Cancer Incidence Higher in ‘Better’ Countries
A new study showed the cancer rate higher in “better” countries with greater access to healthcare, compared to the world’s “worse countries.” Why is this so? The researchers from University’s Adelaide Medical School discovered some answers to this query.
According to the study, this key finding is the result of relaxed “natural selection,” extending the life span of people due to modern medicine. People in these nations have tendencies to survive cancers, thus their genetic backgrounds pass from one generation to the next.
The study found that incidence of cancer was higher in the top 10 countries; countries with low mortality (and fertility) rates, access to quality healthcare and socioeconomic status. These countries included Iceland, Singapore, Japan, Switzerland, Sweden, Luxembourg, Germany, Italy, Cyprus and Andorra
This new discovery was confirmed by anatomy and human evolution expert Professor Maciej Henneberg, a co-author of the study.
“Modern medicine has enabled the human species to live much longer than would otherwise be expected in the natural world. Besides the obvious benefits that modern medicine gives, it also brings with it an unexpected side-effect: allowing genetic material to be passed from one generation to the next that predisposes people to have poor health, such as type 1 diabetes or cancer.”
Natural selection is defined as the process whereby organisms better adapted to their environment tend to survive and produce more offspring.
The research was also co-authored by Wenpeng You, a PhD student, from University of Adelaide.
The Study and Key Results
Based on comparable global data, Mr You and Professor Henneberg considered the top 10 countries with the highest opportunities for natural selection. they were contrasted with the 10 countries with highest opportunities for natural selection among the “worse off” countries of the world: Burkina Faso, Chad, Central African Republic, Afghanistan, Somalia, Sierra Leone, Democratic Republic of the Congo, Guinea-Bissau, Burundi, and Cameroon.
Cancer Rate Higher
The researchers found that the rate of most cancers in the 10 best countries was greater than in the 10 worst countries:
Testicular cancer 14 times higher incidence in the top 10 best countries
Lung cancer 12 times higher (smoking accounts for 50% of this cancer, researchers say)
Skin melanoma 10 times higher
Brain cancer 6.5 times higher
Pancreatic cancer 5.1 higher
Prostate cancer 3.5 higher
Leukemia 3.5 higher
Breast cancer 2.7 times higher
Ovarian cancer 2 times higher
Other Relevant Explanation
Due to high quality of health care in western society, natural selection has been removed as the “janitor of the gene pool.” With this scenario, more people have opportunity to survive cancer. But the result led to accumulation of cancer genetic background at a greater rate from generation to generation.
Henneberg says, “Unfortunately, the accumulation of genetic mutations over time and across multiple generations is like a delayed death sentence.”
In addition, in the countries which are considered “better,” mortality rates are low, allowing more people to pass the cancer mutations to the next generation.
This is confirmed by Mr. You who said, “Low mortality rate and low fertility rate in the ‘better’ world may have formed a self-reinforcing cycle which has accumulated cancer genetic background at a greater rate than previously thought.”
Genetic Engineering Might Be Key to Eradicate Cancer
If natural selection is to be excluded as “janitor of the gene pool,” the researchers say modern society may be faced with a controversial issue. “It may be that the only way humankind can be rid of cancer once and for all is through genetic engineering – to repair our genes and take cancer out of the equation.”
Extending life further without addressing the gene pool may send the cancer rate higher still.
