INLA) was used for Bayesian model implementation. Areas with exceedance probabilities (above a threshold RR = 1.1) greater or equal to 80% were considered to have an elevated risk. The posterior median and 95% credible intervals (CrI) for the spatially structured effect were reported. Predictive posterior checks were conducted through predictive integral transformation values and observed versus fitted values.

RESULTS

The proportion of variance in the RR explained by a spatial effect ranged from 4.4% (male colorectal) to 19.2% (female breast). Lung cancer showed the greatest number of CHSAs with elevated risk (Nwomen = 50/218, Nmen = 44/218), representing 2357 total excess cases. The largest lung cancer RRs were 1.67 (95% CrI = 1.06-2.50; exceedance probability = 96%; cases = 13) among women and 2.49 (95% CrI = 2.14-2.88; exceedance probability = 100%; cases = 174) among men. Areas with small population sizes and extreme SIRs were generally smoothed towards the null (RR = 1.0).

DISCUSSION

We present a ready-to-use approach for small area cancer risk estimation and disease mapping using BYM2 and exceedance probabilities. We developed the smallareamapp R package, which provides a user-friendly interface through an R-Shiny application, for epidemiologists and surveillance experts to examine geographic variation in risk. These methods and tools can be used to estimate risk, generate hypotheses, and examine ecologic associations while adjusting for spatial dependency.

The Path to Eliminating Cervical Cancer in Canada: Past, Present and Future Directions

Cervical cancer remains a common cancer affecting women in Canada. While cervical cancer incidence and mortality in Canada have declined for several decades due to the success of organized, provincial cervical cancer screening programs, further decreases will require enhancement of primary, secondary, and tertiary prevention efforts. The present commentary provides a historical overview of cervical cancer trends in Canada, presents current statistics on cervical cancer incidence, mortality and survival, and discusses future directions in relation to cervical cancer elimination.