▎ WuXi AppTec content team editor
Cancer is the most common cause of death worldwide. In 2020, there will be 19.3 million new cases of cancer worldwide, resulting in nearly 10 million deaths; 1 in 5 people will develop cancer in their lifetime; and 1 in 8 men and 1 in 11 women will die from cancer.
Fortunately, with advances in cancer research, prevention, treatment and care, cancer incidence and mortality have decreased significantly in some countries. So what is the current situation and trend of cancer incidence and mortality in China? And what factors are influencing? What should we do to reduce cancer incidence and mortality?
In response to these questions, researchers from the National Cancer Center of China/Cancer Hospital of the Chinese Academy of Medical Sciences conducted a study. The findings were published in the Chinese Medical Journal and written by Professor Chen Wanqing.
Image credit: 123RF
The results of this study show that:
In 2022, China will have about 4.82 million new cancer cases, resulting in 3.21 million deaths;
The burden of liver, stomach and esophageal cancer in China will decrease, but the burden on lung, colorectal, breast and prostate will increase;
Advances in cancer prevention and care, as well as measures to proactively address an aging population, could help reduce the burden of cancer in China.
New and dead cancers are common in China in 2022
The researchers predict that in 2022, about 4.82 million new cancers will occur in China, and 3.21 million people will die from cancer. Lung cancer remains the most common new cancer and the leading cause of death.
In 2022, the five common new cancers are lung cancer (870,000), colorectal cancer (590,000), stomach cancer (510,000), liver cancer (430,000) and breast cancer (430,000); the common five major dead cancers are lung cancer (770,000), liver cancer (410,000), stomach cancer (400,000), esophageal cancer (320,000) and colorectal cancer (310,000).
The number of new cancers and deaths is significantly higher in men than in women, and the types of common new and dead cancers also vary greatly.
Among men, 2.63 million new cancers are expected, resulting in 1.94 million deaths. The most common new cancers are lung cancer (580,000), stomach cancer (350,000), colorectal cancer (340,000), liver cancer (320,000) and esophageal cancer (240,000). The most common fatal cancers are lung cancer (510,000), liver cancer (300,000), stomach cancer (270,000), esophageal cancer (220,000) and colorectal cancer (180,000).
Among women, 2.2 million new cancers are expected, resulting in 1.26 million deaths. The most common new cancers are breast cancer (430,000), lung cancer (300,000), colorectal cancer (250,000), thyroid cancer (170,000) and stomach cancer (160,000). The most common fatal cancers are lung cancer (260,000), colorectal cancer (130,000), stomach cancer (130,000), breast cancer (120,000) and liver cancer (110,000).
Cancer incidence, mortality trends and influencing factors
Since 2000, the number of new cancers and deaths in China has gradually increased. Overall, China's cancer spectrum is in the transition from developing to developed countries, characterized by a high incidence of lung, colorectal, breast and prostate cancers. The researchers believe that increased morbidity and death rates are largely associated with factors such as lifestyle changes, increased adult numbers, and an aging population.
Among men and women, the incidence and mortality of gastric, liver and esophageal cancers have gradually declined in recent years. However, the incidence of colorectal and prostate cancers has increased significantly in men, and in women, the incidence of seven common cancers, including breast, lung, colorectal, thyroid, cervical, pancreatic and ovarian, has increased since 2000.
It should be noted that since 2000, the mortality rate of thyroid cancer in China, although it has remained stable, has increased sharply. The researchers believe this is related to factors such as increased health awareness, more people performing examinations such as neck ultrasound, and more sophisticated examination instruments.
At the same time, the 5-year relative survival rate of cancer patients has been increasing, from 30.9% in 2003-2005 to 40.5% in 2012-2015, which is greatly related to the early prevention, screening, and improvement of treatment options for cancer. However, the survival rate of some specific types of cancers, such as breast and colorectal cancer, still needs to be improved compared to other developed countries.
How to reduce the incidence and mortality of cancer
The study points out that in the foreseeable future, an aging population is likely to become a major social feature of China. China is one of the fastest growing countries in the world with an aging population. By the end of 2020, China's population aged 60 and over will be 260 million, and it is expected to increase by about 10 million per year in 2021-2025, and the proportion of people aged 60 and over will exceed 30% by 2035. The continued aging of the population means that the rising cancer burden in China is likely to remain unchanged. Therefore, there is a need to integrate healthy ageing strategies into cancer prevention and to strengthen multisectoral collaboration in policy development.
China's cancer spectrum is changing, so high-risk people aged 45-74 should participate in the early screening and detection of cancer in a timely manner, such as colorectal cancer, breast cancer, lung cancer, cervical cancer and upper gastrointestinal cancer.
All people should adhere to the first level of preventive measures for cancer. Approximately 45.2% of cancer deaths in Adults Aged 20 and Older in China are attributable to 5 broad categories of 23 modifiable risk factors, including:
4 behavioral factors, smoking, secondhand smoke, alcohol consumption and physical inactivity;
7 dietary factors, low fruit consumption, low vegetable consumption, low dietary fiber intake, high red meat consumption, insufficient dietary calcium intake, high processed meat consumption and high consumption of pickled vegetables;
2 metabolic factors, overweight and obesity, diabetes;
2 environmental factors, UV exposure and PM2.5 air pollution;
8 infectious agents, Helicobacter pylori, hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), human papillomavirus (HPV), Epstein-Barr virus (EBV), Trematodes warfarinus and human herpesvirus 8 (HHV-8).
In response to these 23 modifiable risk factors, adhering to the first level of cancer prevention measures to control behavioral, dietary, metabolic and environmental factors and prevent infection will play a huge potential and role in reducing cancer incidence and mortality.
Adopt an integrated strategy. Taking cervical cancer as an example, the World Health Organization believes that cervical cancer is expected to become the first cancer to be eliminated globally. However, the incidence and mortality of cervical cancer in China have increased significantly since 2000. Therefore, we adopt a comprehensive strategy, including HPV vaccination, cervical screening, treatment of pre-invasion lesions and invasive cancer, etc., to achieve the goal of eliminating cervical cancer.
brief summary
The researchers point out that the number of new cancers and deaths in China is increasing, and targeted cancer interventions are urgently needed. In addition to focusing on and responding to population ageing and initiating research on certain cancers, more and more comprehensive prevention strategies should be implemented, including health education, dissemination of basic knowledge about cancer, promotion of healthy lifestyles, implementation of effective screening, vaccination programmes, and tobacco control to reduce the burden of cancer.