JMIR Publications

ABSTRACT

Background:

In South Korea, the cancer incidence rate has increased by 51.3% from 2001 to 2020. Nevertheless, the 5-year cancer survival rate from 2016 to 2020 increased by 6.0% compared with that from 2001 to 2005. Cancer survival rates tend to decline with lower socioeconomic status, and variations exist in the survival rates among different cancer types.

Objective:

The aim of this study was to analyze differences in survival rates among patients diagnosed with six types of cancer, stomach, colorectal, liver, breast, cervical, and lung cancers, based on Socioeconomic status using Korean nationwide data.

Methods:

This study used the Korea Central Cancer Registry database linked to the National Health Information Database to follow-up patients diagnosed with cancer between 2014 and 2018 until December 31, 2021. Kaplan-Meier curves stratified by income status were generated, and log-rank tests were conducted for each cancer type to assess statistical significance. Hazard ratios with 95% confidence intervals for any cause of overall survival were calculated using Cox proportional hazards regression models with time since diagnosis.

Results:

When comparing the Medical Aid group to the highest income group, the HRs were 1.72 (95% CI=1.66–1.79) for stomach cancer, 1.60 (95% CI=1.54–1.56) for colorectal cancer, 1.51 (95% CI=1.45–1.56) for liver cancer, 1.56 (95% CI=1.51–1.59) for lung cancer, 2.19 (95% CI=2.01–2.38) for breast cancer, and 1.65 (95% CI=1.46–1.87) for cervical cancer. A higher deprivation index and advanced diagnostic stage were associated with an increased risk of mortality.

Conclusions:

Socioeconomic status significantly mediates disparities in cancer survival in several cancer types. This effect is particularly pronounced in less fatal cancers such as breast cancer. Therefore, it is essential to enhance access to cancer screening, elevate early detection rates, and ensure appropriate treatment for socioeconomically vulnerable populations.