Cancer is one of the most dreaded diseases. It is characterised by a malignant tumor that obstructs the normal functioning of organs. According to a recent analysis from the World Health Organisation (WHO), more than a third of cancer cases in the world are preventable. Cervical, stomach, and lung cancers make up half of the cases. This implies that millions of such deadly cases in the world can be prevented with behavioural changes, timely medical intervention, reduced occupational risks, and an ability to tackle environmental pollutants. It turns out that most preventable cancers can be avoided by making two simple lifestyle changes.Preventable cancers in the worldResearchers say that addressing preventable causes represents one of the most powerful opportunities to reduce the global cancer burden. The analysis also noted that, in 2022, there were approximately 19 million new cases of cancer, and 38 per cent were related to 30 modifiable risk factors. The most common modifiable risk factors are:High BMISmokingInsufficient physical activityAlcohol intakeSmokeless tobaccoAir pollutionExposure to infectious agentsSuboptimal breastfeedingOccupational exposuresWhat are the preventable risk factors for cancer?The most common preventable risk factor, however, was smoking tobacco. It is associated with 15 per cent of all cancer cases in a year. In men, the risk was significantly higher. Smoking contributed to 23 per cent of the new cancer cases globally in men that year. However, smoking alone was not the only cause; air pollution, depending upon the region, played a huge role. In East Asia itself, 15 per cent of lung cancer cases in women were attributed to air pollution. In Western Asia and Northern Africa, 20 per cent of lung cancer cases in men were due to air pollution.After smoking tobacco, the next key lifestyle risk factor was drinking alcohol. It accounted for 3.2 per cent of all cancer cases—approximately 7 lakh. As per researchers’ estimates, drinking alcohol and smoking tobacco account for about 48 per cent of all preventable cancer cases. Infections, however, were associated with 10 per cent of new cancer cases. Among women, the largest share of these cases was attributed to high-risk human papillomavirus (HPV), which contributes to cervical cancer cases. However, with the HPV vaccine being more accessible, cervical cancer cases have reduced.Can smoking give you stomach cancer?Stomach cancer cases are higher among men and are mostly associated with inadequate sanitation, smoking, infections, and poor access to clean water. A first-of-its-kind analysis, this study helps show how much cancer risk comes from preventable causes. By examining these patterns, countries can be alerted to work towards preventing cancers in the first place by taking appropriate steps.Researchers also mentioned in their paper that 4 in 10 cancer cases in the world in 2022 could have been prevented by eliminating the risk factors considered in the study. The study was published in the Nature Medicine journal.