Colorectal cancer is a common malignant tumor of the gastrointestinal tract, which can occur in any part of the colon. In most provinces and cities in China, the mortality rate accounts for four to five of all malignant tumor mortality rates, and there is an increasing trend in recent years. Its incidence rate increases with age, starting from 40 years old and reaching a peak at 60-75 years old. Because of the slow growth rate of cancer tumors, it takes quite a long time before they reach to produce symptoms and signs, and it is not easy to attract attention in the early stage.
Etiology.
The exact etiology is not clear at present. It is generally believed that it is the result of the synergistic effect of multiple pathogenic factors.
1.Genetic factors.
Genetic factors may play an important role in about 20% of colorectal cancer patients.
2.Malignant transformation of benign lesions.
Some benign tumors such as polyps and adenomas can become cancerous; inflammatory bowel diseases and chronic irritation such as ulcerative colitis with extensive lesions, schistosome eggs, chronic diverticulitis and prolonged anal fistula can induce cancer. Therefore, diet is considered to be an extremely important factor.
3.Dietary factors.
High-fat, high-protein and low-fiber foods can increase the incidence of colorectal cancer; fried, fried and baked foods and pickled products contain carcinogens, and the lack of certain other trace elements may also increase the incidence of colorectal cancer.
Clinical manifestations.
Early colorectal cancer can be asymptomatic, and with the development of the disease, according to the location of the lesion, different clinical manifestations are produced.
1. Changes in fecal habits and stool characteristics.
It is often the earliest symptom, i.e. people with regular feces become irregular, constipation or increased stools, feces with blood and mucus; rectal cancer also has thinning of fecal strips, painful anal swelling, feeling of urgency and heaviness, and feeling of incomplete stools.
2.Abdominal pain.
Abdominal pain is inaccurate localization of hidden pain or abdominal discomfort, flatulence, etc.
3, intra-abdominal masses.
A hard, unsmooth surface mass with little mobility can be found.
4, middle and late stage with wasting, anemia and acute and chronic intestinal obstruction.
How to diagnose.
When the disease is suspected, the following tests should be done at the hospital.
1. Occult blood test of stool.
2. Elevated carcinoembryonic antigen.
3.Fiber colonoscopy
4.Barium enema.
Treatment.
At present, surgery is the most effective method to treat colorectal cancer. Surgical treatment can be radical resection, or palliative resection to relieve obstruction and improve systemic symptoms. Chemotherapy has a therapeutic effect on tumors that may remain after surgery, and can reduce postoperative recurrence and metastasis. Pre-operative and post-operative radiotherapy can improve the surgical resection rate of colorectal cancer and reduce post-operative recurrence to a certain extent.
Prevention.
The prevention of colorectal cancer should be done as follows.
1.First of all, we should have good dietary habits, do not favor three highs and one low, i.e. high calorie, high fat (oil), high protein (meat) and low fiber, and eat less barbecue, fried and high-fat greasy food; eat more coarse grains, vegetables and other foods containing more fiber.
There are many harmful carcinogenic substances in feces, which will play a role in the occurrence of colorectal cancer if it stays for a long time.
3.Prevent intestinal diseases and actively treat precancerous diseases, such as Crohn’s disease, ulcerative colitis, constipation, schistosomiasis and polypoid ulcers.
4.See doctor promptly if you find any signs such as change in stool habit, frequency and nature, blood and mucus or pus on the surface of stool, vague abdominal pain, frequent bowel movements, progressive anemia and unexplained weight loss.
5, regular screening of high-risk groups, such as those with family history of colorectal cancer, adenocarcinoma polyps, long-term chronic colitis, and middle-aged and elderly people over 40 years old with unexplained stool abnormalities, should promptly undergo fecal occult blood and exfoliative cell examination, and if positive, then do e-colonoscopy.
6, find a suitable exercise for themselves, enhance physical fitness, improve immunity, self-relaxation, relieve stress and maintain a good state of mind.
7.The World Health Organization has proposed a 16-word health policy to prevent colorectal cancer, namely “reasonable diet, moderate exercise, quit smoking and limit alcohol, and psychological balance”.