Lifestyle and behavioural factors are contributing significantly to cancer deaths, according to a new study published in The Lancet Oncology. The research identifies unsafe sex, tobacco use, unhealthy diets and high body mass index among the leading risk factors. Behavioural risks accounted for 27 per cent of cancer deaths, while metabolic factors contributed 5.9 per cent. Researchers say addressing preventable risks could help reduce the growing cancer burden.