Impact of national Human Development Index on liver cancer outcomes: Transition from 2008 to 2018

Abstract

Background: Liver cancer is the sixth most commonly diagnosed cancer and the fourth leading cause of cancer death worldwide. Socioeconomic development, indicated by the Human Development Index (HDI), is closely interconnected with public health. But the manner in which social development and medical advances influenced liver cancer patients in the past decade is still unknown.

Aim: To investigate the influence of HDI on clinical outcomes for patients with existing liver cancer from 2008 to 2018.

Methods: The HDI values were obtained from the United Nations Development Programme, the age-standardized incidence and mortality rates of liver cancer were obtained from the GLOBOCAN database to calculate the mortality-to-incidence ratio, and the estimated 5-year net survival of patients with liver cancer was provided by the CONCORD-3 program. We then explored the association of mortality-to-incidence ratio and survival with HDI, with a focus on geographic variability across countries as well as temporal heterogeneity over the past decade.

Results: From 2008 to 2018, the epidemiology of liver cancer had changed across countries. Liver cancer mortality-to-incidence ratios were negatively correlated and showed good fit with a modified "dose-to-inhibition response" pattern with HDI (r = -0.548, P < 0.0001 for 2018; r = -0.617, P < 0.0001 for 2008). Cancer survival was positively associated with HDI (r = 0.408, P < 0.01) and negatively associated with mortality-to-incidence ratio (r = -0.346, P < 0.05), solidly confirming the interrelation among liver cancer outcome indicators and socioeconomic factors. Notably, in the past decade, the HDI values in most countries have increased alongside a decreasing tendency of liver cancer mortality-to-incidence ratios (P < 0.0001), and survival outcomes have simultaneously improved (P < 0.001), with significant disparities across countries.

Conclusion: Socioeconomic factors have a significant influence on cancer outcomes. HDI values have increased along with improved cancer outcomes, with significant disparities among countries.

Keywords: Human Development Index; Incidence; Liver cancer; Mortality; Survival.

Figure 1

Worldwide distribution of Human Development Index and liver cancer burden in 2018. A total of 174 countries were classified into four tiers according to different levels of the following: A: Human Development Index (green); B: Age-standardized incidence (blue); C: Age-standardized mortality (red) rates per 100000 population, indicated in a gradient color scale; D: Calculated mortality-to-incidence ratio results, indicated in purple-gradient colors. Countries with data unavailable (light gray) or unreliable (dark gray) are denoted. HDI: Human Development Index.

Figure 2

Correlation between Human Development Index and mortality-to-incidence ratio and its transition from 2008 to 2018. The correlation of liver cancer mortality-to-incidence ratios (MIRs) with national Human Development Indexes (HDIs) with the best-fit lines by modified nonlinear regression (“dose-to-response” model) in A: 2018 (slope = -1.868, HDI₅₀ = 1.27, R2 = 0.261); B: 2008 (slope = -4.989, HDI₅₀ = 1.03, R2 = 0.592); C: Significant reduction in overall MIRs in 64 overlapping countries from 2008 (orange) to 2018 (red). ^aP < 0.0001, Weighted Chi-square test; D: Transition of the correlation patterns of liver cancer MIR with national HDI from 2008 (orange, r = -0.617, P < 0.0001) to 2018 (red, r = -0.548, P < 0.0001), showing a declining tendency of MIRs within the decade; E: MIRs of liver cancer in the four HDI groups, with significant differences among the very high, high, medium, and low groups (indicated in green-gradient colors) and a decreasing tendency in each specific group between 2008 (orange) and 2018 (red). ^bP < 0.001, vs very-high-HDI countries in 2018, one-way ANOVA followed by Tukey-Kramer post hoc test. The statistical significance among countries in 2008 is not indicated. ^cP < 0.001, 2008 vs 2018 in the low-HDI group; ^dP < 0.0001, 2008 vs 2018 in the high-HDI group, paired t-test; F: Regional age-standardized mortality (gray) and incidence (white plus gray) rates per 100000 individuals for liver cancer in 2018 (on the left) and 2008 (on the right), with MIR values denoted. HDI: Human Development Index; MIR: Mortality-to-incidence ratio.

Figure 3

Distributions of liver cancer survival and its correlation with Human Development Index values and mortality-to-incidence ratio. A: Distribution of regional estimated 5-year net survival for patients with liver cancer in 2018, indicated in blue-gradient colors; B: Comparisons of worldwide liver cancer survival between 2008 and 2018. ^aP < 0.001, 2018 (sky blue) vs 2008 (dark blue); C: A positive correlation pattern between the survival of the patients diagnosed in 2010-2014 and the Human Development Index value in 2018 (r = 0.408, P = 0.0027); D: Correlation between national mortality-to-incidence ratio and liver cancer survival in 2018 (r = -0.346, P = 0.0278). HDI: Human Development Index; MIR: Mortality-to-incidence ratio.