Malignant tumors in some organs such as colon or breast, occur more often than others. The researchers suggest that this vulnerability could be the result of natural selection. People are easier to carry a large tumor or paired organs, than in small, for example, heart. Also, it assumes that the larger bodies in the process of evolution, probably less acquired mechanisms to protect against tumor cells. The study is published in the «Trends in Cancer» magazine.
According to scientists, the individual bodies that are most important for the maintenance of human life and the preservation of its ability to reproduce, such as the heart, brain or uterus, can have better protection from cancer, ceteris paribus, than others. This does not mean that the mechanism is a major factor in understanding the differences in the susceptibility of tumors to organs, but it interacts with others.
Many oncologists explain the difference in the prevalence of various types of cancer pathology environmental risk factors and lifestyle, such as smoking or exposure to UV radiation, or internal factors such as the frequency of cell division in the body. However, researchers from Deakin University (Deakin University), Australia, offer a theory of evolution, in addition to the current understanding of the causes of cancer pathology development.
The researchers suggest that natural selection favored the strengthening of protection for anti-bodies, which are essential for human survival and reproduction. Large or paired organs can potentially accumulate more of the oncogenic manifestations, while maintaining functions, while smaller critical organs such as the pancreas may lose function and the presence of a small amount of such manifestations. Thus, according to the theory of evolution, the pancreas has better protection against cancer pathology, than, for example, kidney, with other conditions being equal, in this context. The anti-cancer defense mechanisms can both be varied for different bodies, and as a whole to determine their resistance to the formation of tumors.
Researchers also recommend biologists consider factors such as the condition in which the bodies are, for example, oxygen level, pH or moisture balance, to evaluate the anticancer mechanisms of protection in this respect. Since the survival of tumor cells also depends on favorable conditions in which they are located, the medium of some organs can no longer contribute to the development of tumor cells than others. Given this, more research is needed to carry out a full analysis of the various factors confirms the hypothesis about evolutionary theory, the researchers note.