In 2011, the incidence and death rates of colorectal cancer (CRC) were 23.03/100,000 and 11.11/100,000, respectively. Among them, the incidence rate of colorectal cancer is much higher in urban areas than in rural areas, and the incidence rate of colon cancer has increased significantly. Most of the patients are already in the middle and late stage when they are found. In order to further regulate the diagnosis and treatment behavior of colorectal cancer in China, improve the diagnosis and treatment level of colorectal cancer in medical institutions, improve the prognosis of colorectal cancer patients, and protect medical quality and medical safety, this specification is formulated.
Diagnostic techniques and applications
Clinical performance Early colorectal cancer may have no obvious symptoms, but the following symptoms may appear when the disease has developed to a certain extent.
1.Change in bowel habit.
2. Change in stool characteristics (thinning, bloody stool, mucus stool, etc.).
3, abdominal pain or abdominal discomfort.
4, abdominal masses.
6.Symptoms related to intestinal obstruction.
6.Anemia and systemic symptoms, such as wasting, weakness, low fever, etc.
Disease history and family history
1.Colorectal cancer development may be related to the following diseases: ulcerative colitis, colorectal polyposis, colorectal adenoma, Crohn’s disease, schistosomiasis, etc. Detailed inquiries should be made about
The patient should be asked about the relevant medical history.
The incidence of hereditary colorectal cancer accounts for about 6% of the overall incidence of colorectal cancer, and patients should be asked about their family history.
Hereditary non-polyposis colorectal cancer, familial adenomatous polyposis, melanotic polyp syndrome, juvenile polyposis.
Physical examination
1.General condition evaluation, general superficial lymph node condition.
2.Abdominal visual examination and palpation, check whether there is intestinal pattern, intestinal peristaltic wave, abdominal mass
3.rectal finger examination: Any suspected colorectal cancer must be routinely done by anorectal finger examination. To understand the size, texture, circumference of intestinal wall, basal mobility, distance from the anal verge, infiltration of tumor to the outside of intestine, relationship with surrounding organs, pelvic floor implantation, etc., of rectal tumor. Careful touching is necessary during finger examination to avoid missing diagnosis.
Touch gently, do not squeeze, and observe whether the finger stains with blood.
Laboratory tests
1.Blood routine: to know whether there is anemia.
2.Urinary routine: Observe whether there is hematuria, combine with urinary system imaging to understand whether the tumor invades the urinary system.
3.Fecal routine: pay attention to the presence of red blood cells and pus cells.
4.Fecal occult blood test: It is important for the diagnosis of small amount of bleeding in gastrointestinal tract.
5.Biochemistry and liver function.
6.Patients with colorectal cancer must be tested for CEA and CAl9-9 before diagnosis, treatment, evaluation of efficacy and follow-up; patients with liver metastases are recommended to be tested for AFP; patients with suspected ovarian metastases are recommended to be tested for CAl25.
Endoscopy proctoscopy and sigmoidoscopy are suitable for colorectal lesions with low lesion location. Colonoscopy is recommended for all patients with suspected colorectal cancer, with the following exceptions.
1.The patient’s general condition is poor and difficult to tolerate.
2.Acute peritonitis, intestinal perforation, extensive adhesions in the abdominal cavity.
3, perianal or severe intestinal infection.
4, women during pregnancy and menstruation.
The endoscopy report must include: depth of entry, size of the mass, location from the anal verge, morphology, and extent of local infiltration, and pathological biopsy must be performed for suspicious lesions. Since the colon intestinal canal may be wrinkled during examination, the distance of the distal side of the mass seen by endoscopy from the anal verge may be inaccurate, and it is recommended to combine with CT, MRI or barium enema to clarify the site of the lesion.
Colon cancer is mainly differentiated from the following diseases
1. Inflammatory bowel disease. This disease can show symptoms such as diarrhea, mucus stool, pus and blood stool, increased frequency of stool, abdominal distension, abdominal pain, emaciation, anemia, etc. If accompanied by infection, there can be fever and other toxic symptoms, which are similar to the symptoms of colon cancer, and colonoscopy and biopsy are effective methods of differentiation.
2.Appendicitis. Ileocecal cancer may be misdiagnosed as appendicitis due to local pain and pressure. Especially in advanced stage ileocecal cancer, local necrotic ulceration and infection often occur, clinical manifestations include elevated body temperature, increased white blood cell count, local pressure pain or palpable mass, which is often diagnosed as appendiceal abscess and needs to be distinguished.
3.Intestinal tuberculosis. It is more common in China, and the common sites are in the terminal ileum, cecum and ascending colon. Common symptoms include abdominal pain, diarrhea and constipation alternately, and some patients may have low fever, anemia, emaciation, weakness and abdominal masses, which are similar to those of colon cancer. However, the systemic symptoms of intestinal tuberculosis patients are more obvious, such as low fever or irregular fever in the afternoon, night sweats, emaciation and weakness, which need to be distinguished.
4.Colonic polyps. The main symptom can be blood in the stool, and some patients can also have pus-like stool, similar to colon cancer, barium enema examination can show filling defects, colonoscopy and biopsy is an effective method of differentiation.
5. Schistosomal granuloma. In a few cases, it can become cancerous. Combined with the history of schistosome infection, examination of eggs in the stool, as well as barium enema and fiberoptic colonoscopy and biopsy can help to differentiate.
6.Amoebic granuloma. There may be symptoms of intestinal obstruction or abdominal mass on examination similar to colon cancer. Patients with this disease can find amebic trophozoites and encapsulation during stool examination, and barium enema examination often reveals a huge unilateral defect or circular cut.
7.Lymphoma. Lymphoma occurs in the end of ileum, cecum and ascending colon, but also in the descending colon and rectum. Lymphoma is similar to colon cancer in terms of history and clinical manifestations, but because the mucosa is relatively intact, bleeding is less common: the differential diagnosis mainly relies on colonoscopic biopsy to clarify the diagnosis.
In addition to differentiating rectal cancer from the above diseases, it is also necessary to differentiate from the following diseases.
1. Hemorrhoids. Hemorrhoids usually have painless blood in stool, and the blood is bright red and does not mix with stool. Rectal cancer often has blood in stool accompanied by mucus, which leads to mucus stool and rectal irritation symptoms. Patients with blood in stool must routinely perform rectal finger examination.
2.Anal fistula. Anal fistula is often caused by perianal abscess formed by anal sinusitis. Patients with a history of perianal abscess, local redness, swelling and pain, and rectal cancer symptoms are more obvious differences, the identification is relatively easy.
3.Amoebic enteritis. The symptoms are abdominal pain and diarrhea, and the lesion involving the rectum may be accompanied by urgency. The stool is dark red or purplish blood and mucus. Enteritis can lead to granulation and fibrous tissue proliferation, thickening of the intestinal wall, narrowing of the intestinal lumen, easily misdiagnosed as rectal cancer, fiber colonoscopy and biopsy as an effective means of differentiation.
4, rectal polyps. The main symptom is blood in the stool, colonoscopy and biopsy as an effective means of differentiation.