SOCIAL INEQUALITIES IN CANCER: EPIDEMIOLOGICAL EVIDENCE AND IMPLICATIONS FOR PUBLIC HEALTH POLICIES

Abstract

Introduction

Social inequalities in health represent one of the most persistent challenges in contemporary public health, affecting populations in both low-income and economically developed countries. Socioeconomic factors such as income, education, place of residence, race/ethnicity, and living conditions strongly shape disease risk, access to health services, quality of care, and survival. Many of these differences constitute inequities, as they are avoidable, systematic, and socially unjust. Cancer is a key field in which such inequities are expressed, since major diagnostic and therapeutic advances coexist with marked social differences in incidence, stage at diagnosis, and mortality. Studying inequities in cancer therefore allows the understanding of structural mechanisms underlying health inequalities. In this context, population-based registries and health information systems are strategic tools to identify social gradients, monitor trends, and support targeted public health interventions, as illustrated by the study conducted in Campinas.

Objective

Analyze social inequalities in cancer incidence and mortality and discuss their implications for public health policies using population-based data.

Materials and Methods

A study was conducted in Campinas, Brazil, using data from the Population-Based Cancer Registry and the Mortality Information System from 2010 to 2019. Cancer cases and deaths were classified by tumor site (ICD-10). Socioeconomic conditions were assessed using an area-based social vulnerability index. Age-standardized incidence and mortality rates were calculated and compared across vulnerability strata to identify social gradients and temporal trends. Analyses were based on anonymized secondary data and followed ethical research standards.

Results

A total of incident cancer cases and cancer-related deaths recorded between 2010 and 2019 were analyzed. Incidence rates tended to be higher in less vulnerable areas for selected cancer types, whereas mortality rates were consistently higher in more socially vulnerable strata. Marked inequalities were identified for specific cancers. Cancers of the cervix, stomach, oral cavity, and prostate showed substantially higher mortality rates in the most vulnerable areas compared with the least vulnerable ones. In contrast, breast and colorectal cancers presented higher incidence in less vulnerable areas, but with smaller or reversed differences in mortality, indicating differential access to early diagnosis and effective treatment. Temporal analyses revealed that social inequalities in cancer mortality persisted throughout the study period and, for some cancer sites, increased over time.

Conclusion

These findings reinforce that cancer inequities are not random phenomena, but rather systematic patterns associated with socioeconomic context, access to health services, and opportunities for timely diagnosis and effective treatment. From a public health perspective, these studies emphasize that effective cancer control policies must explicitly incorporate social vulnerability as a key analytical and operational dimension. Policies informed by high-quality epidemiological data can better prioritize high-risk populations, guide equitable allocation of resources, and evaluate the impact of interventions aimed at reducing avoidable cancer mortality.