What is Colorectal Cancer The colon and rectum, commonly known as the large intestine, is the last segment of the digestive system, starting at the end of the small intestine and extending to the anus. Its primary function is to absorb water and store excrement. Colorectal cancer is a condition in which the cells in the colorectum grow out of control and become cancerous, causing cancer cells to invade other parts of the body. Why does colorectal cancer occur? The factors that cause colorectal cancer can be divided into congenital and acquired. Congenital is because of hereditary genes, and the hereditary bowel cancer we know so far only accounts for about 1 to 5% of the total number of bowel cancer, and these patients usually have family history and often develop at a younger age. 1, congenital bowel cancer factors: hereditary bowel cancer can be divided into two types: familial polyposis and hereditary non-polyp colorectal cancer. The genetic gene of familial polyposis is located on the fifth chromosome, and the chance of the patient passing the gene to the next generation is 50%, featuring hundreds of polyps growing in the patient’s colon since adolescence, and these polyps will gradually deteriorate and become cancerous as they grow larger and larger over time. If they are not removed early, the patient will have almost 100% cancer after the age of 40. Patients with hereditary non-polyp colorectal cancer carry at least six different genes. Those with the disease usually suffer from cancer before the age of 45, and most other members of the family also have someone suffering from bowel cancer or other cancers, such as stomach cancer, ovarian cancer, uterine cancer, kidney cancer, etc. 2.Acquired bowel cancer factors: Generally, it is thought to be related to dietary habits. Eating too much red meat and not enough fiber leads to the evolution of intestinal cancer. However, there are some recent scientific reports denying the influence of diet. As for whether exercise can reduce the incidence of bowel cancer, there are many controversies. How does colorectal cancer evolve? The normal mucosal layer of the intestine is constantly metabolizing, and due to a genetic mimicry error, polyps begin to grow in the large intestine. The polyp grows over time and has a 50% chance of becoming cancerous when it reaches 2 centimeters in length. Once cancerous, the cancer cells gradually invade the intestinal wall and then spread to the lymph nodes outside the intestine, and may also metastasize to the liver and other organs. The process from normal intestinal mucosal layer cells to cancer usually takes more than 10 years. Therefore, being able to remove polyps early when they are detected can prevent cancer from occurring. What are the symptoms of colorectal cancer? In the early stage of colorectal cancer, there is no symptom. When the cancer is larger, patients may notice blood in the stool, and they may also notice a change in bowel habits, the frequency of bowel movement may increase from the usual once to three or four times, or decrease to once every two or three days. The shape of the stool may become smaller, and there may be a few days of constipation, followed by a few days of diarrhea, followed by constipation again. Other common symptoms include abdominal pain, abdominal swelling, hard lumps felt in the abdomen, and sometimes a feeling of incomplete bowel movements, i.e., a feeling of needing to have another bowel movement after a while. Sometimes patients lose blood in their body without realizing it, which eventually leads to anemia, fatigue, dizziness and shortness of breath. Patients with advanced bowel cancer may also lose weight. When the cancer progresses to intestinal obstruction, the patient will not be able to pass stool at all, and the whole abdomen will bulge and be very painful. If medical attention is not sought at this point, the bowel will perforate and rupture. Only a small percentage of tumors located in the middle or lower part of the rectum can be detected during anal examination. Therefore, doctors cannot diagnose intestinal cancer by touch alone when examining a patient’s body. Once the doctor presses and feels a hard lump, the cancer is already more serious. Is there a high possibility of colorectal cancer? Generally speaking, the likelihood of developing colorectal cancer after the age of 50 is higher than that of those under 50. In addition, family history is very influential. If no family member has bowel cancer, the chance of developing bowel cancer is 2%. If there is an immediate family member with bowel cancer, the likelihood rises to 6%; if that family member developed cancer before the age of 45, the risk rises to 10%. The risk rises to 16% for two relatives with bowel cancer, and to 50% for three relatives with bowel cancer. The risk of developing bowel cancer is higher than average if you have had previous colorectal cancer or intestinal polyp disease, chronic inflammatory bowel disease, and breast, uterine or other cancers. What treatments are available for colorectal cancer? The main treatment for colorectal cancer is surgical resection. Chemotherapy and radioactive electricity are adjuvant treatments. 1.Surgical resection The purpose of surgery is to remove the cancerous section of intestine and the nearby lymph nodes, and then connect the two ends of the intestine. Many people think that once there is bowel cancer, there must be a permanent stoma, and the feces will no longer come from the anus, but from an artificial hole in the abdomen to discharge the bag. In fact, most bowel cancer surgeries do not require a stoma. Only when the cancer invades the anus is it necessary to remove the anus along with the cancer and a permanent stoma is required. For some rectal cancer tumors with low location, a temporary stoma may be needed until the intestinal interface is repaired and the stoma is put back in place to resume normal bowel movements. As technology advances, surgical methods have also improved. Before the early 1990s, general bowel surgery required a large incision. In the mid-1990s, specialists were able to use smaller incisions. Since the 1990s, minimally invasive surgery has been used to remove bowel cancer. Minimally invasive surgery involves using a laparoscope to see the organs inside the abdomen, removing the bowel cancer tumor through several small 0.5 to 1 cm holes, and then making an incision of about 5 cm to remove the cancerous tumor and dismiss the bowel. The smaller the incision, the less pain and faster recovery after surgery. Over the past few years, there have been further improvements in surgical instrumentation and, where appropriate, bowel cancer tumors can also be operated on robotically assisted laparoscopically, a procedure that allows the surgeon to see more clearly inside the abdomen and the nerve lines in the pelvis, which can reduce accidental damage to other organs. The past few months have seen another medical advancement. A new instrument allows surgeons to use a 3 to 4 cm incision and put in 3 different tools to perform the surgery, reducing the operating time for other incisions in the abdomen (usually 1 to 2 hours). 2.Adjuvant treatment After the bowel cancer is removed, the pathologist will test the removed tissues and evaluate the stage of the cancer before deciding whether further adjuvant treatment is needed. Generally speaking, for stage I and II colon cancer, surgery is sufficient and no further adjuvant treatment is needed. For stage III colon cancer, adjuvant chemotherapy is needed; for stage III rectal cancer, chemotherapy and radioelectric therapy are needed to reduce the possibility of cancer recurrence. Stage IV colon cancer, which has spread and metastasized to other parts of the body, often cannot be completely cured and can only be treated with chemotherapy to stop the cancer from continuing to grow and metastasize. To conclude, colorectal cancer is a preventable cancer and can be cured if detected early. If there is no family member with colon cancer, the chance of developing colon cancer is 2%. With an immediate family member, the likelihood rises to 6%; with a family member who develops cancer before the age of 45, the risk is 10%. With two relatives with bowel cancer, the risk is 16%.