Colon cancer: symptoms, signs, treatment, stages
Malignant tumors of various parts of the gastrointestinal tract are quite common, while colon cancer accounts for about one third of all cases, with half of them localized in the rectum. Symptoms of colon cancer are varied and often nonspecific, so patients do not always rush to the doctor.
As a rule, the disease is recorded in patients older than 50 years, however, and at a younger age the probability of occurrence of neoplasia exists. So, young people 20-30 years malignant intestinal tumors are found in 7% of cases, therefore, the appearance of dangerous symptoms age need not be the «soothing» factor that will allow us to postpone the visit to a specialist.
There is an opinion that most colorectal cancer is diagnosed in men, however statistics this conclusion is not backed up, and the tumors occur equally often in both sexes.
Speaking of bowel cancer usually refers to colonic localization of the tumor. Most commonly affects the rectum and sigmoid and blind. You may experience lesions in areas of the natural curves of the intestine in the hepatic and splenic angles. It happens so because in these departments is carried out the most prolonged contact of the intestinal mucosa with the stool, especially when constipated. In addition, if you change the consistency of the intestinal contents in the direction of a more dense, possible trauma to the mucosa with its promotion, especially in those areas where the lumen of the intestine in a natural way narrows (flexure of the colon in the liver and spleen).
Cancer of the small intestine – a rare phenomenon. Among the reasons is possible to distinguish inflammatory processes, genetic abnormalities, and exposure to carcinogens from food. Symptoms in the initial stages of disease is lacking or is very similar to the manifestations of inflammatory processes (enteritis), Crohn’s disease, celiac disease (gluten intolerance with the development of enteropathy). In such situations, patients may not be aware of the possibility of growth they have a malignant tumor.
Among patients dominated by men, and in women, cancer of the small intestine diagnosed slightly less often.
As a rule, is affected the initial division of the jejunum or ileum final portion, though perhaps the development of cancer of the duodenum, especially if it is ulcerative lesions. Because ulcers are accompanied by chronic relapsing inflammation with subsequent scarring at the edges of the defect, an incomplete regeneration of the mucosa with the formation of polyps, cancer risk increases, therefore, such patients should receive regular examinations by a gastroenterologist, even in the absence of obvious signs of exacerbation of the ulcers.
Due to the fact that colon cancer is more common than thin, it will be discussed below.
Causes and risk factors for tumors of the intestine
The question of the origin of colorectal cancer is still controversial, and the single factor causing the tumor is not named. In most cases a combination of causes, which have an adverse effect on the intestinal mucosa. So, the main reasons can be considered:
- Genetic predisposition (genetic mutations and anomalies);
- The presence of chronic inflammatory processes in the mucosa of the intestine;
- Polyps or polyposis of the intestine;
- Infringement of a motility (constipation).
- The intake of carcinogens outside with food and water.
In addition to these reasons, to promote colorectal cancer can overweight physical inactivity (lack of exercise), old age, often accompanied by constipation and sluggish chronic inflammation of the intestine.
It is known that diet has a direct impact on the condition of the mucous membrane of the colon. Eating large amounts of meat products and the decline in the proportion of fiber, vegetables and fruits, use in the diet of refined oils and carbohydrates inevitably leads to the formation and accumulation in the intestinal contents of the various products of nitrogen metabolism, fatty acids and other substances with carcinogenic properties. In addition, a lack of fiber leads to slower passage of well formed stool in the intestine that greatly increases the contact time of harmful substances with the mucosa.
It is noticed that in countries where the eating habits are to eat mostly plant foods (India, Africa), the proportion of colon cancer among other malignancies is much lower than in those regions where the diet of the inhabitants is dominated by meat and animal fats. This once again proves the role of the nature of food, the possibility of formation of colorectal cancer.
It is believed that for the prevention of tumors of the colon daily you should consume about 200 grams of fresh vegetables and fruits. In the diet should also include bran cereals, bread from wheat flour, etc. These products help to increase stool bulk, which in turn enhances the motility and rate of movement of contents through the intestines, preventing constipation.
About the possibility of a genetic predisposition is evidenced by familial cases of the disease, and among close relatives of the patient the risk of cancer is much higher. Moreover, scientists have identified a number of genes involved in the mechanisms of carcinogenesis (development of cancer). Long been known and described hereditary syndromes accompanied by polyposis of the intestine, inevitably turning into cancer (syndrome Patna-Jeghers, familial diffuse polyposis, etc.).
Chronic inflammation (colitis) to create an unfavorable background when there is permanent damage of the epithelium covering the inner surface of the bowel wall. In the result long current inflammation of disturbed natural regeneration of the mucosa, there are scars and foci of atrophy, which subsequently may become the source of tumor growth. A special role among these processes play a nonspecific ulcerative colitis and Crohn’s disease, which are accompanied by pronounced inflammatory infiltration, ulceration of the bowel wall, scarring with narrowing of the lumen and the appearance of dysplasia of the mucosa.
Colon polyps represent focal protrusions of the mucosa. Not being a tumor, they, nevertheless, can be transformed into cancer. Often polyps are found in the elderly, and the risk of malignancy is directly linked to their size and appearance. It is believed that a polyp over 2 cm in greatest dimension has a fairly high probability of turning into cancer, and the so-called villous polyps, the risk of malignancy is up to 50%. Some patients may occur several polyps at the same time or even a lot of them in different parts of the intestine. This fact explains multicentric cancer growth when there are several isolated tumor foci.
Many patients who have found out a polyp of a section of the intestines start to panic, afraid of getting cancer, but it is worth remembering that early detection and removal of such entities of the intestinal wall is effective for the prevention of a malignant tumor.
Violation of intestinal motility provoked constipation, often leading to changes in the mucosa due to stagnation of feces. In addition to the prolonged contact of the intestinal content, containing aggressive and carcinogenic substances from the inner surface of the intestine, is also important to her injury dense fecal masses, especially in the hepatic and splenic angles.
Receipt of carcinogens from food is gaining clinical importance because of the changing eating habits of people in recent years, the proliferation of fast food, refined foods, etc, along with meats, vegetables grown with the use of different pesticides in the intestines can do benzpyrene, aromatic hydrocarbons, nitrogen-containing compounds with a powerful carcinogenic effect.
In addition to the above reasons, a specific value can have the presence of diverticula – protrusion wall of the intestine, accompanied by chronic inflammation, however malignancy observed rarely.
Characteristics of growth and varieties of colorectal cancer
Like any other malignant tumor, colon cancer, capable of Autonomous growth, is characterized by marked atypia of the cells and their uncontrolled division with the loss of normal tissue differentiation, but there are some features:
Depending on the nature of growth in relation to the intestinal wall, it is customary to distinguish exophytic, endophytic form of cancer and mixed. For cancer of the cecum and right half of the colon is more typical exophytic type of growth, when the tumor protrudes into the lumen of the organ. In the left half of the colon occur most frequently endophytic, or infiltrative forms, in which neoplastic tissue grows the thickness of the intestinal walls and cause narrowing and deformation of the intestine. With the combination of features of both variants of growth talk about the mixed form of cancer.
A very important value in determining prognosis, the characteristics of the course and possible treatment plays a histological structure of malignant tumors of the colon and the degree of differentiation.
Thus, in accordance with the International classification, there are:
- Colloid cancer;
- Signet ring cell;
- Undifferentiated and unclassified forms.
Most often (about 80% of cases) is diagnosed with adenocarcinoma – a glandular cancer originating from the epithelium of the intestinal mucosa. Such tumors are high — moderate — and nizkoeffektivnyj that determines prognosis. Signet ring cell carcinoma frequently affects young people, and squamous often localized in the rectum.
As with other malignancies, in accordance with the TNM classification of stages of disease, determined by the nature of the growth of the tumor and presence of metastasis. Accurate diagnosis with indication of phase is possible only after surgical treatment with removal of the affected portion of the intestine, lymph nodes, tissue and subsequent histological examination.
The spread of cancer cells throughout the body takes place in accordance with the basic laws of metastasis. Through the lymph vessels cancer cells reach the lymph nodes located along the bowel, and then are recorded in mesenteric, para-aortic, and other groups.
The bloodstream metastases are the liver, lungs, bones. Feature of colorectal cancer is very early liver injury, which is associated with the outflow of venous blood through the portal system from the intestine for disposal in the liver.
The so-called implantation metastases occur during germination by the tumor of the entire thickness of the bowel wall and the presence of cancer cells on the peritoneum. The appearance of tumor lesions in the serous membrane is called carcinomatosis. This phenomenon is often accompanied by accumulation of fluid in abdominal cavity – ascites.
Signs and symptoms of colon cancer
Symptoms of colon cancer is quite varied and, however, non-specific, so it is not always possible to suspect a tumor, especially in the early stages. Manifestations of the disease is often reduced to diarrhoeal disorders, pain in the abdomen, the appearance of impurities of blood, mucus and even pus in the stool.
First signs of colon cancer can be loss of appetite, abdominal discomfort, fatigue, irritability, with clear symptoms of a malignant tumor may be a long time absent, and the doctor often requires very carefully to inquire the patient about any complaints.
In General, symptoms of colon cancer are confined to a:
The nature of the pain syndrome depends on the growth of the tumor and its location in the gut. Possible aching, dull or paroxysmal acute pain that requires emergency hospitalization and surgical care. So, cancer of the sigmoid colon and the descending division of the colon due to the high likelihood of developing intestinal obstruction often is accompanied by severe pain, whereas right-sided localization of the disease usually causes aching pain.
Discomfort and intestinal disorders usually accompanied by a variety of inflammatory processes and functional disorders of intestinal motility and even neuroses, therefore, should be subjected to particularly careful examination by the doctor. Symptoms such as rumbling in the abdomen, discomfort and the severity of various violations of the chair in the form of diarrhea, constipation or alternation, painful bowel movements makes the majority of patients. Symptoms are more pronounced when left-sided localization of the tumor.
Cancer of the left half of the colon has a tendency to infiltrative growth, resulting in a relatively short period of time to a narrowing of its lumen and the obstruction of the passage of the stool, so one of the first signs of colon cancer can be acute obstructive intestinal obstruction. The patient may suddenly find themselves on the operating table, unaware of the growth opportunity himself of a malignant tumor.
Pathological impurities in the stool more frequently with the defeat of the ultimate divisions of the colon and rectum. Maybe the appearance of blood, mucus or pus. In cases of bleeding need to differentiate them with those of hemorrhoids when fresh red blood covers detachable intestines, not mingling with them and appearing at the end of defecation. When tumors of the right half of the colon, the blood may not be detected even with the naked eye, however, this study confirms its presence. Mucus appears in the presence of concomitant inflammation or colloid cancers with a pronounced sliseobrazutee by tumor cells. The admixture of pus in their stool – a clear sign of secondary infection collapse of the tumor.
The change in the General condition of the patient occurs when the majority of malignancies, and in cancer of the bowel these symptoms are more pronounced in connection with the violation of absorptive function of the intestinal wall. Patients complain of fatigue, feeling of weakness, decreased performance, and even dizziness. With an increase of symptoms of intoxication by metabolic products of the tumor, the development of anemia the patient’s condition progressively worsens, reduced weight, and the diagnosis of a malignant tumor is virtually certain.
Symptoms of rectal cancer can have some of the features. So, bleeding is the most common and fairly constant feature of the disease. In addition, patients experience pain and a false urge to defecate, feeling of a presence of a foreign body in the rectum.
Video: symptoms of colon cancer
Ways to detect colon cancer
Since there is no symptom, strictly indicate the presence of colon cancer, all cases of treatment of patients with complaints of violations of the intestine should be seen as a possible tumor. In compliance with algorithm of examination of a patient and use all currently available methods, a reliable diagnosis can be made even at the earliest stages.
The scan search starts with detailed explanation of nature of complaints, specify the presence of patients colorectal cancer among close relatives. Special attention is paid to patients with previous inflammatory processes of the bowel, polyps. Next, the doctor performs the inspection, palpation (sometimes the tumor can be felt through the abdominal wall). In all cases, the initial examination the doctor performs a digital rectal exam.
From the instrumental methods is most informative:
- Ultrasound examination of abdominal cavity and small pelvis – to clarify the nature of the tissue changes in the locus of growth of the tumor, presence of metastatic lesions to the liver, etc.;
- Sigmoidoscopy and colonoscopy – possibility of using optics to examine the intestinal mucosa, and if necessary allow you to take pieces of tissue (biopsy) for histological examination;
A special place is occupied by radiological methods – barium enema, review the abdomen with contrast enhancement, irrigography. To carry out these procedures use a contrast agent is a suspension of barium taken by mouth or introduced by enema. Additionally, the intestine can be put on air. In the images you can see the narrowing of the lumen of the intestine, filling defects, the penetration of contrast beyond the organ in the case of the formation of sinus tracts when the entire tumor invasion of the bowel wall.
The result of imaging studies depends on patient preparation, his diet before the study, and the observance of all necessary conditions and procedures is the key to a correct diagnosis, because errors in diagnosis are possible.
Among laboratory investigations include blood test, fecal occult blood, and it is possible to identify cancer-embryonic antigen.
In difficult or advanced cases, CT and MRI.
The important point of diagnosis is a biopsy for histological examination, which allows to determine the type, structure of the tumor, degree of differentiation and depth of penetration into the bowel wall.
Methods for the treatment of colorectal cancer
The treatment of colon cancer is primarily surgical removal of the tumor. It is the most effective and essential component in the fight against the disease. The amount of operation is determined by the tumor localization, its size, and the degree of damage to the surrounding tissues and the presence of metastases.
Malignancy blind, ascending colon and hepatic angle is most often used to remove the entire right half of the colon – right hemicolectomy. If the tumor is located in the splenic angle, descending colon, then make a left hemicolectomy with subsequent connection of the transverse colon and sigmoid colon.
In case of detection of cancer in the transverse colon or the sigmoid remove fragment of the body – resection.
Surgery on the intestine can be done in several stages, the intermediate will have the colostomy on the anterior abdominal wall for a temporary evacuation of the bowel through the hole formed. Subsequently, this treatment ends with reconstructive surgery with the aim of preserving the natural passage contents to the anal canal.
In severe cases removal of the tumor may be accompanied by considerable difficulties and be very traumatic for the patient. In case of impossibility of adequate operative treatment palliative surgery consisting in the imposition of detours outflow of intestinal contents, bypassing the tumor Department.
As an additional method of treatment, especially after palliative surgery, is chemotherapy.
The most difficult and traumatic are considered to be operations on the rectum. In case the location of the tumor in the middle and upper part allowed the resection of the organ with preservation of the anal sphincter, but it is often necessary to remove the entire rectum with formation of a colostomy later in the crotch area for removal of feces.
Such interventions significantly reduce the quality of life of patients and hamper normal adaptation, therefore, often complemented by plastic and reconstructive surgery, allowing to reconstruct the sphincter of the rectum and to maintain the act of defecation, close to natural.
The survival rate for colon cancer may reach 70% after radical surgery, however, the presence of metastases reduces this figure by half.
Food for bowel cancer should be gentle in nature. Should avoid foods that increase flatulence and stimulating peristalsis – fresh vegetables, legumes, sweets. Special care must be exercised to the diet in the early postoperative period, when the healing stitches on the walls of the colon.
Folk remedies in malignant tumors, are not the panacea that will eliminate cancer without the help of professionals, so should not get involved self-medicate in order not to lose time and not to cause harm to the body. A favorable outcome in colorectal cancer is possible only with timely treatment from specialists for cancer.
The prognosis of bowel cancer depends on the stage at which the disease was detected. Thus, when the initial tumor patients live long, while the rate for five-year survival rate reaches 90%, while in the presence of metastases, it leaves not more than 50%. The most unfavorable prognosis in advanced cases, as well as a significant lesion of the rectum, especially in the distal.
It is important to remember that with any illness can be fought, and the effectiveness of the treatment depends on how quickly the patient seeks help, therefore, the appearance of any symptoms, be sure to consult a doctor, do not delay your visit to him and not self-medicate.