Connection between trajectory of primary cancer monitoring indicators and mortality after cancer in South Korea.

Background: Cancer remains a leading global cause of mortality, responsible for nearly 10 million deaths in 2020. Given the country's low birth rate and aging population, the escalating cancer burden poses significant challenges to its healthcare systems. This study aimed to investigate the relationship between lifestyle risk factors and cancer case fatality, emphasizing the collective impact of these factors through a prevention index at the regional level.

Methods: The study focused on ten cancer types, categorizing counties into three levels of cancer incidence rates using group-based trajectory modeling to identify disparities in patterns and levels among groups. Additionally, we segmented the proportions of obesity prevalence, average daily per capita smoking amount, prevalence of smoking, prevalence of high-risk alcohol consumption, prevalence of hypertension diagnosis, prevalence of diabetes diagnosis, and cancer case fatality into three groups through group-based trajectory modeling. Cox proportional hazard models were employed to evaluate the hazard ratios (HR) for cancer case fatality, adjusting for age, sex, income level, and cancer stage.

Results: The study population comprised 294,070 cancer patients, with thyroid, stomach, colorectal, breast, and lung cancers being the most common. The prevention index (PI) levels, calculated from six primary prevention indicators, were categorized into High, Medium, and Low grades. Counties with higher PI levels (H) exhibited significantly lower cancer case fatality among cancer patients compared to those with lower PI levels (L). Across all cancer types, females had lower cancer case fatality compared to males, higher age was linked to higher cancer case fatality, advanced stage cases had the highest cancer case fatality, and the highest income quintile consistently showed the lowest cancer case fatality.

Conclusions: The study highlights the significant inverse relationship between primary prevention indicator levels and cancer case fatality. Higher scores on primary prevention indicators are associated with lower cancer mortality among cancer patients for various cancer types, underscoring the importance of comprehensive, community-based prevention strategies in mitigating cancer risk and improving public health outcomes in South Korea.