A new study shows that two-thirds of cancer cases are caused by ‘bad luck,’ while only one third is caused by genetic or environmental factors. Scientists found that most cancers are triggered by mistakes in cell division that just happen, without a previous cause.
The study was conducted by a team of researchers from the Johns Hopkins Kimmel Cancer Center in Sidney, Australia. The researchers analyzed a series of tissue types affected by cancer following several random mutations that had occurred when the stem cells were dividing.
Scientists analyzed 31 tissue types and the way they divided during an average person’s lifetime. The results revealed that two-third of the cancer cases had as primary cause the “bad luck” factor, rather than genetic disorder, while one-third had as main cause environmental factors such as smoking and bad diet or inherited genetic anomalies.
Bert Vogelstein, author of the study and professor of oncology at the Johns Hopkins University School of Medicine, said that all cancer cases had as primary cause a combination of “bad luck”, environmental factors and heredity. Dr. Vogelstein also said that the new study would help scientists asses which of the three factors contributed more to cancer development.
Researchers found that 22 of the tissue types affected by cancer were caused by sheer ‘bad luck’ which led to DNA mutations during stem cell division. The other nine tissue types acquired cancer because ‘bad luck’ factor combined with environmental agents and bad genetics.
“This study shows that you can add to your risk of getting cancers by smoking or other poor lifestyle factors. However, many forms of cancer are due largely to the bad luck of acquiring a mutation in a cancer driver gene regardless of lifestyle and heredity factors. The best way to eradicate these cancers will be through early detection, when they are still curable by surgery,”
Vogelstein also said.
For the study that proved most cancers are caused by bad luck , researchers used additional data gathered for a previous Indian research which showed that the 30 – 69 years age group had the highest risk of dying from cancer, while most of the cancer deaths among this group – about 42 percent in male patients and 18 percent in female patients – were related to tobacco.
Dr.Vogelstein also said that some heavy smokers do not develop lung cancer at an old age because they have “good luck”, rather than “good genes.” However, “poor lifestyles” can increase the “bad luck” factor in developing cancer later in life, the study also showed.
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