Poverty, tobacco, and nutrition: Is it possible to stop the spread of cancer worldwide?

BarcelonaThere are 19 million people diagnosed with cancer worldwide, and almost half of these cases could have been avoided by changing lifestyle habits and introducing preventative measures. Tobacco, alcohol, and poor diet are some of the direct and modifiable risk factors for this disease, which, due to aging and population growth alone, is expected to grow even further in the coming years. Currently, the world is already seeing a clear and worrying increase in lung tumors, also in non-smokers, and colorectal cancers in people under 45.

The American Cancer Society (ACS) and the International Agency for Research on Cancer estimate that, if no action is taken or prevention policies are implemented in the coming years, cancer figures could increase to more than 33 million cases by 2050. We need to empower citizens and take more preventative and less reactive measures to help bend a curve that is steadily rising.

"Having more and better treatments is important, but we need to put more effort into prevention and public health. If we do our job well, we'll stop seeing half of the cases we see now," says Laia Bruni, an epidemiologist at the Catalan Institute of Oncology (ICO). For example, one in five cancer deaths worldwide is due to tobacco. Currently, lung cancer is the most commonly diagnosed tumor and the leading cause of cancer death worldwide, with 1.8 million deaths annually. Even so, more than one billion people worldwide smoke, as confirmed by the fourth edition of the Cancer Atlas, published this week by the ACS. This is a current snapshot of a group of diseases that cause 10 million deaths worldwide each year.

To understand this scenario, however, ICO research director Ernest Nadal explains that The number of lung cancer cases among non-smokers is rising due to air pollution. The increase is more notable in poor countries, where, in addition to greater pollution, smoking is also more deeply rooted, as it is a habit associated with low purchasing power. The same is true for alcohol consumption, which is responsible for 750,000 cases of cancer each year worldwide. In fact, in addition to lung cancer, lower-income countries are also experiencing a marked increase in the incidence of colorectal and breast cancer due to these risk factors associated with social determinants.

Anticipating the disease

Furthermore, in many of these countries, it is important to note that prevention programs such as screening to detect the disease early, as well as access to preventive treatments such as vaccination, are lacking. In fact, a preventable cancer like cervical cancer has long been the leading cause of cancer death in women in 29 countries in sub-Saharan Africa. In many of these states, less than 10% of women between the ages of 30 and 49 have ever undergone screening, compared to most so-called Western countries, where the percentage is close to 80%. Coverage for the human papillomavirus (HPV) vaccine, which is highly effective in preventing this cancer, varies considerably across regions: it ranges from 3% in Central and South Asia to 86% in Australia and New Zealand.

Bruni, an HPV expert, explains that in Catalonia, first-dose coverage is very good, reaching 90%, which has significantly reduced the incidence of this cancer. "Before, we used opportunistic screening: women would go to the gynecologist and get tested. We found that those who had undergone several tests over the years had a much lower risk, while 80% of women who developed cancer had never been tested," she exemplifies. Therefore, she once again focuses on social determinants and insists that it is necessary to improve access to preventive strategies worldwide to reduce cancer cases. Colon and breast cancer screenings are also carried out in Catalonia, but coverage is "below what is desirable," Bruni laments.

Access to treatment is another outstanding task. According to the Cancer Atlas, cancer mortality rates are "disproportionately higher" in many low-income countries due to lower survival rates, since more than 90% of the population in these territories lacks access to safe surgical care. Furthermore, in highly populated countries (more than one million inhabitants), especially in sub-Saharan Africa, they also lack access to radiotherapy.

However, cancer cases are also on the rise in wealthy countries. Specifically, the incidence rates of colorectal cancer in young adults (under 45 years of age) in many high-income countries, due in part to the obesity epidemic and unhealthy diet. Nadal explains that this increase is also being detected in pancreatic cancer and warns that, in both cases, these tumors often begin in advanced stages and are highly aggressive.