Colorectal cancer is a common malignant tumor of the gastrointestinal tract, accounting for the second place of gastrointestinal tumors. The most common site is rectum and the junction of rectum and sigmoid colon, accounting for 60%. The incidence is mostly after 40 years old, and the ratio of men to women is 2:1.
Pathological classification.
Rectal cancer can be divided into the following categories according to histopathological classification
1.Glandular epithelial carcinoma
(1) Papillary adenocarcinoma: all or most of the tumor tissues are papillary in structure, the incidence is 0.8% to 18.2%.
(2) Ductal adenocarcinoma: the tumor tissue forms a duct-like structure, the incidence is 66.9% to 82.1%. This type can be divided into three levels: (1) highly differentiated adenocarcinoma; (2) moderately differentiated adenocarcinoma; and (3) poorly differentiated adenocarcinoma.
(3) Mucinous adenocarcinoma: The cancer cells secrete a lot of mucus and form a “mucus paste”.
(4) Indolent cell carcinoma: The tumor is composed of indolent cells without glandular duct-like structure.
(5) Undifferentiated carcinoma: the cancer cells grow diffusely in patches or in masses, without forming glandular ducts or other tissue structures.
(6) Adenosquamous carcinoma: also known as adenosquamous cell carcinoma, the adenocarcinoma and squamous carcinoma components in this type of tumor cells exist in mixed intervals.
(2) Squamous cell carcinoma: squamous cells are the predominant carcinoma.
3) Carcinoid tumors originate from neuroendocrine cells of neural ridge origin, and can also be derived from glandular epithelium.
Pathogenic risk factors
The etiology of rectal cancer is not fully understood by Western medicine, but the following factors are considered to be closely related to carcinogenesis.
(1) Dietary factors: high fat, high meat and low fiber diet are closely related to the occurrence of rectal cancer. High fat diet not only stimulates the increase of bile secretion, but also promotes the growth of certain anaerobic bacteria in the intestine. .
(2) Genetic factors: In the families of rectal cancer patients, about 1/4 have a family history of cancer, half of which are also gastrointestinal tumors. Due to the genetic change of normal cells, patients with cancer get a susceptibility from heredity, plus some stimulating factors, so that the tissue cells grow rapidly and develop into cancer, and the cell genetic mutation becomes malignant cells with tumor genetic characteristics, which is manifested as the familial nature of cancer.
(3) Polyps: The development of rectal cancer is closely related to polyps. It is believed that rectal polyps are pre-cancerous lesions, especially familial polyadenomatous polyposis, which has a great possibility of cancer; papillary adenomatous polyps, which also have more chances of cancer.
(4) Chronic inflammatory stimulation: chronic inflammatory stimulation can lead to the occurrence of rectal cancer. Such as schistosomiasis, amebic dysentery, chronic non-specific ulcerative colitis, chronic bacillary dysentery, etc., can be carcinogenic through granuloma, inflammatory and pseudopolyposis stages. Patients with ulcerative colitis with a duration of more than 10 years are prone to evolution, and the malignancy of carcinoma is high, easy to metastasize, and the prognosis is poor; related data statistics, the incidence of patients with intestinal cancer suffering from colitis is 8 to 10 times higher than those without colitis.
In addition, the occurrence of tumor is also closely related to mental factors, age, endocrine factors, environmental stress capacity, climatic factors, immune malfunction and viral infection, etc., but rectal cancer can only occur under certain conditions.
Clinical manifestations
I. Early symptoms
Rectal cancer lacks symptoms in the early stage and patients have no obvious abnormal changes. When the mass reaches 1~2cm, due to the erosion of the tumor, the intestinal mucosa suffers from foreign body stimulation of the mass, and the secretion increases, so a small amount of mucus is discharged during defecation, mostly in the front of the stool or attached outside the stool. As the tumor increases, the mucus secretion also increases. Sometimes, with the increase of intra-abdominal pressure by exhaustion or sudden coughing, mucus may flow out from the anus. When the tumor increases and forms ulcers or necrosis combined with infection, there will be obvious symptoms of rectal irritation and changes in the number of bowel movements and nature of stool. The number of bowel movements increases, from 2 to 3 times a day, with mucus stool, thin stool, or mucus and blood stool. It is often misdiagnosed as “enteritis”, “dysentery”, “ulcerative colitis” and so on. However, the diarrhea symptoms of rectal cancer are not like colitis, which has a rapid onset and quick improvement; nor is it like dysentery, which typically presents with symptoms of urgency. The rectal irritation symptoms of rectal cancer are both slow and progressive, and the irritation symptoms are obvious when combined with infection, which can be temporarily improved after symptomatic treatment, but those who still have mucus and blood stools after longer treatment should be given sufficient attention. The patient should go to the hospital for detailed examination when the following conditions occur
① Abnormal stool habits, increased frequency of bowel movements, along with a small amount of mucus stools, mucus blood stools, those who do not improve after treatment, or those who improve after treatment but relapse, should be promptly diagnosed and treated.
(2) If there is a history of mucus stool or diarrhea, but the symptoms are mild and suddenly increase, and the number of bowel movements and nature of bowel movements change, the diagnosis should be confirmed by re-examination.
③If constipation and diarrhea alternate without obvious reasons and do not improve with short-term treatment, and if no abnormality is found in the stomach after barium fluoroscopy, the rectal area should be examined in the hospital.
④ If the bowel movement is laborious, and the expelled stool has pressure marks, is grooved flat and thin, etc., rectal examination must be done. Any of the above four conditions should be promptly checked in the hospital. Where available, it is best to ask a surgeon or anorectal surgeon to examine.
II. Middle and late stage symptoms
The clinical characteristics of early stage rectal cancer are mainly blood in stool and change of bowel habit. Blood in stool as the only early symptom accounts for 85% when the cancer is confined to rectal mucosa, but unfortunately it is often not taken seriously by patients. In addition to the general symptoms such as loss of appetite, weight loss and anemia, patients with middle and advanced rectal cancer also have symptoms of local irritation of cancer such as increased number of bowel movements, incomplete bowel movements, frequent bowel movements, and heavy weight after urgency. The enlargement of cancer may cause narrowing of intestinal cavity and intestinal obstruction.
Rectal cancer often invades the surrounding tissues and organs, such as bladder and prostate, causing frequent urination, urgent urination and difficulty in urination. Invasion of the presacral plexus can cause pain in the sacrococcygeal and lumbar areas. Rectal cancer can also metastasize to the liver distantly, causing hepatomegaly, ascites, jaundice, and even malignant fluid and other manifestations.
Rectal cancer is easy to be misdiagnosed. In the early stage, when there is an increase in the number of stools, mucus and pus and blood in the stool, it is easy to be misdiagnosed as dysentery, enteritis or hemorrhoids, thus losing the opportunity of early treatment. Therefore, adults should be alert when abnormal bowel movements occur and undergo proctoscopy or sigmoidoscopy if necessary.
Diagnosis
Medical history and symptoms.
Changes in bowel habits or stool properties, mostly manifested as increased frequency of stools, unformed or thin stools, blood and mucus in stools. Sometimes constipation or diarrhea alternates with constipation, and stools become thin. Pain in the middle and lower abdomen, varying in severity, mostly vague or distending pain. Patients with right hemi-colon cancer often find abdominal masses. Pay attention to the presence of systemic symptoms such as blood craving, emaciation, weakness, edema, hypoproteinemia, etc. In case of tumor necrosis or secondary infection, patients often have fever.
Physical examination reveals that.
Abdominal masses can be felt or found during finger-intestinal examination, which are mostly hard with pressure pain and irregular in shape. Anemia, emaciation, and cachexia. In cases with lymphatic metastases, compression of venous return may cause ascites, edema of the lower limbs, jaundice, etc.
Ancillary tests.
Blood count shows small cell anemia and increased sedimentation. X-ray shows barium filling defect, stiffness of the intestinal wall, reduced or absent peristalsis, irregular colonic pouch, narrowing or dilatation of the intestinal canal. Colonoscopy can clarify the nature of the lesion, size, and some even find early lesions. In addition, serum carcinoembryonic antigen (CEA), ultrasound, and abdominal CT examination can also help in the diagnosis.
It should be distinguished from inflammatory bowel disease, intestinal tuberculosis, and colon polyposis.
Treatment measures
Basic treatment plan
The treatment of colorectal cancer takes surgery to remove the cancer as the first choice, supplemented by radiotherapy, chemotherapy and Chinese medicine, etc. Recently, many scholars have adopted endoscopic resection treatment for early colorectal cancer, which has also achieved good results. As for how to choose the best plan, it should be based on different clinicopathological stages. After a lot of clinical practice, it is proved that the combined treatment plan of Chinese and Western medicine is as follows: Dukes′A stage, surgery and Chinese medicine can be given without chemotherapy; Dukes′B stage, surgery, chemotherapy and Chinese medicine after surgery, and radiation therapy can be given for rectal cancer; Dukes′C stage, surgery, chemotherapy and Chinese medicine after surgery for colon cancer, and radiation therapy before or after surgery for rectal cancer, and chemotherapy and Chinese medicine; Dukes′C stage, surgery, chemotherapy and Chinese medicine can be given for rectal cancer. For Dukes′D stage, radiotherapy, chemotherapy, herbal medicine and immunotherapy are the main treatments, while surgery is only for palliative resection or symptomatic treatment. Chinese and western medicine have their own strengths in treating tumors, so the treatment of colorectal cancer must give full play to the respective advantages of Chinese medicine, adhere to long-term treatment, relieve the patient’s psychological state, do a good job in psychotherapy, increase diet and nutrition, and improve their own immune function. In this way, we can achieve better curative effect.
Surgical treatment.
It is the most effective method to eradicate node and rectal node cancer. Patients who are suitable for surgery should be treated with early surgical resection.
Chemotherapy.
After radical surgery of colorectal cancer, there are still 50% cases of recurrence and metastasis, therefore, preoperative and postoperative chemotherapy has the potential to improve the 5-year survival rate after radical surgery. Anti-cancer drugs are preferred to fluorouracil, followed by mitomycin and adriamycin.
Radiotherapy.
Preoperative radiotherapy can shrink the tumor and improve the resection rate, and postoperative radiotherapy can kill the residual tumor cells. Radiotherapy alone, which is only used for advanced rectal cancer cases, has the function of hemostasis, analgesia and prolonging survival.
Endoscopic treatment.
For early stage mucosal layer cancer, it can be resected endoscopically, and for advanced tumor, stent can be placed endoscopically to prevent stenosis and obstruction.
Traditional Chinese medicine treatment.
It can be used as adjuvant and supportive treatment to improve symptoms and prolong survival.
Colorectal cancer liver metastasis
Liver metastasis is very common in colorectal cancer, with 20%-40% of patients having liver metastasis at the time of diagnosis, and the incidence of heterochronic liver metastasis is as high as 50%. The average survival of liver metastasis without treatment is 16-18 months, while that of extensive metastasis is only 3-5 months. Therefore, liver metastasis is the leading cause of death in colorectal cancer patients (60-71%).
Because of the anatomical features of colonic venous reflux, sometimes the liver may be the only site of metastasis in colorectal cancer and liver resection offers an important therapeutic opportunity. Therefore, the importance of its surgical resection cannot be overstated. For unresectable metastatic lesions, non-surgical treatment methods include the following.
(1) systemic chemotherapy: the current chemotherapy regimen is still based on 5-Fu, with an efficiency of 18% a 31% and a median survival of 8-14.2 months, and there are reports of individual cases surviving for more than 10 years with the application of urea oral therapy.
(2) Hepatic artery perfusion chemotherapy: most cases are suitable for hepatic artery perfusion chemotherapy, the most common drugs are 5-Fu, MMC and DDP, with an efficiency of 48%-62% and a 2-year survival rate of 47%.
(3) Hepatic artery embolization chemotherapy: its principle is to make the chemotherapeutic drugs highly concentrated in liver metastases and block the blood supply of liver cancer lesions.
(4) Chinese medicine treatment of toxic side effects of transhepatic artery or systemic chemotherapy: often according to the different stages of the disease for evidence-based treatment. ①In the first week after chemotherapy, most patients have varying degrees of nausea, vomiting, loss of appetite, fatigue, dizziness, etc. A few patients may have diarrhea, and from the second week after chemotherapy, there may be a decrease in the white blood cell count, which is mostly due to weakness of the spleen and stomach; evidence of deficiency of both qi and blood during this period, the treatment is based on strengthening the spleen and stomach, nourishing qi and blood, and Zi Chen Xia Liu Jun Tang with Huang Qi and Coix seeds is the basic formula. In the 3rd-4th week after chemotherapy, the discomfort of gastrointestinal tract reaction caused by chemotherapy has basically disappeared, diet and physical strength have gradually recovered, mostly seen with pale tongue or petechiae or petechiae, white or yellowish greasy moss, stringent or astringent pulse, which are mostly positive deficiency and evil real, positive deficiency is mostly spleen deficiency and qi deficiency, while evil real is mostly damp-heat accumulation and qi stagnation and blood stasis. The treatment is to both attack and supplement, to strengthen the spleen and benefit the qi, to clear heat and dampness, to regulate qi and disperse knots, and to activate blood stasis. The formula is based on Si Jun Zi Tang with addition: Radix Codonopsis, Radix Astragali, Poria, Rhizoma Atractylodis Macrocephalae, Radix Glycyrrhizae, Radix et Rhizoma Sulfortii, Rhizoma Polygonati, Radix et Rhizoma Polygonatii, Radix et Rhizoma Curcumae. According to the theory of “wood over earth” and “when we see liver disease, we know that liver transmits spleen, so we should first strengthen the spleen”, the deficiency of spleen and stomach qi often runs through all stages of the disease, therefore, in the treatment process, we always focus on strengthening the spleen and benefiting the qi, because the spleen and stomach is the origin of the latter and the source of qi and blood biochemistry. If the spleen and stomach are weak, there is no source of biochemistry, then there is a deficiency of vital energy, and phlegm, dampness, stagnation and toxicity will remain, and all medicines will be ineffective. By strengthening the spleen and cultivating the soil, promoting appetite, and improving the body’s ability to resist disease, we can achieve the purpose of supporting the positive and dispelling the evil.
(5) Intra-focal chemotherapy: alcohol or chemotherapy drugs are injected directly into the foci under the guidance of ultrasound, so that the foci have a high concentration of drugs, while the impact on the surrounding tissues is small.
(6) Radiotherapy: It is very effective in relieving pain (55%-95%), but it is less effective in prolonging survival.
(7) Chinese medicine treatment: for cases of liver metastases that cannot be surgically resected, Chinese medicine treatment has considerable value in improving the general condition, enhancing the patient’s immunity and prolonging survival. The prescriptions are mainly to support the root of the disease, activate blood circulation and remove blood stasis, and dredge the liver and bile.