IV. Surgical treatment
(a) The standard of surgical treatment for intestinal cancer.
(2) Surgical treatment of rectal cancer.
The principle of laparoscopic treatment of rectal cancer surgery is the same as that of colon cancer. Zheng Naiguo, Department of General Surgery, Guiyang Second Affiliated Hospital of Traditional Chinese Medicine
1. Local excision of rectal cancer (T1N0M0)
The treatment and handling principles of early rectal cancer (T1N0M0) are the same as those of early colon cancer.
Early rectal cancer (T1N0M0) must meet the following requirements if resected through the anus.
(1) Invasion of intestinal circumference <30%.
(2) Tumor size <3 cm.
(3) Negative incisional margin (>3 mm from the tumor).
(4) Mobile, not fixed.
(5) Within 8 cm from the anal verge.
(6) Only for T1 tumors.
(7) Endoscopically resected polyps with cancerous infiltration or indeterminate pathology.
(8) without vascular lymphovascular infiltration (LVI) or nerve infiltration.
(9) High-moderate differentiation.
(10) No evidence of lymph node enlargement on pretreatment imaging.
Note: Local resection specimens must be spread and fixed by the surgeon, marked with orientation and sent for pathological examination.
2. Rectal cancer (T2-4, N0-2, M0).
Radical surgical treatment must be pursued. Low anterior resection is recommended for upper and middle rectal cancer; combined abdominoperineal resection or cautious choice of anus-preserving surgery is recommended for low rectal cancer. The principle of total mesenteric resection for rectal cancer must be followed for middle and lower rectal cancer, and the rectal mesentery should be free as sharply as possible, and the whole block should be removed together with the distal mesentery of the tumor. The distal cut edge of the intestinal wall should be ≥2 cm from the tumor, and the distal cut edge of the rectal mesentery should be ≥5 cm from the tumor or the whole rectal mesentery should be removed. The anal sphincter function, urination and sexual function were maintained as much as possible under the premise of radical treatment of tumor. The treatment principles are as follows.
(1) Resect the primary tumor and ensure adequate incisional margin, with the distal incisional margin at least 2 cm from the distal end of the tumor. for lower rectal cancer (less than 5 cm from the anus) with the distal incisional margin 1 to 2 cm from the tumor, intraoperative frozen pathological examination is recommended to confirm the negative incisional margin.
(2) Excision of lymphatic adipose tissue in the drainage area.
(3) Preserve the pelvic autonomic nerve as much as possible.
(4) After neoadjuvant (preoperative) radiotherapy, an interval of 4 to 8 weeks is recommended for surgery.
(5) Combined organ resection is recommended for tumors invading surrounding tissues and organs.
(6) For patients with rectal neoplasm combined with intestinal obstruction, with high clinical suspicion of malignancy and no pathological diagnosis, not involving anal preservation and tolerating surgery, dissection is recommended.
(7) For resectable rectal cancer that has caused intestinal obstruction, stage I resection anastomosis, or Hartmann’s procedure, or stage II resection after fistula, or stage II resection after stenting to relieve obstruction is recommended. Intraoperative bowel irrigation is recommended prior to stage I resection anastomosis. If the risk of anastomotic fistula is estimated to be high, Hartmann procedure or stage I resection anastomosis and prophylactic enterostomy are recommended.
(8) If the tumor is locally advanced and unresectable or clinically intolerant to surgery, palliative treatment is recommended, including optional radiation therapy to manage uncontrollable bleeding, stenting to manage bowel obstruction, and supportive therapy.
3. Liver and lung metastasis of rectal cancer.
The treatment principles for liver and lung metastases of rectal cancer are the same as those for colon cancer.
V. Internal medicine treatment
(a) Neoadjuvant treatment of colorectal cancer.
The purpose of neoadjuvant treatment is to improve the rate of surgical resection, increase the rate of anal preservation and prolong the disease-free survival of patients. The recommended neoadjuvant radiotherapy is only applicable to rectal cancer <12cm from the anus. Except for liver metastases from colon cancer, neoadjuvant therapy is not recommended for patients with colon cancer before surgery.
1. Neoadjuvant radiotherapy for rectal cancer.
(1) Neoadjuvant radiotherapy based on fluorouracil drugs is recommended for preoperative treatment of rectal cancer.
(2) Direct surgery is recommended for T1-2N0M0 or patients with contraindication to radiotherapy, and neoadjuvant therapy is not recommended.
(3) Patients with T3 and/or N+ resectable rectal cancer are recommended for preoperative neoadjuvant radiotherapy.
(4) Patients with T4 or locally advanced unresectable rectal cancer must undergo neoadjuvant radiotherapy. After treatment, they must be re-evaluated and considered for feasibility of surgery.
In neoadjuvant radiotherapy, the recommended chemotherapy regimen is continuous infusion 5-FU, or 5-FU/ LV, or capecitabine monotherapy. The recommended duration of chemotherapy is 2-3 months. For radiotherapy regimens, please refer to the principles of radiation therapy.
2. neoadjuvant chemotherapy for rectal cancer with liver metastases.
Patients with rectal cancer with combined liver and/or lung metastases, resectable or potentially resectable, are recommended to be treated with preoperative chemotherapy or chemotherapy in combination with targeted agents: cetuximab (recommended for patients with wild-type K-ras gene status), or in combination with bevacizumab.
Chemotherapy regimens recommended are FOLFOX (oxaliplatin + fluorouracil + aldehydic folic acid), or FOLFIRI (irinotecan + fluorouracil + aldehydic folic acid), or CapeOx (capecitabine + oxaliplatin). The recommended time frame for treatment is 2-3 months.
After treatment must be re-evaluated and considered for feasibility of surgery
(ii) Adjuvant treatment for colorectal cancer.
Adjuvant therapy is not recommended for patients with stage I (T1-2N0M0) or with contraindications to radiotherapy.
1. Adjuvant chemotherapy for colorectal cancer.
(1) Adjuvant chemotherapy for stage II colorectal cancer (???) . Patients with stage II colorectal cancer should be confirmed to have the following high-risk factors: poor histological differentiation (grade III or IV), T4, vascular lymphatic infiltration, preoperative intestinal obstruction/bowel perforation, and insufficient lymph nodes detected in the specimen (less than 12).
①Stage II colorectal cancer without high-risk factors is recommended for follow-up observation or chemotherapy with single-agent fluorouracil-based drugs.
②For stage II colorectal cancer, adjuvant chemotherapy is recommended for those with high-risk factors. The chemotherapy regimen recommended is 5-FU/LV, capecitabine, 5-FU/LV/oxaliplatin or CapeOx regimen. The duration of chemotherapy should not exceed 6 months. Testing of tissue specimens for MMR or MSI is recommended when available, and single-agent adjuvant chemotherapy with fluorouracil-based agents is not recommended if dMMR or MSI-H is present.
(1) Adjuvant chemotherapy for stage II colorectal cancer (???) . For patients with stage III colorectal cancer, adjuvant chemotherapy is recommended. The recommended chemotherapy regimen is 5-FU/CF, capecitabine, FOLFOX or FLOX (oxaliplatin + fluorouracil + aldehydic folic acid) or CapeOx regimen. Chemotherapy should not be administered for more than 6 months.
2. Adjuvant radiotherapy for rectal cancer.
For T3-4 or N1-2 rectal cancer ≤12cm from the anal verge, preoperative neoadjuvant radiotherapy is recommended. If preoperative neoadjuvant radiotherapy is not performed, adjuvant radiotherapy is recommended, of which fluorouracil-based single agent is recommended for the chemotherapy regimen. For the radiotherapy plan, please refer to the principles of radiotherapy
(iii) Advanced/metastatic colorectal cancer chemotherapy.
Currently, drugs used for the treatment of advanced or metastatic colorectal cancer: 5-FU/LV, irinotecan, oxaliplatin, capecitabine and targeted drugs, including cetuximab (recommended for patients with wild-type K-ras gene) and bevacizumab.
1. Tumor K-ras gene status should be tested before treatment; EGFR is not recommended as a routine test.
2. Combination chemotherapy should be used as the first and second line treatment for patients with metastatic colorectal cancer who can tolerate chemotherapy. The following chemotherapy regimens are recommended: FOLFOX/ FOLFIRI/CapeOx±cetuximab (recommended for patients with wild-type K-ras gene), FOLFOX/ FOLFIRI/CapeOx±bevacizumab.
3. Patients with more than three lines of chemotherapy are recommended to enter clinical studies. Irinotecan in combination with targeted agents may also be considered for patients who did not choose targeted agents in the first and second lines of therapy.
4. For patients who cannot tolerate combination chemotherapy, the recommended regimen is 5-FU/LV± targeted agents, or 5-FU continuous infusion, or capecitabine alone.
5. Patients with advanced disease who have very poor general or organ function status are recommended for best supportive care and chemotherapy is not recommended.
6. If metastatic recurrence is confined to the liver, local treatment targeting the liver lesion is recommended.
7. For local recurrence of colorectal cancer, multidisciplinary evaluation is recommended to determine whether there is a chance of re-excision and whether preoperative radiotherapy is appropriate. If combined with radiotherapy, fluorouracil-based monotherapy or combination chemotherapy can be chosen according to the patient’s physical condition, or if only chemotherapy is suitable, the above principles of drug therapy for advanced patients will be applied.
(iv) Local/regional chemotherapy.
Intraoperative or postoperative regional slow-release chemotherapy and intraperitoneal thermal perfusion chemotherapy are not routinely recommended at present.
Radiation therapy specification for rectal cancer
(a) Indications for radiation therapy for rectal cancer.
The main purpose of radiotherapy or radiotherapy for rectal cancer is adjuvant treatment and palliative treatment. The indications for adjuvant treatment are mainly for stage II-III rectal cancer; the indications for palliative treatment are local recurrence and/or distant metastasis. For some patients who cannot tolerate surgery or have strong desire to preserve anus, radical radiotherapy or radiochemotherapy can be tried.
1. Radiotherapy is not recommended for stage I rectal cancer. However, radical surgery is recommended after local resection with one of the following factors; postoperative radiotherapy is recommended for those who refuse or cannot be operated.
(1) Postoperative pathological stage of T2.
(2) Tumor maximum diameter greater than 4 cm.
(3) Tumor occupying more than 1/3 of the intestinal circumference.
(4) Hypofractionated adenocarcinoma.
(5) Nerve invasion or choroidal aneurysm embolus.
(6) Positive margin or tumor <3mm from the margin.
(2) If the clinical diagnosis is stage II/III rectal cancer, preoperative radiotherapy or preoperative simultaneous radiotherapy is recommended.
3.Pathological diagnosis of stage II/III rectal cancer after radical surgery, if preoperative radiotherapy is not performed, postoperative simultaneous radiotherapy must be performed.
4. Locally advanced inoperable rectal cancer (T4) must be treated with preoperative simultaneous radiotherapy and re-evaluated after radiotherapy for radical surgery.
5. For locally recurrent rectal cancer, surgery is preferred; if surgery is not possible, radiotherapy is recommended.
6. Stage IV rectal cancer: for primary stage IV rectal cancer, chemotherapy ± radiotherapy of the primary lesion is recommended, and resectability is re-evaluated after treatment; palliative reduction radiotherapy is performed for metastases if necessary.
7. Recurrent metastatic rectal cancer: for patients with resectable local recurrence, surgical resection is recommended before considering whether to perform postoperative radiotherapy. For patients with unresectable local recurrence, preoperative simultaneous radiotherapy is recommended, and surgical resection should be pursued.
(B) Radiation therapy techniques.
1. Definition of target area. The primary tumor high-risk recurrence area and regional lymphatic drainage area must be irradiated.
(1) High-risk recurrence area of primary tumor includes tumor/tumor bed, rectal mesenteric area and presacral area, and target area of low to medium rectal cancer should include sciatic rectal fossa.
(2) The regional lymphatic drainage area includes the lymphatic drainage area of the common iliac vessels in the true pelvis, the rectal mesenteric area, the lymphatic drainage area of the internal iliac vessels and the closed lymph node area.
(3) For those with tumors and/or residuals, whole pelvic irradiation followed by local reduction of the field for additional irradiation.
(4) Radiotherapy for recurrent pelvic lesions.
(1) Without previous history of radiotherapy, irradiation of the primary tumor high-risk recurrence area, regional lymph node drainage area (true pelvic area) and local additive radiotherapy for tumor are recommended.
②Prior history of radiotherapy, decide whether or not to have radiotherapy according to the situation.
2. Irradiation technique.
Choose different radiotherapy techniques according to the radiotherapy equipment the hospital has, such as conventional radiotherapy, 3D conformal radiotherapy, intensity-modulated radiotherapy, image-guided radiotherapy, etc.
(1) CT simulation positioning is recommended, if there is no CT simulation positioning, conventional simulation positioning must be performed. Prone position or supine position with filling bladder is recommended.
(2) Multi-field irradiation in three or more fields is mandatory.
(3) If intensity-modulated radiotherapy is used, plan verification must be performed.
(4) Local dosing can be done by intraoperative radiotherapy or external irradiation techniques.
(5) Radioactive particle implantation therapy is not recommended for routine application.
3. Dose of irradiation.
Whether using conventional irradiation techniques or new techniques such as 3D conformal radiotherapy or intensity-modulated radiotherapy, there must be a clear way of defining the irradiation dose. The dose of conventional irradiation should be defined by isocenter point.
(1) DT45-50.4Gy at 1.8-2.0Gy per session for 25 or 28 sessions is recommended for areas with high risk of recurrence of primary tumor and regional lymphatic drainage. For preoperative radiotherapy with 5×5 Gy/5 times/1 week or other dose fractionation, the effective biological dose must be ≥30 Gy.
(2) For those who have tumor and/or residual, whole pelvic irradiation followed by local field reduction with additional DT10-20 Gy. (3) The chemotherapy protocol and sequence of synchronous radiotherapy.
1. Chemotherapy regimen for synchronous radiotherapy. 5-FU or 5-FU analogues are recommended as the base regimen.
2. Sequence of postoperative radiotherapy and adjuvant chemotherapy. After radical surgery for stage II-III rectal cancer, the sandwich treatment model of synchronized radiotherapy followed by adjuvant chemotherapy or 1-2 cycles of adjuvant chemotherapy, synchronized radiotherapy and then adjuvant chemotherapy is recommended. (To be continued)