Dear Editors,
We have read with interest the article by Liu H et al.1 published in your journal regarding liver cancer mortality in China and would like to compare it with that of our country, Spain, which is a European and Mediterranean country with a population of 48 million inhabitants.
In Spain, the most frequently diagnosed cancers in 2024 are expected to be those of the colon and rectum, followed by breast, lung, prostate, and urinary bladder cancers. These are followed by non-Hodgkin's lymphoma, pancreatic cancer, kidney cancer, oral cavity and pharynx cancers, uterine corpus cancers, stomach cancer, and liver cancer. The expected frequency in 2024 is similar to that of 2020.2 When compared with the incidences of cancers globally in 2020, it is evident that liver cancer has a lower incidence in Spain.3
The cancers responsible for the highest number of deaths worldwide were lung cancer (18.2% of all cancer deaths), colorectal cancer (9.5%), liver cancer (8.4%), stomach cancer (7.8%), and breast cancer (6.9%). As for liver cancer mortality in Spain in 2022, it was in 6th position,2 and in previous years, it was in a similar position. This contrasts with China, where liver cancer was the 2nd leading cause of cancer death.4
Table 1 and Figure 1 show the results of liver cancer mortality in Spain from 2008 to 2020, by sex and total population each year.5 In 2020, there is a significant difference compared to the mortality rate found in China, which is 25.57 per 100,000 inhabitants;1 Spain's rate is 2.4 times lower. One of the most effective strategies for preventing hepatocellular carcinoma is the hepatitis B vaccine. Spain was one of the first countries to implement a universal immunization plan in 1991.6 China also started a nationwide vaccination program in 1992; however, from 1973 to 1984, the prevalence of hepatitis B virus was 9.6%. As a result, in 2021, the prevalence dropped to around 3%. However, among high-risk groups, it remains high at over 5% and varies throughout the country, making China have the highest viral load of hepatitis B virus in the world.7 This contrasts with Spain, where, according to last year's data, the prevalence of hepatitis B virus was 1%, with around 500 cases per year, often due to faulty vaccination in childhood.8 Therefore, one key to the difference in the mortality rate may be related to prevalence.
Table 1Mortality rate per 100,000 inhabitants from 2008 to 2020 by sex and total mortality rate in Spain5
| Year | Mortality rate per 100,000 inhabitants in men | Mortality rate per 100,000 inhabitants in women | Total mortality rate per 100,000 inhabitants |
|---|
| 2020 | 14.7 | 6.64 | 10.6 |
| 2019 | 15.57 | 6.52 | 11.03 |
| 2018 | 15.53 | 6.57 | 10.96 |
| 2017 | 15.69 | 6.78 | 11.15 |
| 2016 | 14.95 | 6.67 | 10.74 |
| 2015 | 15.14 | 6.72 | 10.86 |
| 2014 | 14.87 | 7 | 10.87 |
| 2013 | 14.68 | 6.63 | 10.59 |
| 2012 | 14.65 | 6.89 | 10.72 |
| 2011 | 14.33 | 6.78 | 10.52 |
| 2010 | 13.62 | 6.9 | 10.24 |
| 2009 | 13.13 | 6.84 | 9.95 |
| 2008 | 13.2 | 6.62 | 9.88 |
Table 2 and Figure 2 show the mortality rate by age group in Spain in 2022, indicating that as age increases, the mortality rate is higher,5 similar to trends in China.1 If we compare the data on mortality rates in Table 1 with the mortality rate by age group in Table 2, we can see that it is higher in men.5 Risk factors for liver cancer include excessive alcohol consumption, smoking, viral or autoimmune hepatitis, congenital liver disease, medication, or non-alcoholic fatty liver disease.9 Among these, alcohol consumption and smoking are more prevalent in men in Spain,5 as in China.1
Table 2Mortality rate per 100,000 inhabitants in 2022 by age and sex in Spain5
| Years | Mortality rate × 100,000 inhabitants in men | Mortality rate × 100,000 inhabitants in women |
|---|
| 15–19 years old | 0.077 | 0 |
| 20–24 years old | 0.08 | 0 |
| 25–29 years old | 0.389 | 0 |
| 30–34 years old | 0.361 | 0.14 |
| 35–39 years old | 0.575 | 0.19 |
| 40–44 years old | 0.935 | 0.47554 |
| 45–49 years old | 1.93 | 0.845 |
| 50–54 years old | 7.915 | 2.085 |
| 55–59 years old | 19.18 | 5.075 |
| 60–64 years old | 31.53 | 7.72 |
| 65–69 years old | 41.996 | 10.478 |
| 70–74 years old | 58.32 | 13.28 |
| 75–79 years old | 67.78 | 23.86 |
| 80–84 years old | 84.11 | 33.82 |
| 85–89 years old | 87.9 | 47.06 |
| 90–94 years old | 104.65 | 52.035 |
| >95 years old | 74.45 | 43.67 |
Regarding population distribution, in Spain, all autonomous communities and regions have a mortality rate of around 10 per 100,000 inhabitants, similar to those shown in Table 1,5 unlike China, where the rate was higher in rural areas.1
In conclusion, liver cancer is one of the most deadly cancers globally, especially in men, and it is vitally important to effectively manage risk factors, with hepatitis B vaccination being one of the most effective tools.
Declarations
Funding
None to declare.
Conflict of interest
The authors have no conflict of interests related to this publication.
Authors’ contributions
Study design: JGC, JI; Data collection; JGC, INEP; Manuscript writing: JGC, GM; Supervision: JI. All authors have approved the final version and publication of the manuscript.