Inequalities in mortality from breast and gynecological cancers according to level of education: a population-based study in Spain

Abstract

Background/Objectives: Educational level is one of the classic axes of inequality in public health. The recent incorporation in Spain of this information into individual mortality data makes it possible for the first time to analyze the cancer mortality risk gradient according to educational level in this country. Breast and gynecological cancers are a major public health issue, accounting for more than 30% of all cancer mortality among women in Spain. They are strongly related to lifestyle choices, preventive care, or adherence to screening programs, factors that are often conditioned by educational level. The aim of this study is to assess the magnitude of the educational gap in the risk of mortality from these cancers in women residing in Spain. Methods: The population data and mortality from breast and gynecological cancers in the period 2016-2020 by age (from 30 years old), level of education (from primary to doctorate) and province of residence, were provided by the Spanish National Institute of Statistics. For each tumor and two age groups (30-44 and 45+), the risk of mortality by educational level were estimated using a Poisson regression model adjusted for age and province. The relative risk (RR) of cancer mortality was also calculated by comparing the group with the highest level of education with the group with the lowest level. This RR was given for the entire cohort when no interaction was found between educational level and the age group. Results: Mortality risk was inversely associated with level of education for most gynecological cancers (cervix, corpus uterus, vulva, vagina). This was particularly the case for cervix cancer (RR = 0.26, 95%CI = 0.19 to 0.36) in young women (30-44 years) and for vulva cancer (RR = 0.48, 95%CI = 0.32 to 0.72). On the other hand, this relationship was inverted for breast cancer (RR = 1.43, 95%CI = 1.35 to 1.52) and ovarian cancer (RR = 1.21, 95%CI = 1.09 to 1.35). Conclusions/Recommendations: The relationship between mortality risk and educational level changes markedly whether the cancer is breast or gynecological. The identification of groups of women at high risk of death from these cancers according to their level of education and age group can be useful for targeting interventions and monitoring cancer disparities.