Causes of cancer
Modern science currently cannot be completely certain of what causes cancer, but generally the cause can be attributed to two major factors:
Generally, internal factors include race, heredity, age and gender. There are differences in cancers that occur across the globe. Although cancer can be attributed to a certain extent to different living habits, race and heredity, which are commonly recognized as important factors, cancer is most likely to occur with age. Despite most cancers occur in people who are 40 – 60 years old, certain cancers specifically occur in children. Cancer incidence is also different between men and women. Liver cancer, nasopharyngeal cancer, lung cancer, stomach cancer and esophageal cancers are often seen in Taiwanese men while cervical cancer, breast cancer, gastric cancer and colorectal cancer are more common among Taiwanese women.
Long-term stimulus of external factors can cause gene mutation. These external factors are also called carcinogenic factors and can be categorized into three types:
A. Chemical factors
Currently, there are many known chemical substances that are carcinogenic. Their cancer-causing ability has been time-tested from animal experiments. The polycyclic hydrocarbons in cigarettes are powerful carcinogens. Most notably, aflatoxin that commonly exists in fermented foods can cause liver cancer.
In addition, waste, tar, soot, dust, car waste, aromatic beauty agent dyes, herbicides and pesticides from organic chemical factories, as well as food additives (coloring, flavoring, preservatives, etc.), excessive growth hormone, arsenic and mercury can all directly or indirectly poison people and/or pollute our living environment. Gradually, they will have a cancer causing effect.
B. Physical factors
Of the physical factors that cause cancer, the most important is radiation. The offspring of old Nagasaki and Hiroshima residents still have a very high likelihood of developing leukemia to this day. Long-term mechanical stimulation can also cause cancer. Gallstones and kidney stones have a very close correlation with gallbladder cancer and renal pelvis cancer.
Furthermore, long-term sunlight, ultraviolet radiation and local heating exposure can also be carcinogenic factors.
C. Biological factors
Biological factors that can cause cancer are generally viruses. Many types of tumors have been found to be related to viral infections. Viral infection of cells has an effect on chromatin, which can cause the chromatin to mutate and produce cancer.
Some other biological factors such as mold, aflatoxin and Chinese liver fluke have been perceived as being related to liver cancer. Smoking is related to lung cancer and chewing betel nut is related to the occurrences of oral cancer.