In 2018, there were an estimated 9.6 million cancer deaths and 18.1 million new cases of cancer worldwide [1,2], with lung cancer and breast cancer each accounting for approximately 11.6% of new cancer cases . As the incidence of cancer has been on the rise since 1990, it would be easy to assume that the number of cancer-related deaths has increased proportionally; however, global cancer deaths per 100,000 individuals has, in actuality, decreased over time .
Incidence and death rates
Age-standardised cancer incidence rates vary depending on gender and by country. It is estimated that in 2019 the combined age-standardised cancer incidence rate will be 198 per 100,000; for women the rate is approximated to be 193 per 100,000 and for men, 219 per 100,000 . When investigating the rate (excluding incidences of melanoma) by country, nine of the top ten countries belonged to Europe, Oceania and North America, with Hungary displaying the highest rate of 353 incidences per 100,000 individuals .
Cancer is believed to be responsible for approximately 1 in 6 global deaths [1,2], with lung cancer accounting for 18.4% of cancer deaths in 2018 . In general, high-income countries tend to have high cancer mortality rates; across North America, Europe and Oceania, mortality rates are typically close to 150 per 100,000, while rates across Latin America, Asia and some parts of Africa can be around 50–125 per 100,000 . The number of cancer deaths may therefore be influenced by three factors: an actual change in the incidence of cancer, changes in population size and changes in population age.
Common risk factors
In spite of the statistics, the World Health Organization (WHO) estimates that 40% of all cancer deaths are preventable. With this in mind, it is worth considering the most common cancer-causing risk factors; currently, smoking is the largest cancer-causing risk factor, followed by obesity, and alcohol consumption also has a major role . There are approximately 1.1 billion smokers worldwide, with most living in low- or middle-income countries. Smoking is a risk factor for 15 types of cancer, including mouth, throat and lung, with the latter being the most common cause of cancer death worldwide . A decrease in the number of smokers could therefore have a significant impact on global cancer incidence and, consequently, cancer deaths .
Obesity is responsible for more than 1 in 20 cancer cases in the UK and is linked to several types of cancer, including breast, bowel, pancreatic, kidney and liver . It is understood that obesity may cause cancer because of the capacity of fat cells to make hormones and growth factors that increase cell division, which consequently raises the risk of a cancer-causing mutation developing . The number of people with obesity has also risen dramatically in the past few decades, and with its link to cancer this rise may result in an increase in cancer incidence .
Alcohol consumption has been linked to seven different types of cancer, including mouth, throat, breast, bowel and liver . In the UK, alcohol consumption is responsible for approximately 11,900 cancer cases a year . The reasons that alcohol causes cancer are not yet fully understood; however, the increased risk may be the result of a number of effects: the degradation of alcohol to acetaldehyde, which can damage and prevent the repair of DNA; hormonal changes causing dysregulation of cell division; and the increased absorption of other carcinogenic substances in the mouth and throat .
The WHO preventive methods
The WHO has suggested several methods to prevent cancer through the reduction of identified risk factors . It targets a reduction in obesity through the promotion of a healthy diet and increased regular physical activity, as well as a reduction in alcohol consumption through pricing, taxation and legislation, including minimum purchase age limits, restrictions on hours of sale and drink-driving laws . In addition, for smoking there is the ‘Core provisions of the WHO Framework Convention on Tobacco Control’, targeting a reduction in tobacco demand and supply, and an improvement in mechanisms for technical cooperation .
|Core provisions of the WHO Framework Convention on Tobacco Control|
|Demand reduction||Increases in tobacco product price and tobacco tax|
|Protection from tobacco smoke exposure|
|Regulation of the contents of tobacco products|
|Regulation of tobacco product disclosures|
|Ensure that packaging and labelling include health warnings and are in accordance with the provisions of the WHO Framework Convention on Tobacco Control.|
|Provision of education and training, and improvement of communication to raise public awareness|
|Banning of tobacco advertising, promotion and sponsorship|
|Reduction in measures concerning tobacco dependence and cessation|
|Reduction in supply||Reduction of illicit trade in tobacco products|
|Prohibition of sales to and by minors|
|Provision of Support for economically viable alternatives|
|Technical cooperation||Resources for tobacco control activities should be mobilised, especially in low- and middle-income countries|
|Cooperation should be promoted in the scientific, technical and legal fields in order to strengthen tobacco control, especially in low- and middle‑income countries|
In conclusion, cancer accounts for 1 in 6 deaths in the current global health climate , with the incidence of cancer often being greater in countries with a high income . Additionally, there are a number of identified risk factors, such as smoking, alcohol consumption and obesity, that can be modified and minimised through lifestyle changes [7–9]. As these risk factors are becoming increasingly better understood, new frameworks are being put in place to try to prevent cancer cases from developing, thereby decreasing both incidence and mortality rates. However, societal changes such as the increasing levels of obesity are a continuing cause for concern [6–12].
About World Cancer Day
World Cancer Day is an initiative of the Union for International Cancer Control, It is marked on February 4 to raise awareness of cancer and to encourage its prevention, detection, and treatment.
Read more, here: https://www.worldcancerday.org
- GLOBOCAN. Global cancer data 2018. Available at: https://www.iarc.fr/wp-content/uploads/2018/09/Globocan_01.jpg. Accessed January 2019.
- World Health Organization. Cancer: Key facts. Available at: https://www.who.int/news-room/fact-sheets/detail/cancer. Accessed January 2019.
- GLOBOCAN. Cancer today: The five most commonly diagnosed cancer types. Available at: https://www.iarc.fr/wp-content/uploads/2018/09/Globocan_02-e1536765200858.jpg. Accessed January 2019.
- Roser M and Ritchie H. Cancer. Available at: https://ourworldindata.org/cancer#are-death-rates-from-cancer-rising. Accessed January 2019.
- Bray F, Ferlay J, Soerjomataram I et al. Global Cancer Statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2018; 68 (6): 394–424.
- Cancer Research UK. Causes of cancer and reducing your risk. Available at: https://www.cancerresearchuk.org/about-cancer/causes-of-cancer. Accessed January 2019.
- Cancer Research UK. How does smoking cause cancer? Available at: https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/smoking-and-cancer/how-does-smoking-cause-cancer. Accessed January 2019.
- World Health Organization. Tobacco: Key facts. Available at: https://www.who.int/news-room/fact-sheets/detail/tobacco. Accessed January 2019.
- Cancer Research UK. Does obesity cause cancer? Available at: https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/obesity-weight-and-cancer/does-obesity-cause-cancer. Accessed January 2019.
- Bleich S, Cutler D, Murray C et al. Why is the developed world obese? Annu Rev Public Health 2008; 29: 273–195.
- Cancer Research UK. Does alcohol cause cancer? Available at: https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/alcohol-and-cancer/does-alcohol-cause-cancer. Accessed January 2019.
- World Health Organization. Cancer control: Knowledge into action: WHO guide for effective programmes: Prevention. Available at: http://apps.who.int/iris/bitstream/handle/10665/43575/9241547111_eng.pdf?sequence=1. Accessed January 2019.