Cancer of the rectum
this malignant epithelial tumor of the intestine. Intestinal tumors differ in shape, location (blind, colon, rectum, anal canal), have different histological structure. Disease, particularly colorectal cancer, is common enough. In developed countries it is on the leading places in the overall statistics of cancer. In the 90-ies of the last century, the number of cases of malignant tumors of the intestine in the US was 140150 thousand a year. In the CIS countries over the last years this pathology began to meet more often. Among the female diseases she has moved from 6th to 4th place, and the male on the 3rd. Ahead of this cancer, only cancer of the lung, stomach and breast cancer.
The doctors can’t name a single cause of colon cancer and other parts of the large intestine leading to the development of the disease. Most likely, we are talking about the cumulative effect of multiple factors. The most dangerous heredity, chronic diseases of the colon, diet, the unfavorable external environment.
Thoroughly scientists investigate the effect of diet on the development of pathology. For example, it was found that in areas where people consume large amounts of meat and little fiber, often observed colorectoral cancer. This is because, due to the consumption of large amounts of meat in the body increases the concentration of fatty acids.
At the same time, in regions where the predominant vegetable food, and consequently, a greater amount of fiber in India, Central Africa, the frequency of bowel cancer less. This is due to the fact that the use of cellulose leads to the formation of a larger volume of stool, dilutes carcinogens, and links. She also contributes to a more rapid movement of fecal matter through the intestines, thus decreasing the time of contact of the mucosa with carcinogenic formations.
This hypothesis is supported by chemical theory. She also calls the cause of tumor development mutagenic effects of some exogenous and endogenous chemicals on the epithelium of the intestine.
Carcinogenic substances are formed when a wrong heat treatment products, Smoking. Using this product, people expose their bodies to risk of the formation of point mutations, translocations. Those, in turn, lead to the conversion of cellular proto-oncogenes to active oncogenes. This starts the mechanism of synthesis of oncoproteins, which contribute to the degeneration of cells.
The second risk factor is a chronic inflammatory disease of the large intestine, the most dangerous of which is ulcerative colitis. Such patients suffer from colon cancer is much more common than others. Here is the value for the duration of the disease, its clinical course. So, if the duration of disease to 5 years, the risk of cancer is fairly small and is only 05%, then to 15 years, it is already significantly higher than 5,230%.
At particular risk are people with experience of the disease 30 years up to 50%. There is also a correlation between colon cancer and Crohn’s disease, but it is much lower than when ulcerative colitis to 26.6 %.
The reason for malignant tumors are colorectal polyps. Index of malignancy of solitary polyps is at 4%, multiple of 20%. But especially dangerous villous education they increase the likelihood of developing cancer up to 40%. Polyps almost never occur in young people, but the elderly find them often enough. As shown by the autopsy, such formations are found in 30%.
Very high probability of developing malignant tumors in the intestine in those people who are first-degree relatives of those who suffered from colorectal cancer and colon cancer, familial diffuse polyposis, Gardner syndrome, syndrome Turko. The presence of these diseases involves surgical intervention to remove polyps or the affected portion of the colon. If this is not done, then almost all patients with these pathologies then faced with one or even several cancer. Family cancer syndrome that is passed by autosomally dominant type, is the cause of multiple adenocarcinomas of the colon. A third of patients with this disease after 50 years of facing colorectal cancer.
For cancer of the colon characterized by the same basic law of growth and other cancers. It is characterized by relative autonomy and uncontrolled growth of tumors is accompanied by loss of organic-histotechnol structure. However, there are its own peculiarities. Colon cancer develops more slowly than other types of cancer, for example cancer of the stomach. The tumor over a longer period of time within the body, distributed in the intestinal wall not deeper than 3 cm from the visible border.
Often the process of tumor growth accompany inflammatory processes. They can be transmitted to neighboring tissues and organs. At the same time through the inflamed infiltrate grows and the tumor itself. So there are locally advanced malignancies without distant metastasis. Distant metastasis also has its own characteristics. It is characterized by the lymph nodes, liver (hematogenous), and sometimes other organs, including the lungs. Multicentric growth another feature of colon cancer. This implies the sequential or simultaneous formation of multiple tumors in the colon and other organs.
For colon cancer characteristic of the diversity in the nature of the histological structure and growth. This has given rise to a very broad categorization of the disease based on various parameters.
According to the forms of growth
- exophytic grows into the lumen of the intestine
- endophytic grows in thicker walls
- saucer-like tumor, ulcer the combination of the two previous forms.
Depending on the histological structure of colon cancer by the international classification
- adenocarcinoma highly, moderately or poorly-differentiated
- mucous adenocarcinoma . Distinguish colloid, mucous, mucoid cancer
- perseverations, or mucocilliary cancer
- undifferentiated cancer.
If you mean cancer of a direct division of the colon, then the list above according to the International classification need to add squamous cell carcinoma, which are divided into keratinizing and neorogovevayuschy, glandular-squamous cell carcinoma and basal cell or bataliony cancer, which is a kind of cloacogenic cancer.
Adenocarcinoma is diagnosed in 80% of cases of colon cancer, so it is considered the most common form of this disease.
Projection is extremely important degree of differentiation, depth of germination of the tumor, the clarity of its boundaries, the frequency of nodal metastasis. For example, the best is the prognosis of patients with well-differentiated than nizkoeffektivnyj, tumors.
Poorly differentiated tumors
- mucous adenocarcinoma (mucous kolloidnyi cancer). It is characterized by large secretion of mucus and congestion in different size lakes
- Perevalny or mucocilliary cancer. It was not helped young people. This form of cancer is marked vnutriserdechne massive growth and has no clear boundaries. This circumstance does not allow to determine the exact boundaries of resection. For Perevalnogo cancer characterized by rapid proliferation of the metastasis. A cancer with relatively small lesions of the mucosa of the intestine covers the whole wall and the nearby organs and tissues. This greatly complicates radiographic and endoscopic diagnosis
- distal cancer. Most often it affects the distal third of the rectum, and sometimes other parts of the body
- glandular-squamous cell carcinoma is quite a rare form of the disease
- undifferentiated cancer. This form of cancer develops when vnutriserdecna the growth of tumors. This fact the physician should consider defining the scope of surgical intervention.
In domestic medical practice share a stage 4 colon cancer. Before defining the stage of diagnosis of cancer of the rectum and colon as a whole
- In stage, the tumor grows in the mucous and submucous layer of the body. In this stage the colon cancer has their own signs.
- In and stage the tumor affects no more semicircle intestine and lies within the intestinal wall. Regional metastases in the lymph nodes there.
- In b stage the tumor invades the whole wall of the intestine.
- and the stage is diagnosed when the affected area exceeds a semicircle intestine.
- In the b stage, the tumor can be any size, is observed the formation of metastasis.
- For stage IV characteristic of the large tumor that sprouted in the surrounding organs, accompanied by the formation of metastases.
In the world of medical practice is widespread also classification of S. E. Dukes (1932), where the stages are identifiable by an index AD. But the most informative is considered to be the International classification according to the TNM system adopted in 1997.
The stage of the disease, including early cancer of the rectum, is determined on the basis of results of preoperative studies, intraoperative revision and a remote segment of tissue.
There are a number of symptoms that indicate cancer of the rectum and of other parts of large intestine. These include intestinal bleeding, abdominal pain, lack of kaloizverzhenie, tensely.
Such clinical manifestation as bleeding is observed in all patients with colon cancer. Red blood indicates the presence of pathology in the anal canal, dark on the left half of the colon. An even more obvious sign of blood, mixed with mucus and feces. If we are talking about cancer of the right half, it is indicative of hidden bleeding, which is accompanied by anemia, weakness, pale skin.
For late stage cancer of the rectum and left colon characterized by disorders of defecation. Sometimes this symptom is also manifested at the early stages of the disease, then you need urgent surgery.
Often patients who subsequently are diagnosed with rectal cancer and metastases complain of feeling of incomplete kaloizverzheniya or false urge to defecate. Very often abdominal symptoms occur, patients experience weakness, lack of appetite, weight loss. At later stages, the disease manifests itself hepatomegalia and ascites.
Diagnosis of cancer of the rectum performed by a proctologist, or
the corresponding specialization. It includes
- digital examination of the rectum
- Ultrasound sensor
- barium enema
- CT scan and MRI.
Treatment of rectal cancer and other parts of the colon is carried out by removal of the malignancy and areas of regional nodal metastasis. Recovery from rectal cancer after surgery depends on the correct preparation of the colon. The most common method uncindery diet in combination with medication laxative action and cleansing enemas.
If there are distant metastases, the treatment we are talking about complex palliative interventions that are aimed at prevention of complications, in particular the development of pain syndrome.
In advanced forms of cancer surgery of the rectum, rather, is a method of symptomatic treatment.
The prognosis of colon cancer depends primarily on the stage of the disease. If treatment is started in the initial stages, the 5-year survival rate is 90%. However, this rate deteriorates with disease progression. So, if the defeat has affected the lymph nodes, the 5-year survival rate is not more than 50%. The projections for cancer of the rectum is slightly worse only 50%, and depends on the real stage of tumor development.