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Colon Cancer: Causes Signs Symptoms Stages Therapies

Colon Cancer: Causes Signs Symptoms Stages Therapies. Colon cancer is a common malignant tumor of the digestive tract that occurs in the colon. It is more likely to occur at the junction of the rectum and the sigmoid colon.

The incidence is highest in the 40-50-year-old age group, and the ratio of male to female is 2 to 3:1. Incidence rate accounts for the 3rd of gastrointestinal tumors

Colon Cancer: Causes Signs Symptoms Stages Therapies.

Overview

Malignant tumors originating from the epithelium of the colonic mucosa are relatively common.
They are often asymptomatic in the early stage, and manifest as blood in the stool and abdominal pain after progression.
Surgery is the main treatment method.
Early diagnosis and treatment, most patients can achieve long-term survival.

Disease definition

Colon cancer refers to a malignant tumor of the digestive tract derived from colonic epithelium. The incidence of colon cancer in some countries from high to low is sigmoid colon, cecum and ascending colon, descending colon and transverse colon.

Epidemiology

The incidence of colon cancer in some countries has been on the rise in recent years. The incidence of colon cancer in urban areas is higher than that in rural areas, and men are higher than women.

The incidence of colon cancer is at a low level before the age of 35, and the incidence increases rapidly after the age of 35, and the incidence increases with age.

Type of disease

According to the general classification

Ulcer type: The tumor forms an ulcer that reaches or penetrates the muscular layer of the intestinal wall, grows into the deep layer of the intestinal wall and infiltrates the surroundings, and metastasizes earlier. Protruding type: The main body of the tumor protrudes into the intestinal cavity.

When the mass increases, there may be ulcers on the surface, and there is little infiltration to the surroundings. Infiltrating type: The tumor infiltrates into all layers of the intestinal wall, thickening the local intestinal wall and narrowing the intestinal cavity, but there is often no bulge or ulcer on the surface.

According to histological classification

Adenocarcinoma: It is the most common type of colon cancer and can be divided into tubular adenocarcinoma, papillary adenocarcinoma, mucinous adenocarcinoma and signet ring cell carcinoma.

Adenosquamous cell carcinoma: relatively rare, also known as adenosquamous cell carcinoma. The tumor is composed of squamous cell carcinoma and adenocarcinoma cells. Undifferentiated cancer: The cancer cells are flaky or clumpy, do not show a glandular tube-like structure, the cells are arranged irregularly, and the prognosis is poor.

Classification according to anatomy

Left colon cancer: Refers to the cancer that occurs in the colon on the left half of the abdomen, including about the left 1/3 transverse colon cancer, descending colon cancer and sigmoid colon cancer.

Right colon cancer: refers to cancers that occur in the colon on the right side of the abdomen, including ascending colon cancer and about 2/3 transverse colon cancer on the right side.

Disease stage

According to the degree of colon cancer invasion (T stage), local lymph node metastasis (N stage) and distant metastasis (M stage), colon cancer is staged.

At present, the American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) 8th edition colorectal cancer TNM staging system is commonly used internationally. According to the TNM staging, colon cancer can be divided into stages 0 to Ⅳ according to its severity.

Early colon cancer (stage 0~I):

the primary tumor is limited to the mucosa or submucosa, without lymph node metastasis or distant metastasis.

Stage Ⅱ colon cancer (stage Ⅱ):

The primary tumor invades the muscular layer of the intestinal wall without lymph node metastasis or distant metastasis.

Stage III colon cancer (Stage III):

Regardless of the depth of the primary tumor invasion, there is regional lymph node metastasis, but no distant metastasis.

Stage IV colon cancer (stage IV):

tumor metastasis to other organs, such as liver, lung, bone, and brain; abdominal implantation and metastasis; distant lymph node metastasis, such as supraclavicular lymph node metastasis.

Causes

The etiology of colon cancer is relatively complex, and may be the result of the synergistic effect of environment, diet, living habits, and genetic factors.

Basic cause

The etiology of colon cancer is still unclear. Most colon cancers evolve from adenomatous polyps and undergo various stages of hyperplasia, adenoma, carcinogenesis and corresponding chromosomal changes. Carcinogenesis involves multiple genes.

Predisposing factors

Dietary factors

The incidence of colon cancer is closely related to dietary factors, including: low-fiber diet, high-fat and high-protein diet, lack of trace elements and vitamins (including lack of calcium, selenium, molybdenum, antioxidant vitamins A, C, E and β-carotene ).

Genetic factors

Genetic factors play an important role in the pathogenesis of colon cancer. About 5% to 20% of colon cancers are hereditary colon cancers, including family hereditary diseases such as Lynch syndrome, familial adenomatous polyposis, and black spot polyp syndrome. People with a family history of colon cancer have a higher risk of colon cancer in their immediate family members than those without a family history.

Age factor

Most patients diagnosed with colon cancer are older than 50 years old.

Mental factor

Long-term mental depression is also considered a risk factor for colon cancer.

Chemical carcinogens

Nitrosamines and their compounds are the most important chemical carcinogens that cause colon cancer. Methyl aromatic amines in fried and baked foods are also closely related to the occurrence of colon cancer. In addition, bile acids and cholesterol can also form a variety of chemical carcinogens under the action of the intestinal anaerobic flora.

Gastrointestinal diseases

Patients with ulcerative colitis, Crohn’s disease, colon adenoma, and rectal polyps will also increase the probability of colon cancer.

Bad habits

Tobacco is a clear carcinogen, and smoking is closely related to the occurrence of colon adenoma. Long-term exposure to very light physical activity may be a predisposing factor for colorectal cancer, because physical activity can promote intestinal peristalsis, help excretion of feces, and reduce the contact time of carcinogens in the intestine and feces. In addition, obesity is also a risk factor for colon cancer.

Parasites

Suffering from schistosomiasis is also considered to be one of the causes of colon cancer.

Symptoms

The symptoms of colon cancer are related to the course of the disease and the anatomical part of the disease. There may be no obvious symptoms in the early stage of the disease.

As the disease progresses, left colon cancer and right colon cancer each have their relatively specific symptoms. If the tumor metastasizes, it may cause dysfunction of the metastatic organ, such as impaired liver function, jaundice, dyspnea, dizziness, headache, or pain at the site of bone metastasis.

Typical Signs and Symptoms

Weight loss and wasting

The common symptoms of colon cancer patients are caused by long-term abdominal distension and abdominal pain in colon cancer patients, which leads to weakened digestion and absorption functions, which in turn causes malnutrition, significant weight loss, and severe weight loss.

Main manifestations of left colon cancer

It is more likely to cause complete or partial intestinal obstruction, because the intestinal lumen of the left half of the colon is relatively narrow, especially the intestinal lumen of the sigmoid colon is tortuous, and most of the feces have been formed and dried up, so intestinal obstruction is prone to occur. In addition, common symptoms of left colon cancer may include changes in bowel habits, blood in the stool, diarrhea, abdominal pain, and bloating.

Main manifestations of right colon cancer

In the early stage, it may be discomfort with abdominal distension, and the main clinical symptoms are loss of appetite, nausea, vomiting, anemia, fatigue, and abdominal pain. Cancer of the right colon can cause iron deficiency anemia, showing symptoms such as fatigue, fatigue, and shortness of breath. Due to the wide intestinal cavity of the right colon, there are no obvious symptoms in the early stage, and abdominal symptoms will not appear until the tumor grows to a certain size. This is also one of the main reasons why the staging of right colon cancer is often late at the time of diagnosis.

Accompanying symptoms

Symptoms of local tumor invasion

Colon cancer invades surrounding tissues or organs, causing corresponding clinical symptoms. For example, if colon cancer invades the small intestine that it is in contact with or adheres to and forms an internal fistula, it can cause symptoms of postprandial diarrhea and discharge of incompletely digested food.

Symptoms of tumor metastasis

Colon cancer can spread to the liver, lungs, bones and other parts through blood, causing liver function damage, jaundice, dyspnea, dizziness, headache, or pain in the bone metastasis. If cancer cells are widely planted and spread in the peritoneum, ascites symptoms may occur; if plant metastases infiltrate or compress the intestinal tube, intestinal obstruction may occur, and symptoms such as abdominal pain, vomiting, bloating, and stopping of gas and defecation may occur.

Seek medical attention

When symptoms such as bloody stools, bloating and abdominal pain, changes in stool characteristics and bowel habits, and obvious weight loss, you should seek medical attention in time.

The doctor will make a comprehensive judgment based on the patient’s medical history, symptoms, physical examination, colonoscopy, and imaging examination results. Among them, colonoscopy plus biopsy pathological examination is of vital importance for the diagnosis of colon cancer; imaging examination can provide a reliable basis for clinical staging.

Treatment department

General surgery, colorectal surgery, gastroenterology, endoscopy

Related inspections

Endoscopy

According to different inspection sites, it can be divided into sigmoidoscopy and colonoscopy. Among them, because 5% to 10% of colorectal cancer are multiple cancers (ie, ≥2 colorectal cancers in different segments of the intestine), and colonoscopy can observe all from the anal orifice to the ileocecal area when the intestine is fully prepared Large intestine, so colonoscopy is widely used. Colonoscopy biopsy to obtain pathological diagnosis is an important means to make a clear diagnosis of colon cancer, and it is also the basis for formulating treatment plans.

Laboratory examination

Laboratory tests are of little significance for the specific diagnosis of rectal cancer, but for economic reasons, doctors may choose the following tests:

Stool occult blood test: It is valuable for prompting early colon cancer and diagnosing a small amount of bleeding in the digestive tract, and can be used as a preliminary screening method for colon cancer. Tumor marker examination: Carcinoembryonic antigen (CEA) and CA19-9 have relatively limited effects in the detection of early colon cancer, but they can be used to determine prognosis and recurrence after surgery.

Film degree exam

In order to further evaluate the clinical stage, the doctor may perform the following imaging examinations to assess the prognosis and formulate a treatment plan.

CT: It is considered to be one of the better methods for judging the staging and prognosis of colon cancer. It is of great significance in understanding the degree of colon cancer invasion, whether there is lymph node metastasis, and judging the resectability of the tumor. CT includes plain scan CT and enhanced CT. Among them, enhanced CT is based on plain scan CT and intravenous injection of contrast agent, which can increase the local contrast and improve the diagnostic accuracy.

Ultrasound: Routine ultrasound examinations of liver, gallbladder, pancreas, spleen and kidney are performed for colon cancer to understand the metastasis and invasion of colon cancer.

Magnetic resonance imaging (MRI): The common metastasis site of colon cancer is the liver. If liver metastasis of colon cancer is suspected, doctors can use upper abdominal MRI to evaluate liver metastasis. MRI also includes plain MRI and enhanced MRI, where enhanced MRI can also improve the diagnostic accuracy.

Positron emission computed tomography (PET-CT): Doctors will use it in two situations, one is colon cancer that is suspected of metastasis; the other is postoperative examination of patients suspected of colon cancer recurrence or metastasis, which is helpful for evaluation Whether there is colon cancer metastasis in the whole body organs.

Air-barium double-contrast radiography (barium meal X-ray): Colon air-barium double-contrast radiography can find early superficial mucosal lesions, but it is more valuable in the diagnosis of advanced colon cancer, and it is more intuitive to judge the location and length of colon cancer.

Differential diagnosis

Right colon cancer should be distinguished from intestinal amebiasis, intestinal tuberculosis, schistosomiasis, appendix disease, Crohn’s disease; left colon cancer should be distinguished from hemorrhoids, functional constipation, chronic bacillary dysentery, and ulcerative colitis , Crohn’s disease, rectal polyps, diverticulitis, etc. The main identification method is colonoscopy + pathological examination.

The symptoms of left colon cancer are similar to those of rectal cancer, with obstruction, changes in stool characteristics, and blood in the stool as the main symptoms. The method of identification is digital rectal examination + colonoscopy.

Both right colon cancer and tuberculosis can have changes in bowel habits such as diarrhea and constipation, as well as symptoms such as bloating, abdominal pain, weight loss, anemia, and fever. Colonoscopy + pathological examination can distinguish these two diseases.

Treatment

The treatment of colon cancer should adopt the principle of individualized comprehensive treatment. Doctors will systematically apply a variety of treatment methods according to the patient’s physical state, tumor pathological type, and scope of invasion (stages), in order to radically cure the tumor and improve the cure. rate.

The scope of colon cancer invasion is different, and the treatment principles are correspondingly different:

Patients with very early colon cancer can obtain good therapeutic effects under endoscopic treatment;
patients with early colon cancer can achieve radical cure through surgical treatment;
patients with advanced colon cancer can be treated mainly by surgery, combined with radiotherapy, chemotherapy and targeted therapy The comprehensive treatment plan can make some patients achieve the goal of radical cure;
For patients with locally advanced colon cancer who cannot be operated for various reasons, a comprehensive treatment model with chemotherapy as the core can improve the survival of patients;
Recurrence or distant metastatic colon For cancer patients, comprehensive treatments such as chemotherapy, targeted therapy, surgery, intervention, and radiotherapy can be used to prolong the survival of patients. Most malignant tumors are generally considered to have relatively short survival if they metastasize, but if colon cancer The metastasis is relatively limited. After adopting an active treatment mode, the patient can still obtain a longer survival.

Acute treatment

If the primary colon cancer is accompanied by acute symptoms such as perforation, bleeding, and obstruction, and meets the indications for emergency surgery, emergency surgery can be considered.

General treatment

The general treatment of colon cancer needs to pay attention to nutritional support treatment. The vast majority of patients with malignant tumors have malnutrition, and patients with gastrointestinal malignancies represented by colon cancer have a higher probability of malnutrition.

The daily intake of nutrients and the intake form of the patient should be considered based on the patient’s height, weight, nutrient absorption and tolerance.

Patients with colon cancer should take care to prevent intestinal obstruction while undergoing nutritional support treatment. Therefore, they should eat a relatively easy-to-digest liquid and semi-liquid diet, and avoid eating foods that easily cause flatulence, such as soy milk, milk, etc.

In addition, pain management is also an important part of the general treatment of colon cancer patients. The doctor will conduct pain assessment, control pain, and actively prevent and deal with adverse reactions that may be caused by pain medication.

Surgical treatment

Surgical treatment is at the core of the treatment of colon cancer. Not only can early-stage patients have long-term survival after surgery, but for patients with local recurrence or distant metastasis, surgery can also be performed after treatment such as radiotherapy and chemotherapy. Get a better survival period.

Preoperative discussion

The surgeon will determine the location of the surgical opening and the method of surgery based on the patient’s condition, the location and stage of the tumor, and other diseases that the patient has in the past, and try to achieve complete resection of the tumor and regional lymph nodes.

Preoperative evaluation

Before the operation, the doctor will conduct a risk assessment of the operation, including heart function assessment, lung function assessment, liver and kidney function assessment, and nutritional status assessment.

Surgical approach

There are two types of conventional open surgery and laparoscopic surgery. In most cases, laparoscopic surgery has less trauma, faster recovery, and fewer complications than conventional open surgery. Different parts of colon cancer have different surgical methods, such as right hemicolectomy, transverse colectomy, left hemicolectomy, and sigmoid colectomy.

When choosing a surgical method, in addition to factors such as the stage of the disease, the age of the patient, and lymphatic drainage, it must also be considered to ensure that the blood supply is sufficient for anastomosis and reconstruction of the intestine after sufficient intestinal tube removal.

Postoperative care

Generally speaking, patients should fast properly after operation, and adequate parenteral or enteral nutrition support should be provided at this time; when patients recover from anal exhaust, they can consider taking food by mouth. At the beginning, they should gradually transition to a liquid diet and pay attention to eating less. Eat more meals to avoid bloating and indigestion caused by eating too much at one time.

Postoperative recovery

Respiratory function exercises should be adhered to. It is recommended that patients start spontaneous coughing, expectoration, and deep breathing immediately after the operation. The purpose is to prevent atelectasis and lung infection. In addition, patients should strive to get out of bed early to reduce intestinal adhesion and prevent Thrombus formation is conducive to postoperative recovery.

Chemotherapy

Chemotherapy refers to the use of chemical drugs to kill cancer cells to achieve the purpose of treatment. Scientific research has shown that colon cancer may have distant metastasis in the early stage of the disease, and chemotherapy can kill these distant metastatic microscopic lesions, thereby reducing the recurrence and recurrence of patients. Transfer probability.

Before chemotherapy, the doctor will evaluate the patient’s physical condition and complications. For example, perform routine blood tests, liver and kidney function, and electrocardiogram within 1 week before chemotherapy to confirm that the heart, liver, kidney, and hematopoietic functions are not abnormal, and the patient There should be no serious complications such as active gastrointestinal bleeding, gastrointestinal obstruction, perforation, embolism, and shock.

Commonly used chemotherapy drugs for colon cancer

5-Fluorouracil (5-FU) infusion, leucovorin, irinotecan, capecitabine, oxaliplatin, raltitrexed, etc.

Common chemotherapy regimens for colon cancer

Fluorouracil-based single-drug regimen (such as oral capecitabine single-drug regimen, simplified biweekly 5-FU infusion/LV regimen), CapeOx regimen (also known as XELOX regimen, refers to oral capecitabine combined with oxali Platinum), FOLFOX regimen (refers to 5-FU+ leucovorin+ oxaliplatin), FOLFIRI (refers to 5-FU+ leucovorin+ irinotecan), FOLFOXIRI regimen (refers to 5-FU+ leucovorin+ oxaliplatin) +Irinotecan). For unresectable metastatic colon cancer, cetuximab or bevacizumab can be used in combination on the basis of the above chemotherapy regimen according to the patient’s genetic examination report.

For patients with radical resection of the tumor, the chemotherapy used before surgery is called neoadjuvant chemotherapy, which can shrink the tumor, create favorable conditions for surgery, and kill micrometastasis (lesion diameter <1mm), reducing the chance of recurrence and metastasis. .
For patients with radical resection of the tumor, the chemotherapy used after surgery is called adjuvant chemotherapy. For high-risk stage II or III colon cancer patients, postoperative adjuvant chemotherapy is recommended, because postoperative adjuvant chemotherapy can improve the patient’s 3-year recurrence-free survival rate. The 3-year overall survival rate is higher than that of patients who do not receive adjuvant chemotherapy after surgery.
Chemotherapy can also be applied to patients with recurrence or metastasis after treatment, and the combination of chemotherapy and targeted drugs can greatly improve the treatment response rate and survival rate of advanced colon cancer. Active treatment of advanced colon cancer patients can significantly extend the median overall survival.
Chemotherapy can also shrink colon cancer masses and give patients who are otherwise inoperable a chance of surgery. It is a very important treatment method in the treatment of colon cancer.

Adverse Chemotherapy

Gastrointestinal reactions: chemotherapy-related nausea and vomiting can occur several hours or days after chemotherapy, and can be relieved by antiemetic drugs.
Bone marrow suppression: White blood cells, platelets, and hemoglobin may decrease after chemotherapy, and nutrition can be restored to normal after chemotherapy; if bone marrow suppression is severe, you need to go to the hospital for treatment. Liver function damage: serum aminotransferase, alkaline phosphatase, and bilirubin levels may increase after chemotherapy, indicating liver function damage.
Peripheral sensory neuropathy: Those who use oxaliplatin may develop peripheral sensory neuropathy characterized by peripheral neuritis, sometimes accompanied by spasm and sensory disturbances around the mouth, upper respiratory tract, and upper digestive tract.
Delayed diarrhea: People who use irinotecan may have delayed diarrhea. Diarrhea often occurs on the 5th day after medication and lasts for an average of 4 days.

Targeted drug therapy

The main targeted drug treatments for colon cancer are: bevacizumab and cetuximab.

Bevacizumab

A monoclonal antibody that binds to vascular endothelial growth factor (VEGF), inhibits the proliferation and angiogenesis of tumor vascular endothelial cells, and can also inhibit tumor metastasis.

Bevacizumab combined with chemotherapy has a good effect as the first-line treatment for liver metastases of unresectable colorectal cancer.

Similarly, the efficacy of bevacizumab in second-line treatment after tumor progression has also been confirmed. Chemotherapy combined with bevacizumab has a good disease control rate and conversion resection rate, and it is expected that patients who cannot be treated with surgery can obtain surgery opportunities.

However, bevacizumab can easily cause bleeding and delayed wound healing. If surgery is required after its treatment, it is recommended that the timing of the operation be 6 to 8 weeks after the last bevacizumab use.

Cetuximab

It is another monoclonal antibody that can bind to epidermal growth factor (EGF) receptors to block intracellular signal transduction pathways, thereby inhibiting the proliferation of cancer cells and inducing apoptosis of cancer cells.

Cetuximab alone or combined with chemotherapy has good clinical effects in the treatment of colorectal cancer liver metastases. However, it is currently believed that cetuximab only has a good effect on the treatment of wild-type patients with RAS and BRAF genes. Or BRAF gene mutation type patients does not improve the efficacy, it is recommended for RAS and BRAF gene wild-type patients.

Cutting-edge treatment

Immune checkpoint inhibitor therapy

Immune checkpoint inhibitors can prevent tumor cells from evading the immune system. Common immune checkpoint inhibitors are drugs that target PD-1 or PD-L1: PD-1 inhibitors, such as Pembrolizumab and Nivolumab; PD-L1 inhibitors , Such as Atezolizumab (Atezolizumab). In recent years, immune checkpoint inhibitors have achieved “miraculous effects” in diseases such as melanoma and non-small cell lung cancer.

In metastatic colon cancer, although immunosuppressants have achieved encouraging effects, they have limited benefits, and are currently only suitable for patients with high microsatellite instability or mismatch repair gene defects (MSI-H/dMMR) At present, only MSI-H/dMMR patients are recommended, but this part of patients only accounts for about 5% to 8% of all patients. More researches on immune checkpoint inhibitors for the treatment of colon cancer are still underway at home and abroad, and they are expected to become effective options for colon cancer treatment in the future.

Other treatments

Endoscopic treatment

Compared with traditional surgery, endoscopic resection of colon cancer without lymph node metastasis and precancerous lesions has the advantages of less trauma, fewer complications, faster recovery, and lower cost. For T1 early stage bowel cancer with low risk factors, the effect is similar to surgery. In principle, T1 stage lesions without lymph node metastasis or with extremely low risk of lymph node metastasis, low residual and low risk of recurrence can be first tried for endoscopic resection. If the tumor cannot be removed, or postoperative pathology suggests high-risk factors, salvage surgery is required.

Prognosis

The prognosis of colon cancer depends on factors such as the clinical stage of the disease, histopathology, and whether it can be cured by surgery. The prognosis of different stages is different.

The 5-year survival rate of patients with early colon cancer (T1 tumor confined to the mucosal layer without lymph node metastasis) can reach 90%, but there is a certain risk of recurrence, which is about 1.2% to 4.9%. For locally advanced stage II to III colon cancer patients, after comprehensive treatment such as surgery and chemotherapy, the 5-year survival rate is 50% to 78%. For patients with local recurrence or distant metastasis, surgical treatment after radiotherapy and chemotherapy can also obtain a better survival period. Patients with extensive metastasis can choose chemotherapy, targeted therapy, traditional Chinese medicine treatment and immunotherapy to prolong their survival.

Complication

Surgical complications

Intestinal perforation:

Generally, the intestinal perforation is caused by the intestinal injury during the endoscopic resection of the mass due to the large mass and deep infiltration. If intestinal perforation occurs, surgical removal of the diseased intestine should be performed.

Bleeding:

It is usually caused by inaccurate hemostasis of the operation or the loss of surgical sutures. After the operation, the patient should be observed for bleeding and changes in heart rate and blood pressure. If abnormalities are found, report to the doctor in time.

Anastomotic fistula:

It is the most serious complication after colon cancer surgery. It refers to the formation of anastomotic fistula due to incomplete intestinal anastomotic tissue caused by various reasons. The cause is patient factors, such as diabetes, malnutrition, and immunity. Defects, long-term use of hormones, large tumors, etc.; in addition, intraoperative anastomotic tension is too high, poor blood supply to the anastomosis, etc. are also causes of anastomotic leakage.

Atelectasis and pulmonary infection:

The patient’s ventilation function is affected by the long operation time, the patient’s poor respiratory function or the artificial pneumoperitoneum of the operation, resulting in atelectasis and pulmonary infection. Therefore, it is very important for patients to start early after surgery. Spontaneous coughing, expectoration and deep breathing and other respiratory rehabilitation

Recurrence/metastasis

The recurrence or metastasis of malignant tumors is an inherent feature of the disease. In theory, once a patient is diagnosed with malignant tumors, no matter how soon or late the stage is and the length of time after treatment, there is a possibility of recurrence or metastasis.

Recurrence or metastasis in patients with general malignant tumors is often a sign of poor prognosis and a short expected survival period. However, if the metastasis of colon cancer patients is more limited, active treatment may also have a better survival time.

The main ways of colon cancer metastasis are: lymph node metastasis, hematogenous metastasis and abdominal implantation metastasis. The common metastatic sites are: liver, lung, brain and bone.

The liver is the main target organ for blood metastasis of colorectal cancer. About half of colorectal cancer patients develop liver metastases during the course of the disease. About 30% of them are metachronous liver metastases found after radical resection of the primary tumor. About 25% of liver metastases were found when colon cancer was first diagnosed, which is called simultaneous liver metastasis.

For patients with liver metastases that are initially resectable and concurrent liver metastases, when the primary tumor has no bleeding, obstruction or perforation, the liver metastases are technically easy to remove, and there are no adverse prognostic factors, hepato-intestinal synchronization can be considered /Staging resection.

If liver metastases can be excised initially, but they are technically difficult to remove, and there are adverse prognostic factors, neoadjuvant therapy can be performed first for liver metastases, followed by selective liver metastasis resection.

If liver metastases are not resectable at the beginning, conversion therapy can be considered to try to turn “unresectable” into “resectable”. Generally speaking, the prognosis of patients who can successfully remove liver metastases can be significantly improved compared with those who cannot be removed.

Daily care

Daily life care of colon cancer is very important to the survival and prognosis of patients. Nutritional support treatment and rehabilitation exercises for colon cancer patients are related to the severity of postoperative complications, the speed of physical recovery and the length of survival.

In addition to the patient’s self-management, the patient’s family should pay attention to the patient’s timely monitoring of changes in the condition, regular follow-up visits, and promptly seek help from the doctor if they feel unwell.

Home care

Patients should eat foods that are easy to digest and have less residue, such as egg custard, minced meat, and enteral nutrient solutions. They should maintain unobstructed stools and eat melons and vegetables. After that, gradually transition to a normal diet and eat more fiber-rich foods such as green leafy vegetables.

Colon cancer patients are often accompanied by digestion and absorption disorders or diarrhea leading to insufficient nutrition, water and electrolyte intake, etc. You can increase the intake of salt and protein substances in the usual diet based on the results of blood tests.

The care of the fistula is an important part of the home care of colon cancer patients. Patients and their families should learn about the care of the fistula, dressing changes, and replacement of drainage bags.

It is necessary to create a comfortable and relaxed family environment, pay attention to the mental state of patients, avoid increasing the psychological burden of patients, and give patients sufficient psychological comfort.

Daily life management

Maintain a relaxed and happy mood and establish a regular life routine.
Appropriate exercise, such as slow walking and other aerobic exercises.
Avoid overwork and colds.
Keep drinking water.
Quit smoking and limit sugar, avoid irritating drinks such as alcohol.
Eat meat, eggs, milk and other high-quality protein foods appropriately, increase the intake of fresh vegetables and fruits, and avoid excessively greasy foods.

Daily condition monitoring

The monitoring of stool traits and bowel habits is an important part of the monitoring of the condition of colon cancer patients. If there are blood in the stool, diarrhea, fever, etc., changes in the condition may occur and prompt medical treatment is required.

Body weight is an important indicator to measure changes in the condition and recovery of patients with colon cancer. Patients with colon cancer should monitor their weight changes. If there is no obvious cause of weight loss, they should seek medical attention in time.

Regular follow-up is recommended after treatment for colorectal cancer:

Regular CEA and CA19-9 monitoring, once every 3 to 6 months, for a total of 2 years, then once every 6 to 12 months, for a total of 5 years, and once every 1 to 2 years after 5 years.
CT or MRI of the chest, abdomen, and pelvis is performed once every six months for 2 years, and then once a year for 5 years.
It is recommended to perform colonoscopy within 1 year after surgery. If full colonoscopy cannot be performed due to tumor obstruction before surgery, check it 3 to 6 months after surgery; each time colonoscopy is found to have advanced adenoma (villous adenoma, diameter ＞1cm, or high-grade dysplasia), need to be re-examined within 1 year; if no advanced adenoma is found, re-examination within 3 years, and then every 5 years.
PET-CT is not a routinely recommended examination item. For patients who have or are suspected of having recurrence and distant metastasis, PET-CT can be considered, and recurrence and metastasis can be excluded by examination or imaging.

Special attention items

Patients with colon cancer should pay special attention to their diet, because after surgery, chemotherapy and other treatments, colon cancer patients will cause intestinal stenosis, intestinal peristalsis dysfunction and intestinal adhesions to a certain extent. When eating foods that are easy to digest and have less residue, they should be maintained. Unobstructed stools, be alert for intestinal obstruction. If symptoms such as abdominal distension, abdominal pain, anus stop to pass gas and defecation, nausea and vomiting, etc., you should consult a doctor promptly.

Prevention

Preventive measures for colon cancer are mainly to avoid some high-risk factors, such as quitting smoking, avoiding fried foods, changing bad eating habits, increasing dietary fiber and vitamin intake, appropriately increasing physical exercise and maintaining a happy mood, etc., which can be seen in daily life management Partial description.

In addition, colon cancer screening of the population can detect colon cancer or precancerous lesions at an early stage, play a role in early diagnosis and treatment and prevention, improve the quality of life of colon cancer patients and increase the effectiveness of treatment.

According to the newly updated colorectal cancer screening guidelines of the American Cancer Society (ACS), it is recommended to start colorectal cancer screening at the age of 45, and it is strongly recommended that adults over the age of 50 undergo regular colorectal cancer screening.

The guidelines also recommend an annual fecal occult blood test, or a multi-target fecal DNA test every 3 years, or a sigmoidoscopy every 5 years, or a full colonoscopy every 10 years. The examination method can be selected according to the preference of the examinee, but it must be noted that if the stool examination has a positive result, colonoscopy is required to further confirm the cause.

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