At present, cancer is still an incurable disease and is too much of a threat to people’s health. Once you have cancer, it is basically a death sentence! It can be imagined how painful and helpless cancer patients are. But if it can be detected early, then the result is different and at least a five-year survival rate can be guaranteed. We would not only wonder if there is any easiest way to detect the appearance of cancer if we have it, but even detect the abnormality as well. The first thing that comes to our mind should be whether abnormalities can be detected from the blood routine. It is important to know that routine blood test is the most common test used in hospitals, and it is also the one we often do in our daily testing. If the doctor can detect abnormalities in the routine blood of cancer patients, it should be very meaningful for early detection of cancer. Is that in fact the case? The actual situation is that a small number of cancer patients can have obvious abnormalities in their blood routine, and most of them may have mild abnormalities or basically normal blood routine. The reasons for this are as follows: a. Generally clinicians only notice changes in the number of the three cell lines (red blood cells, white blood cells, platelets) and hemoglobin, but routine blood results also contain more information, for example, information on blood cell changes in malignant tumors can be obtained from the most common routine blood results. Cancer can invade the whole body tissues, and red blood cells, white blood cells and platelets can show corresponding abnormal changes during the development of cancer, and these abnormal changes can be seen by blood routine. Secondly, blood routine of cancer patients with blood system will indeed show obvious abnormalities, such as abnormal increase of white blood cells, abnormal decrease of white blood cells, red blood cells and platelets, etc. Doctors will further conduct further tests such as bone aspiration to clarify the diagnosis. Third, in other cancer patients, the blood routine will not be as obviously abnormal as leukemia. However, because cancer is a chronic wasting disease, some patients may have anemia in their blood routine, especially for middle-aged and elderly patients. If anemia appears in blood routine, we must find out the cause, especially for those with long-term low fever and wasting, they may be cancer patients. Although not all cancers can be detected abnormally from blood routine, there are many ways to diagnose cancer through blood, such as the often used tumor markers, most cancers have corresponding sensitive tumor markers. For example: a. CEA, CA199, CA72.4 are commonly used for gastric cancer; b. Tumor markers for colorectal cancer are similar to those for gastric cancer; c. AFP for liver cancer; CA199 is relatively sensitive for pancreatic cancer; d. PSA for prostate cancer; e. SCC, NSE, CEA, CA125 are commonly used for lung cancer; f. CA125 is commonly used for peritoneal metastatic cancer or primary peritoneal cancer; g. CA125 is commonly used for gynecologic tumors; g. CA125 is commonly used for gynecologic tumors. of inheritance; vii. Gynecological tumors often have CEA, CA125, CA153, etc.