Liver cancer mortality trends in South Africa: 1999-2015.

Background: In South Africa (SA), liver cancer (LC) is a public health problem and information is limited.

Methods: Joinpoint regression analysis was computed for the most recent LC mortality data from Statistics South Africa (StatsSA), by age group, sex and population group. The mortality-to-incidence ratios (MIRs) were calculated as the age-adjusted mortality rate divided by the age-adjusted incidence rate.

Results: From 1999 to 2015, the overall LC mortality significantly decreased in men (- 4.9%) and women (- 2.7%). Overall a significant decrease was noted in black African men aged 20-29 and 40-49 years, and white women older than 60 years but mortality rates increased among 50-59 and 60-69 year old black African men (from 2010/2009-2015) and women (from 2004/2009-2015). The mortality rates increased with age, and were higher among blacks Africans compared to whites in all age groups - with a peak black African-to-white mortality rate ratio of six in men and three in women at ages 30-39 years. The average MIR for black African men and women was 4 and 3.3 respectively, and 2.2 and 1.8 in their white counterparts. Moreover, decreasing LC mortality rates among younger and the increase in rates in older black Africans suggest that the nadir of the disease may be near or may have passed.

Conclusions: Findings of population-age subgroup variations in LC mortality and the number of underdiagnosed cases can inform surveillance efforts, while more extensive investigations of the aetiological risk factors are needed.

Impact: There was a large race, sex and age differences in trends of LC mortality in SA. These findings should inform more extensive evaluation of the aetiology and risk factors of LC in the country in order to guide control efforts.