Rectal cancer: general information

In order to clearly understand what rectal cancer is, it is necessary to have information about the anatomy, physiology and mechanism of development of such a disease. This article contains the main points characterizing this malignant pathology.

ICD 10 code (according to the international list of diseases):

• C 00-D 48 – various neoplasms inside the body.
• C 00-C 97 – neoplasms with malignant course.
• C 15-C 26 – neoplasms with a malignant course, localized in the digestive system.
• C 20 – malignant neoplasm in the rectum (lymphoma, cancer, etc.).

First, let's figure out what the rectum is - it is the final section of the large intestine, so to speak, the transition from the large intestine to the anus. Why is this section singled out as a separate category? The main function of the rectum is to hold and store formed fecal matter that is ready for defecation.

The intestine consists of three layers:

• mucous layer - covers the cavity of the rectum, serves to secrete a special mucus that ensures easy movement of feces;
• muscular layer - the middle tissue, consisting of muscle fibers that maintain the shape of the intestine and, by contracting, progressively move the fecal masses outward;
• The peritoneal layer is a cushioning fatty tissue that literally envelops the rectum.

Also, when describing rectal cancer, it is necessary to pay attention to the lymph nodes, which are present in sufficient quantities around this organ. Lymph nodes retain not only pathogenic microorganisms (bacteria and viruses), but also cancer cells.

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Rectal Cancer Statistics

According to statistics, malignant neoplasms are considered the leading cause of death in global medicine. Every year, 7 to 8 million people on the planet die from this disease. Of these, rectal cancer ranks third.

Most cancer cases are registered in developed regions and large cities. To be more precise, more than one million patients with a diagnosis of rectal cancer are diagnosed annually: more than half of them are fatal. The disease mainly occurs in people over 40 years of age. The average age of the disease is 55-65 years. However, young patients from 20 to 25 years are also not an exception. It is no secret that cancer is getting younger every year, and its incidence is increasing. And the further forecast of the World Health Organization is not optimistic: in the future, scientists predict an increase in mortality from cancer.

After surgery to remove a cancerous tumor in the rectum, the so-called "five-year survival rate" is approximately 35-75%. Such a large range is explained by the fact that the degree of patient survival can directly depend on the type of oncology, the location of the tumor relative to the intestine, the quality and scope of the surgical intervention, as well as the literacy and experience of the operating surgeon.

If the patient has regional metastases, this feature reduces the expected survival value by 30-40%.

Even though cancer treatment methods are constantly improving, the effectiveness of therapy remains relatively unchanged. It's all about relapses, which occur in patients who have had surgery in about 10-40% of cases.

Of course, patient survival rates may vary significantly across countries and regions. Therefore, statistics should not be trusted blindly. The average rate is based on the vast majority of registered cases, but the risk level for any given patient may be completely different. It is wrong and unacceptable to tell a cancer patient how long they have left to live. This is not so much a question of statistics as it is a question of the level of care provided to the patient, the quality of medical examinations, and the person’s overall health.

Causes of rectal cancer

The causes of the formation of malignant diseases of the rectum are currently under study. So far, there are only assumptions and hypotheses that a cancerous tumor can appear as a result of some chronic pathologies, for example, as a consequence of anal fissures, ulcerative inflammation of the intestine or proctitis.

The hereditary-genetic factor plays a major role in the development of cancer. That is, any person may have a higher risk of developing intestinal oncology if someone in his family suffered from diffuse polyposis or malignant intestinal diseases. Diffuse polyposis is a disease that is characterized by the occurrence of a large number of polyps (benign tumors) in the lumen of the large intestine or rectum. Such multiple polyps can be transmitted genetically from an older family member to a younger one, and they also carry a high risk of cancerous degeneration.

The development of cancer is also facilitated by individual nutritional principles. The following are among the alimentary risk factors:

• insufficient consumption of vegetables, as well as cereals, grains, and various porridges;
• excessive consumption of animal fats and meat products.

Defecation disorders such as constipation (especially chronic) lead to the fact that stagnant feces begin to decompose in the intestines, causing irritation of the mucous membrane with decay products.

Factors such as excess weight, physical inactivity, and overeating also contribute negatively to the development of cancer. The involvement of bad habits in the development of malignant diseases of the rectum has been established. Thus, smoking and alcohol irritate not only the stomach, but also the entire intestinal mucosa, which can cause inflammatory reactions and even oncology.

Harmful professional activities cannot be discounted – work related to toxic and radioactive waste, chemical substances, etc.

In addition, rectal cancer is not uncommon among patients with the human papilloma virus, as well as among homosexuals who practice anal sex.

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Pathogenesis

Inflammatory reaction in the rectal tissues, mechanical damage to the mucous provoke stimulation of regenerative processes. But with prolonged and frequent inflammatory phenomena and tissue integrity disorders, recovery processes can be disrupted. This is how, for example, polyps appear. With a genetic predisposition to polyposis, the intestinal mucosa has a tendency to pathological growth of polyps from birth. The development of these small tumors is slow and often unnoticeable.

Over time, polyps can undergo malignant degeneration, tumor cells change structure and cancer occurs.

A cancerous neoplasm exists and grows for a long time without leaving the rectum. Only after years can the tumor grow into nearby tissues and organs. For example, cancer often grows and spreads into the posterior vaginal wall, prostate, bladder, and urethra. As with any oncopathology, sooner or later metastasis begins - the separation of tumor cells and their spread throughout the body. First of all, the lymphatic and circulatory systems are affected, with the help of which malignant cells are transferred to the liver, lungs, brain, kidneys, and other organs.

The growth of rectal cancer is a fairly long process, if compared with any other tumor localization. Thus, cancer cells slowly develop in the intestinal tissues, without penetrating into their depth. The malignant process can be hidden behind local inflammation: degenerated cells conveniently develop inside the inflammatory infiltrate, where entire cancer colonies can form.

Often, it is precisely because of the slow and hidden growth that the symptoms of rectal cancer are detected at fairly late stages of development, when the tumor is already quite large and has distant metastases. And even then, patients do not always seek medical help, mistakenly taking the true signs of malignancy for anal fissures or manifestations of hemorrhoids.

Indeed, diagnosing this disease is difficult for many reasons. Firstly, as we have already said, the early stages of the disease often do not manifest themselves in any way. Secondly, patients are often embarrassed to seek help, considering the symptoms they have not to be that serious. And this is despite the fact that in our country it is recommended that all people over 40 years of age periodically examine their intestines for malignant diseases.

Treatment of rectal cancer is mainly surgical. The volume and type of surgical intervention, as well as additional treatment methods are selected depending on the location of the tumor, the degree of its invasion into tissues and nearby organs, the presence of metastases, the patient's condition, etc.

Unfortunately, rectal cancer is not a rare and quite serious pathology that requires long-term and complex treatment. Therefore, in order to avoid the disease or at least to start treatment in a timely manner, it is important to follow all recommended prevention methods.