Cancer is a disease that makes human beings smell discolored, causing nearly ten million deaths every year and enveloping the entire human world in fear.
Cancer is generally a general term for malignant tumors, which refers to diseases caused by abnormal proliferation of cells and invasion of other parts of the body, caused by abnormal mechanisms that control cell division and proliferation. There are more than a hundred known cancers in humans.
THE INTERNATIONAL AGENCY FOR CANCER (IARC), A SUBSIDIARY OF WHO, RELEASED THE 2018 GLOBAL CANCER REPORT, WHICH PROVIDES RELEVANT DATA ON CANCER INCIDENCE AND MORTALITY IN 185 COUNTRIES AND TERRITORIES.
With an estimated 18.1 million new cases of cancer and 9.6 million deaths worldwide in 2018, lung cancer is the cancer with the highest incidence (11.6%) and mortality (18.4%) globally, making it the "number one killer of cancer families".
In addition to other objective factors, the cumulative risk of cancer before the age of 75 is 21.4% and the risk of death is 17.7%.
But cancer rates vary from country to country, and surprisingly, cancer rates are generally higher in developed countries than in developing countries.
The cumulative cancer rate of the Australian population before the age of 75 is as high as 41.9%, New Zealand is as high as 39.7%, the United States is 33.3%, and the developed countries in Europe are generally above 30%. The highest cancer rate in Asia is in South Korea at 29.8 percent, in Japan at 24.6 percent and in China at 20.6 percent. And in almost all countries, men have higher cancer rates than women.
But this cancer rate is only superficial, and it is related to the detection level of various countries, and the detection level in developed countries is higher, and more cancer patients are diagnosed.
In terms of cancer mortality (mortality/incidence), developed countries are lower than developing countries, with Australia only 20%, New Zealand 22%, the United States 26%, Japan 34%, China reaching 65%, and poor countries in Asia and Africa approaching 90%.
Developed countries have high cancer rates and low mortality rates, mainly because of the high level of medical care, and another important reason is that a large proportion of them are diagnosed with cancer in the early or middle stages and are easier to treat. In the end, it is related to the level of medical treatment and testing ability.
At a time when the cancer problem is so serious, the Internet is still full of a lot of misinformation about cancer, which will undoubtedly mislead and harm some cancer patients.
On the Internet, we often see such articles, such as "Sharks must not be cancerous", "Elephants must not be cancerous", "Animals must not be cancered", etc., these articles are mainly divided into two types under the banner of "popular science", one is the marketing article written by the interest group to ask the water army, and the other is the low-quality self-media written by the low-quality self-media who do not understand anything. The former is very harmful, we must pay attention to screening, and the latter should be regarded as a joke.
A large number of studies have confirmed that cancer is not an "exclusive disease" of humans, and cancer or cancerous phenomena can be found in almost all mammals, birds, reptiles and even invertebrates and plants. Let's look at some examples.
Sharks are deeply harmed by rumors, in the middle of the last century, foreign rumors that "sharks are not allowed to cancer", so that a large number of sharks were killed, their cartilage was made into anti-cancer drugs, sold to cancer patients at high prices, seeking wealth and killing, and the harm was endless. But for various reasons, this rumor has only been gradually dispelled in this century.
Tumors in the jaws of great white sharks
In 2004, researchers at the University of Hawaii published a List of Cancers in Lower Animals, documenting 42 tumors found in cartilaginous fish, including at least 12 malignant tumors and tumors throughout the body, and even in shark cartilage. In 2013, Australian scientists found a large tumor in the jaw of a great white shark, and they also found a tumor in the head of a short-tailed shark. As of 2013, scientists had found tumors in at least 23 shark species.
Although tumors are not necessarily cancer, the discovery of tumors confirms that they have the possibility of cancer, and the "sharks must not be cancerous" rhetoric is self-defeating.
Another animal that has been rumored on the Internet as "not cancer-free", elephants, can actually get cancer.
In 2015, researchers analyzed autopsy reports of 644 dead elephants and found that 3% of elephants had cancer, but the potential cancerous cells in elephants were 100 times higher than in humans, and the cancer rate was much lower than that of humans, due to tumor suppressor genes in elephants. P53 is an important tumor suppressor gene, with only 1 part (2 alleles) in normal humans, while African elephants have 20 copies of P53 (40 copies) and Asian elephants have 15-20 copies of P53 (30-40), far more than humans.
In addition, the long-lived mammal baleen whales in the ocean have similar anti-cancer mechanisms, so that they are large and long-lived, but have a low cancer rate. However, as marine pollution increases, cancer rates in cetaceans are increasing, and studies of stranded beluga whales have found that 18% of individuals have tumors. Naked mole rats also have a variety of anti-cancer mechanisms, resulting in them becoming the mammals with the lowest rate of cancer.
But "low cancer rate" does not mean "no cancer", don't be deceived by word games.
Many people think that animals that are larger and longer are more likely to get cancer, so many people use "humans live long, all humans are prone to cancer" to explain human cancer problems, but this is not the case.
Epidemiologist Professor Richard Peto proposed the famous Peto's Paradox (Peto Paradox), which overturned the view that "larger and longer-lived animals are more likely to get cancer", large, long-lived animals have a set of methods to inhibit the occurrence of cancer, if humans can crack the secrets, it will be of great help to overcome the cancer problem.
Let's look at a small number of examples of cancer found in animals.
There is one animal that is more affected by cancer than humans, and that is the Tasmanian devil. This grumpy marsupial is found only in Tasmania, Australia, and a strange disease was observed in Tasmanian in Tasmanian, australia, at the end of the last century, called "Tasmanian devil facial tumor disease", the infected Tasmanian devil's face will grow a huge tumor, and then suppuration and ulceration, the infected population in 12-18 months mortality rate reached 100%, resulting in a 80% reduction in the number of Tasmanian devils in 20 years.
In 2019, the last Sumatran rhinoceros in Malaysia died of cancer, and less than 80 of this species are still alive, and I am afraid that it is not saved.
Pappochelys rosinae
The earliest known cancer patient, a primitive turtle, was found by pathological archaeologists on a fossil leg bone of a 240-million-year-old paleontologist, Pappochelys rosinae, very similar to human osteosarcoma. The Rochesian turtle is the ancestor of turtles, but has not yet evolved a turtle shell and looks like a lizard.
Turtles with tumors
But 240 million years later, turtles, seen as symbols of longevity, have not been able to escape cancer. For example, turtle fibroma mastoma can cause a decrease in the number of turtles.
Dinosaurs also get cancer.
A 2003 study of more than 10,000 dinosaur fossils found that 3 percent of platypus fossil samples had signs of cancer. Not long ago, there was a news that a malignant tumor similar to osteosarcoma was found in the fossil of 77 million-year-old ceratosaurus unearthed in Canada.
The risk of cancer in humans' favorite pet cats and dogs is comparable to that of humans, with the National Cancer Institute saying more than 27 million dogs are diagnosed with cancer each year. More than 50% of dogs over the age of 10 die of cancer. Among them, the Golden Retriever has the highest incidence of cancer, reducing the average lifespan of the breed to 10.5 years. The chance of cancer in cats is about the same as that of dogs.
In the news of 2010, a parrot raised by American woman Anne Rory was diagnosed with squamous epithelial cell carcinoma in 2009 and could only live for two months at most. Anne resolutely spent £50,000 on chemotherapy for it, and the parrot survived for more than a year after chemotherapy.
The above are all higher animals, and invertebrates also have cancerous phenomena.
August Dorn, a professor at the University of Mainz, found that after the stomach nerves of orthodonous insects are severed, insects develop pseudo-tumors of the midgut.
On the left is the cancerous hydra, and on the right is the normal hydra
Scientists have found cancerous phenomena in tapeworms, planarian worms, and hydra, and tapeworm cancer can even harm humans.
A 2015 report in the New England Journal of Medicine reported that a 41-year-old man with AIDS had cancerous changes in a parasite, Taenia breavide, and transmitted cancer cells to him, causing cancerous tumors in his body. Human parasites get cancer, and the result endangers the host, which is really magical.
Plants can also produce tumors, such as coronary galls, but they usually do not turn into cancer and are not fatal, so I will not say more here.
It can be seen that cancer is really the same, whether it is the "spirit of all things" humans, or invertebrates and plants, can not escape its clutches.