Rectal cancer refers to cancer from the dentate line to the junction of the rectum and sigmoid colon. It is one of the most common malignant tumors in the digestive tract. The location of rectal cancer is low, and it is easily diagnosed by digital rectal examination and sigmoidoscopy. However, because of its location deep into the pelvic cavity, the anatomy is complicated, the operation is not easy to complete, and the postoperative recurrence rate is high. The middle and lower rectal cancer is close to the anal sphincter, and it is difficult to preserve the anus and its function during the operation. It is a difficult problem in the operation, and it is also the most controversial disease in the surgical method. The median age of onset of rectal cancer in China is about 45 years old. The incidence of young people is on the rise.
The etiology of rectal cancer is still not very clear, and its incidence is related to social environment, eating habits, genetic factors, etc. Rectal polyps are also a high-risk factor for rectal cancer. At present, it is basically recognized that excessive intake of animal fat and protein and insufficient intake of dietary fiber are high-risk factors for rectal cancer.
1. Early rectal cancer is mostly asymptomatic.
2. Rectal cancer growth
To a certain extent, changes in bowel habits, bloody stools, pus and bloody stools, tenesmus, constipation, diarrhea, etc. appear.
Gradually become thinner, and in the later stage, there will be obstruction of defecation, weight loss and even cachexia.
Urinary tract irritation, vaginal discharge of fecal fluid, pain in the sacrum and perineum, and edema of the lower extremities occur when invading the surrounding organs such as the bladder, urethra, and vagina.
1. Digital rectal examination
It is a necessary inspection step for the diagnosis of rectal cancer. Approximately 80% of patients with rectal cancer can be found by digital rectal examination when they visit a doctor. Palpable hard, uneven masses; late palpable intestinal stenosis, fixed masses. See filthy pus and blood with feces on the finger cot
Proctoscopy should be performed after the digital rectal examination to assist in the diagnosis under direct vision. Observe the shape of the mass, the upper and lower edges and the distance from the anal edge, and take the mass tissue for pathological biopsy to determine the nature of the mass and its degree of differentiation. The cancer is located in the middle and upper part of the rectum and cannot be touched by the fingers. Sigmoidoscopy is a better method.
3. Barium enema, fiber colonoscopy
It is not very helpful in the diagnosis of rectal cancer, so it is not listed as a routine examination, and it is only used when excluding multiple colorectal tumors.
4. Pelvic magnetic resonance examination (MRI)
Understanding the location of the tumor and the relationship with the surrounding adjacent structures can help to accurately stage the preoperative clinical stage and formulate a reasonable comprehensive treatment strategy, such as: surgery or radiotherapy first?
5. Abdominal and pelvic CT
Can understand the location of the tumor, the relationship with adjacent structures, whether there is metastasis around the rectum and other parts of the abdominal and pelvic cavity. The staging of rectal cancer is very important.
6. Chest CT or chest X-ray examination
Know whether there are metastases in the lungs, pleura, mediastinal lymph nodes, etc.
Generally, patients with stool bleeding should be highly vigilant in clinical practice. Do not make a diagnosis of "dysentery" or "internal hemorrhoids" lightly. Further examinations must be performed to rule out the possibility of cancer. For the early diagnosis of rectal cancer, we must pay attention to the application of digital rectal examination, proctoscope or sigmoidoscopy. Pathological diagnosis can be obtained through microscopic examination.
The treatment of rectal cancer needs to be based on surgery, supplemented by comprehensive treatment of chemotherapy and radiotherapy.
(1) Surgical treatment
There are two types: radical and palliative.
1. Radical surgery
(1) Combined transabdominal and perineal resection (Miles operation) It is suitable for lower rectal cancer less than 7cm from the anal margin. The scope of resection includes the sigmoid colon and its mesangium, rectum, anal canal, levator ani muscle, sciatic rectal fossa and around the anus The skin and blood vessels are ligated and cut below the root of the inferior mesenteric artery or the branch of the left colon artery, and the corresponding para-arterial lymph nodes are cleaned. Make a permanent colostomy (artificial anus) in the abdomen. This surgical resection is complete and the cure rate is high.
(2) Transabdominal low resection and one-stage extraperitoneal anastomosis, also called anterior resection of rectal cancer (Dixon operation), is suitable for upper rectal cancer more than 12cm from the anal margin. Resection of the sigmoid colon and most of the rectum in the abdominal cavity, freeing the peritoneum The rectum below the reflex part is anastomosed with the sigmoid colon and the rectal cut end outside the peritoneum. This operation is less invasive and can retain the original anus, which is ideal. If the cancer is large and has infiltrated the surrounding tissues, it should not be used.
(3) Resection of rectal cancer with preserving anal sphincter is suitable for early rectal cancer 7 to 11 cm from the anal margin. If the cancer is large, the degree of differentiation is poor, or the upper main lymphatic vessels have been infarcted by cancer cells and there are lateral lymphatic metastases, this surgical method is not completely removed, and it is better to combine abdominal and perineal resection. The currently used anal sphincter-preserving rectal cancer resection includes anastomosis with a stapler, low abdominal resection-transanal valgus anastomosis, transabdominal free-transanal drag-out resection and anastomosis, and transabdominal transsacral resection. Specific situation selection.
2. Palliative surgery
If the cancer is locally infiltrated or extensively metastasized and cannot be cured, in order to relieve the obstruction and reduce the patient’s suffering, palliative resection is feasible. The intestinal segment with cancer is resected limitedly, the distal rectum is sutured, and the sigmoid colon is used as a stoma. (Hartma surgery). If it is not possible, only a sigmoid colostomy is performed, especially in patients with intestinal obstruction.
Radiotherapy plays an important role in the treatment of rectal cancer. At present, it is believed that the survival period of late-stage mid-to-low rectal cancer is longer than that of surgery followed by concurrent radiotherapy and chemotherapy before surgery.
For patients with postoperative pathological stages of rectal cancer as stage II and stage III, postoperative chemotherapy is recommended. The total chemotherapy time is half a year.
(4) Treatment of patients with metastasis and relapse
1. Treatment of local recurrence
If the scope of the local recurrence is limited and there is no recurrence or metastasis in other parts, surgical exploration and excision can be performed. For patients who have not received pelvic radiotherapy, radiotherapy for recurrent lesions in the pelvic cavity can temporarily relieve pain symptoms.
2. Treatment of liver metastases
In recent years, many studies have confirmed that the effect of surgical resection of rectal cancer and liver metastasis is not as pessimistic as originally thought. Liver metastasis in patients with rectal cancer, whether it exists at the same time as the primary tumor or after the primary tumor is removed, if the liver metastasis can be completely removed, the survival rate can be improved. For single metastases, segmental or wedge resection is feasible. For patients with multiple liver metastases that cannot be surgically removed, systemic chemotherapy can be used first to shrink the tumor to a time when the tumor can be surgically removed, and the same effect can be achieved. For some patients, even if intense chemotherapy cannot reduce liver metastases to the extent that they can be surgically removed, palliative chemotherapy is given.
Patients who have no chance of surgical resection receive systemic chemotherapy. If there is pain, bleeding and obstruction caused by the metastatic site, corresponding palliative treatment measures, such as radiotherapy, analgesics, and fistulas, can be used.
Department of Anorectal, Tongchuan Hospital of Traditional Chinese Medicine, Dazhou City