There are usually no symptoms in the early stages of cancer, and most people are caught by accident during a routine checkup.
Symptoms of anorexia, wasting, pain, sluggishness and constipation do not appear until later stages, when the tumor has grown so large that it compresses or invades neighboring tissues. Why is that?
Dr. Guo Xiaoqiang, a science writer in the field of life sciences, explains that it has to do with the properties of cancer cells. Everyone has cancer cells in their body. Cancer cells are essentially “harmless” and the body doesn’t react too much to their presence.
In the early stages of cancer, cancer cells proliferate more slowly, and although the immune system is activated to eliminate some of them, the intensity of the process is low and it is not specific enough for the body to recognize the cancer and distinguish it from other normal cells.
In addition, the volume of early tumors is relatively small, almost will not affect the normal function of the body, coupled with the compensatory function of some organs is very strong, so that some cancers develop to the middle and late stage, still do not have obvious symptoms.
However, once cancer cells proliferate faster, their numbers increase in a short period of time, and they exceed the immune system’s capacity, they can have many negative effects, such as excessive consumption of nutrients in the body, destruction of vital organs and tissues, and eventually death from malnutrition, organ failure and complications.
In addition, many people’s cancer is found to be advanced, also related to these two factors
Neglect of diagnosis and treatment
The early symptoms of some cancers are nonspecific and easily confused with those of other diseases. In addition, many patients often neglect diagnosis and treatment, or although abnormal indicators were found during physical examination, they did not go to the hospital for further examination to clarify the cause, so they missed the opportunity for treatment.
There is no habit of physical examination
Many people think they are in good health and are not willing to have regular physical examinations, but in fact, the early lesions of some cancers can be found through routine examinations. For example, Pap smears used in routine gynecological examinations can detect early cervical cancer.