Association of Life-Course Educational Attainment and Breast Cancer Grade in the MEND Study

Educational level and characteristics of invasive breast cancer: findings from a French prospective cohort

PURPOSE

Breast cancer (BC) characteristics are known to influence patients survival. Social differences have been reported by previous studies for those characteristics but questions persist because of inconsistent conclusions. We aimed to investigate the impact of education on BC stage, grade, and hormone receptor (HR) status, while adjusting for potential confounders including a broad set of health behaviors, anthropometric measures, and reproductive factors.

METHODS

In the French E3N cohort, 5236 women developed a primary invasive BC for which there was available information on stage, grade, and HR status. No multivariate analyses was performed for BC stage based on the lack of association in bivariate analyses. Odds ratios and confidence intervals were estimated using multinomial logistic regression models for BC grade or binomial logistic regression models for HR status of BC.

RESULTS

Women with a lower education were diagnosed with higher grade BC compared to women with a higher education (1.32 [1.12; 1.57]). This association was slightly attenuated after adjustment for covariates independently and more strongly affected in the fully adjusted model (1.20 [0.99; 1.45]). A significant association was observed between lower education and HR- status of BC (1.20 [1.02; 1.42]) attenuated after adjustment for age at first childbirth (1.12 [0.95; 1.33]).

CONCLUSION

In this cohort, education was associated with BC grade and HR status but not stage at diagnosis. The link between education and BC grade was not entirely explained by the different adjustments. A specific mechanism could be at play and deserves further investigations.

Association of educational attainment with cancer mortality in a national cohort study of black and white adults: A mediation analysis

Background

Low educational attainment is associated with excess cancer mortality. However, the mechanisms driving this association remain unknown.

Methods

Using data from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, we evaluated the associations of participant and parental/caregiver education with cancer mortality using Cox proportional hazards models, adjusting for socio-demographic characteristics and health conditions. We used principal components analysis to generate indices of measures representing the social determinants of health (SDOH) and health behaviors. We used structural equation modeling to determine if the association between educational attainment and cancer mortality was mediated by these domains.

Results

Among 30,177 REGARDS participants included in this analysis, 3798 (12.6%) had less than a high school degree. In fully adjusted models, those without a high school education experienced about 50% greater risk of death than high school graduates and higher (White participants HR: 1.47; 95% CI: 1.23, 1.76 and Black HR: 1.54; 95% CI: 1.33, 1.79). There was evidence of a modest mediation effect for the association between education and cancer mortality by the SDOH domain score (White total effect HR: 1.25; 95% CI: 1.18, 1.33, indirect effect HR: 1.04; 95% CI: 1.03, 1.05, direct effect HR: 1.21; 95% CI: 1.14, 1.28 and Black total effect HR: 1.24; 95% CI: 1.18, 1.29, indirect effect HR: 1.04; 95% CI: 1.03, 1.05, direct effect HR: 1.19; 95% CI: 1.14, 1.24). There was no evidence of mediation by the health behaviors score. No significant associations were found for female caregiver/mother's or male caregiver/father's education (N = 13,209).

Conclusions

In conclusion, participant education was strongly associated with cancer mortality, and this association was partially mediated by the SDOH domain score.

Evaluation of the Dynamics of Breast Cancer Incidence in Kyrgyzstan: Component Analysis

BACKGROUND: In 2020, 19.2 million cases of all types of cancer were registered worldwide, of which 11.7%, that is, 2.3 million, related to breast cancer (BC). The global burden of cancer is increasing worldwide, with the majority of new cancer cases and related deaths occurring in low- and middle-income countries. OBJECTIVE: The study is to conduct a component analysis of the dynamics of the incidence of BC in Kyrgyzstan. METHODS: Primary data were for registered patients with BC (International Classification of Diseases – C50) in the whole country during the period of 2003–2017. Evaluation of changes in BC incidence in the population of Kyrgyzstan was performed using component analysis according to the methodological recommendations. RESULTS: The study period, 7850 new cases of BC were recorded. The incidence rate increased from 17.70°/0000 (2003) to 19.03°/0000 in 2017 and the overall growth was 1.34°/0000, including due to the age structure – ΣΔA=2.08°/0000, due to the risk of acquiring illness – ΣΔR=−0.55°/0000 and their combined effect – ΣΔRA=−0.19°/0000. The component analysis revealed that the increase in the number of patients with BC was mainly due to the growth of the population (ΔP=+71.8%), changes in its age structure (ΔA=+35.5%), and changes associated with the risk of acquiring illness (ΔR=+8.4%). The increase and, in some cases, the decrease in the number of patients in the regions of the republic is due to the influence of demographic factors and risk factors for getting sick. CONCLUSION: The component analysis assessed the role of the influence of demographic factors and the risk of acquiring the disease on the formation of the number of patients and the incidence of BC, while geographical variability was established. The implementation of the results of this study is recommended in the management of anticancer measures for BC.