Colorectal cancer is a general term for colon and rectal cancer, and statistics have found that more than 80% of colorectal cancers have reached the middle and late stages once detected, so colorectal prevention and early detection are especially important, and colorectal cancer can be prevented, and there are at least three ways to prevent colorectal cancer: etiological prevention (establishing correct eating habits); active treatment of precancerous diseases (people with clear family history of colorectal cancer, receiving genetic prediction and intervention treatment); and active Participating in regular health checkups (screening) are effective methods for early detection of colorectal cancer.
1.The relationship between colorectal “polyps” and colorectal cancer
The so-called “polyp” refers to the various bulges that grow in the intestine (mucosal surface). Medically speaking, there are two types of polyps: tumor and non-tumor. The former type is called “adenoma”, which is a real benign tumor. The latter type of polyp is not a tumor, and in fact, not all adenomas turn into cancer. The most likely to become cancerous is the aforementioned “familial adenomatous polyposis”, which can have abdominal pain, diarrhea, blood in the stool, or no symptoms until after the cancer is detected. It has been observed that this disease occurs around the age of 20, develops symptoms around the age of 33, becomes cancerous around the age of 39, and dies at an average age of 42.
It has been found that 80% of such patients have “congenital retinal pigment epithelial hyperplasia” as a sign that the suspect can detect the disease through eye examination (fundoscopy). Since the disease is familial, if one member of the family is diagnosed, others should be examined (including fundoscopy). Some of these “adenomas” are associated with skin, muscle, bone, or brain tumors, some with dark spots on the skin and mucous membranes (hyperpigmentation of the palms of the hands and lips), and some with nail atrophy, hair loss, and dark spots on the skin. Since polyps grow in the intestine, the diagnosis cannot be confirmed without special examination, but we can be reminded to go to the doctor through the above-mentioned characteristic manifestations.
2.Schistosomiasis and colorectal cancer
It has been found that the incidence of colorectal cancer in schistosomiasis endemic areas is higher, and therefore it is believed that schistosome eggs are deposited in the intestinal mucosa and cause mucosal carcinoma there through mechanical or chemical stimulation. Others have found early signs of cancer in the intestinal mucosa at the site of schistosome egg deposition.
Based on these findings, some people believe that intestinal schistosomiasis can cause colorectal cancer. However, there are also many data proving that the incidence of colorectal cancer is not higher in schistosome-endemic areas than in other regions, and that there is no significant difference between the incidence of cancer found at sites of schistosome egg deposition and at non-schistosome egg deposition sites. In conclusion, there is no definite conclusion whether schistosomiasis enteropathy can cause colorectal cancer, but as a kind of chronic irritant of the intestinal tract, active treatment of schistosomiasis is still very necessary for the prevention of colorectal cancer.
3.Colon tumor is not necessarily colorectal cancer
The colorectal tumors we usually talk about include benign and malignant. Benign tumor of the colon is also called “adenoma”, which is the excessive proliferation of colonic glands (mucus-secreting tissue in the colon). This is a kind of benign tumor that is not harmful to human body. However, since it has the possibility of developing into cancer, it is called “precancerous lesion” in medical science. Once this tumor is found, even though it is not malignant, it should be treated and reviewed actively.
4.How to know if I have colon cancer?
The main symptom of colon cancer is blood in stool, followed by diarrhea, anemia, abdominal pain, weight loss and so on. Once these symptoms appear, you should go to hospital immediately. According to domestic case statistics, the misdiagnosis rate of colorectal cancer is as high as 41.5%. One important reason is that people lack understanding of the symptoms of colorectal cancer, which delays the time of consultation. Some cases are also due to the lack of vigilance of the receiving doctors, who neglected to examine carefully, mistaking blood in stool for hemorrhoids and treating pus and blood as dysentery. Some people analyzed the time from symptom to diagnosis of colorectal cancer patients: only 810% were diagnosed within one month, 25% were diagnosed in 1~3 months, and 64.3% in 36 months.
5.Why are most of the patients who come to the hospital already in the middle or late stage? What is the difference between early stage and late stage colorectal cancer treatment results?
Because early stage colorectal cancer is often asymptomatic; some patients have symptoms (even doctors) mistaken for hemorrhoids, dysentery, appendicitis and colitis. Once the disease is not cured for a long time, the disease is already in the middle or late stage when cancer is suspected. The five-year survival rate of early stage cancer can reach 90-95% after surgery (even under colonoscopy), while the survival rate of late stage cancer is only 10%.
6.How to get early diagnosis?
Regular screening of healthy people (health physical examination); necessary treatment of pre-cancerous diseases (such as treatment of adenoma and ulcerative colitis); genetic monitoring of immediate family members of colorectal cancer are the main ways to obtain early diagnosis.
7.Can colorectal cancer be prevented? How to prevent it?
The reason why colorectal cancer can be prevented is that before the occurrence of colorectal cancer, there often exists a long period of precancerous disease in the intestine (colorectal polyps – a benign intestinal tumor). Generally speaking, the average time from adenoma to cancer is about 5 to 7 years. At this stage, doctors can remove the adenoma by colonoscopy and prevent the development of colorectal cancer. Even if the adenoma has started to become cancerous, if the cancer cells have only invaded the most superficial layer (mucosal layer) of the large intestine, the doctor can remove this tumor under colonoscopy and achieve a cure.
How can these precancerous diseases and early cancers be detected early? A more effective method is to conduct regular special medical checkups for healthy people, that is, “screening” for colorectal cancer. The screening method generally consists of two stages, firstly, simple, painless and inexpensive tests such as fecal occult blood test (blood hidden in the feces that cannot be seen by the eyes) are used for screening.
Since many causes can cause positive occult blood (such as intestinal inflammation, hemorrhoids, upper gastrointestinal diseases, and even certain foods and drugs), once such “occult blood” is detected in the stool, colonoscopy must be done to clarify the diagnosis. Domestic and foreign census data show that among colorectal cancers detected by census, “curable cancer” can reach more than 90%. When it comes to colonoscopy, many people are afraid of pain and are reluctant to undergo the examination.
A retired elderly cadre found positive “fecal occult blood test” during the physical examination, and the doctor advised him to have a colonoscopy in time, but he refused to undergo the examination because he heard others say that colonoscopy is “painful”. 8 months later, he felt “anal drop”. After 8 months, he felt “anal drop” and had more than 10 bowel movements per day, and sometimes he could see blood on the stool. Under the repeated urging of his family, he underwent a colonoscopy and was found to have rectal cancer, which was at an advanced stage.
Whether colonoscopy is painful or not depends on two factors: one is the skillfulness of the doctor, and the other is the bowel type and tolerance level of the patient. The electronic colonoscope we currently use has good flexibility, so if the patient’s colon is not too long, it should not be too painful. But everyone’s colon has a certain degree of curvature, tortuous, lying in the abdominal cavity, coupled with the injection of gas when entering the mirror. The patient will have some “uncomfortable” feeling. In order to reduce the patient’s pain, major hospitals across the country have implemented colonoscopy under general anesthesia, to achieve a complete painless.
8.What people should be screened for colorectal cancer?
I suggest that in China, patients who have suffered from colorectal tumor, patients who have suffered from ulcerative colitis for more than 10 years, patients who have been suffering from gallbladder removal for 10 years, patients who have 2 relatives in their family suffering from colorectal cancer or other cancers, or patients with schistosomiasis who suffered from cancer before the age of 50 and have not been cured, patients who have undergone pelvic tumor surgery and have undergone prolonged radiotherapy all belong to colon cancer screening. Those who have undergone radiation therapy are all high-risk groups for colorectal cancer and should undergo colonoscopy once a year.
9.What treatment is needed for colorectal cancer?
The primary treatment method for colorectal cancer is surgery. As most of colorectal cancer is polyp type, if the cancer occurs at the top of the polyp and it is early cancer, it can be removed under colonoscopy without opening the colon. If the cancer occurs at the root of the polyp, or if the cancer is ulcerative or suspected to have metastasis, the corresponding intestinal canal must be removed and lymph node dissection must be performed. Whether chemotherapy or radiotherapy is needed after surgery depends on whether the cancer is metastatic or not, the degree of differentiation of the cancer and the overall condition of the patient.