top of page

Colorectal Cancer|Colon Cancer

1. Basic knowledge

        Colorectal cancer is cancer that occurs in the large intestine (colon, rectum, anus) arising from benign polyps called adenomas, and there are cancers that arise directly from the normal mucosa. Colorectal cancer that arises in the mucosa of the large intestine gradually penetrates deep into the large intestine wall, spreads into the large intestine wall, and spreads in the abdominal cavity or in the lymphatic and blood streams on the large intestine wall, and also metastasizes to other organs such as lymph nodes, liver and lungs department.



        There are hardly any symptoms in the early stages, and symptoms only appear once it begins to progress. Symptoms include bloody stools (blood mixed in the stool), bloody stools (red or red-black stools are caused by intestinal bleeding where blood sticks to the surface of the stool), diarrhea, constipation, thin stools, stomach pain, abdominal pain, anemia, weight loss, etc. .


        The most common symptom is bloody stool, and benign diseases such as hemorrhoids can also cause bleeding symptoms. If the cancer is not tracked properly, the cancer may not be discovered until it has progressed. Early detection and consultation with gastroenterology, gastroenterology, and anus are very important.


        With the development of cancer, some symptoms such as anemia caused by chronic bleeding, constipation and diarrhea caused by intestinal stenosis may occur. The metastasis of colorectal cancer is first found in the lung or liver mass, and the development will lead to intestinal obstruction, constipation, abdominal pain, vomiting and other symptoms.



        The occurrence of colorectal cancer is related to lifestyle habits. Consumption of red meat (cattle, pork, sheep, etc.), processed meat (bacon, ham, sausage, etc.), alcohol consumption and smoking all increase the risk of cancer. People with excess body fat, abdominal obesity, and tall height also have a higher risk of colorectal cancer. In addition, it is also related to family history, especially in families with familial polyposis colorectum or hereditary nonpolyposis colorectal cancer syndrome.


2. Treatment

Disease period:

      Issue 0_cc781905-5cde-3 194-bb3b-136bad5cf58d_Cancer lodged in mucosa

      Phase I _cc781905-5cf58d_ 94-bb3b-136bad5cf58d_Cancer stays in the existing muscle layer_cc781905 -5cde-3194-bb3b-136bad5cf58d_

      II_cc781905-5cf58d_ II_cc781905-5cf58d_ 94-bb3b-136bad5cf58d_period cancer Invade the existing muscle layer 

      III_cc781905-5cf58d_ III_cc781905-5cde-31 94-bb3b-136bad5cf58d_ stage lymph node metastasis

      IV_cc781905-5cf58d_ IV_cc781905-5cde-31 94-bb3b-136bad5cf58d_period exist Hematogenous (liver, lung) or peritoneal dissemination


(1) Endoscopic treatment

        Removing cancer from the inside of the large intestine is less taxing on the body than surgery, and is a safe treatment, but symptoms such as bleeding and perforation may occur. Whether hospitalization is required between treatments depends on the medical institution and the extent of confirmed cancer spread. If it exceeds the scope of treatment and there is a risk of lymph node metastasis, additional surgery may be required.


side effect:

        Endoscopic treatment is usually painless, complications are rare, and side effects often include bleeding and perforation.

(2) Surgery

        The treatment of colorectal cancer is still mainly based on surgical resection. For patients with lymphatic or other organ metastasis, adjuvant therapy such as chemotherapy or radiation therapy is needed to improve.


        If endoscopic treatment is refractory, surgery will be performed. During surgery, not only the cancer is removed, but also the bowel and lymph nodes that have allowed the cancer to spread may be removed. Organs may also be removed if necessary if the cancer has spread to surrounding organs. After the intestine is removed, the remaining intestine will be sutured, and if the intestine cannot be connected, an artificial anus will be required.

  • Colon Cancer Surgery

       In order to remove the lymph nodes around the cancer at the same time, about 10 cm of bowel is removed from the cancer site. Since the extent of bowel to be removed depends on where the cancer is located, surgeries include ileostomy, right hemicolectomy, transverse colectomy, left colectomy, and sigmoid resection. On the other hand, when the large intestine is blocked by cancer and it is not possible to remove the cancer, bypass surgery may be done to allow food and stool to flow.

refer to:


  • rectal cancer surgery

       The rectum is located in the deep and narrow part of the pelvis, surrounded by the prostate, bladder, uterus, ovaries, etc., and its outlet is connected to the anus. According to the location and progress of rectal cancer, choose the appropriate operation through surgery, such as partial rectal resection, anterior segment resection, proctectomy, sphincterectomy, etc.  

  • rectal region resection

       Only the cancer and its vicinity need to be removed, and if the cancer is near the anus, a transanal resection is performed while observing the endoscope to eliminate the cancer.


  • Anterior Segmentectomy

This is a surgical method in which the cancerous intestine is removed by incision from the side of the stomach, and then stitched together. The incision of the high anterior resection above the inversion of the peritoneum is sutured in the bowel, and the incision of the low anterior resection is sutured. During inferior resection, a temporary artificial anus is constructed.


  • Proctectomy

       For cancer tumors that grow in the lower rectum near the anus, the rectum and anus will be resected together, and a permanent artificial anus will be installed. Artificial anus. In addition to the removal of the rectum, there is also a Hartmann operation to create an artificial anus when the anus is not removed or the intestine is not sewed.


  • Sphincter Resection (ISR)

       Even in low rectal cancers close to the anus, if certain conditions are met, only a part of the anal sphincter (the muscle tightens the anus) can be removed to preserve the anus and avoid the construction of a permanent artificial anus.

  • laparoscopic surgery

       In laparoscopic surgery, the stomach is inflated with carbon dioxide and the inside of the stomach is viewed with an endoscope while surgery is performed. The advantage of laparoscopic surgery is that the abdominal slit is smaller than that of laparotomy, and there is less pain and faster recovery after surgery. However, the operation time is often longer than that of laparotomy, and the cost is slightly higher.

Postoperative complications:

        Incomplete suture, wound infection, intestinal obstruction, urinary system disease, defecation disorder, influence of sexual life, artificial anus.

(3) Radiation therapy

  • adjuvant radiation therapy

       Covers resectable rectal cancer. Radiation therapy is mainly given before surgery (preoperative radiation) and can be given along with medical treatment.

  • palliative radiation therapy

       Pain caused by tumor in rectal cancer, bleeding and pain caused by metastasis to bone, the purpose is to improve nausea, vomiting, dizziness and other symptoms caused by metastasis to brain.

side effect:

        Side effects that may occur during treatment include tiredness, nausea, vomiting, loss of appetite, dermatitis, and leukopenia. Head irradiation can cause headaches, nausea, hair loss, and more. Abdominal or pelvic irradiation may cause symptoms such as diarrhea and abdominal pain.

        The side effects of long-term radiation therapy range from intestinal and bladder bleeding, cystitis, enteritis, frequent defecation, frequent urination, and formation of ducts.

(4) Drug therapy

  • "Adjuvant chemotherapy" aims to suppress postoperative recurrence

  • "Chemotherapy for unresectable and recurrent colorectal cancer" in cases where surgical cure is difficult


        The drug that is the basis of chemotherapy is 5-FU. The method of administration of 5-FU is only with instillation drug therapy. 5-FU is usually used in combination with other drugs, including oxaliplatin combined with FOLFOX and irinotecan combined with FOLFIRI in addition to 5-FU and leucovorin.

        In the above "Chemotherapy for unresectable and recurrent colorectal cancer", it is sometimes used in combination with molecularly targeted drugs. Molecular targeted drugs, such as Aisiting Injection, Ramucirumab, Erbitux, Vibix, and Rou Aizuo.

        With the advancement of preventive measures to alleviate side effects, many patients can also receive chemotherapy in their daily lives without affecting their lives.


3. Rehabilitation

Depending on symptoms and treatment conditions, where attention is required in daily life varies.

(1) Daily life after endoscopic treatment

            The function of the large intestine will not be affected by endoscopic treatment, and you can live a normal life for about a week after the treatment.


(2) Daily life after surgery (surgical treatment)

            After the operation, you can start with light exercise, such as walking and stretching, and you can resume your daily life before the operation within 1 to 3 months, but do not overuse your abdomen for strenuous exercise within a few months, and gradually expand your activities according to your physical strength scope.

For colorectal cancer-related drug information, please refer to the Medical Assistant Blog colorectal cancer

bottom of page