With the increase of people’s health awareness, many middle-aged and elderly people will have regular medical checkups including blood tests, abdominal ultrasound, chest X-ray, etc., but few people will take the initiative to do intestinal health checkups.
Colorectal cancer is a preventable and treatable malignancy. Due to the effectiveness of preventive measures and health education, the incidence and mortality rate of colorectal cancer in the United States are in a declining stage; while the incidence and mortality rate of colorectal cancer in China are in a rapidly increasing stage. The symptoms of colorectal cancer (i.e. colorectal cancer) are insidious, and in the early stage of the disease or even in the late stage of the disease, patients may not have obvious local symptoms, so that many patients have already reached the middle and late stage when they are diagnosed, and the treatment effect is greatly reduced. Therefore, health check of the intestinal tract is especially important. As early colorectal cancer has no specific symptoms, how to detect colorectal cancer early through physical examination?
1. Rectal finger examination
Doctors can judge the anorectal diseases through the simplest and direct palpation and observation. More than half of colorectal cancers occur in the rectum, while 80% of rectal cancers belong to the middle and low level, rectal anal finger examination can be found to make preliminary judgment on perianal diseases and colorectal cancers.
The rectum of adults is generally 15 cm long, and the rectal intestinal wall below 7-8 cm from the anal opening can be directly palpated by hand, and a slightly elevated nodule on the rectal mucosa can be found. More than half of the colorectal cancer patients in China are rectal cancer, and among the rectal cancer patients, about 60-70% are low to middle rectal cancer. In other words, 70% of rectal cancers (about one-third of colorectal cancers) can be detected through anal finger examination. If the doctor finds mucus sticking to the finger sleeve during this examination, it means that there is purulent blood discharge in the patient’s rectum. Most rectal cancers, especially low-grade rectal cancers, can be detected by rectal finger examination. In addition, the shape, texture and mobility of the cancer can also be clarified through rectal examination.
2.Fecal occult blood test
Stool occult blood test is of great value in the diagnosis of gastrointestinal bleeding and is often used as a screening indicator for the early diagnosis of gastrointestinal malignancies.
Why do occult blood test to screen colorectal cancer: when there is a small amount of bleeding in the GI tract, there is usually no blood in stool, black stool and other manifestations, and there is no abnormality in the appearance of stool to the naked eye. In fact, not only colorectal cancer, but also gastrointestinal tumors such as gastric cancer, in the early stage of tumor development, the tumor will erode the mucosa and submucosa blood vessels, resulting in very small amount of gastrointestinal bleeding, which is difficult to judge with the naked eye. For people without a history of gastric disease, if a positive fecal occult blood test is found during physical examination, it is recommended to do it again at a later time. If it is still or continues to be positive, then it is necessary to be alert, first of all, to exclude gastrointestinal tumors, the most common sites of gastrointestinal tumors are stomach, colon and duodenum. (Attachment: positive fecal occult blood test: intermittent positive in the case of ulcerative bleeding in the peptic tract; and often persistent positive in the case of gastrointestinal tumors, so it can be used as a differentiation between benign and malignant bleeding.)
The chance of people developing colorectal cancer increases significantly after the age of 40. According to statistics, about 75% of colorectal cancer patients are in this age group. Therefore, people should do fecal occult blood test once a year from the age of 40 to be alert to bleeding caused by polyps or tumors. First of all, fecal occult blood test is more convenient and easier to do screening than colonoscopy and anal examination fingerprints, and one test costs about ten dollars.
3.Colonoscopy.
Colonoscopy is the most effective means to detect early colorectal cancer. Colonoscopy not only can clearly observe the intestinal tract, but also can take suspicious lesions for pathological examination under direct vision, which is conducive to the detection and confirmation of early and micro colorectal cancer.
At present, few people take the initiative to do colonoscopy for two main reasons: firstly, people lack knowledge about colorectal cancer, and secondly, people are difficult to accept or even afraid of this invasive examination method. This kind of fear makes many patients delay their conditions, resulting in many clinical cases of colorectal cancer not being diagnosed and treated at an early stage and missing the opportunity for treatment.
With the development of medical technology and the improvement of physicians’ proficiency, the discomfort of colonoscopy has been greatly reduced, and the examination time has been greatly shortened, taking about a quarter of an hour to complete a colonoscopy. In addition, painless colonoscopy under intravenous anesthesia is also an option.
Another major significance of colonoscopy is the detection and minimally invasive treatment of colon polyps, especially precancerous lesions such as adenomatous polyps, through endoscopy. We know that most colorectal cancers originate from adenomatous carcinoma. It may take several years or even longer from the occurrence of adenoma to the onset of cancer. If adenoma can be detected through colonoscopy and minimally invasive treatment through endoscopy at the asymptomatic stage when adenoma is not cancerous or early cancerous, the chance of its transformation to cancer can be blocked.
Theoretically, half of the children of patients with familial polyposis will develop colon polyposis, and they will pass the disease on to their offspring.
Screening should be enhanced for high-risk groups prone to colorectal cancer, mainly for the following categories of people
1. Parents, siblings and children who have one of them suffering from colorectal cancer should have fecal occult blood test and colonoscopy from the age of 40.
2. People with familial adenomatous polyps are affected because of defects in their associated genes. Patients with this disease almost always develop colon cancer after the age of 40. Therefore, all members of such families should have regular colonoscopies starting from adolescence.
3. Patients with ulcerative colitis are at greater risk of developing colorectal cancer, and this risk usually begins eight years after the patient’s onset. Therefore, patients with total colitis should have a colonoscopy every 1-2 years after 8 years of illness. Patients with left hemicolectasis should have a colonoscopy every 1-2 years after 15 years of disease.
4.In the past, it has been believed that the polyps of patients with nigrostriatal polyposis will not become cancerous. However, recent clinical data show that the chance of malignant transformation of melanotic polyposis is 20%-23%. Therefore, patients with melanotic polyposis should also undergo regular checkups.
Colorectal cancer mainly includes colon cancer and rectal cancer. In recent years, the incidence of colorectal cancer in China has been increasing year by year, and only 5% of all patients with colorectal cancer can be diagnosed at an early stage. Clinically, the early diagnosis rate of colorectal cancer is low, which is mainly because people do not pay enough attention to the early signs of the disease.
Colorectal cancer is a curable disease
During the past decade, with the continuous development of science, significant progress has been made in the diagnosis and treatment of colorectal cancer. The biology of colorectal cancer, as well as the genetic mechanisms involved in tumorigenesis, are better understood. As a result, lesions can be detected at an earlier stage and a better staging system can be established using molecular genetic monitoring; surgical techniques can be improved to reduce postoperative mortality and recurrence rates; at the same time, the emergence of highly effective therapeutic drugs has enabled colorectal cancer treatment protocols to be constantly updated, resulting in longer survival and higher quality of life, and even early stage patients can be cured. Therefore, tumor treatment emphasizes one word “early”, early detection, early diagnosis and early treatment.
General population: It refers to people who are not at high risk of colorectal cancer, and we recommend that these people can start to receive colorectal cancer screening after the age of 45, and the examination should be conducted once every 5-10 years on average. For high-risk groups, excluding those with family history, we recommend to start screening for colorectal cancer at the age of 40, with an average of once every 3-5 years.
People with family history: For people with family history, we recommend visiting a large oncology center as early as possible to determine whether the group has a genetic predisposition through careful collection of family history and some necessary tests, including genetic testing, by experienced clinicians. If there is a genetic predisposition, the patient will be followed closely by the clinician according to a specific follow-up protocol for hereditary tumors. If there is no apparent genetic predisposition, the population is followed up according to the screening protocol for high-risk groups.
Fecal occult blood test and anal examination finger examination can be used as screening tools for colorectal cancer, which can provide clues for early diagnosis and are recommended once a year. Before colonoscopy becomes universally available, fecal occult blood test and anal examination finger examination are good supplements.