Stages of colon cancer and their prognosis
Colon cancer is divided into different stages in order to adapt the therapy and thereby improve the chance of recovery and life expectancy.
The main criterion is the depth of penetration of the tumor into the intestinal layers. Another important criterion is whether the tumor has spread to lymph nodes or to another tissue. The more advanced the stage, the more intensive the therapy must be.
What are the stages of colon cancer?
There are different classifications for staging. The UICC classification divides the stages based on therapy and life expectancy. It is in turn based on the TNM classification. This is divided into stages T1-T4. The T-staging is based on the depth of penetration - i.e. based on how many intestinal layers are affected by the tumor. In addition to the T stages, additional information is given. Another point is how many lymph nodes are infiltrated by the tumor.
Finally, there is a classification as to whether the tumor has spread to another organ, i.e. whether distant metastases are present. The exact classification based on the TNM classification can only be made after the operation using the specimen removed.
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Colon cancer UICC stage 1
Stage 1 of the UICC classification is the easiest stage. Here the tumor is still quite small. Stage 1 tumors are characterized by the fact that they have not yet spread to lymph nodes or metastasized to other organs. Furthermore, the tumor must not have spread too far locally in the intestine. It may not be more than the T2 stage of the TNM classification. This means that it has maximally spread into the muscle layer of the intestine.
Colon cancers start from the mucous membrane inside the intestine and from there continue to spread outwards. Before stage 1, there is a special stage - stage 0. Here, doctors speak of "carcinoma in situ". It is a very early stage of cancer. It is only in the mucous membrane of the intestine and is not invasive, so it cannot spread to other organs and is very treatable.
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Chances of recovery / life expectancy for stage 1 tumors
The chances of recovery are very good for a stage 1 tumor.
As a therapeutic measure, the tumor is operated on. It can either be done from inside the intestine or part of the intestine is removed. As a rule, no further therapy is required. In medical circles, life expectancy is given using the 5-year survival rate. It says what percentage of the sick are still alive after 5 years. In stage 1 it is over 90%. In the early stage T0, the chances of survival are even higher.
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Colon cancer UICC stage 2
Stage 2 of the UICC classification involves tumors that have also not yet spread to other organs or lymph nodes, but are larger locally in the intestine than in stage 1. They are therefore stage T3 or T4 cancers. In these stages the tumor has already spread to the outermost layer of the intestinal wall or the fatty tissue that surrounds the intestine. In the T4 stage, the tumor has already infiltrated the peritoneum or other organs in the area.
Even if the examinations did not initially establish that the cancer had spread to other organs or lymph nodes, it is not unlikely that the examination of the removed tumor will diagnose affected lymph nodes. In some cases, metastases already exist, but they are still quite small and will only be recognized later, when they have continued to grow. However, this does not have a major impact on therapy, since in both cases radiation and chemotherapy are carried out in addition to the surgical removal of the tumor.
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Chances of recovery / life expectancy stage 2
The chances of recovery are still quite high in stage 2 at around 60-85% - provided that the tumor has not already spread to the lymph nodes or has metastasized. In contrast to stage 1, the tumor is treated with chemotherapy and radiation in addition to surgery.
Radiation or chemotherapy takes place before the operation and after the operation the therapy is supplemented with chemotherapy again. The exact schemes of radiation or chemotherapy are decided individually with the doctor.
Read more on the topic: Chemotherapy for colon cancer
Colon cancer UICC stage 3
Stage 3 is defined independently of the local size of the tumor. The decisive factor is whether the tumor has spread to nearby lymph nodes. This is a bad sign as the tumor can spread throughout the body via the lymphatic system. In many cases, the tumor has unfortunately already spread to the lymph nodes. As a rule, this can only be determined in the pathology after the operation on the basis of the removed tumor.
If there are affected lymph nodes, the chances of recovery decrease. As in the first two stages, an operation is carried out in which the cancer is excised. The therapy is supplemented by chemotherapy or radiation in advance and after the operation there is also another chemotherapy. As a result, the treatment of stage 3 colon cancer is a lengthy, intensive and exhausting process. Treatment can take a year.
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Chances of recovery / life expectancy stage 3
In stage 3, 40 to 50 patients out of 100 sufferers live after 5 years. Individual factors are also important for the chances of recovery at this stage. This includes e.g. the age of the person concerned or the general physical condition. Because the fight against colon cancer takes a lot of strength and robs the body of a lot of energy. Many people with cancer lose weight during the disease phase. In addition, the body is also attacked by the strong drugs that are necessary to treat the cancer.
Furthermore, it differs from person to person how the chemotherapy is tolerated. Some patients have to stop chemotherapy due to side effects, while others tolerate chemotherapy relatively well. Ultimately, the colon cancers differ, the development of which is based on different mutations (genetic changes).
This means that they in turn respond differently to the therapy. In addition to the quality of the therapy, there are many other factors that cannot be influenced that decide whether the fight against cancer is successful or not.
Colon cancer UICC stage 4
Stage 4 is the terminal stage of colon cancer. Colon cancer is classified as stage 4 if the tumor has metastasized (spread to other organs). Stage 4 is divided again into stages 4a and 4b. In stage 4a only one other organ is affected by metastases, while in stage 4b metastases were found in at least two other organs. It is irrelevant how big the actual colon cancer is. The presence of metastases means that tumor cells have already spread in the body and the cancer is therefore very destructive.
The division of stage 4 into 4a and 4b is important for further treatment. In stage 4a, an operation is carried out with removal of the metastases as far as possible. In stage 4b, the medical options are very limited. Colon cancer is unfortunately no longer curable.
Read more on the topic: End-stage colon cancer
Chances of recovery / life expectancy stage 4
Since the colon cancer is already well advanced in stage 4, the chances of recovery are unfortunately significantly worse than in the other stages. In stage 4a the survival rate after 5 years is 5-10%. The therapy is very intensive and requires a lot of strength from those affected. The colon cancer and metastases are removed in an operation. However, it is not always possible to completely remove the metastases or the cancer surgically. Colon cancer often spreads to the liver. Here, the metastases are usually easy to remove as long as there is still sufficient intact liver tissue left.
In addition to surgery, intensive radiation and chemotherapy are also necessary in stage 4 to prevent the risk of tumor recurrence (tumor recurrence) and the occurrence of new metastases. Most recurrences occur in the first two years after treatment.
In stage 4b, colorectal cancer is unfortunately no longer curable. There is only palliative therapy. This means that drugs are used to improve the patient's quality of life and relieve their symptoms from the disease, such as Relieve pain. The 5-year survival rate for stage 4b is less than 5%.