One-third of the cancer cases in the Netherlands are caused by unhealthy lifestyles and living conditions, according to research by the TNO institute. And this means some 40,000 cases of cancer a year could be prevented if people lived healthier lives, says cancer charity KWF Kankerbestrijding. The figures are based on statistics from 2019, before the coronavirus pandemic, when there were fewer diagnoses because of pressure on hospitals dealing with Covid cases. Smoking remains the leading cause of cancer, accounting for…