With the improvement of living standard and change of diet structure, the incidence of colorectal cancer is increasing, according to the data, the average annual incidence of colorectal cancer in China is 130,000, and the average annual increase is 4%, and it has risen to the second place of cancer incidence in Shanghai and surrounding areas. The latest statistics show that the incidence rate of colorectal cancer in Shanghai is 48/100,000 for men and 45/100,000 for women, which is close to that of developed countries in the West. China has entered the ranks of regions with high incidence of colorectal cancer, and this disease is increasingly threatening people’s physical and mental health.
1.Preventing colorectal cancer by removing the colon?
Modern people pay more and more attention to the prevention and health care of diseases in daily life, and pay more attention to the knowledge of tumor prevention. It is well known that people can reduce the occurrence of colorectal cancer through diet and regular examination.
2.Colorectal cancer prevention ‘varies from person to person’ Colorectal cancer is a kind of disease that can be effectively prevented by adopting reasonable measures. In addition to maintaining healthy living and eating habits, regular checkups should be conducted for early detection of precancerous lesions. The prevention of colorectal cancer should be ‘individualized’. Different groups of people receive different screening programs. General population: refers to people who are not at high risk of developing colorectal cancer, 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 3-5 years on average, and the examination methods mainly include fecal occult blood and colonoscopy. High-risk group: People with family genetic history are recommended to visit a specialist as soon as possible, and through careful collection of family history by experienced clinicians and some necessary examinations, including genetic testing, to determine whether the group has genetic predisposition. If there is a genetic predisposition, the patient will be closely followed by the clinician according to the specific follow-up protocol for hereditary tumors. If there is no obvious genetic predisposition, the population will be followed up according to the screening protocol for high-risk groups.
So, what kind of screening results will recommend removal of the entire colon?
3.Hereditary colorectal cancer Among patients with colorectal cancer, about 20% of them have a family history of colorectal cancer, and the family history of 5-10% of them is in accordance with Mendel’s law, i.e., in line with the characteristics of autosomal dominant inheritance. Clinically, based on the presence or absence of polyposis, hereditary colorectal cancer can be divided into two major categories: hereditary polyposis and hereditary non-polyposis colorectal cancer. Hereditary polyposis can be subdivided into hereditary adenomatous polyposis, which includes familial adenomatosis FAP and Turcot syndrome, and hereditary dysplasia polyposis, which includes Peutz-Jeghers syndrome and familial juvenile polyposis. The 18-year-old patient had familial adenomatous polyposis, a group of autosomal dominant syndromes characterized by multiple adenomas in the colorectum, which accounts for approximately 1% of colorectal cancers. The clinical features are adenomatous polyps and microadenomas that spread throughout the colon and number more than 100. Adenomas begin to appear in patients in their teens, and if left untreated, almost 100% of patients will develop colorectal cancer by age 40. Because of the large number of adenomas in FAP patients, it is impossible to remove all adenomas through colonoscopy, and because 100% of patients will eventually turn into colorectal cancer, surgical resection of the entire colon is currently the most effective means to prevent adenomas from becoming cancerous in FAP patients.
4.Does the absence of family history mean that I will not get hereditary colorectal cancer?
60%-70% of familial adenoma patients have a clear family history of colorectal cancer or polyps, carrying genetic mutations inherited from previous generations; another 30% of FAP patients are new cases with no family history, and these patients are often not found to be FAP patients until they develop polyps or cancer symptoms. The occurrence of bowel cancer in this group of patients is related to the mutation of the gene. Therefore, young people should pay great attention when they have symptoms such as blood in stool, change of stool habit, abdominal pain, anemia, and weight loss. Colonoscopy or barium examination: When colonoscopy or barium enema examination reveals hundreds of polyps in the colorectum, the possibility of FAP should be considered first. Through colonoscopy to understand the distribution of polyps, biopsy of polyps and suspected cancerous lesions, and removal of some polyps, the symptoms of some patients can be relieved while the diagnosis is clear.
5.Prevention of hereditary colorectal cancer 1）Surgery Surgical operation removes the site of tumor occurrence, thus avoiding the occurrence of tumor. The standard surgical procedure is total colectomy and ileal storage pouch anal canal anastomosis. However, the technical requirements of this surgery are very high, so it is recommended to do it in higher level hospitals and experienced doctors.
(2) Drug therapy Since the 1980s, the status of NSAID in the prevention and treatment of colorectal cancer and colorectal adenoma, especially familial adenomatosis (FAP) adenoma, has been gradually gaining attention. The molecular mechanism of tumor growth regulation lies mainly in the inhibition of cyclooxygenase-2 (COX-2) activity. However, traditional NSAIDs such as sulforaphane also inhibit COX-1, which is continuously expressed in normal cells of the digestive tract, and therefore have many side effects, including digestive discomfort and ulcers. The new generation of NSAIDs, coxib drugs, can selectively inhibit COX-2, so the gastrointestinal side effects are small and well tolerated by patients. However, Celecoxib is expensive and often unaffordable for domestic patients, therefore, sulforaphane is still a good choice.
6.Disease monitoring for hereditary colorectal cancer patients and their family members The risk of colorectal cancer for family members of hereditary colorectal cancer patients is very high, and annual colonoscopy should be performed since the age of 12. If polyps do not occur after the age of 24, colonoscopy can be changed to every two years until the age of 34, and then every three years until the age of 44. Since colorectal cancer will occur in almost all patients with familial adenoma, colonoscopy is not an effective means of prevention and treatment. Once FAP is diagnosed, subtotal colectomy should be considered to reduce the risk of colorectal cancer. For residual rectum, colonoscopy and surgical or electrocautery removal of polyps should be performed at least once a year.
There is no need to be overly afraid of hereditary colorectal cancer, but early prevention is needed if there is a family history of hereditary cancer. It is necessary to do self-care, change bad eating habits, develop good living habits, strengthen physical exercise and enhance resistance; also maintain a good attitude and look at cancer correctly. In addition, you should go to a specialist, explain your family history, record and register, and under the guidance of the specialist, undergo regular annual medical check-ups and screenings, so that once early signs of cancer are detected, you should receive timely treatment to control the disease.