Internal Medicine

The course of colon cancer

introduction

Colon cancer is the second most common cancer in women and the third most common in men. Like most other cancers, colon cancer is divided into different stages. This is done according to the so-called TNM classification. The course of the disease depends largely on the stage of the tumor. While intestinal tumors that are discovered at a very early stage have a good to very good chance of a cure, this can happen with a tumor that is discovered at a very late stage and has already spread (metastasized) has to look different.

The course of colon cancer is therefore very different. The total 5-year survival rate for colon cancer is just over 50%. This means that just over half of the patients are still alive 5 years after diagnosis. Life expectancy is strongly dependent on the tumor stage. In the early stages of the disease, i.e. stage I, around 95% of the sick are still alive after 5 years. In the most advanced stage, stage IV, the 5-year survival rate is only about 5%.

This is how colon cancer is discovered

In colon cancer, tumor growth occurs in the area of the large intestine (colon carcinoma) or in the area of the rectum / rectum (rectal carcinoma). In the vast majority of cases, colon cancer develops from a precancerous stage, the so-called colon polyps. It usually takes several years for a polyp that is still benign to develop into a malignant tumor. This is why prevention plays a crucial role in colon cancer. For this purpose there are colon cancer screening examinations which are financially covered by the statutory health insurance from the age of 55. Experts actually recommend starting such colon cancer screening examinations as early as the age of 50, as there is a significantly increased risk of developing colon cancer from this age.

A full colonoscopy is performed during colon cancer screening. A long, flexible tube with a camera is inserted into the intestine via the anus at the end and carefully pushed forward to the transition from small intestine to large intestine. The entire intestine is inspected using a camera. If conspicuous areas of the mucous membrane are discovered, small tissue samples can be taken using pliers.

It is much more common, however, that polyps are discovered during the screening colonoscopy. Unless there are very many or extremely large polyps, these are removed during the colonoscopy. They will then be sent to a histopathological institute and examined under a microscope. The pathologist can then determine whether the tumor is benign or whether malignant cells have already been found. He can also see whether, in the case of malignant cells, the tumor has been completely ablated or whether a new ablation (Re-resection) necessary is. In addition to the preventive colonoscopy, from the age of 50, the annual digital rectal examination, i.e. the family doctor checking out the lower anal canal with your finger, and a test for blood in the stool every 2 years are recommended as colon cancer screening examinations.

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diagnosis

If an abnormal mucosal finding is discovered in a colonoscopy and the histopathological examination confirms that it is bowel cancer, several further examinations follow. These include an ultrasound examination of the abdomen, an X-ray examination of the lungs, possibly a CT or MRI examination of the abdomen and chest as well as a determination of tumor markers. Depending on the location of the tumor, an endosonographic examination may also be used.

An ultrasound device is inserted into the anus to better assess the spread of the tumor. All of the examinations mentioned are referred to as so-called tumor staging. The exact tumor stage can only be determined when all the test results are available. The therapy strategy is then also based on the tumor stage. In stages I to III, if the general condition of the patient allows, the tumor is removed by surgery.

Read more on the topic: Stages of colon cancer and their prognosis

From stage II onwards, chemotherapy is usually carried out after the operation. In tumor stage IV, the treatment strategy depends on whether the scattered foci (metastases) can be surgically removed or not. Once the colon cancer therapy has been successfully completed, follow-up care follows. For this purpose, examinations are carried out at certain intervals over a period of 5 years, which should make a recurrence of colon cancer (relapse) detectable in good time. These include the physical examination, the determination of tumor markers, the ultrasound examination of the abdomen, the CT examination of the abdomen or chest and another colonoscopy.

More on this: How is colon cancer diagnosed

Cure for colon cancer

Depending on the stage of the tumor, healing can take place through surgical removal of the tumor alone or through a combination of surgical tumor resection and chemotherapy. In tumor stage IV, an additional surgical resection of scattered foci (Metastases) become necessary. Whether or not a cure can be achieved through the therapy options mentioned cannot always be foreseen. The earlier the tumor is discovered, the smaller it is, the better the chances of recovery. It also plays an important role whether and how many lymph nodes are affected by tumor cells and whether the tumor has already spread. If the tumor has been completely removed, a 5-year follow-up will follow as there is a risk of recurrence within the first 5 years (Relapse) is highest.

Read more on the subject at: Is Colon Cancer Curable?

Course of an inoperable colon cancer

Colon cancer inoperability can have various reasons. It may have become so large and have infiltrated important structures that complete removal is not possible. In the case of colon cancer, however, this is usually not the decisive point. In the vast majority of cases, the tumor can - at least in theory - be radically removed. However, this may mean that larger parts of the colon or rectum must also be removed. Not infrequently this can also mean the creation of an artificial anus.

However, a tumor can also be inoperable if it has spread to such an extent that complete surgical removal of all tumor cells is not possible. Tumors in lower tumor stages can also be inoperable. Namely when the patient is in poor general condition so that the risks of anesthesia and surgery are too high. So-called palliative therapy is used in all of these cases. Palliative means that the goal of therapy is not healing, but alleviating symptoms and extending life.Examples of palliative therapy for colorectal cancer are partial removal of the tumor or metastases if these represent a burden. This can be the case, for example, if the tumor obstructs the intestinal lumen so that the food becomes blocked (intestinal obstruction). As part of palliative therapy, attempts can then be made to remove the tumor to such an extent that the intestinal passage can be restored at least temporarily. Chemotherapy without surgery is also palliative because it does not cure but can alleviate symptoms and / or prolong life. In addition, pain therapy plays an important role in palliative treatment.

Further information:

Chemotherapy for colon cancer
Radiation therapy for colon cancer

Course without treatment

Colon cancer is - like most other cancers - a tumor disease that ends fatally without treatment. How quickly the tumor progresses, however, varies greatly. If no treatment is available, one of the greatest risks is that sooner or later the growth of the tumor in the intestinal lumen will lead to an intestinal obstruction (Ileus) is coming. This is a clinical picture that, if left untreated, can often be fatal within a few hours. In the case of untreated colon cancer, metastasis can also occur, i.e. tumor cells can spread from the intestine into the entire body. How long the life expectancy is with colon cancer that is not treated cannot be said in general terms. This varies greatly from person to person and depends on numerous different factors.

Read also: Life expectancy in colon cancer

Signs of an end stage

End-stage colon cancer is not characterized by symptoms that are specific to that stage. Numerous complaints can occur with advanced colon cancer. These include blood in the stool, severe abdominal pain, an intestinal obstruction, significant weight loss and increasing paleness due to bleeding in the tumor area. In addition, the daughter tumors can cause symptoms if metastasized. These depend on the localization. However, all of the above symptoms can occur at an earlier stage of the tumor and are not a specific sign of a particular stage of colon cancer.

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