According to a new study, up to 90% of cancers are as a result of modern lifestyle choices such as drinking, smoking and spending too much time in the sun.
The findings conflict with research published earlier this year which stated that two-thirds of cancers were caused simply by “bad luck.”
In the most recent study, doctors at the Stony Brook Cancer Center in New York employed computer modeling, population statistics and genetic information to reach their conclusions.
Director of the clinic, Dr Yusuf Hannun, questioned is cancer just a matter of bad luck? At some degree it is, but that bad luck can also involve a lot of modifiable factors.
He added that for example, we may come into this world with one cancer-causing bullet in the chamber of the gun; therefore we’d have a one in six chance of getting cancer over our lifetime. But once you begin smoking or sunbathing excessively, it’s the same as adding three more bullets into the chamber.
That individual still has a chance of not getting cancer, but they’ve increased remarkably – they have tripled or even quadrupled – their odds of getting cancer.
The research team at Stony Brook state that their data proves that only between 10 to 30 per cent of cancers are caused by intrinsic factors such as DNA.
Published in the journal Nature, this new study adds credibility to public health advice which states that not smoking or drinking, avoiding pollution and sunburn, and maintaining a healthy weight are the best ways to prevent cancer.
The team came to the following conclusions about the divide between environmental and natural causes for certain cancers:
- Skin cancer: 86% ultraviolet radiation from the sun – 14% naturally
- Colorectal cancer: 75% poor diet – 25% naturally
- Oesophaegal cancer: 75% alcohol and tobacco – 25% naturally
- Cervical cancer: 90% human papilloma virus – 10% naturally
- Anal cancer: 90% human papilloma virus – 10% naturally
- Lung cancer: 86% smoking – 14% naturally
- Liver cancer: 80% alcohol, Hepatitis B and C
In an earlier study in January, researchers from the Johns Hopkins University School of Medicine in Baltimore examined 31 types of cancers and discovered that 22 were generally “bad luck.”
These included ovarian, testicular, bone, pancreatic and brain cancers – as well as leukemia.
The other nine types of cancers, including skin cancer known as basal cell carcinoma and smoking-affiliated lung cancer, were more heavily influenced by environmental and hereditary factors.
Overall, they assigned 65% of tumours to random mutations in genes that can spark cancer growth.