Sigmoid colon cancer: symptoms, treatment, surgery, prognosis
The share of cancer of the sigmoid colon accounts for almost a third of all cases of malignant epithelial neoplasms of the large intestine. Usually the disease is detected at the age of 40-60 years, more often in men.
At first, the tumor does not produce any characteristic symptoms, so its timely detection can be difficult. The growth of the cancer cells to spread to all layers of the intestinal wall, blood and lymph vessels move lymph nodes and internal organs.
Sigmoid colon cancer refers to the varieties of cancer that can be successfully treated provided they are detected early. In this regard, of special importance is the timely visit to the doctor when there are any changes in the bowel. In some States, diagnostic colonoscopy is recommended as screening method for detecting cancer, since the number of diagnosed patients is growing from year to year, and with increased morbidity and mortality.
In industrialized countries the number of patients is so great that the colon cancer came out on the prevalence of the leaders, losing place only to tumors of the stomach, breast and lungs. In Russia, colon cancer ranked fourth among women and third among male population and in the United States die from diseases fifty thousand people annually. These figures are frightening and require special vigilance not only from doctors but also from potential patients of oncological clinics.
Causes and stage of cancer of the sigmoid colon
It is usually difficult to set a specific cause of neoplasia, since there is a combined effect of the environmental factors, heredity, lifestyle. In respect of intestinal tumors according to the law of the main place belongs to the nature of power and related features of the chair. The causes of colon cancer, apply equally to the sigmoid, but this body more susceptible to tumors in a number of circumstances:
- Longer contact of the mucosa with the contents of the intestine;
- Tighter feces, damaging the intestinal wall;
- High frequency of inflammatory and precancerous changes of the sigmoid bowel.
The major causes of cancer of the sigmoid colon:
Tumor stage is determined by its size, degree of damage to the intestinal wall, the presence of nearby or distant metastases:
- 1 stage, when the tumor is less than 2 cm, do not grow into the muscle layer of the intestinal wall and does not give metastases, is the most favorable;
- 2 stage of the disease is accompanied by a further increase in the size of the tumor nodule that takes up half the circumference of the bowel, it is possible to identify isolated metastases in local lymph nodes (stage 2B);
- 3 stage neoplasia characterizes the emergence of local metastasis, and the cancer goes beyond the half of the circumference of the sigmoid colon;
- Stage 4 is the most unfavorable, in which a possible detection of distant metastases, and invasion of surrounding tissues and adjacent organs, complications – fistulas, peritonitis, etc.
Depending on the characteristics of growth in the sigmoid colon are exophytic neoplasm protruding into the lumen of the intestine, and endophytic growing infiltrative in the body wall, resulting in significant narrowing. Cancer of this localization is particularly prone to endophytic growth, therefore the main complication is usually intestinal obstruction.
Histological structure involves the allocation of adenocarcinoma, mucous cancer, non-differentiated forms.
Most commonly in the sigmoid colon adenocarcinoma reveal that with a high degree of development of the tumor cells is quite sensitive to all kinds of treatment that allows to achieve good results.
Symptoms of cancer of the sigmoid colon
In the initial stages of the disease signs of the tumor may not be at all or they are few and nonspecific. This fact is often not possible to promptly detect a tumor, unless the patient undergoes regular examinations.
The first symptoms of cancer may become dyspepsia – bloating, rumbling in the abdomen, intermittent pain, and constipation. These signs are not always cause the patient to go to the doctor, especially if the latest a long time suffering from chronic colitis and was accustomed to such violations.
The growth of the tumor, the clinical picture becomes more diverse and includes:
- The abdominal pain localized in left side, dull, aching or cramping and is quite intense, and eventually becomes constant;
- Dyspepsia – belching, vomiting, nausea, rumbling, bloating;
- Violations of the chair in the form of diarrhea or constipation in the later stages and when endophytic tumor growth, among the symptoms is dominated by constipation;
- The presence of pathological admixtures in feces is mucus, blood, pus.
Common symptoms of cancer of the sigmoid colon becomes extreme weakness, weight loss, fever, fatigue. A number of patients due to bleeding of the tumor, anemia, skin become pale and fatigue and weakness worse.
Sigmoid colon cancer can recall for a very acute inflammatory process of the abdominal cavity, and the prevalence of symptoms of dyspepsia, the disease was mistaken for the ulcer, cholecystitis, pancreatitis etc.
Bowel neoplasms metastasize via the lymphatic or blood vessels, spread by contact on the surface of the peritoneum. First lymphogenic metastases in regional lymph nodes, then affects the parenchymal organs, the most noticeable one is the liver. Sigmoid colon cancer with liver metastases, in addition to the above symptoms may occur with jaundice, pain and heaviness in the right hypochondrium, impaired appetite, bitter taste in the mouth. With a substantial amount of damage possible to probe metastatic nodes in the enlarged liver.
For the symptoms described can only roughly be suspected neoplastic process, so after inspection and conversations with the patient assigned more tests. The most informative endoscopic methods, sigmoidoscopy, colonoscopy, during which it is possible to take a piece of the tumor for histological examination. Do not lose their relevance and radiographic methods – barium enema receiving barium sulfate as a contrast agent.
In addition to the instrumental, are held and laboratory study of General and biochemical blood tests, examination of feces for occult blood. If you suspect a metastatic process should be ultrasound of the abdomen, chest x-ray, bone scintigraphy.
Treatment of cancer of the sigmoid colon depends on the stage of the tumor, the patient’s General condition and presence of complications. Still, the main and the most effective method is surgery, which may be supplemented with radiation and chemotherapy. The best treatment results can be achieved in the early stages when the tumor has not yet metastasized and no complications in the form of intestinal obstruction. In advanced cases, therapy is palliative and is aimed at improving the quality of life of critically ill.
Principles of surgical treatment of cancer of the sigmoid colon
The choice of intervention is determined by the size and stage of tumors.
I-II stages of the operation is most effective because it manages to remove the entire tumor with the sigmoid colon area, but in advanced cases, surgical treatment will be only palliative.
Surgery gut always require careful preparation of the patient and from the surgeon is necessary to observe the principles of surgery of cancer. Elastichnost includes a complex of measures aimed at preventing the proliferation of cancer cells in the process of operation, including careful handling of the intestine, early ligation of blood vessels. The most radical treatment is needed to remove fragment of the colon with the tumor margins at least 5 cm in the direction of healthy tissues, while a considerable amount of damage may require the removal of the entire half of the colon. Excision of regional lymph nodes that collect lymph from the growth of tumors, helps to minimize the risk of subsequent tumor metastasis.
If neoplasia has not given complications, the patient is assigned to a planned operation that will need to comply with uncindery diet for three to five days, in the same period, appointed laxatives and cleansing enemas. Perhaps flushing the digestive tract with special preparations (fortrans, for example). To prevent infectious complications are shown antibiotics.
Types of surgery for cancer of the sigmoid colon:
- Distal resection;
- Segmental resection;
- A left hemicolectomy.
The first two types of operations are possible in localized forms of tumor growth and mean excision of the sigmoid colon area with the tumor. With the progression of the disease or a large size distribution of tumors is shown the removal of the entire left half of the colon (left hemicolectomy).
The important point in the treatment of cancer of the sigmoid colon is the restoration of the natural passage of intestinal contents. Possibly, the edges sewn with a gut as soon as the tumor is removed. In other cases, it is possible to create a temporary fecal fistula in the abdominal wall (colostomy) which subsequently usually sutured.
Deletion of the fragment of the intestine with the restoration of the passage of feces may be carried out simultaneously or in several stages. With overall good condition of the patient and adequate preparation for surgery, if the tumor has not gone beyond the second stage and did not give complications, possible single-step operation in which excised the affected area of the intestine, lymph nodes, and a fragment of the mesentery, after which the ends of the gut sewn together immediately and restore its patency without imposing a colostomy.
In cases where the tumor resulted in intestinal obstruction, the patient’s condition is severe, and surgery is performed in urgent or emergency basis, of immediate intervention, not a speech, because the risk of postoperative complications is high. Such patients are shown a two — or three-step intervention.
In the first stage removes the affected part of the bowel with formation of colostomy (the fecal fistula) in the abdominal wall. To the normalization condition, the patient is forced to live with a colostomy, and when the condition becomes satisfactory, it is possible to restore continuity of the bowel by diverting feces naturally. Usually between these stages is from two to six months.
A three-stage operation is indicated for acute intestinal obstruction due to the closure of the colon neoplasm. The first step is colostomy to decompress the bowel, and the discharge of the contents, followed by removal of the tumor and the intestine, and after stabilization of the patient (third stage) the colostomy is eliminated, and recovering the removal of content through the rectum.
Palliative surgical treatment in advanced stages of the disease when radical get rid of the tumor is impossible, there are distant metastases, and the patient’s condition does not involve a long and traumatic interventions.
As palliative care is carried out the creation of the colostomy on the anterior abdominal wall or the imposition of bypass anastomoses (connections) to pass the contents of the bowel bypassing the growth of cancer.
The presence of a fecal fistula in the abdominal wall requires careful skin care around such holes, regular hygienic procedures and diet, preventing constipation. Usually it is recommended sparing diet with the exception of smoked, fatty and fried foods, starchy foods and «fast» carbohydrates. Assigned if necessary laxatives.
Early postoperative period involves the conduct of detoxification treatment, if necessary – intravenous infusion fluid. To facilitate emptying of the bowel is administered mineral oil, from the second day, the introduction of a light liquid food, and after becoming a normal chair the patient is transferred to normal diet.
Prognosis after surgery is determined by the initial condition of the patient and stage of disease. In the case of timely diagnosis of early forms of cancer 5-year survival rate is 90%, whereas in the third stage survive only a third of patients. Recurrence after surgical treatment, usually associated with a lack of efficacy interference or violation of surgical technique. In the absence of distant metastases, local recurrence of cancer can be treated by re-operation.
Surgical tactics in complicated forms of cancer of the sigmoid colon
The most common complication of the tumor, growing in the sigmoid colon, is a bowel obstruction. It develops more often in the tumor than with cancer of the right half of the colon because of the more narrow lumen of the sigmoid colon, more dense content closer to the anal channel. In addition, the tumor in this Department often grows the body wall and causes stenosis (narrowing) of the lumen, making it more difficult passage of feces.
Intestinal obstruction is a serious complication that often requires emergency surgical intervention, when the time for preparation there is no patient, so no question of simultaneous operation also can not be. Usually immediately is the elimination of the obstruction by applying a colostomy or intestinal anastomosis. If the patient is diagnosed with a cancer of 4 degrees, then such an operation becomes the final treatment because the removal of the affected intestine is not advisable and technically impossible.
In the initial stages of cancer after bowel decompression and stabilization of the patient is the second stage of treatment – resection of the sigmoid colon or the left half of the colon. Between stages usually takes several months. Operation Hartmann, proposed for the treatment of cancer of the sigmoid colon is excision of the tumor fragment of the intestine with the creation of a colostomy, and subsequently produced the restoration of intestinal continuity.
Another threatening complication of cancer of the sigmoid colon can become peritonitis when perforation of the intestinal wall leads to the release of content into the abdominal cavity inflammation of the serous membranes. Peritonitis can be combined with intestinal obstruction. In such cases, it may be carried out a three-stage operation of Zeidler-Schloffer. Intervention involves the creation of sigmoscopy to drain the stool, then deleted the section of bowel with the tumor and restored the continuity of the intestine, but salmostoma is retained. After 2-3 weeks, when the patient’s condition is normalized, and the seams on the intestines heal, the surgeon removes a colostomy and intestinal contents is given in a natural way.
Chemotherapy and radiation
Chemotherapy for cancer of the sigmoid colon has no independent value, but is used in a combination therapy. It is possible to use as a single drug, and several.
For monohimioterapii usually used 5-fluorouracil, which is administered intravenously in a total dose of 4-5 grams per course, or Ftorafur intravenously or orally (up to 30 grams).
Chemotherapy involves the use of several drugs, the most effective against this type of tumor to 5-fluorouracil, Ftorafur, vincristine, adriamycin and others. The regimen determined by the physician-chemotherapist. The patient may require several courses of chemotherapy at intervals of 4 weeks.
Chemotherapy often entails a lot of side effects in the form of a painful nausea, vomiting, severe weakness, therefore, symptomatic therapy with the appointment of antiemetic drugs, excessive drinking, vitamin and mineral supplements the patient is required.
Irradiation for cancer of the sigmoid colon is very rare. This is due to the low sensitivity of the tumor to radiation and the risk of complications such as perforation of the colon in the growth of tumors. Irradiation may make sense before the planned operation, as in this case it is possible to reduce the size of the tumor, respectively, and the interference will be more safe and effective. After removal of the cancer, the treatment can be directed at the elimination of cells that might remain in the growth zone of the tumor.
The prognosis of cancer of the sigmoid colon and its prevention
The prognosis of cancer of the sigmoid colon can be favourable only in the first stage of the disease survive more than 90% of patients. As the worsening of the cancer this percentage decreases to 82% at 2 stage. On the 3rd stage of the tumor five years there are about 55% of patients and with the fourth – only every tenth.
Prevention of cancer of the sigmoid colon possible, and the sooner it is started, the higher the probability to avoid a dangerous disease. The first thing is to normalize the nature of power and chair. Constipation is an important risk factor of the tumour, their elimination therefore largely helps to prevent cancer. The decrease in the share of meat products in favor of plant fiber, fresh vegetables and fruits can reduce the likelihood of the tumor.
Another important event can be considered a timely treatment of inflammatory processes (sigmoid), colon polyps, diverticulitis (protrusions). Regular visits to the doctor, especially patients at risk, allows time to not only detect precancerous condition, but to diagnose primary cancer, when persistent may cure disease.