Educational inequalities in cancer incidence and mortality: A population-based cancer registry study in Italy.
TL;DR
Education inequalities in cancer showed tumour-specific patterns for some cancers, whereas for others they emerged after diagnosis, and population-based registry data can help identify where prevention and care pathways may be strengthened.
Abstract
Background
Socioeconomic position is associated with differences in cancer incidence and outcomes after diagnosis. However, evidence jointly evaluating incidence and mortality after diagnosis within the same population remains limited in Southern Europe. This study assessed educational inequalities in cancer incidence and five-year mortality after diagnosis in the Lazio Region, Italy.
Methods
This retrospective population-based registry linkage study used data from the Lazio Region Cancer Registry. All malignant cancers diagnosed between 2013 and 2020 were included, excluding non-melanoma skin cancers. Educational level was obtained through linkage with 2011 census data and classified into four categories, using higher education as the reference group. Incidence rate ratios (RRs) were estimated separately by tumour site and sex using age-standardised population-based rates. Five-year mortality after diagnosis was analysed using Cox proportional hazards models fitted separately by tumour site and sex, adjusted for age at diagnosis, year of diagnosis, marital status, comorbidities, and hospital of diagnosis.
Results
Educational gradients (graded differences in incidence or mortality across the four educational categories, relative to the high-education reference group) differed by tumour site and sex. The strongest incidence gradients were observed for stomach cancer, with RRs in the lowest educational group of 2.04 (95% CI 1.81-2.29) in male patients and 2.11 (95% CI 1.77-2.52) in female patients. Lung cancer incidence was also higher among less educated male patients (RR 1.75; 95% CI 1.65-1.85). In contrast, breast cancer and melanoma showed higher incidence among more educated patients, an inverse gradient relative to the other tumour sites. Five-year mortality after diagnosis was higher among less educated patients for several tumour sites. In the lowest educational group, HRs reached 1.40 (95% CI 1.28-1.53) for colorectal cancer in male patients, 1.47 (95% CI 1.33-1.64) for breast cancer in female patients, and 2.10 (95% CI 1.48-2.99) for melanoma in female patients.
Conclusions
Educational inequalities in cancer showed tumour-specific patterns. For some cancers, inequalities were mainly evident in incidence, whereas for others they emerged after diagnosis. Population-based registry data can help identify where prevention and care pathways may be strengthened.