Colon cancer, according to statistics, is the second most common cancer located 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 cases of this type of cancer among both sexes. Particularly high risk for people over 55 years. Colon cancer deaths are also increasing. Within two years, 85% of patients die from the disease.
Colon cancer is most common in developed countries, where people prefer unhealthy, refined foods. The most common disease is in Australia and North America. The disease is somewhat less common in Europe, and in Asian countries, Africa and South America is very rare. In our country, a similar diagnosis is made in approximately 17 cases per 100 thousand people.
Localization
The colon is the largest division in the large intestine, in which feces are formed from the liquid chyme. This area of the intestine is actively involved in the work of the gastrointestinal tract, therefore, stagnation in it is extremely undesirable. Eating a large number of refined foods, additives of toxic content cause various malfunctions in the functioning of the intestine, the development of polyps and the growth of adenomas, which can subsequently become malignant.
The colon is located directly behind the cecum and includes several sections: ascending, transverse, descending and trailing. In the colon there are quite a few vulnerable and sensitive places. These, for example, are various bends and contractions due to physiology, in which feces tend to accumulate and stagnate. In half the cases, the tumor is localized in the sigmoid colon. In 23% of cases, the cecum is affected. Other departments are less likely to suffer from the disease. But cancer of the ascending colon is often diagnosed.
Causes
The exact reasons for the development of such cancer have not been established. However, there are a number of factors that are proven can provoke the multiplication of malignant cells. Among them:
- Genetic predisposition. The incidence among those for whom this form of cancer has been identified among close relatives is significantly increasing.
- Unbalanced diet, eating refined foods and animal fats.
- Inactive lifestyle, lack of motor activity, overweight, lack of exercise.
- Constipation in a chronic form. In this case, the risk of injury to the intestinal bends by excessively dense feces increases.
- Hypotension and intestinal atony in the elderly.
- The presence of a history of precancerous diseases, such as familial polyposis, Crohn’s disease, diverticulosis, ulcerative colitis of a nonspecific nature, adenomatous polyps of a single species.
- The age of the patient. Incidence increases among patients older than 50 years.
- Work in harmful working conditions in the workplace.
Types and stages
The mucous membrane, which envelops the colon, consists of the so-called glandular epithelium. In the vast majority of cases, cancer of the transverse colon is diagnosed with the following varieties:
- Adenocarcinoma. Neoplasm arises from epithelial cells.
- Mucous adenocarcinoma. Malignant neoplasm containing a large amount of mucus.
- Cricoid Cell Carcinoma. Cancer cells have the form of vesicles that are not interconnected.
- Squamous or glandular squamous. At the heart of this type of tumor are squamous cells or glandular species.
- 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 metastases and disorders in the lymph nodes.
- First one. It is characterized by the development of a small tumor of the primary type, which is formed in the mucosa or submucosal thickness. Regional or distant metastases are absent.
- The second one. The neoplasm does not occupy a 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.
- The third stage of colon cancer. The tumor begins to germinate in the entire thickness of the intestinal wall, affects neighboring organs. Multiple metastases, however, are localized only in the lymph nodes.
- Fourth. The tumor affects adjacent organs, has a large size. Multiple metastases are observed, 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 occur, as a rule, in a latent form, and the disease is detected during routine medical examinations in the diagnosis of other pathologies. Many patients complain of constant constipation, soreness and discomfort in the intestine, general weakness and poor health when they see a doctor.
If the neoplasm is localized in the right part of the colon, then patients often complain of dull pain in the abdomen, malaise, and weakness. The examination shows a moderate degree of anemia, and even palpation of the tumor is possible even at an early stage of the development of the disease.
For left-sided localization of cancer of the ascending colon, dull pain, as well as flatulence, bloating, rumbling, regular constipation are characteristic. Feces in appearance resemble sheep droppings, you can see traces of mucus and blood in it.
The pains are 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, a feeling of heaviness in the abdomen. Inflammation in the intestinal wall provokes constriction and impaired motility, which leads to alternating constipation and diarrhea, bloating and rumbling in the stomach. The decay of the tumor leads to the appearance in the stool of impurities of blood, pus and mucus. Intoxication of the body increases, which is manifested by fever, weakness, anemia, rapid fatigue and weight loss.
Symptoms of colon cancer are important to recognize in a timely manner.
Medicine distinguishes several main forms of oncology, each of which is characterized by a certain set of symptoms:
- Obstructive. The main symptom is bowel obstruction. Partial blockage leads to rumbling, a feeling of fullness, cramping painful seizures, difficult discharge of gases and feces. With a narrowing of the lumen of the intestine, obstruction develops in acute form, which involves surgical intervention.
- Toxic anemic. This form is characterized by weakness and anemia, rapid fatigue and pallor of the skin.
- Dyspeptic. Manifested by nausea and vomiting, belching, 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 stool.
- Pseudo-inflammatory. It is accompanied by severe abdominal pain, fever. Bowel disorders are mild. ESR and white blood cells increase in the blood.
- Tumor-like. Symptoms of colon cancer are mild or absent. In this case, the neoplasm can be palpated.
Complications
In the absence of appropriate treatment, the symptoms increase over time, and further progression of the disease leads to complications such as bowel obstruction, abscess, phlegmon, bleeding, perforation of the intestinal wall with peritonitis, etc.
Intestinal obstruction due to overlapping neoplasm of 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.
The inflammatory process in cancer of the hepatic bend of the colon is observed in approximately every tenth case and takes the form of phlegmon or purulent abscess. Most often this is manifested in neoplasms of the cecum or ascending sigmoid colon. This process is triggered by the entry of pathogenic microorganisms through the lymph nodes into the surrounding tissue.
Perforation of the intestinal wall occurs quite rarely, however, it is this complication that can lead to death. Rupture causes ulceration of the tumor and its decay. At the same time, the contents of the intestine enter the peritoneum and cause peritonitis. When intestinal contents enter fiber in the back of the intestine, an abscess or phlegmon occurs.
In some cases, the growth of the neoplasm and damage to the hollow organs is possible, which becomes the cause of the appearance of fistulas. Complications significantly worsen the overall prognosis for patients with colorectal cancer.
Diagnostics
Detection of a tumor in the colon is impossible only taking into account the collected medical history and examination of the patient. External signs of the presence of a neoplasm, as a rule, are absent. Upon examination, the specialist assesses 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 the diagnosis of colon cancer include blood sampling for biochemical analysis to identify specific antigens, as well as feces for the presence of 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 An examination method 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 barium suspension. The contrast medium is injected 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 examination and computed tomography. With their help, it is possible to clarify the extent of the tumor and 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. Moreover, in addition to a radical surgical operation, chemo- and radiation therapy is also carried out.
The therapeutic regimen and type of surgical intervention is prescribed 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 health condition, are taken into account. If complications and metastases are absent, then radical methods are preferred. The affected areas of the intestine are removed along with the regional lymph nodes and the mesentery.
With right-sided localization of the tumor, a so-called hemicolectomy is performed. As a result of such an operation, the cecum, as well as the ascending and third parts of the transverse colon, together with part of the terminal ileum, are removed. Along with these manipulations, regional lymph nodes are removed. Next, an anastomosis is formed, that is, the small and large intestine is connected.
With left-sided lesions of the colon, a corresponding 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, mesentery and regional type lymph nodes are removed. In conclusion, 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 a tumor is found in the middle and lower part of the sigmoid colon, a resection of the mesentery and lymph nodes is performed. Next, an anastomosis is formed.
If a malignant neoplasm affects neighboring organs and tissues, a combined operation is performed to remove the affected areas.
If the cancer is found in advanced form and is not operable, then a palliative surgery is performed. To this end, overlay anastomoses or fecal fistula are superimposed. This helps to prevent intestinal obstruction, since this complication greatly weakens the patient's body and worsens the conditions for surgical intervention. In the appointment of 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 probability of successful completion of the operation and the possibility of further manipulations, a phased surgical treatment is performed. In this case, a resection is first performed and a colostomy is formed, and at the next stage, 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 supplemented by radiation therapy. Therapeutic procedures can be carried out several weeks after the operation. The tumor growth zone is irradiated. At the same time, radiation therapy can cause a number of side effects, since during the irradiation the intestinal mucosa is damaged. Adverse reactions can manifest as nausea, vomiting, and loss of appetite.
Chemotherapy is the next step in treatment. Today, modern drugs are used that cause a minimal amount of side effects. However, in some cases, nausea and vomiting, rashes of an allergic nature, leukopenia, etc. are possible.
Prognosis for patients
For colon cancer, the prognosis is moderately favorable. Depending on the stage of the disease and the localization of the neoplasm, a five-year prognosis of survival is half the cases if cardinal surgical therapy is performed. If the neoplasm has not spread to other organs, all patients will be able to live for five years.
The favorable 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 metastasis in colon cancer, this figure is halved. Most often they are localized in the liver.
Metastases may appear even a few years after surgery. In such a situation, combination therapy is carried out aimed at removing them surgically with the further use of chemotherapy.
What is the survival rate for colon cancer is interesting to many.
The greatest chances of a successful surgical intervention and a favorable prognosis are in patients who have a disease identified in the initial stages of development. In the absence of treatment and in advanced cases, mortality for five years is one hundred percent. The prognosis for cancer of the ascending colon is disappointing.
Prevention
Any preventive measures in this case are aimed at early diagnosis of cancer, which involves regular screening of the population. In this case, automated screenings are very important, which make it possible to refer the patient to a high-risk group with a further referral to endoscopy. Clinical examination and therapy of patients who have been diagnosed with cancer or a pre-tumor state is very important. Even a benign tumor is an occasion to lie down for examination.
Cancer prevention involves maintaining a healthy lifestyle with the exception of bad habits and maintaining a balanced diet. It is necessary to inform the population about the need to eat rationally and correctly, to exclude refined dishes and animal fats in favor of fiber-rich foods, fruits, vegetables and dairy products.
In addition, it is necessary to lead an active lifestyle, play sports, walk, connect swimming, running, etc. Such preventive measures can significantly reduce the risk of cancer.
Colon Cancer Reviews
Reviews about the treatment of this pathology are in large numbers. Unfortunately, she is diagnosed very often. The scary thing is that they reveal it already in the last stages, when treatment is often not effective. It is important to undergo timely examinations, fight chronic diseases, and lead an active lifestyle. Then you can reduce the risk of this pathology.