Colon cancer, according to statistics, is the second most common oncological disease localized in the gastrointestinal tract. In addition, this disease occupies 5-6% of all oncological pathologies. Over the past few decades, there has been an increase in the incidence of this type of cancer among both sexes. The risk is especially high for people over 55 years of age. The number of deaths from colon cancer is also on the rise. Within two years, 85% of patients die from the disease.
Colon cancer is most common in developed countries where people have a preference for unhe althy, refined foods. This disease is most common in Australia and North America. The disease is somewhat less common in Europe, and in Asian countries, Africa and South America it is very rare. In our country, a similar diagnosis is made in about 17 cases per 100,000 people.
Localization
Colonthe intestine is the largest section in the large intestine, in which feces are formed from liquid chyme. This area of the intestine is actively involved in the work of the gastrointestinal tract, so congestion in it is highly undesirable. Eating a large number of refined foods, toxic additives cause various malfunctions in the functioning of the intestines, the development of polyps and the growth of adenomas, which can subsequently become malignant.
The colon is located directly behind the caecum and includes several sections: ascending, transverse, descending and trailing. There are quite a few vulnerable and sensitive places in the colon. These are, for example, various bends and narrowings due to physiology, in which stool masses tend to accumulate and stagnate. In half of the cases, the tumor is localized in the sigmoid colon. In 23% of cases, the caecum is affected. Other departments are affected less frequently. But cancer of the ascending colon is diagnosed frequently.
Reasons
The exact causes of the development of such cancer have not been established. However, there are a number of factors that have been proven to provoke the reproduction of malignant cells. Among them:
- Genetic predisposition. The incidence of this form of cancer among close relatives is increasing significantly.
- Unbalanced diet, eating refined foods and animal fats.
- Inactive lifestyle, lack of physical activity,overweight, physical inactivity.
- Constipation in a chronic form. In this case, the risk of injury to the intestinal folds by excessively dense feces increases.
- Hypotension and intestinal atony in the elderly.
- History of precancerous diseases such as familial polyposis, Crohn's disease, diverticulosis, non-specific ulcerative colitis, single adenomatous polyps.
- Age of the patient. The incidence is increasing among patients older than 50.
- Working in hazardous working conditions at work.
Types and stages
The mucous membrane that envelops the colon consists of the so-called glandular epithelium. In the vast majority of cases, cancer of the transverse colon is diagnosed by the following varieties:
- Adenocarcinoma. Neoplasm arises from epithelial cells.
- Mucoid adenocarcinoma. A malignant neoplasm containing a large amount of mucus.
- Ricoid cell carcinoma. Cancer cells are shaped like vesicles that are not connected to each other.
- Squamous or glandular-squamous. This type of tumor is based on squamous epithelial cells or its glandular variety.
- Undifferentiated carcinoma.
It is generally accepted to divide colon cancer into the following stages:
- Zero. Only the mucous membrane is affected, there are no signs of infiltrative growth, as well as metastasesand disorders in the lymph nodes.
- First. It is characterized by the development of a small tumor of the primary type, which is formed in the mucous or submucosal thickness. There are no regional or distant metastases.
- Second. The neoplasm does not occupy the semicircle of the intestinal wall, does not involve adjacent organs, and does not extend beyond the intestine. Perhaps the appearance of metastases in the lymph nodes.
- Third stage of colon cancer. The tumor begins to grow into the entire thickness of the intestinal wall, affecting neighboring organs. Metastases are multiple, however, localized only in the lymph nodes.
- Fourth. The tumor affects adjacent organs, has a large size. There are multiple metastases, including distant ones.
Signs and forms
The symptomatic picture depends on the type of neoplasm and its localization, as well as on the stage of development and size. The first stages of colon cancer proceed, as a rule, in a latent form, and the disease is detected during a routine medical examination when diagnosing other pathologies. Many patients, when contacting a doctor, complain of constant constipation, soreness and discomfort in the intestines, general weakness and deterioration in he alth.
If the neoplasm is localized in the right side of the colon, then patients often complain of dull pain in the abdomen, malaise and weakness. The examination shows a moderate degree of anemia, while even at an early stage of the development of the diseasepossible palpation of the tumor.
For left-sided localization of cancer of the ascending colon is characterized by: dull pain, as well as flatulence, bloating, rumbling, regular constipation. The stool looks like sheep droppings, and traces of mucus and blood can be seen in it.
Pain is caused by the inflammatory process and can have a different character, pulling, sharp, cramping in the case when intestinal obstruction occurs. Patients complain of nausea, loss of appetite, belching, feeling of heaviness in the abdomen. Inflammation in the intestinal wall provokes narrowing and dysmotility, which leads to alternating constipation and diarrhea, bloating and rumbling in the abdomen. The collapse of the tumor leads to the appearance of blood, pus and mucus in the feces. Intoxication of the body increases, which is manifested by fever, weakness, anemia, fatigue and weight loss.
It is important to recognize the symptoms of colon cancer in a timely manner.
Medicine distinguishes several main forms of oncology, each of which is characterized by a certain set of symptoms:
- Obturation. The main symptom is intestinal obstruction. Partial blockage leads to rumbling, a feeling of fullness, cramping painful attacks, difficulty passing gases and feces. With the narrowing of the intestinal lumen, acute obstruction develops, which requires surgical intervention.
- Toxico-anemic. This form is characterized by weakness and anemia, fatigue and pale skin.
- Dyspeptic. Presents with nausea and vomitingbelching, soreness in the upper abdomen, aversion to food, bloating and heaviness.
- Enterocolitic. It is characterized by intestinal disorders, when diarrhea alternates with constipation, patients complain of a feeling of fullness, bloating and rumbling of the abdomen, as well as dull pain. Blood and mucus appear in the feces.
- Pseudo-inflammatory. Accompanied by severe pain in the abdomen, fever. Intestinal disorders are slightly expressed. ESR and leukocytes increase in the blood.
- Tumorous. Symptoms of colon cancer are mild or absent. In this case, the neoplasm can be palpated.
Complications
In the absence of appropriate treatment, symptoms increase over time, and further progression of the disease leads to complications such as intestinal obstruction, abscess, phlegmon, bleeding, perforation of the intestinal walls with peritonitis, etc.
Intestinal obstruction is caused by the neoplasm blocking the intestinal lumen. This complication occurs in 15% of patients. Most often it is observed with left-sided localization of the tumor in the colon.
Inflammatory process in cancer of the hepatic flexure of the colon is observed in about every tenth case and takes the form of phlegmon or purulent abscess. This is most often manifested in neoplasms of the caecum or ascending sigmoid colon. This process is provoked by the entry of pathogenic microorganisms through the lymph nodes into the surrounding tissues.
Perforation of the intestinal wall is quite rare, however, this is exactly whatcomplication can lead to death. The rupture causes ulceration of the tumor and its disintegration. The contents of the intestine enter the peritoneum and cause peritonitis. When the contents of the intestine enter the fiber behind the intestine, an abscess or phlegmon occurs.
In some cases, growth of neoplasm and damage to hollow organs is possible, which causes fistulas. Complications significantly worsen the overall prognosis for patients with transverse colon cancer.
Diagnosis
Identification of a tumor in the colon is impossible only taking into account the collected history and examination of the patient. External signs of the presence of a neoplasm, as a rule, are absent. On examination, the specialist evaluates the physical condition of the patient, bloating, pallor of the skin, palpation may reveal the presence of fluid in the peritoneum. Palpation of the neoplasm through the abdominal wall is possible only with a large tumor size. To clarify the diagnosis, it is necessary to conduct a thorough examination using both instrumental and laboratory types of research.
Laboratory methods for diagnosing colon cancer include blood sampling for biochemical analysis to detect specific antigens, as well as stool testing for occult blood.
Instrumental research methods are:
- Sigmoidoscopy. Allows you to assess the condition of the intestinal sections. The simplest and most common research method.
- Colonoscopy. Methodresearch through an endoscope, which makes it possible to carry out a visual examination of the intestine and take material for histological analysis.
- X-ray examination. It is carried out using a barium suspension. A contrast agent is administered with an enema or by mouth, after which pictures are taken. This study allows you to determine the size and shape of the neoplasm, the presence of expansion or narrowing of the intestine.
- Ultrasound and computed tomography. With their help, it is possible to clarify the extent of the tumor and to obtain an image of the anatomical structures. These methods are absolutely safe and painless.
Colon cancer treatment
Treatment is carried out exclusively by surgical methods. At the same time, in addition to radical surgery, chemotherapy and radiation therapy are also carried out.
The therapeutic scheme and type of surgical intervention is appointed by a specialist oncologist, taking into account a combination of many factors. The type of neoplasm and its localization, the stage of tumor development, the presence of metastases and complications, as well as the patient's age and general he alth are taken into account. If complications and metastases are absent, then radical methods are preferred. The affected parts of the intestine are removed along with the regional lymph nodes and the mesentery.
With right-sided localization of the neoplasm, the so-called hemicolectomy is performed. As a result of such an operation, the caecum is removed, as well as the ascending and third parttransverse colon together with part of the terminal ileum. Along with these manipulations, the removal of regional lymph nodes is performed. Next, an anastomosis is formed, that is, the small and large intestines are connected.
If the colon is affected on the left side, an appropriate hemicolectomy is performed, oriented to this side. In this case, a third of the transverse and the entire descending colon, part of the sigmoid colon, the mesentery and lymph nodes of the regional type are removed. Finally, as in the previous case, an anastomosis is formed.
If the neoplasm is small and localized in the middle of the transverse colon, a resection is performed, into which the omentum and lymph nodes fall. If the tumor is found in the middle and lower part of the sigmoid colon, resection of the mesentery and lymph nodes is performed. Next, an anastomosis is formed.
If a malignant neoplasm has affected neighboring organs and tissues, a combined operation is performed to remove the affected areas.
If the cancer is found in an advanced form and is not operable, then a palliative operation is performed. For this purpose, bypass anastomoses or a fecal fistula are performed. This helps to prevent intestinal obstruction, since this complication greatly weakens the patient's body and worsens the conditions for surgical intervention. When prescribing any surgical procedures, the surgeon must adequately assess the patient's condition.
The tactics of surgery for colon cancer is selected for each patient individually. If there is a possibility of a successful completion of the operation and the possibility of further manipulations, a phased surgical treatment is performed. In this case, first a resection is performed and a colostomy is formed, and at the next stage, the stoma is sutured. If the patient's condition is assessed as weak and the cardiovascular system cannot withstand the phased treatment, one operation is performed.
Surgery should be complemented by radiation therapy. Therapeutic procedures can be carried out a few weeks after the operation. The area of tumor growth is irradiated. At the same time, radiation therapy can cause a number of side effects, since the intestinal mucosa is damaged during irradiation. Adverse reactions may include nausea, vomiting, and loss of appetite.
Chemotherapy is the next stage of treatment. To date, modern drugs are used that cause a minimum number of side effects. However, in some cases, nausea and vomiting, allergic rashes, leukopenia, etc. are possible.
Prognosis for patients
Prognosis for colon cancer is moderately good. Depending on the stage of the disease and the localization of the neoplasm, the five-year survival prognosis is half of the cases, subject to cardinal surgical therapy. If the neoplasm has not spread to other organs, all patients will be able to live for five years.
Auspiciousnessthe prognosis directly depends on the appearance and spread of metastases in regional lymph nodes. In their absence, we can talk about five-year survival in 80% of cases. In the presence of metastases from colon cancer, this figure is halved. Most often they are localized in the liver.
Metastases can appear even years after surgery. In such a situation, combined therapy is carried out, aimed at removing them surgically, followed by the use of chemotherapy.
What is the survival rate for colon cancer, many people wonder.
The greatest chances for a successful surgical intervention and a favorable prognosis are patients in whom the disease was detected at the initial stages of development. In the absence of treatment and in advanced cases, mortality within five years is one hundred percent. The prognosis for cancer of the ascending colon is poor.
Prevention
Any preventive measures in this case are aimed at early diagnosis of cancer, which involves regular examinations of the population. In this case, automated screenings are very important, which make it possible to classify the patient as a high-risk group with further referral for endoscopy. Clinical examination and therapy of patients who have been diagnosed with cancer or a precancerous condition is very important. Even a benign tumor is a reason to go for an examination.
Cancer prevention involvesmaintaining a he althy lifestyle with the exclusion of bad habits and maintaining a balanced diet. It is necessary to bring to the attention of the public information about the need to eat rationally and properly, to exclude refined foods and animal fats in favor of foods rich in fiber, fruits, vegetables and dairy products.
In addition, it is necessary to lead an active lifestyle, play sports, walk, swim, run, etc. Such preventive measures can significantly reduce the risk of developing cancer.
Colon cancer reviews
Reviews on the treatment of this pathology abound. Unfortunately, it is diagnosed very often. The scary thing is that it is detected already in the last stages, when treatment is often not effective. It is important to undergo examinations in a timely manner, fight chronic diseases, and lead an active lifestyle. Then you can reduce the risk of this pathology.
