Bowel cancer is one of the most common oncological diseases in the world. It is most common in Western countries. The largest average frequency is noted in the CIS and Eastern Europe. The lowest incidence is in Asia and Africa. Men are diagnosed with bowel cancer more often than women. In recent years, with the introduction of new methods of treatment, it has been possible to significantly reduce the mortality rate of bowel cancer. Nevertheless, the late diagnosis of the disease remains a major problem, as it does prevents the timely administration of the necessary therapeutic measures. Let's discuss what bowel cancer is, how quickly it develops and where it gives metastases.
How quickly does the bowel cancer develop?
The bowel cancer develops rapidly. The clinical course and rates of progression depend on many factors:
- Histological type of tumor
- Type of growth, which determines when bowel cancer will give metastasize
- Degree of tumor differentiation
The degree of differentiation of the tissues from which the tumor grows, influence how long bowel cancer will develop. Low-differentiated tumors grow faster than moderately differentiated tumors. Highly differentiated tumors have the best prognosis.
Classification of colon cancer
There is a large number of classifications of malignant intestinal tumors. In clinical practice, the most commonly used ones are:
- TNM classification(determines the stage of the tumor)
- Histological classification
- Types of cancer by localization
- Types of cancer based on the degree of tissue differentiation
The nature of growth is also determined. It can be endophytic, exophytic or mixed. Endophytic growth occurs when the tumor grows inside the organ wall. It is characterized by a more unfavorable course, because it sprouts faster into neighboring organs and gives metastasis earlier. Exophytic growth occurs when the tumor grows toward the intestinal cavity.
According to the histological classification, there are the following types of bowel cancer:
- Adenocarcinoma (95% of all neoplasms)
- Carcinoid tumors
- Stromal tumors
The histotype of the tumor influences how long the bowel cancer will last. Adenocarcinoma can be mucous. Then it has a worse prognosis, as the bowel cancer in this case develops quickly and is more difficult to treat. These types of tumors are divided into mucous, mucoid and colloidal. There are also ring-shaped and mucocellular carcinomas. The histological type is determined by biopsy. It influences the treatment course of the disease.
Depending on the localization, there are such types of cancer:
- Cancer of sigmoid colon - half of all cases
- Cecum - 20% of cases
- Ascending, descending or transverse colon
- Hepatic or splenic flexure
From a clinical point of view the most important classification is TNM. Before we proceed to discuss it, we need to understand how and where the bowel cancer metastasizes.
Where bowel cancer metastasizes?
Metastases are secondary tumors. They are formed because the tumor cells spread throughout the body in various ways. Bowel cancer with metastases has a much worse prognosis than bowel cancer which did not metastasize. Metastases develop in the late stages of cancer. First, regional metastases are formed. Later appear distant metastases.
Bowel cancer metastases have certain characteristics. There are three types of metastasis:
- Lymphogenous - through the lymphatic vessels
- Hematogenous - through the blood
- Implant (contact) - when bowel cancer metastases spread through the abdominal cavity
Where does lymphogenous bowel cancer metastasize?
The lymphogenous metastasis are the first to develop. They develop during the third stage of bowel cancer. The order of occurrence of metastatic tumors is determined by the anatomy of lymphatic vessels and the location of the lymph nodes to the tumor.
As a rule, the sequence, where the bowel cancer gives metastases, is as follows:
- Epicolic (supracous) and paracolic (intestinal) lymph nodes.
- Mesenteric or intermediate nodes.
- Lymph nodes at the root of the mesentery of the large intestine, as well as para-aortic (located near the abdominal aorta) lymph nodes.
Later, metastases spreading through the lymph nodes get into the lymphatic system. It is located at the level of 1-2 lumbar vertebrae. Through the lymphatic drainage system, tumor cells spread into the venous system. They also penetrate the supraclavicular lymph nodes.
Where does hematogenous bowel cancer metastasize?
Hematogenous metastasis are manifested later than lymphogenous ones. They develop after the tumor spreads into the blood vessels. Most often bowel cancer metastasizes in the liver, lungs and bones.
Another way metastases spread is by the growing of the tumor into the abdominal cavity. It gradually increases in size. In later stages, the tumor spreads from the intestine into the cavity of the peritoneum. Parts of the tumor come off and spread to other organs.
Bowel cancer stages
The stage of bowel cancer is determined on the basis of three criteria:
- The size of the tumor
- The presence of regional metastases
- The presence of distant metastases
Stage 0. This is localized cancer or carcinoma in situ. The most favorable stage. There are no metastases. The tumor did not even spread beyond the intestinal mucosa.
Stage 1. Cancer has already spread beyond the mucosa - on the submucosa or into the muscle layer. There are no metastases yet.
Step 2A. New growth spread to all layers of the intestine. But it did not spread to neighboring organs. There are no metastases.
Stage 2B. The tumor has already gone beyond the walls of the intestine. But it has still not given metastases and has not spread to neighboring organs.
Step 2C. The tumor has grown through all the walls of the intestine, has gone beyond its limits, and already infiltration of neighboring tissues is observed. However, at 2nd stage of bowel cancer there are no metastases yet.
Step 3A. Often patients ask at what stage of bowel cancer do metastases occur. It is at the third stage when they appear. There are only the metastases in the lymph nodes, and they are not yet present in the organs. At 3A degree the tumor grows in the submucosa of the intestinal wall and spreads to 4-6 of the nearest lymph nodes. It can also spread through the entire intestine and affect 1 to 3 lymph nodes. Possible infiltration into adipose tissue.
Stage 3B. Stage 3 of category B is diagnosed in one of the following three cases:
- The cancer spreads to all layers of the intestine and to the peritoneum, but does not reach the internal organs, spreads into adipose tissue, affects 4-6 of neighboring lymph nodes
- The tumor grows into the muscle membrane or through all the layers of the intestine and spreads to 4-6 adjacent lymph nodes
- The tumor penetrates into the submucosal layer or into the muscular layer of the intestine, and also spreads to 7 or more adjacent lymph nodes
Step 3C. It is diagnosed in such cases:
- The cancer spreads to all the walls of the intestine, extends to the visceral part of the peritoneum (the one which covers the internal organs), but does not spread into the organs themselves, also spreads to the 4-6 nearest lymph nodes
- The tumor grows through all layers of the intestine, as well as 7 or more lymph nodes
- The tumor grows through all the walls of the intestine, spreads to adipose tissue and affects minimum 1 lymph node
There are no distant metastases in stage 3 of bowel cancer. They appear only at the last stage of intestinal cancer.
Step 4A. Stage 4 of bowel is characterized by the appearance of distant metastases. It is also divided into three subtypes. Bowel cancer of the 4th degree of subtype A is characterized by the tumor germination of all layers of the intestine. There is at least 1 distant metastasis (liver or lungs, as well as distant lymph nodes). In this case, regional metastases may be absent.
Step 4B. The tumor completely or partially affects the intestinal wall. Regional metastases may or may not be present. There is a minimum of 1 distant metastasis on the organs or several distant metastases on the lymph nodes.
Step 4C. Bowel cancer of stage 4 subtype C is characterized by complete germination of the organ wall, by the presence of regional metastases and tumor spreading to far-located areas of the peritoneum. In this case, distant metastases may not be present.
The most common metastases of bowel cancer are found in the liver. They are observed in 50% of patients with this disease. They are caused by a late diagnosis of oncopathology, as it is usually detected late - in the third or fourth stages.
Diagnosis and treatment of cancer in Germany
Cancer can be detected at an early stage, if the diagnosis is carried out in a timely manner. After all, in most cases cancer does not develop "out of nowhere". There are many precancerous diseases that can be detected and treated in a timely manner, preventing malignancy. People can also conduct periodic check-ups, which will allow for the detection and removal of the tumor in a timely manner, before the appearance of metastases.
The main precancerous diseases of the bowel cancer are:
- Crohn's disease
- Chronic inflammation of the large intestine
- Ulcerative colitis
- Diverticula of the intestine
Polyps can be multiple or single. Single ones are more dangerous. Sooner or later they degenerate into cancer in 40-50% of cases.
Bowel cancer is most common in Western countries. Therefore, doctors from countries such as Germany have the greatest experience in the treatment of such pathologies and have achieved the highest success rate doing that. The field of medicine is well developed in Germany. Therefore, you can travel to Germany for the most effective medical care.
To organize diagnostics and treatment in Germany, contact Booking Health for assistance.
We will help:
- Find a suitable clinic
- Solve all organizational issues with the administration
- Receive insurance that covers additional expenses in case of complications
- Save up to 70% of the treatment cost
We will also reduce the waiting time for treatment and seek urgent treatment, which is very important in case of bowel cancer. After all, this disease is developing rapidly, and the longer you do not receive medical care, the greater the risk that the tumor will give metastasis. You will also receive a full service package. We will help with the preparation of the documentation, provide an interpreter and meet you at the airport to transport you to the clinic by car. With Booking Health you can rest assured and fully concentrate on your health, avoiding the need to solve organizational issues.
Choose treatment abroad and you will for sure get the best results!
Author: Dr. Nadezhda Ivanisova