Colorectal cancer is one of the malignant tumors with high morbidity and mortality worldwide, with an annual global incidence of 1.02 million and nearly 530,000 deaths, while the incidence of colorectal cancer in China has exceeded two times that of the world. The incidence of colorectal cancer in China is increasing, while the incidence of rectal cancer and low-grade rectal cancer is higher in China, and there is a trend of rejuvenation. The etiology of rectal cancer is still not very clear, and its development is related to genetic factors, dietary habits, living habits, environmental factors and so on. In addition, benign diseases, such as rectal polyps and inflammatory bowel disease malignancy, are also high-risk factors for rectal cancer. Therefore, it is important to eat more dietary fiber foods, exercise in appropriate amount, and early treatment of high-risk benign lesions, such as early removal of polyps by colonoscopy and treatment of inflammatory bowel disease, etc., for the prevention and treatment of rectal cancer. There are usually no typical symptoms in the early stage of rectal cancer.
Early diagnosis is of great significance for the treatment of rectal cancer. It mainly includes.
1.Early symptoms: change in bowel habit, bloody stool, urgency and heaviness, etc;
2. Rectal finger examination: hard and uneven masses can be palpated, which is an important means to diagnose rectal cancer. About 80% of rectal cancer patients can be detected through rectal finger examination;
3.Fecal occult blood test: tumor bleeding usually causes bloody stool and black stool. Fecal occult blood test can help to diagnose rectal cancer at an early stage;
4.Fiber colonoscopy: It is the most important examination means to clarify the diagnosis of tumor. Once the diagnosis is clear, CT, MR and rectal ultrasound should be performed to further clarify the local stage and distant metastasis, and PET-CT examination should be performed to understand the systemic metastasis if necessary.
The treatment of rectal cancer is mainly based on surgery, supplemented by chemotherapy, radiotherapy, biological therapy and other comprehensive treatments.
(I) Surgery
There are two kinds of surgical treatment: radical and palliative.
1.Radical surgery
(1) Transabdominal perineal colectomy (Miles procedure): classical low rectal cancer surgery, applicable to rectal cancer patients whose distance from the anus is less than 125px. It requires permanent abdominal colostomy (artificial anus), which is highly radical and has a high cure rate, but the operation is more traumatic and the patient’s quality of life decreases after the operation.
(2) Transabdominal rectal pre-cancer resection (Dixon surgery): it is suitable for patients with rectal cancer greater than 125px from the anus. This operation is less damaging and can preserve the anus, and the patient has high quality of life after surgery, but it is not suitable for low rectal cancer.
(3) Rectal cancer resection with preservation of anal sphincter: the existing rectal cancer resection with preservation of anal sphincter includes anastomosis by anastomosis, transabdominal low resection – transanal exenteration anastomosis, transabdominal free – transanal drag-out resection anastomosis, and transabdominal transsacral resection, but it is only suitable for patients with rectal cancer greater than 75px from the anus.
2.Palliative surgery
If the cancer has extensive local metastasis and cannot be cured, in order to release the obstruction and reduce the patient’s pain, palliative resection is feasible, with limited resection of the cancerous intestinal segment, suture closure of the distal rectal cut and sigmoid colon stoma (Hartman operation). With the improvement of surgeon’s surgical skills, this type of surgery is now less commonly used, and is only used temporarily for emergency surgery to relieve obstruction, or for temporary surgery in the first stage of staged surgery.
(ii) Adjuvant treatment
Radiotherapy and chemotherapy have an important position in the treatment of rectal cancer. At present, it is believed that simultaneous preoperative radiotherapy and chemotherapy can help improve the surgical resection rate, reduce the postoperative recurrence rate and prolong the postoperative survival time for middle and low stage rectal cancer with late local staging. In addition, postoperative adjuvant radiotherapy for intermediate and advanced rectal cancer is important to reduce the postoperative recurrence rate and prolong the postoperative survival time. As an adjuvant treatment for rectal cancer when other treatments are ineffective, biologic therapy has not yet been carried out on a large scale because its clinical efficacy has yet to be further evaluated and the cost of treatment is relatively expensive.
The treatment characteristics of rectal cancer in our hospital.
(1) Early detection of rectal cancer. Non-invasive screening technology for colorectal tumors, i.e. the new DNA methylation stool test, can detect 85% of bowel cancer (the detection rate is close to that of colonoscopy, the cost is only 60% of that of colonoscopy, and it is completely painless), and the specificity is as high as 90%.
(2) Anal preservation technology for low rectal cancer and ultra-low rectal cancer. Our hospital is the first to carry out preoperative neoadjuvant treatment for rectal cancer to improve the rate of anus preservation during surgery. Preoperative neoadjuvant treatment can reduce the tumor volume to different degrees, decrease the degree of peri-cancerous infiltration, increase the distance between the lower edge of the tumor and the dentate line, and control the preoperative microscopic cancer and subclinical lesions, thus achieving the effect of preoperative stage reduction and increasing the rate of anus preservation during surgery. Prophylactic ileostomy can reduce the incidence of postoperative anastomotic fistula, and placing a thicker anal tube in the anus and crossing the anastomosis can reduce the incidence of postoperative anastomotic stricture. For super rectal cancer (tumor is less than 75px from the anal verge), our hospital adopts the rectal invasive interosseous resection technique (ISR) to further improve the rate of anal preservation. The follow-up found that the survival rate and local recurrence rate of anal preservation patients did not change significantly, but the quality of life of patients improved significantly.
(3) “Three-step” function-preserving surgery. Our hospital carries out “three-step” radical rectal cancer surgery with preservation of pelvic autonomic nerve by “revealing the nerve – preserving the fascia – protecting the pericardium”, and takes the lead in establishing a new scheme of function-preserving surgery for low rectal cancer. In the first step, the sacral plexus and bilateral inferior abdominal nerves (ejaculatory nerve) are revealed, the integrity of the deep fascia of at least one side of the pelvic wall is preserved in the second step, and the envelope of the seminal vesicle gland (Denonvilliers fascia) is preserved in the third step without anatomical separation. Clinical studies have shown that this “three-step approach” significantly improves the rate of preservation of sexual and voiding functions after surgery, ensuring both radical surgical cure and improving the patient’s postoperative quality of life, but the local recurrence rate does not increase significantly
(iv) New treatment plan for obstructive rectal cancer. Our hospital adopts the new program of “emergency endoscopic placement of catheter for decompression and elective first-stage resection”, which has significantly improved the prognosis of patients with obstructive colorectal cancer and reduced complications. For obstructive colorectal cancer, we advocate the Hartmann procedure, which can take into account the advantages of both stage I and stage II surgery, as it can completely resect the cancer in stage I, overcoming the disadvantage of spreading the cancer, and at the same time, staging the surgery, allowing adequate intestinal preparation, improving the safety of surgery and reducing the occurrence of anastomotic fistula. The traditional surgical method of “colostomy first and anastomosis in the second stage” is limited to emergency surgery when the patient is in poor general condition and cannot tolerate a longer operation. Studies have shown that preoperative hepatic artery combined with regional arterial infusion chemotherapy is safe and effective, which can significantly reduce the incidence of postoperative liver metastasis in stage III colorectal cancer and prolong the survival of patients.
(E) New strategy for prevention of liver metastasis in rectal cancer. Preoperative hepatic artery combined with regional arterial infusion chemotherapy (PHRAIC) can effectively prevent the occurrence of liver metastasis after radical surgery for colorectal cancer. The protocol mainly uses hepatic artery combined with regional arterial infusion chemotherapy (fluorodeoxyuridine + mitomycin + oxaliplatin) 7 d before surgery.
(vi) Multidisciplinary diagnosis and treatment model. Rectal cancer is not a single specialty disease, but a group of disease syndromes involving multiple disciplines, so the diagnosis and treatment mode of rectal cancer also needs to gradually change from single surgical treatment to multidisciplinary comprehensive treatment mainly based on surgical treatment. Therefore, our hospital has established a rectal cancer diagnosis and treatment center, and in the process of standardized diagnosis and treatment of rectal cancer: firstly, we will screen the patients from the high-risk group, then the doctors of gastrointestinal endoscopy will take enough tumor tissue biopsy, the doctors of pathology will clarify the pathological diagnosis, combined with the doctors of imaging department to comprehensively assess the clinical stage of the patients, the molecular diagnosis department will give the genetic or epigenetic characteristics of the patients, and then the doctors of colorectal and anal surgery, chemotherapy department and radiotherapy department will give the genetic or epigenetic characteristics of the patients. Then, the doctors of colorectal surgery, chemotherapy and radiotherapy will discuss and determine the specific treatment strategy according to the individual situation, and finally follow up the treatment effect on a regular basis.