Lifestyle has little impact on cancer?

For the most part, tumors are unaffected by lifestyle

06/01/2015

After the cancer diagnosis, those affected usually ask first why exactly they have met the fate of a tumor disease. Was it the unhealthy way of life, are the genes to blame or just bad luck? A current, in the trade magazine „Science“ Published study now concludes that the majority of diseases are random - neither the genes, nor the way of life play the crucial role here.

For most cancer patients, their illness is a hard blow, often accompanied by self-doubt and guilt. After all, there is the question of how to blame one's own lifestyle for the outbreak of the disease. Although an unhealthy lifestyle has so far been considered the major risk factor in many cancers. But a recent study shows that the impact of lifestyle is much lower than expected. Rather, most cancers are simply due to biological bad luck.

Together, cancer expert Bert Vogelstein and bioinformatician Cristian Tomasetti of the Johns Hopkins University School of Medicine Baltimore (USA) have written in the journal „Science“ presented a mathematical model that determines the probability of a tumor disease based on the number of cells in an organ or on the percentage of long-lived stem cells found here and their frequency of division. According to the authors of the study, about two-thirds of the cancers could be explained with the model.

Biological bad luck as an explanation for cancer
The question of why is in cancer according to the oncologist Professor Vogelstein „quite a reasonable question.“ It is assumed that „All cancers are caused by a combination of pitch, environmental influences and heredity“ become. The US researchers continue to write that their model can determine what proportion of the three factors in the development of various cancers. „They found that 22 (of 31 cancers examined) were largely due to the pitch factorrandom DNA mutations in cell division are explainable“, as reported by the Johns Hopkins University School of Medicine. The other nine cancers are more marked by lifestyle and genes, and these are exactly the kinds of cancers that one would expect, including lung cancer associated with smoking and skin cancer associated with increased sun exposure, reports Professor Vogelstein.

Lifestyles in many cancers without decisive influence
Although the lifestyle has a significant impact on the development of around one-third of cancers, a healthy lifestyle can significantly reduce the risk here. But in a majority of malignant tumors, the influence of environmental factors is rather low. Here is the best way to minimize the health risk, according to the researchers, the early detection. With their help, a large part of the tumors can be discovered at such an early stage that successful treatment is still possible, stresses Professor Vogelstein. While efforts to reduce the risk of cancer must be continued by maintaining a healthy lifestyle, it may also help the affected cancer patients to know that their disease was not their own fault but a biological misfortune.

Division of Stem Cells of Significance
The number of stem cells and their rate of division may also differ in similar tissue, as is the case for example in the large and small intestine. According to the researchers, both organs are exposed to nearly comparable environmental influences or substances, and yet colon cancer is significantly more common than small bowel cancer. This is due to the higher rate of division of stem cells in the colon, write Vogelstein and Tomasetti. Overall, it can be stated that organs whose tissues contain many high-rate stem cells are particularly frequently affected by cancer. According to the researchers, it remains an important message that cancer can often not be prevented, which is why significantly more funds must be put into early detection and further improvements in therapy. (Fp)