What is Colon Cancer?

Colon cancer is a common malignant tumor of the digestive tract that occurs in the colon. It occurs at the junction of the rectum and the sigmoid colon. The incidence rate is highest in the 40-50 age group, and the male to female ratio is 2 to 3: 1. The incidence of gastrointestinal tumors ranked third. Colon cancer is mainly adenocarcinoma, mucinous adenocarcinoma, and undifferentiated cancer. The general morphology is polypoid and ulcerative. Colon cancer can develop along the intestinal wall, spread up and down along the longitudinal diameter of the intestine, or infiltrate deep into the intestinal wall. In addition to lymphatic, blood flow and local invasion, it can also be implanted into the abdominal cavity or spread along the suture or incision surface. . Patients with chronic colitis, patients with colon polyps, and obese men are susceptible groups.

Basic Information

English name

colon cancer

Visiting department

Oncology

Multiple groups

Patients with chronic colitis, family history of familial multiple bowel polyps and colon cancer

Common locations

colon

Common causes

High-fat recipes with insufficient fiber intake

Common symptoms

Bloating, indigestion, mucus or purulent bloody stools

Contagious

no

Causes of Colon Cancer

Colon cancer is mainly associated with a high-fat and low-fiber diet. Chronic inflammation of the colon causes a higher incidence of bowel cancer than the general population. With colon polyps, the incidence of colon cancer is five times higher than that without colon polyps. Familial multiple bowel polypoma has a higher incidence of canceration. Genetic factors may also be involved in the development of colon cancer.

Clinical manifestations of colon cancer

There can be no symptoms in the early stages, and abdominal distension and indigestion can be manifested in the middle and late stages, followed by changes in bowel habits, abdominal pain, mucus or bloody stools. After tumor ulceration, blood loss, and toxin absorption, symptoms such as anemia, low fever, fatigue, wasting, and lower limb edema often occur. If abdominal distension, abdominal pain, constipation, or inability to defecate, physical examination shows abdominal distension, bowel type, local tenderness, auscultation, and bowel sounds, suggesting that incomplete or complete bowel obstruction may occur. If the tumor infiltrates and adheres to the omentum and surrounding tissues, an irregular mass is formed. In the later stage, liver, lung metastasis signs such as jaundice, peritoneal effusion, and edema, cachexia, swollen supraclavicular lymph nodes, and other metastatic tumors may appear. The clinical manifestations of different colon cancer sites are as follows:

Right colon cancer

The right semicolonic cavity is large, the stool is liquid, and the tumors are mostly ulcerous or cauliflower-like cancers, which rarely form ring-shaped stenosis and obstruction rarely occurs. If the cancer ruptures, bleeds, and bleeds, secondary infections are accompanied by toxin absorption, and may include abdominal pain, stool changes, abdominal mass, anemia, weight loss, or cachexia.

2. Left colon cancer

The left semicolon has a small bowel cavity and dry stools. Left colon cancer is often infiltrating, and can easily cause annular stenosis, which is mainly manifested by acute and chronic intestinal obstruction. The mass of the mass is small. It has neither ulceration and bleeding nor absorption of toxins. Rare anemia, weight loss, and cachexia are difficult to spread. Colon cancer often has organ metastases, and distant metastases are mainly liver. Lymphatic metastasis generally spreads from near to far, and there are out-of-order metastases. Lymphatic metastasis is more likely after a cancer invades the intestinal muscularis. Colon cancer cells or cancerous emboli can also be transferred through the blood, first to the liver, and then to lungs, brain, bone, and other tissue organs. Colon cancer can also directly infiltrate surrounding tissues and organs, fall out of the intestinal cavity, and can be implanted on the mucosa elsewhere. Those who spread to the entire abdomen can cause cancerous peritonitis and peritoneal effusion.

Colon cancer test

1. Digital anal examination and rectal microscopy

Check for rectal polyps, rectal cancer, internal hemorrhoids, or other lesions.

2.Sigmoidoscopy and fiber colonoscopy

Microscopic examination can find cancer, observe its size, location and local infiltration range.

3. Plain film of abdomen

Applicable to the case of acute intestinal obstruction, the colon above the obstruction site is inflated and swollen.

4. Barium enema

It can be seen that the intestinal wall of the cancerous area is stiff, poorly dilated, the peristalsis is weakened or disappeared, the shape of the colonic bag is irregular or disappeared, the intestinal cavity is narrow, the mucosal folds are disordered, destroyed or disappeared, and the filling defect is etc. Barium air double contrast imaging is more helpful for the diagnosis of pedicled tumors in the colon.

5. Carcinoembryonic Antigen (CEA)

It is of little value in the diagnosis of early tumors, and has certain help in inferring prognosis and judging recurrence.

Colon cancer diagnosis

The early symptoms of colon cancer are often insignificant and often missed. For middle-aged and older patients, a careful history and physical examination should be carefully examined. The possibility of colon cancer should be considered when the following symptoms occur:

1. Recent changes in bowel habits and persistent abdominal pain.

2. The fecal occult blood test continued to be positive.

3. Feces are thin or carry blood and mucus.

4. The abdomen can be palpable.

5. Unexplained weakness, anemia, weight loss, etc.

Differential diagnosis of colon cancer

Colon benign tumor

The course is long, the symptoms are mild, X-ray shows local filling defects, regular morphology, smooth surface, sharp edges, intestinal cavity is not narrow, and the colon bag is intact.

2. Colitis disease

Refers to tuberculosis, schistosomiasis granuloma, ulcerative colitis, dysentery and other intestinal inflammatory lesions, each with its own history. Stool microscopy can have its special findings. X-ray examination of the affected bowel is longer. Colonoscopy and histopathological examination are also different, which can further confirm the diagnosis.

3. Other

Colonic spasm: X-ray examination shows a small intestinal stenosis, which is reversible.

Appendiceal abscess: A history of appendicitis, with a mass in the abdomen, but an X-ray shows that the mass is outside the cecum

Colon Cancer Treatment

Endoscopic minimally invasive treatment of early cancer can be treated with endoscopic minimally invasive treatment. The treatment of advanced cancer is based on surgery, supplemented by chemotherapy, immunotherapy, Chinese medicine and other supportive treatments to improve the surgical resection rate. Reduce relapse rate and improve survival rate. Principles of surgical treatment: try to cure as much as possible, protect the pelvic vegetative nerve, preserve sexual function, urination function and defecation function, and improve the quality of life. The surgical method is as follows:

1. Right hemicolectomy is applicable to cancers of the cecum, ascending colon, and colonic liver curvature.

2. Left hemicolectomy is suitable for cancer of descending colon and spleen flexure of colon.

3. Transverse colonectomy is suitable for transverse colon cancer.

4. In addition to resection of the sigmoid carcinoma, sigmoid colon cancer should also be performed in descending colon resection or partial rectal resection.

5. The principle of surgery with intestinal obstruction, the patient's condition allows, can be used for one-stage resection and anastomosis. If the patient is in poor condition, a colostomy can be performed first, and a second-stage radical resection is performed after the condition improves.

6. The principle of surgery that cannot be used for radical surgery. When the tumor is widely infiltrated or cannot be removed from the surrounding tissues and organs, the bowel is obstructed or may be obstructed. It can be used for short circuit surgery or colostomy. If distant organs metastasize and local tumors are still allowed to be removed, local palliative resection can be used to relieve symptoms such as obstruction, chronic blood loss, and infection.