The impact of interventions addressing socioeconomic inequalities in cancer-related outcomes in high-income countries: A systematic review

Socio-Economic Inequalities in Beliefs About Cancer and its Causes: Evidence From two Population Surveys

OBJECTIVE

People's beliefs about cancer can affect the actions they take to prevent and detect the disease. We investigated socio-economic inequalities in beliefs about cancer and its causes in the general population.

METHODS

We analyzed data from the representative probabilistic Spanish Oncobarometer survey (N = 4769, 2020) and the non-probabilistic weight-corrected Spanish Cancer Awareness Survey (N = 1029, 2022). Beliefs about cancer, recognition of cancer symptoms, and recognition of risk factors were measured with the Awareness and Beliefs about Cancer questionnaire. Endorsement of mythical causes was measured with the CAM-Mythical Causes questionnaire. The effects of socio-economic status (SES) were investigated in multiple regression analyses adjusted for age, sex, and personal and family cancer history.

RESULTS

Individuals with lower SES were more likely to endorse pessimistic beliefs (e.g., "cancer is a death sentence"), and less likely to endorse optimistic beliefs about cancer (e.g., "people with cancer continue with normal activities"). Individuals with lower SES also recognized fewer cancer symptoms and risk factors and endorsed more mythical causes of cancer. The gap in knowledge regarding cancer causes was wider among people with low SES, who were more likely to endorse several mythical causes than some established risk factors included in cancer prevention recommendations.

CONCLUSIONS

Socio-economic inequalities in beliefs about cancer are robust and multidimensional and indicate worse preparedness to act against the disease among lower socio-economic groups. Differences in beliefs about disease outcomes and causes are likely one of the multiple contributors to cancer disparities and should be targeted and monitored in prevention efforts.

A systematic review of public health interventions to address breast cancer inequalities in low- and middle-income countries

BACKGROUND

Breast cancer is the most diagnosed cancer in the world, with a worse prognosis documented in low- and middle-income countries. Inequalities pertaining to breast cancer outcomes are observed at within-country level, with demographics and socioeconomic status as major drivers.

AIM

This review aims to aggregate all available evidence from low- and middle-income countries on public health interventions that can be utilized to reduce breast cancer inequalities within the breast cancer continuum.

METHODS

The study was a systematic review and narrative synthesis of available literature, with the literature search conducted between September and October 2021. The search was re-run in September 2022 to update the review. PubMed, Scopus, Embase, African Index Medicus and LILACS were searched, based on predetermined criteria. Randomized controlled trials, cohort studies and quasi-experimental studies were included for review, while studies without an intervention and comparator group were excluded. The Joanna Briggs Institute family of checklists was used for quality assessment of the included studies. Data pertaining to study design, quality control and intervention effectiveness was extracted.

RESULTS

A total of 915 studies were identified for screening and 21 studies met the selection criteria. Only one study specifically evaluated the impact of an intervention on breast cancer inequalities. Diverse, multi-level interventions that can be utilized to address breast cancer inequalities through targeted application to disadvantaged subpopulations were identified. Educational interventions were found to be effective in improving screening rates, downstaging through early presentation as well as improving time to diagnosis. Interventions aimed at subsidizing or eliminating screening payments resulted in improved screening rates. Patient navigation was highlighted to be effective in improving outcomes throughout the breast cancer continuum.

CONCLUSION

Findings from the systematic review underline the importance of early detection in breast cancer management for low- and middle-income countries. This can be achieved through a variety of interventions, including population education, and addressing access barriers to public health services such as screening, particularly among under-served populations. This study provides a comprehensive database of public health interventions relevant to low- and middle-income countries that can be utilized for planning and decision-making purposes. Findings from the review highlight an important research gap in primary studies on interventions aimed at reducing breast cancer inequalities in low- and middle-income countries.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42021289643.

Colorectal cancer and occupational exposure to solar ultraviolet B radiation in Denmark

OBJECTIVES

Solar ultraviolet B radiation (UV) may reduce the risk of cancer, including colorectal cancer (CRC), although the evidence is inconclusive. To contribute with evidence, the present largescale register-based nested case-control study aimed to investigate the association between occupational UV exposure and CRC in Denmark.

METHODS

The Danish Cancer Registry was used to identify a total of 12,268 men and women diagnosed with primary CRC before age 70. Five controls matched on year of birth and sex, alive and free of CRC at the time of diagnosis of the index case were randomly selected from The Danish Civil Registration System. Occupational UV exposure was assessed by obtainment of full employment history from the Danish Supplementary Pension Fund Register, which was linked to a job exposure matrix. Conditional logistic regression was used to estimate odds ratios (ORs) with corresponding 95% confidence intervals.

RESULTS

We observed an inverse association between longer duration of UV exposure and CRC in women (≥20 years: OR = 0.84, 95% CI: 0.69-1.03), while no noteworthy associations were observed in men. When focusing on colon cancer only, longer duration of UV exposure (>20 years: OR = 0.92, 95% CI: 0.83-1.01) and higher cumulative UV exposure (highest exposure category: OR = 0.90, 95% CI: 0.83-0.99) were indicated to lower the risk in the study population including both men and women, although the risk reduction appeared to be more evident for women. No consistent risk patterns were observed for rectal cancer.

CONCLUSIONS

The present study suggests a modest protective effect from long-term occupational UV exposure on the risk of colon cancer. The effect may be greater in women and these findings need further attention in future large-scale studies.

Assessing the implementation of interventions addressing socioeconomic inequalities in cancer screening in high-income countries

Background: The context of an intervention may influence its effectiveness and success in meeting the needs of the targeted population. Implementation science frameworks have been developed, but previous literature in this field has been mixed. This paper aimed to assess the implementation success of interventions, identified from a systematic review, that reduced inequalities in cancer screening between people in low and high socioeconomic groups.

Design and Methods: The implementation framework by Proctor et al. was utilised to assess the potential success of 6 studies reporting on 7 interventions in the “real-world” environment. A standardised rating system to identify the overall implementation success of each intervention was established.

Results: Four interventions (57%) demonstrated high potential to be implemented successfully. Interventions included enhanced reminder letters and GP-endorsed screening invitations, containing evidence on the acceptability, from participants and stakeholders, appropriateness and direct cost of the intervention.

Conclusion: While some interventions reduced socioeconomic inequalities in cancer screening participation, there have been missed opportunities to integrate the experiences of the targeted population into design and evaluation components. This has limited the potential for transferability of outcomes to other settings.