Contents
What is bowel cancer?
bowel cancer – This is a malignant degeneration of the glandular epithelium, mainly of the colon or rectum. In the first stages, sluggish symptoms are characteristic, distracting from the primary pathology and resembling a disorder of the gastrointestinal tract. The leading radical method of treatment is surgical excision of the affected tissue.
Epidemiology
In official medicine, colorectal cancer is referred to as colorectal cancer. This is a collective name, consisting of two roots: “colon” and “rectum”. It is in the corresponding parts of the intestine that the maximum number of primary malignant tumors is detected.
Colon (Latin colon) is a colon with four successive sections:
ascending, which is located vertically on the right side of the human body;
descending – vertically on the left side;
transverse – connects the ascending and descending sections, is located in the upper part of the abdominal cavity, just below the stomach and liver;
sigmoid – forms a kind of short bend in the form of the letter (Σ), is located below on the left side and connects the descending and rectum.
The rectum (Latin rectum) is the rectum (located in the small pelvis).
In the caecum and appendix (the third section of the large intestine) and the small section (duodenum, jejunum, ileum), malignant neoplasms are much less common. The average frequency of detection of cancer outside the large intestine is 0,4-1,0% of all cases of intestinal oncology.
Important epidemiological features of bowel cancer:
occupies a leading position in the structure of oncological diseases, inferior: in men – to stomach cancer and lung cancer, in women – to breast cancer;
the most common morphological form of this cancer is adenocarcinoma (malignant degeneration of benign intestinal polyps, consisting of glandular tissue);
the probability of developing adenocarcinoma in the intestine is 98-99%, the incidence of sarcoma and other types of tumors does not exceed 1-2%;
the most common localization of the tumor: in the rectum (about 50%), in the sigmoid colon (up to 40%), in the descending and ascending colon (about 7%), in the transverse colon (about 3%);
in women more often (up to 55%), cancer of the colon is diagnosed, in men (up to 60%) – of the rectum;
the disease occurs at any age, a sharp rise in the incidence is noted after 40 years, the peak falls on the period from 60 to 75 years.
The paradox is that colorectal cancer is not a pathology with difficult to detect symptoms. This disease can be detected by modern instrumental and laboratory methods even at the earliest stages, but it is characterized by a significant number of diagnostic errors associated with the multiplicity of clinical manifestations of the disease.
In this regard, it is very important:
qualifications and oncological alertness of doctors performing primary appointments in the district polyclinic;
attentiveness of patients (especially older and elderly) suffering from disorders of the gastrointestinal tract and at risk of colorectal cancer.
Diagnosis of any disease, and especially in the early stages, is always a dialogue between the doctor and the patient. Very often, information from a patient who correctly describes the signs of the disease is crucial.
However, the patient’s alertness is not the main link in the timely diagnosis of cancer for the following reasons:
The doctor conducting the appointment in the clinic, in the flow of patients, may not pay attention to the signs of oncology. Its symptoms are varied, possibly erased, especially since increased fatigue, weight loss, diarrhea, blood in the feces, discomfort or pain in the abdomen, palpitations (the main signs of the first stages) resemble many diseases, and are effectively, albeit temporarily, eliminated. medicines.
It is sometimes psychologically difficult for a local therapist to replace a previously made diagnosis associated with a banal chronic indigestion with a frightening one – cancer, and in a timely manner refer the patient to a specialist for a highly sensitive examination;
Only the patient knows about his own predisposing risk factors for oncology in the form of similar diseases in blood relatives, the peculiarities of his personal lifestyle, the nature of work, nutrition, the presence of some individual delicate symptoms.
The knowledge gained within the framework of this educational article will help an ordinary person to understand the causes of the disease in an amount sufficient to draw the attention of a polyclinic doctor to this problem during the initial appointment.
Cancer is not always a death sentence! This is the situation when it is better to make a mistake in assuming a formidable diagnosis than to mistakenly make a banal diagnosis. For the timely detection of pathology, a prepared patient is needed who does not become depressed only from the suspicion of oncology in his body.
Bowel cancer symptoms
Diagnosis of cancer only by clinical symptoms is unpromising due to the numerous manifestations of the disease. The following description of the symptoms is given to show the variety of manifestations of the pathology, and to confirm the importance of competent medical diagnosis with modern methods.
Colorectal cancer has no characteristic (pathognomonic) symptoms. There are several groups of bowel cancer symptoms that characterize various pathological processes inside the patient’s body.
Toxic-anemic symptoms
The initial stages of bowel cancer are accompanied by a violation of the integrity of the mucous membranes of the intestinal walls.
As a result, the gates of infection open, the contents of the intestine enter the bloodstream, causing intoxication, which manifests itself:
increased fatigue, weakness, headache, nausea, other signs of intoxication;
elevated body temperature, joint pain (a consequence of toxicosis);
loss of blood from small vessels of the intestinal wall, anemia, pallor of the mucous membranes, a decrease in hemoglobin levels, thickening of the blood, a change in its other indicators and, as a result, a change in the rhythm of the heart and breathing.
You can confuse the disease with a variety of intoxications caused, for example, by inflammatory diseases of the heart, joints or upper respiratory tract.
Enterocolitic inflammation of the large intestine: symptoms
This inflammation is formed mainly with extensive damage to the mucous membranes, when toxins begin to enter the blood from the surface of the damaged membranes, while in addition to intoxication, intestinal dysfunction occurs.
Pathology manifests itself:
an increase in body temperature, reminiscent of an infectious fever;
constipation and more often – diarrhea;
increased gas formation as a result of rotting of the contents of the intestine, bloating and rumbling;
involvement in the pathogenesis of intestinal sphincters that regulate peristalsis. The process is accompanied by periodic pain in the abdomen (left or right), especially after eating;
mucus visible as blood and pus in the stool.
In the absence of cancer alertness, the doctor may confuse these symptoms with dysentery, inflammatory processes in the large intestine.
Dyspeptic bowel disorder: symptoms
This disorder is found when a large number of pain receptors are involved in the pathogenesis and irritation as a result of ulceration of the walls of the mucous membranes, as well as at the initial stages of metastasis to the liver.
Symptoms appear as:
severe pain in the abdomen;
unpleasant belching – a sign of damage to the sphincters and liver;
nausea and vomiting – toxemia;
diarrhea or constipation – a violation of intestinal motility;
elevated body temperature.
Dyspeptic bowel disorder resembles an inflammatory process in the appendix (this is part of the colon), as well as in organs adjacent to or functionally associated with the large intestine (pancreas, stomach, small intestine, gallbladder).
Obstructive blockage of the intestinal lumen: symptoms
Blockage is detected when the tumor metastasizes and the formation of inflammatory adhesions around it.
Pathology is usually manifested by signs of partial blockage of the lumen of the colon in the form of:
prolonged constipation that is not eliminated by enemas and laxatives;
heaviness in the abdomen;
increased pain after eating.
Signs of blockage resemble diverticulosis (the formation of pockets filled with feces in the walls of the intestines), adhesive disease, spastic pain in the intestines, the presence of fecal stones (calculi) in the lumen of the rectum.
When the small intestine is involved in carcinogenesis, symptoms of acute and complete obstruction of the intestine, invagination (protrusion of the walls), intestinal volvulus are formed. These phenomena are manifested by severe pain, indomitable vomiting, sometimes immediately after eating, a rapid rate of formation of cancer symptoms.
Pseudo-inflammatory (resembling general inflammation) symptoms
They develop in the late stages of oncology with metastases to the lungs, ovaries, and other organs, very often the symptoms are combined with a palpable tumor.
The following signs of the disease are found:
heat;
severe, persistent pain in the abdomen, sometimes of unclear localization;
purulent and bloody discharge from the anus during defecation;
constipation, inability to defecate without an enema, difficulty in evacuating intestinal gases;
symptoms associated with metastasized organs, such as cough with lung involvement, dyspepsia with liver involvement, genital discharge with carcinogenesis involvement.
The first signs of bowel cancer
It is advisable to detect the first signs of intestinal cancer using instrumental methods of visual examination of the walls of the large intestine, with probing or radiation methods, without penetrating into the body.
The basis for the appointment of instrumental or laboratory studies are:
at-risk groups;
age over 40 years, but there are cases of the disease at a younger age;
the presence of some signs indicating damage to the gastrointestinal tract against the background of any other symptoms, for example, a combination of disorders of cardiac and excretory functions against the background of intestinal disorders.
A very important role in this period is played by the competent oncological alertness of a general practitioner, because in 70-90% of cases people turn to a general practitioner in the early stages of the disease, often for reasons that have no visible relation to cancer.
The doctor usually thinks about the possible layering of oncology when the following subjective sensations appear in the patient (at least three at the same time), including:
general weakness;
fatigue;
pain in a certain anatomical area of the abdomen (see the anatomy of the intestine above);
progressive weight loss;
a slight but persistent increase in body temperature;
blood or mucus in the stool;
dark (black) stools;
pallor of mucous membranes and skin;
lack of relief after effective medical manipulations.
Naturally, these signs are not an accurate indication of cancer; one should always take into account the patient’s suspiciousness, the individual threshold of pain sensitivity, and other clinically important parameters for diagnosis. When the doctor confirms the patient’s complaints, the diagnosis is clarified on the basis of clinical, instrumental and laboratory studies.
It is inappropriate to list the primary macro- and microscopic changes in the intestinal walls that are detected by diagnosticians during examinations in this article, since such knowledge is purely professional.
Causes of bowel cancer
Colorectal cancer is common among people with a predominant diet of animal proteins and fats, leading a sedentary lifestyle – these are residents of Europe and North America (regardless of race).
This gives reason to believe that it is the excess of meat food in the diet against the background of a deficiency of plant fiber necessary for peristalsis and bowel movements during defecation, and a sedentary lifestyle are the main causes of colorectal cancer. The theory of racial resistance to cancer is untenable.
The three most likely pathways leading to colon cancer (although the true causes of the onset and development of carcinogenesis are not fully known):
I. group of reasons
In some cases, precancerous stages proceed without clinical manifestations in the form of dysplasia (changes at the cellular level). A person feels completely healthy for a long time, periodic disorders are taken for minor violations that are eliminated with minimal effort. Cancer in this case is a surprise for both the patient and the doctor.
II. group of causes
Another part of precancerous conditions is disguised as chronic pathologies. Certainly, a fatal link between certain diseases of the gastrointestinal tract and colorectal cancer has been proven.
Here are some of the most significant diseases that most likely precede cancer:
Polyposis of the large intestine (the probability of malignant degeneration (malignancy) is up to 100%), sometimes associated with genetic disorders in close relatives. Not all are precursors of cancer, the most dangerous polyposis:
diffuse familial, has the following clinical signs – frequent defecation, more than five times a day, stools mixed with blood, pain or discomfort in the abdomen of varying intensity;
villous, has the following signs – abundant mucus during defecation (up to 1,5 liters per day), other symptoms (see diffuse polyposis);
Turcot syndrome is a rare hereditary disease that combines a brain tumor and polyposis of the large intestine, symptoms of polyposis, see above;
Peutz-Jeghers-Touraine syndrome – a combination of age spots on the face and polyps in the large intestine in relatives.
Diseases of the gastrointestinal tract (the probability of malignancy is up to 90%):
nonspecific ulcerative colitis – diarrhea, frequency of defecation up to 20 times a day, blood or pus in the stool caused by ulcers on the intestinal walls, pain in the lower abdomen, bloating of intestinal loops (protrusion of the lower abdomen);
Crohn’s disease or nodular inflammation of the mucous membranes of any parts of the gastrointestinal tract (from the mouth to the rectum) – increased fatigue, weight loss, high fever, severe pain that mimics appendicitis, as well as diarrhea and vomiting.
Diseases associated with metabolic disorders (probability of malignancy up to 10%):
type XNUMX diabetes mellitus (non-insulin dependent) – increased thirst, large volume of urine with normal urination frequency, itching, dry skin, obesity, weakness, prolonged healing of skin and muscle injuries.
III. group of causes
Diseases that do not precede cancer, but often overlap with the disease and confuse the clinical picture.
This is true if the doctor supervises the patient for a long time, for example, about:
hemorrhoids;
diverticula (pockets in the walls of the intestines);
chronic intestinal obstruction;
anal fissures or fistulas;
other diseases of the lower gastrointestinal tract.
Each disease has its own typical clinical picture with the same or common symptom for all of the listed diseases – difficult, painful defecation.
Stages of bowel cancer
The division of the pathogenesis of cancer into different stages is accepted throughout the world. There are different approaches to this issue, but the entire medical community has recognized the expediency of division. This way of classification greatly simplifies the description of carcinogenesis and standardizes its understanding. In our country, it is generally accepted to distinguish four main stages of cancer and several possible options within each stage.
For the diagnosis of bowel cancer, the following classifications have been proposed, including those used abroad:
S. Dukes et al., six stages in total, the principle of determining the depth of tumor germination and the presence of metastases in the lymph nodes is used;
TNM (Latin equivalents of the first letters meaning “tumor”, “lymph node”, “metastasis”) is an international classification widely used by Russian doctors. Only 4 stages of cancer, one stage of precancer. The classification abbreviation contains its principle.
There are other classifications as well. We will focus on the TNM classification, as the most common in our country, and describe the characteristic features of each stage.
When there is no reason to consider changes indicating signs of cancer as established, this condition has a symbol – (Tх). If there are signs that indicate precancerous symptoms, then use the designation (Tis). The designation N is used to describe involvement of regional lymph nodes in carcinogenesis.x), and if it is precisely established that the nodes are not damaged, then this is denoted by (N0). The letter M (metastasis) is not used in the description of precancer.
Colon cancer stage 1
In the medical history, examination protocols and other official medical documents, it is indicated by a combination of letters and numbers (T1 N0 М0). This is the initial stage, clinically it is manifested by general symptoms of intoxication. During instrumental examination, it is visualized as a small, mobile, dense formation or ulcer (T1). Changes are found in the mucous membrane or submucosal layer. Lymph nodes are not affected (N0). No metastases (M0).
Colon cancer stage 2
There are two options for describing this stage in medical documents with the results of instrumental studies: (T2 N1 М0) or (T3 N0 М0). These variants differ in the size of the tumor. Namely, the size of the tumor is described from a third to a half of the diameter of the intestine (T2 иТ3). In one variant, there are signs of damage to nearby lymph nodes (N1) and there are no damages in the second one (N0). Distant metastases are always absent (M0).
Colon cancer stage 3
This form of colorectal cancer is distinguished by a variety of morphological and cytological forms of carcinogenesis.
There are seven possible descriptions, including milder manifestations, denoted:
(T4 N0 М0) – the tumor occupies more than 50% of the diameter of the intestine, the lymph nodes are not affected, there are no metastases;
(T1 N1 М0) – a small mobile tumor, the nearest lymph nodes are affected, without distant metastases in the liver;
(T2 N1 М0) – a tumor up to 30% of the diameter, the nearest lymph nodes are affected, there are no metastases;
(T3 N0 М0 ) – a tumor up to 50% of the diameter of the intestine, no lesions of the lymph nodes, no metastases.
Relatively more severe forms of the third stage are designated:
(T4 N1 М0) – a massive tumor encircling the intestine, adhesions are formed with neighboring organs and tissues, the next 3-4 lymph nodes are affected, there are no distant metastases;
(T1-4 N2 М0) – the size of the tumor does not matter, more than four intestinal lymph nodes are affected (N2), no metastases.
(T1-4 N3 М0) – the size of the tumor does not matter, the lymph nodes along the large blood vessels are affected (N3), that is, there is a massive spread of cancer cells throughout the body, there are no distant metastases yet.
Colon cancer stage 4
This is the last, most dangerous stage of the disease, characterized by distant metastases in the body. In medical documents, it can be indicated (T1-4, N1-3 M1). The size of the tumor and the defeat of regional lymph nodes are not of fundamental importance. However, there are always distant metastases, usually in the liver (M1).
Metastases in the intestine
A feature of colorectal cancer is distant metastases to the liver, much less often they are found in the lungs, brain, genitals and omentum. Germination of malignant cells in vital organs greatly reduces the likelihood of successful treatment of patients.
Prognosis of the disease
There is no system of early cancer prediction in Russia. The reason is the chronic lack of funding for useful activities. Therefore, there are no highly sensitive methods for detecting cancer available for mass use.
Occult blood tests widely used in our clinics give many false results, and DNA diagnostics is still limitedly available for mass research.
Modern forecasting mainly depends on the literacy and oncological alertness of a doctor who is able to find a connection between diseases of the gastrointestinal tract and cancer precursors. The prognosis is based on the doctor’s subjective feelings and the results of the patient’s visual examination, so up to 20% of Russian patients have the primary diagnosis – intestinal cancer with distant metastases.
Ways to improve objective forecasting methods are based on the introduction of highly effective instrumental and laboratory techniques into mass medical practice.
In the presence of an already formed tumor, the most promising methods for objectively predicting the rate of metastasis development are the determination of specific protein markers, including the Oncotype Dx colon test and others.
How long do people live with bowel cancer?
The question contains a fatal sense of the mortal danger of cancer. But let’s be optimistic, because in the early, and sometimes in the late stages of the disease, doctors achieve amazing success in the radical treatment of this form of oncology.
The answer to the question about life expectancy can be divided into two parts:
the first concerns the quality and duration of life after diagnosis;
the second is the frequency of examinations in order to detect oncology at the earliest possible stages.
Information about the five-year survival rate of patients with bowel cancer, often used in scientific research to show trends and patterns of the disease, is incorrect in the context of a popular article, because the body of each individual person has a different margin of safety, depending on:
age;
associated pathologies;
bad habits;
living conditions;
stress and so on.
Of the above, only age cannot be corrected. Proper treatment of concomitant pathologies, giving up bad habits, choosing a diet, eliminating stress significantly increase the likelihood of not getting sick, and the patient’s chances of recovery and a significant prolongation of life with the help of surgeons and doctors of other specialties increase.
A quality life is possible even with a significant excision (resection) of a part of the intestine and the imposition of a colostomy (holes for removing feces to the outside, bypassing the anus). The presence of a colostomy with normal care is not a significant factor that reduces the quality of life.
On the other hand, the earlier cancer is detected, the greater the chance of successful treatment. Following this logic, it can be assumed that exceptionally frequent examination gives chances for early detection of the disease and prolongation of life. Fortunately, this is not entirely true.
Early confirmation of the diagnosis is possible with examinations with an interval of one year. Indeed, from the first mutations to the onset of clinical stages, an average of two to three years pass.
For a significant increase in the duration and quality of life, screening studies should be carried out annually after the age of forty.
When the disease is detected in the later stages, proper patient care and maintaining a good hygienic condition of the colostomy play an important role in prolonging life.
How long a person lives after treatment depends on the neglect of the disease, as well as on other factors listed above.
Diagnosis of bowel cancer
The choice of diagnostic scheme is determined by the doctor. The minimum includes screening studies, first of all, fecal occult blood analysis, which is a very simple and widely available method used in the most primitive laboratories.
Patients at risk should donate feces once a year to exclude hidden bleeding, this method allows you to determine a tumor or polyp with a diameter of 2 cm;
With a positive test for occult blood, fibrosigmoscopy is prescribed, or rectomanoscopy with video fixation or a contrast study of the colon.
A real breakthrough in the diagnosis of bowel cancer occurred after the widespread introduction of radiation diagnostic methods into medical practice, for example, contrast radiography or more modern methods:
computed tomography and its modifications (CT, MSCT);
ultrasound diagnostics through the abdominal wall and with the help of sensors inserted into the intestine (ultrasound, TRUS, others);
magnetic resonance imaging and its modifications (MRI)
positron emission tomography (PET-CT).
A promising method is the laboratory determination of DNA markers of bowel cancer. After all, this form of the disease is one of the few that can be determined long before the onset of the clinical stage, and thus save life without painful medical procedures.
Bowel cancer treatment
Modern methods of colorectal cancer treatment are based on radical surgical removal of the tumor, surrounding tissues and metastases. Radiation and chemotherapy methods are used as auxiliary methods. In the medical literature, there is information about a significant prolongation of the life of patients operated on at stages 3-4 of bowel cancer. Some sources indicate a three-year survival rate of 50%, and a five-year survival rate of 30% of patients in surgical departments. The use of combined methods allows us to hope for better results in patient survival.
Chemotherapy for bowel cancer
The main limiting factor in the widespread use of chemotherapy in this form of cancer is the resistance of the main forms of intestinal tumors to cytotoxic drugs.
Chemotherapy is used systemically, before or after surgery. In some cases, local administration into the blood vessels that feed the metastases is indicated. The main drug used for chemotherapy is 5-fluorouracil. In addition to it, other cytostatics are used – capecitabine, oxaliplastin, irinotecan and others. To enhance their action, immunocorrectors are prescribed (interferogens, stimulants of humoral and cellular immunity).
Surgery to remove a tumor in the intestine
It is generally accepted that this is the only radical treatment for bowel cancer. There are various techniques, including:
traditional methods of resection of the affected segment of the intestine and surrounding vessels;
operations through miniature incisions of the abdominal wall;
removal of a tumor with a package of lymph nodes and metastases using a high-frequency knife.
The method and method of surgical intervention is chosen by the attending physician based on the recommendations of the council. It has been proven that the quality of the operation and the likelihood of re-development of the tumor directly depend on the training of the team of surgeons and the equipment of the specialized clinic.
Bowel cancer prevention
Oncological diseases are cunning and unpredictable. It is worth thinking about prevention for people who have a hereditary predisposition to cancer, or have diseases that can transform into cancer, as well as all people over the age of 40.
General recommendations for lifestyle changes include:
Increased motor activity;
Enrichment of the diet with foods containing fiber;
Refusal of bad habits (smoking, drinking alcohol).
Regular aspirin reduces the chance of developing some forms of bowel cancer. It must be taken after meals. Usually this inexpensive drug is prescribed for hypertension in order to reduce blood viscosity. There is strong scientific evidence for the suppression of some forms of colorectal cancer with daily low doses of aspirin.
Attention! Aspirin should not be taken in large doses, as there is a high probability of erosion, ulcers, gastroduodenitis and gastric bleeding.
Even simple annual screening tests for fecal occult blood reduce the chance of developing cancer by 18-20%.
Methods of probing and visual assessment of the intestinal walls are limitedly used as preventive diagnostics.