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Page 2 of 13 Jiang et al. Hepatoma Res 2020;6:52 I http://dx.doi.org/10.20517/2394-5079.2020.47

Conclusion: Over the past decades, the survival rates of liver cancer have gradually improved, but great variations
are also observed globally. Worldwide, younger patients with liver cancer have experienced a better prognosis.
Gender disparity in liver cancer survival was not obvious.

Keywords: Primary liver cancer, relative survival rate, prognosis, population-based study, cancer registration

INTRODUCTION
Primary liver cancer (PLC) is the sixth most common cancer and the fourth most common cause of
[1]
cancer death worldwide . The top five countries with the highest incidence of liver cancer are Mongolia
(71.8/100,000), Thailand (33.7/100,000), North Korea (32.3/100,000), Japan (27.9/100,000), and China
[2]
(27.6/100,000) . In the United States, the incidence has increased rapidly by 2% to 3% per year from
2007 to 2016, although the change was smaller than that in previous years . According to Global cancer
[3]
[1]
statistics 2018 , an estimated 841,080 incident cases of liver cancer occurred worldwide, with 392,868 in
China, accounting for 46.71%.
Certainly, incidence, mortality, and prevalence are commonly applied to describe the burden of disease.
However, it is also crucial to comprehend and employ survival rate, which is another important descriptive
indicator of disease burden and widely used in the evaluation of cancer prognosis. Survival data are
available from three sources: clinical studies, hospital-based follow-up data, and population-based follow-
[4]
up data . Interpretations of the outcomes of each source are different. The population-based follow-up
data include the survival information of all patients in the population, which can reflect the cancer survival
status of the entire population. Population-based survival data usually exclude death certificate only (DCO)
and autopsy cases during analysis because evidence of diagnosis is weak.

Cancer registries are the premise and foundation of cancer prevention and control. They help obtain
comprehensive, accurate, and timely information on the incidence, mortality, survival, and other
[4]
factors related to cancer in the population . Survival analysis can be conducted with these data, and
provide valuable indicators such as population-based relative survival rate (RSR) for the effectiveness of
[5]
cancer control and reflect the prospects of cure in a country or region . To describe the global pattern,
chronological changes, and enable comparisons between different populations or regions, this review
collected all available population-based survival rates of primary liver cancer in different populations.

METHODS
Data source
A literature search of related studies from 1 January 2000 to 30 April January 2020 was conducted using
the databases of CNKI, Wanfang Data, PubMed, Web of Science, EMBASE and SEER, with the following
keywords: “liver cancer”, “hepatocellular carcinoma”, “HCC”, “population-based survival studies”, “relative
survival”, “observed survival” “cancer registry”. Two researchers collected the data independently according
to the search criteria, and 129 articles were retrieved by titles and abstracts. After screening with the
following criteria: (1) provided RSR or observed survival rate (OSR) of patients with primary liver cancer;
and (2) data were population-based or from cancer registries, and excluding duplicate, incomplete or
unavailable articles. The final analysis included 53 studies, 9 of which were in Chinese and the remaining
44 were in English [Figure 1].

Statistical analysis
Estimates of one to five-year RSRs from the published studies were extracted. We used overall and age-
standardized 5-year RSR mainly to describe and compare different countries or regions, age groups, and