It was believed that both lifestyle conditions and genetic factors could help raise cancer risk in people, but a new study reveals that random chance could also play a huge role as well.
You have to understand that cancer varies greatly depending on the region that is going to be affected. For instance, people are 11 times more susceptible to lung cancer than brain cancer.
For quite some time, many researchers attributed lifestyle conditions such as exposure to cigarette smoke and ultraviolet radiation to a much higher risk of developing cancer. However, neither this or genetic predisposition can explain fully the marked variability in cancer rates across the many different tissues in our bodies. That is about to change with the introduction of a possible third factor.
The Researchers of Johns Hopkins University may have found a potential factor that could influence cancer rates in our body.
Cristian Tomassetti, a mathematician and Bert Vogelstein, a cancer geneticist, used the available data on the number of stem cells and their supposed rates of cell division in about 31 different tissues in our bodies.
Both of them found that around 65 percent of the variability of cancer risk among the many different tissue types could be explained by looking at the number of stem cell divisions a particular tissue undergoes in its lifetime.
By plotting the total number of cell divisions against potential cancer risks, there was no doubt that they have a strong relationship. This data could be applied to cancers with couple hundreds and thousands of fold differences in its lifetime, said Volgenstein.
Giovanni Parmigiani, a statistician at the Dana-Farber Cancer Institute who had previously collaborated with the two, said that the message is clear. Although this looks simple, it does give light to cancer etiology.
In Tomassetti and Vogelstein’s study, it turns out that the Basal and Colorectal tissues have the highest number of cell divisions among the many different tissues that were analyzed. This proves that they, too, provide the highest cancer risk as is evidenced by the statistics given by the World Health Organization.
Although the supposed link to cell divisions and the number of bodily mutations is not new, the method to which the authors arrived at the conclusion is new, said Hudson.
Both Volgenstein and Tomassetti said that despite the minuscule differences in the rates of mutation among the different human cell types, the extent to which the stem cell divisions occur within an organ could potentially explain the increased cancer risk.
Ordinary cells do not necessarily mean that you’re going to get cancer simply because they do not live long enough, unlike their stem cell counterparts. Stem cells have the ability to differentiate and self-renew and they have the power to create clonal cell populations right inside a particular tissue.
It is important to note that although the number of cell divisions and somatic mutations could be a factor for increased risk of cancer, genetic and environmental factors could also potentially lead to cancer as well.