Moving towards tailored, region-specific cancer-control measures in China
Authors: Tomohiro Matsuda, Manami Inoue
Journal: The Lancet Global Health (2019)

The burden of cancer is rising rapidly in Asia, particularly in low-income and middle-income countries (LMICs) where the prevalence of communicable diseases is also high. There is an overwhelming need for countries such as China to adopt and implement cancer control actions based on reliable data and valid evidence from studies done in the local population. In view of the large differences in cancer incidence reported between Western and Asian populations,1Bray F Ferlay J Soerjomataram I Siegel RL Torre LA Jemal A Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries.CA Cancer J Clin. 2018; 68: 394-424Crossref PubMed Scopus (50311) Google Scholar the population attributable fraction (PAFs) for cancer risk factors in Asia are also expected to be completely different. In Japan and South Korea, for example, dietary risk factors are less attributed than in Western countries, and risk factors related to gastric cancers (Helicobacter pylori infection) and liver cancer (hepatitis B virus and hepatitis C virus) account for a higher proportion of the total PAF than in Western countries in addition to tobacco smoking and alcohol consumption.2Inoue M Sawada N Matsuda T et al.Attributable causes of cancer in Japan in 2005—systematic assessment to estimate current burden of cancer attributable to known preventable risk factors in Japan.Ann Oncol. 2012; 23: 1362-1369Crossref PubMed Scopus (128) Google Scholar, 3Park S Jee SH Shin HR et al.Attributable fraction of tobacco smoking on cancer using population-based nationwide cancer incidence and mortality data in Korea.BMC Cancer. 2014; 14: 406Crossref PubMed Scopus (103) Google Scholar, 4Park S Shin HR Lee B et al.Attributable fraction of alcohol consumption on cancer using population-based nationwide cancer incidence and mortality data in the Republic of Korea.BMC Cancer. 2014; 14: 420Crossref PubMed Scopus (26) Google Scholar In The Lancet Global Health, Wanqing Chen and colleagues5Chen W Xia C Zheng R et al.Disparities by province, age, and sex in site-specific cancer burden attributable to 23 potentially modifiable risk factors in China: a comparative risk assessment.Lancet Glob Health. 2019; 7: e257-e269Summary Full Text Full Text PDF PubMed Scopus (119) Google Scholar report findings of a comparative risk assessment study of cancer burden attributable to 23 potentially modifiable risk factors in China by calculating the PAF. For the first time in China the researchers used estimated nationwide mortality data and all the available study results and published meta-analyses to obtain the most accurate indicator of PAF since a previous study.6Wang JB Jiang Y Liang H et al.Attributable causes of cancer in China.Ann Oncol. 2012; 23: 2983-2989Crossref PubMed Scopus (83) Google Scholar The study was thorough and well executed; the methods used to calculate PAF were standardised to previous publications and were suited to addressing the study questions. Findings showed that the PAF for the 23 risk factors varied substantially across the provinces. In both sexes combined, it ranged from 35·2% in Shanghai to 52·9% in Heilongjiang (and from 40·9% in Shanghai to 56·4% in Guangdong among men and from 26·9% in Shanghai to 48·0% in Heilongjiang among women). The current challenges China is facing are innovative and unprecedented in Asia, since the other Asian countries previously cited stop short of analysing the risk factors for the whole country, and not by region. At the same time, such an analysis is necessary for such a massive country with diverse cultural backgrounds. China must be an appropriate model for the other populated countries. In China, a cancer control intervention specific to the environment is no longer an optional policy, it is a standard policy. More tailor-made and evidence-based cancer control activities considering regional disparity could become the standard going forward.7Sherman EJ Primack BA What works to prevent adolescent smoking? A systematic review of the National Cancer Institute's Research-Tested Intervention Programs.J Sch Health. 2009; 79: 391-399Crossref PubMed Scopus (25) Google Scholar In their study, Chen and colleagues5Chen W Xia C Zheng R et al.Disparities by province, age, and sex in site-specific cancer burden attributable to 23 potentially modifiable risk factors in China: a comparative risk assessment.Lancet Glob Health. 2019; 7: e257-e269Summary Full Text Full Text PDF PubMed Scopus (119) Google Scholar provide an initial overview of cancer burden that will now be used to generate hypotheses for further research, both in clinical oncology and epidemiology. Although the article is generally clear, further discussion on the reliability of mortality data and the publications on risk factors would have been prudent. China still does not have a complete death certification and vital statistics system, which would of course enrich understanding of regional disparities in the cancer burden. Additionally, population-based cancer registries (PBCRs) cover only 30% of the entire Chinese population; however, we strongly expect the researchers of present study to investigate PAF on cancer incidence in the near future. Evidence from the present study should be used to focus primary prevention efforts on reducing the number and proportions of cancers attributable to modifiable risk factors in China. Regional adoption of effective primary cancer prevention strategies has vast potential to reduce the burden of cancer and disparities in China. With high-quality PBCR data, evidence from local settings can be created and evidence-based interventions can be planned, monitored, and evaluated in the most efficient manner. Most of the evidence for PAF calculation can be established only by matching cohort study participants list with PBCR databases. However, few Asian countries have high quality PBCRs that are fully utilised for cancer control. It is therefore uncertain whether the disparity in Asia reflects the true cancer risk difference. We hope that the current study will have indirect educational benefits, which will form the basis for ongoing cancer control activities in Asia. Aligned with the Global Initiative for Cancer Registry Development organised by the International Agency for Research on Cancer (IARC), a coordinated programme of activities to build in-country capacity for cancer surveillance through structured support is ongoing.8Pineros M Znaor A Mery L Bray F A Global cancer surveillance framework within noncommunicable disease surveillance: making the case for population-based cancer registries.Epidemiol Rev. 2017; 39: 161-169PubMed Google Scholar IARC and the collaborating centres in Japan, Thailand, China, and South Korea will leverage their resources to provide technical training and educational materials. As the prevalence of cancers in some countries is unknown and cannot be estimated from the data of other countries, we hope that the current study will motivate the governments in LMICs to provide reliable information that prioritises and monitors policy programmes for cancer control. Accordingly, the general population in Asian countries will benefit from gaining greater awareness of prevention and treatment options for cancers. We declare no competing interests. Disparities by province, age, and sex in site-specific cancer burden attributable to 23 potentially modifiable risk factors in China: a comparative risk assessmentThe PAFs of cancers attributable to potentially modifiable risk factors vary substantially across provinces in China. Regional adoption of effective primary cancer prevention strategies has a vast potential to reduce the burden of cancer and disparities in China. Smoking, poor diet, and infection warrant particular policy attention as they contributed a large proportion to the total cancer burden. Full-Text PDF Open Access