The incidence of colorectal cancer in China is rising, who is more likely to get colorectal cancer---Public Science of Digestive Diseases 0078 Post
2014-10-12 Gastroenterology popular science
Colorectal cancer is one of the common malignant tumors of the digestive tract. In Western economically developed countries, for every 25 babies born, 1 person will develop colorectal cancer in the future. In China, the incidence of colorectal cancer has increased year by year due to changes in dietary habits and other factors in the past 20 years.
Investigating the reasons, there are two reasons for the increasing incidence of gastrointestinal tumors in Guangzhou and surrounding areas. On the one hand, it stems from the traditional dietary habits of residents in Fujian and Guangdong. The common pickled products, brine and fish sauce in the recipes are all The reason for the high incidence of gastrointestinal cancers; on the other hand, the absolute amount of high-fat, high-protein, and low-fiber foods consumed by Guangzhou residents has increased significantly. The fast-paced modern lifestyle has also contributed to the spread of cancer.
What causes colorectal cancer? Studies have shown that factors such as diet, environment, genetics, and race are all related to the incidence of colorectal cancer. The dietary factors and environmental factors are more important. Take Japan as an example. In the 1950s, Japan was the same as China, and it was a country with a lower incidence of colorectal cancer. With the economic recovery and development after the war, the incidence and mortality of colorectal cancer in Japan are also increasing. According to the statistics of the Japanese Cancer Society, from 1947 to 1978, the mortality rate of colorectal cancer increased approximately 2 times, while other cancers such as lung cancer only increased by 60%, gastric cancer and cervical cancer decreased by 30% and 60% respectively. ---Colorectal cancer can be said to be a disease of wealth to some extent.
Analyze the reasons. First, it is caused by an increase in fat diet and a decrease in fiber diet. In recent years, the incidence of colorectal cancer in cities in China has increased, which is also related to changes in diet. Second, the environment is closely related to colorectal cancer. Environmental factors mainly include: lack of selenium in the soil; the impact of schistosomiasis. In China, the high-risk area of schistosomiasis is also the high-incidence area of colorectal cancer; smoking can easily cause colorectal cancer. The third is genetic factors. About 10% of colorectal cancers are related to genetic factors. Therefore, the offspring of patients diagnosed with familial colorectal polyposis, hereditary non-polyposis colorectal cancer, and sporadic hereditary colorectal cancer should be closely followed. At the same time, some benign tumors of the large intestine called polyps cannot be ignored. People who have long-term ulcerative colitis also have a greater chance of getting colorectal cancer.
To sum up, people with one of the following conditions should be regarded as high-incidence groups of colorectal cancer: adults in high-incidence areas of colorectal cancer, such as large cities in China and the southeast coast; patients with colorectal adenoma, have multiple families Family members of gonadenomatosis; patients with colorectal cancer before; patients with schistosomiasis; family members of patients with colorectal cancer; members of cancer family syndrome; people who have received radiation therapy in the pelvis (someone reported that 10-20 years after pelvic radiotherapy is easy Suffering from rectal cancer); In patients with chronic ulcerative colitis, some people believe that the chance of developing colorectal cancer in patients with this disease is 10 times higher than that of normal people.
[What are the symptoms of colorectal cancer]
The symptoms and clinical manifestations of colorectal cancer depend on where the tumor grows, the size of the cancer, and the disease stage. We can roughly divide the large intestine into three parts, one is the right colon, the other is the left colon, and the third is the rectum. The stool in the right colon is more watery. At this time, the stool is like a fecal soup. When it reaches the left colon, the stool begins to become semi-solid. The rectum is about 1518 cm long, and the stool reaches the rectum, it is almost formed, and stimulates the surrounding nerves and defecation muscles to produce stool. Therefore, when colorectal cancer begins to grow, and the diameter of the cancer is less than 0.5 cm, no matter where it grows, it is almost asymptomatic. However, as the tumor grows and invades surrounding normal tissues, blood vessels and nerves, a series of symptoms will appear.
Features of right colon cancer
When the stool is in the right colon, it still presents a semi-fluid and sparse paste, so it is not easy to have bleeding symptoms caused by feces rubbing the cancer focus. It is often due to the necrosis and shedding of the cancer focus. The small peristalsis makes the blood and mushy stool evenly mixed, which is not easy to detect with the naked eye. Due to long-term chronic blood loss and no obvious changes in bowel habits, patients often seek medical attention for anemia. Data show that among 226 patients with right colon cancer, 58.8% have hemoglobin below 10 grams. With the increase of the cancer, the right side abdominal pain can touch the abdominal mass, which accounts for about 79.1% of the symptoms. At the same time, the invasion of the intestinal wall by the tumor can cause dull pain, and even cause pericolitis, and the pain will gradually increase. If paroxysmal abdominal pain occurs, it is often accompanied by obstructive symptoms, but the most common symptoms of right colon cancer are anemia, abdominal mass, and abdominal pain. Barium enema imaging shows the intestinal wall stiffness and filling defect.
Features of left colon cancer
As the stool enters the left colon from the right colon, due to the reabsorption of water, the stool gradually changes from a thin paste to solid, so the situation of blood in the stool caused by stool friction is in the left colon
Cancer cases are far more common than right colon cancer cases. Because the macroscopic symptoms of blood in the stool of left colon cancer prompt patients to seek medical treatment in time, the anemia caused by long-term chronic blood loss is not as prominent as in patients with right colon cancer. Similarly, in 226 patients with left colon cancer, only 38% had hemoglobin below 10 grams. At the same time, paroxysmal abdominal pain caused by intestinal obstruction, left colon cancer is more common than right colon cancer, and there are reports that it is about 8 times more common. This is mainly due to the dryness and formation of stool, which is difficult to pass through cancer. Therefore, blood in the stool and intestinal obstruction are the main manifestations of left colon cancer.
Features of rectal cancer
Rectal cancer and sigmoid colon cancer account for more than 70% of colorectal cancer patients, and rectal cancer also accounts for more than half of all colorectal cancer patients. Due to the low focus, the main clinical manifestations are blood in the stool and changes in bowel habits. Hematochezia accounts for 90% of rectal cancer, mostly fresh blood and dark red blood, which is not mixed with stool, and is the blood oozing after tumor necrosis falls off and forms the ulcer surface. Heavy bleeding is rare. As the lesion stimulates the intestines, the number of stools is increased, and the number of stools can reach more than ten or dozens of times a day. Therefore, rectal cancer is often misdiagnosed as chronic dysentery or hemorrhoids. If you have the above symptoms, you should first suspect whether you have colorectal cancer, and you should go to the hospital immediately. It is best to go to a specialist cancer hospital to find a doctor for further examination. As the disease progresses and cancer spreads and metastasizes throughout the body, some symptoms of advanced cancer may also appear. Late-stage patients may have symptoms such as anemia, edema, ascites, a lump on the left clavicle, hepatomegaly, and jaundice.
For patients with early gastrointestinal cancers, if they are detected and treated in time, the 5-year survival rate can exceed 90%, but for advanced patients, the probability is less than 10%, so "early detection, early diagnosis, and early treatment" The concept has become an important means to prevent cancer and maintain a healthy digestive tract. However, when many people talk about endoscopy, their complexion changes greatly. They always feel that it is very painful to do gastroscopy and colonoscopy. In fact, with the continuous improvement of endoscopy technology, endoscopy has become easy and easy nowadays. Chen Xueqing For example, through the nasal endoscopy, the diameter of the insertion end is only about 5 mm, which greatly reduces the foreign body sensation, and the entire inspection can be completed in 15 minutes. Moreover, compared with imaging examinations, colonoscopy and gastroscopy can directly observe the shape of the lesion, with clear vision, strong resolution, and high accuracy of biopsy rate.