In recent years, colorectal cancer, which occurs more frequently every year, has become the third-most malignant tumor in the world. As people's lifestyle changes, the spectrum of cancer is also changing. Among them, colorectal cancer, commonly known as colorectal cancer, has a rapid increase in incidence. According to statistics, the incidence of colorectal cancer in China has increased from 12 per 100,000 in the early 1970s to 56 per 100,000 at present. The growth rate is about 4.2% per year, far exceeding the international level of 2%. Compared with Westerners, the incidence of rectal cancer in China is higher than that of colon cancer, about 1.5:1; the proportion of young people (<30< span="">years old) is higher, accounting for about 15%.
[Reporter] Hello, Professor Ma, the incidence of rectal cancer in China is obviously increasing and younger. What are the clinical symptoms of rectal cancer?
[Professor Ma] Early rectal cancer is mostly asymptomatic. When the tumor progresses to a certain period, it can cause bowel symptoms such as changes in bowel habits. Late rectal cancer can also cause systemic symptoms due to multiple distant metastases.
1. Changes in bowel habits. The number of bowel movements has changed from once a day to two or three times. After each bowel movement, there is a feeling of incomplete stool; the shape of stool begins to change, for example, from thick to thin; stool becomes black or dark red, stool becomes thinner and has mucus; Increased frequency, but no stool.
2. Mucous stools and pus and blood stools. When the cancer ruptures, the stool often contains bright red or dark red blood and mucus, and the stool and blood are mixed; there are pus or blood in the stool, frequent stools or diarrhea and constipation; stool shape changes, thinning, flattening or banding Groove.
3. Anemia and weight loss. As the disease progresses, patients may experience chronic wasting symptoms, such as anemia, weight loss, fatigue and fever, and even cachexia, which is often accompanied by fatigue and unexplainable weight loss, blood in the stool, insufficient intake, and excessive consumption related.
4. Abdominal pain and bloating. Intestinal cancer patients suffer from abdominal distension and abdominal pain due to intestinal obstruction, and the incidence of abdominal pain is higher than the incidence of abdominal distension. The pain is mostly in the middle and lower abdomen, with varying degrees of severity, mostly dull pain or fullness.
5. Alternate diarrhea or constipation. If there are symptoms such as diarrhea and constipation alternately, it may be because the growth of cancer has affected the normal physiological functions of the intestine, and the possibility of cancer should be considered.
6. Repeated hemorrhoids that do not heal, unexplained anemia, weight loss; unexplained stomach pains; unhealed anal ulcers, persistent anal pain. What needs to be highly vigilant is that in some cases, hemorrhoids and tumors coexist, which are often covered by hemorrhoids and delay the timely detection and diagnosis of tumors.
[Reporter] Is the irregularity of modern people's daily life and diet the main cause of rectal cancer?
[Professor Ma] The cause of rectal cancer is still unclear, 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. Dietary factors
Previous studies have shown that high fat and high protein intake is related to the incidence of rectal cancer. Among them, the cause of the disease caused by high-fat diet may be that fat can promote the synthesis of bile acids, which indirectly inhibits the intestinal reabsorption of bile acids, increasing the concentration of bile acids in the colorectal. Cancer-promoting effect. In addition, the lack of multiple vitamins, intestinal flora imbalance and excessive intake of nitrite compounds may all play a role in the pathogenesis of rectal cancer.
2. Impact of large intestine related diseases
Ulcerative colitis, colorectal polyps, and adenomas are all related to rectal cancer. At present, it is believed that adenomatous polyps, villous adenomas, and familial multiple polyposis are precancerous lesions of rectal cancer. The formation of carcinogenesis follows the "inflammation-proliferation-carcinogenesis" pathway and is a multi-step, multi-stage evolutionary process, and this process is accompanied by changes in DNA methylation levels, growth factors, etc., leading to cell differentiation and growth Abnormal, and finally formed a malignant tumor characterized by invasion and metastasis.
3. Influence of age and genetic factors
1) Age factor: It has been thought that the incidence of rectal cancer increases with age. The prevalence age of colorectal cancer is 50 to 70 years old, and the malignant degree of rectal cancer is high in young and middle-aged patients aged ≤40.
2) Genetic factors: In addition to colorectal cancer patients caused by familial polyposis or malignant transformation of ulcerative colitis, about 5-15% of other colorectal cancer patients have an obvious family history of tumors, collectively referred to as Hereditary non-familial polyposis colorectal cancer (Hereditary Nonpolyposis Colorectal Cancer, HNPCC), also known as Lynch syndrome. The specific manifestations are as follows: (1) More than three family members have colorectal cancer, two or more of them are of the same generation; (2) At least two similar generations have the disease; (3) At least one of them is before the age of 50 Diagnosed as colorectal cancer.
[Reporter] According to statistics, colorectal cancer is the third largest malignant tumor in the world. What are the effective methods for the treatment of rectal cancer?
[Professor Ma] Surgery is the main treatment for rectal cancer. If there is no contraindication to surgery, radical resection of rectal cancer should be performed as soon as possible. Adjuvant chemotherapy for rectal cancer is based on fluorouracil. Preoperative radiotherapy and chemotherapy can reduce the volume of rectal cancer, increase the rate of surgical resection, and reduce the rate of local recurrence.
<< span="">Surgical treatment>
1. Radical surgical resection is still the main treatment for rectal cancer. If there is no contraindication to surgery for rectal cancer that can be removed, radical resection of rectal cancer should be performed as soon as possible. Rectal cancer is clinically divided into low rectal cancer (within 125px from the dentate line), median rectal cancer (5～250px from the dentate line) and high rectal cancer (over 250px from the dentate line). This classification has important reference value for the choice of radical surgery for rectal cancer. The selection of surgical methods should be comprehensively judged based on factors such as the location, size, activity, degree of cell differentiation, and bowel control ability before surgery.
2. Local resection: suitable for early rectal cancer with small tumors, confined to the mucosa or submucosa, and highly differentiated. Local resection can be performed via anal and transsacral approach. The normal mucosa around the tumor should be removed 1cm, and the method of side-cutting and seaming can be used for local resection, which is convenient for operation and less bleeding. Local resection for early rectal cancer can achieve a 5-year survival rate of 80% to 100%.
3. Radical resection of abdominal perineum combined with rectal cancer (Miles operation): It was first reported by Miles in 1908. It is suitable for lower rectal cancer below peritoneal reflex and middle and upper rectal cancer with late lesions and heavier invasion. The scope of resection includes the distal end of the sigmoid colon, the entire rectum, the inferior mesenteric artery and its regional lymph nodes, the total mesentery, the levator ani muscle, the fat in the sciatic rectal fossa, the anal canal and the skin around the anus, subcutaneous tissue and all anal sphincter. A permanent single cavity sigmoid stoma was performed in the left lower abdomen. In Miles operation, some people use gracilis or gluteus maximus instead of sphincter for in situ anoplasty, but the effect is uncertain.
4. Transabdominal radical resection of rectal cancer (low anterior rectal resection, Dixon operation): First reported by Dixon in 1939, it is currently the most clinically used radical resection of rectal cancer with anal preservation. It is suitable for rectal cancer more than 125px from the dentate line. Dixon surgery is also reported for rectal cancer at a closer distance. But in principle, radical resection is the premise, and the distal resection margin is required to be more than 50px from the lower edge of the cancer. Its basic operation is to remove the tumor and a certain length of normal intestinal tube at the upper and lower ends through the abdomen, and perform colon-rectal anastomosis. Because the anastomosis is located near the dentate line, patients are prone to frequent bowel movements and poor bowel control ability during the postoperative period. Due to the application of double stapling technology, the operation is not complicated.
In the early 1980s, Heald proposed the surgical principle of total mesorectal resection (TME), emphasizing that the spread of cancer cells in the connective tissue around the rectum should be followed. There are three main points: ①In the presacral space under direct vision Perform sharp separation in the middle; ② Maintain the integrity of the pelvic fascia visceral layer; ③ Resection of the distal mesorectum of the tumor shall not be less than 125px.
5. Transabdominal rectal cancer resection, proximal stoma, and distal closure surgery (Hartmann surgery): It is suitable for rectal cancer patients who cannot tolerate Miles surgery or who are not suitable for Dixon surgery due to poor general general conditions.
6. Colon-anal anastomosis (Parks operation): It was first proposed by Parks in 1972, that is, the rectum was excised through the abdomen and anus, and then the colon-anal anastomosis was performed in the perineum. It is suitable for tumors 5～150px from the anus, and the distal resection margin of the tumor is 2～75px long. The anastomosis can still be located on the dentate line, and because of the transabdominal operation, it can achieve good radical curative effect. Anal function.
There are many surgical methods for radical resection of rectal cancer. But the classic surgical methods are still Miles surgery and Dixon surgery. Many scholars have modified the Dixon operation and evolved it into other surgical methods (such as various drag-out anastomosis). However, since the stapler can complete the anastomosis in any position of the rectum and anal canal, other modified surgical methods have been clinically used. Used less frequently. Laparoscopic Miles and Dixon operations have the advantages of less trauma and quick recovery. However, there is still controversy regarding the dissection of lymph nodes and the treatment of invaded surrounding organs. When rectal cancer invades the uterus, the uterus can be removed together, which is called posterior pelvic organ dissection; when rectal cancer invades the bladder, rectum and bladder (for men) or rectum, uterus, and bladder are removed, called total pelvic dissection.
While performing radical resection of rectal cancer, the quality of life of the patient must be fully considered, and urinary function and sexual function should be protected as much as possible during the operation. The two sometimes have to weigh the pros and cons and choose the surgical method. For advanced rectal cancer, when the patient has difficulty defecation or intestinal obstruction, a sigmoid double-chamber stoma is feasible.
Adjuvant chemotherapy for rectal cancer is based on fluorouracil. The route of administration includes arterial infusion, portal vein administration, intravenous administration, postoperative intraperitoneal catheter infusion administration and warm perfusion chemotherapy, etc., mainly intravenous administration. The timing of chemotherapy, how to combine medication and dosage, etc. vary according to the patient's condition and personal treatment experience. Commonly used drugs are fluorouracil, oxaliplatin, mitomycin, cytarabine and so on.
<< span="">Neoadjuvant radiotherapy and chemotherapy>
In Europe, neoadjuvant radiotherapy and chemotherapy for rectal cancer have been recognized by many medical centers. Rectal cancer received radiotherapy for 2Gy each time, 5 times/week, with a total dose of 46Gy before surgery, and was supplemented with fluorouracil-based chemotherapy, such as FOLFOX-6 regimen and MAYO regimen for 2 to 4 courses, followed by chemotherapy after surgery. Preoperative radiotherapy and chemotherapy can reduce the size of rectal cancer and achieve staging effect, thereby increasing the rate of surgical resection and reducing the rate of local recurrence. Multi-center, random, and large sample data show that neoadjuvant radiotherapy and chemotherapy are beneficial for the treatment of rectal cancer.
[Reporter] Rectal cancer seriously endangers people's health. How to prevent rectal cancer and early diagnosis and treatment?
[Professor Ma] Although the early symptoms of rectal cancer are relatively insidious and not very specific, if patients pay attention to some symptoms in the anorectal area, they can still be detected early:
2. The following symptoms should be taken seriously. Such as the recent continuous abdominal discomfort, dull pain and abdominal distension, anal swelling; unexplained anemia or weight loss in a short period of time; sudden touching of an abdominal mass, etc. The above symptoms sometimes indicate that the tumor is progressing quickly, and should be paid attention to and go to the hospital for examination and treatment in time.
3. Treat related diseases in time. For example, rectal benign lesions: polyps, adenomas, etc., are generally called precancerous lesions, which require timely endoscopic treatment or surgical treatment to prevent cancer. Chronic inflammatory bowel disease also requires timely and standardized treatment, which can reduce the occurrence of colorectal tumors.
[Experts' key reminder] Now with the popularity of the Internet, many patients like to check the Internet for themselves after they develop symptoms. However, we also found that many patients either avoid medical problems and always think that they cannot be rectal cancer, and eventually delay the early diagnosis and treatment; or they like to sit in the table, always think that there is no cure for cancer, and they do not understand the current treatment of rectal cancer. The latest development, only to know that sighing all day, only increases the worry. In fact, it is not difficult to diagnose rectal cancer early. About 70% of rectal cancers can be found through "digital rectal examination", which is simple and painless. After discomfort and symptoms appear, as long as the patient goes to the anorectal specialist in time, the specialist can use digital rectal examination to find most rectal tumors, and a small number of patients can also be diagnosed with proctoscopy or colonoscopy. Therefore, the key to the early diagnosis and treatment of rectal cancer is to avoid fluke when symptoms appear and seek medical attention as soon as possible.