Colorectal cancer is one of the most common types of cancer in the western world. Every year
- around 59,000 people in Germany every year according to cancer registry data for 2018
- 4500 people in Switzerland according to krebsliga.ch
from colon or rectal cancer. Together with malignant tumors of the sigmoid colon (small intestine), rectal cancer accounts for more than 60% of all malignant bowel tumors. Men are affected slightly more frequently than women. Overall, colorectal cancer is the third most common tumor disease in men and the second most common in women.
On average, those affected are over 60 years old at the time of diagnosis. In rare cases, however, much younger people can develop the disease if they have a genetic predisposition.
Possible localization of rectal cancer © bilderzwerg | AdobeStock
Like other types of cancer, rectal cancer is divided into stages .
Stage I represents the earliest form, in which the tumor only affects the superficial layers of the intestinal mucosa. Higher stages reflect the extent to which the tumor has spread. Stage IV means that the tumor has already formed offshoots (distant metastases) in more distant organs.
The tumor usually grows very slowly. The earlier the stage, the better the chances of recovery. The aim is therefore to diagnose the tumor at an early stage so that it can be treated at an early stage.
Up to 90% of all carcinomas in the bowel are so-called adenocarcinomas. This means that they develop from the glands of the intestinal mucosa.
Like colon cancer, rectal cancer usually develops from intestinal polyps, i.e. benign tumors of the intestinal wall mucosa. Intestinal polyps are therefore regarded as a precursor to a possible later bowel cancer.
Depiction of intestinal polyps (here in the large intestine) © tussik | AdobeStock
One of the most important risk factors for the development of bowel cancer is age. While bowel cancer is still extremely rare at the age of 30, the risk increases significantly with age. More than 90 % of all rectal cancers only develop after the age of 50.
However, genetic predisposition also plays an important role - it can increase the risk of bowel cancer by up to three times. For this reason, patients are always asked about cases of bowel cancer in direct relatives. In the case of rare hereditary diseases, there is a high risk of developing bowel cancer at a young age.
There is also a slightly increased risk with chronic inflammatory bowel diseases. These include
These risk factors cannot be influenced. However, there are also so-called lifestyle risk factors that are within everyone's control:
- Smoking
- Excessive alcohol consumption
- a high-fat, low-fibre diet with a high proportion of red meat or processed sausage products
- lack of exercise
- being overweight
A healthy and balanced diet is an important factor for good health, even with cancer © sonyakamoz | AdobeStock
For most people affected, the tumor causes little or no symptoms for a long time. In the early stages, it is therefore usually discovered by chance, for example during a routine examination.
Cancer screening examinations therefore play an important role in the early detection of cancer. In Germany, this is covered by statutory health insurance from the age of 50. In Switzerland, basic insurance also covers the costs of cancer screening for people between the ages of 50 and 69.
If symptoms occur, they are usually not very characteristic at the beginning. They are often either not noticed or ignored by those affected. These include stool irregularities such as frequent bowel movements or alternating constipation and diarrhea.
Visible blood in the stool can also indicate cancer of the rectum. In addition, patients often suffer from
- nausea,
- a feeling of fullness,
- flatulence,
- pain during bowel movements or
- cramps.
The non-specific general symptoms of a tumor disease include
- Weight loss,
- heavy night sweats,
- fever and
- reduced performance.
Later, gradual blood loss via the stool often leads to anemia, which manifests itself in
- Pallor,
- tiredness and
- increased susceptibility to infections
to infections.
In addition to other unspecific symptoms, rectal cancer can also cause night sweats © kolotype | AdobeStock
If the tumor is more advanced, it constricts the bowel further and further. This can lead to changes in the shape of the stool, so-called pencil stools. In the worst case, even intestinal obstruction is possible. This is usually accompanied by severe cramp-like pain.
At a later stage, the tumor can also spread beyond the intestine and grow into neighbouring organs.
It can also formmetastases in other organs. Cancer cells are spread to other organs via the bloodstream and lymphatic system. There they can form metastases.
In rectal cancer
- in tumors of the upper and middle third of the rectum, primarily the liver,
- tumors of the lower third of the rectum mainly affect the lungs.
affected.
Even though a wide range of technical examination options are now available, digital rectal examination with a finger is part of the diagnostic process. Up to 10 % of rectal tumors are detected in this way.
Colonoscopy is the most important way of confirming the diagnosis. Material is removed and the diagnosis can be confirmed. In addition to the rectoscopy, a complete colonoscopy should always be performed, as so-called secondary tumors can be present in up to 7% of cases.
If the diagnosis of rectal cancer is confirmed, further clarification of the tumor stage is carried out. This allows the doctors to assess the extent of the tumor and the tumor environment.
This includes
- Endosonography (internal ultrasound),
- sectional imaging of the small pelvis, preferably with magnetic resonance imaging. If this is not possible (e.g. in the case of claustrophobia or a pacemaker), computer tomography is used.
The search for distant metastases is carried out using ultrasound of the upper abdominal organs and X-ray of the lungs or also using computer tomography.
The determination of the so-called tumor markers (CEA and CA 19-9) is particularly important for follow-up care. A baseline value is therefore determined at the time of initial diagnosis.
Examinations are of great importance in the context of early detection. Early diagnosis significantly improves the chances of recovery. Screening colonoscopy is of great importance here. This allows rectal cancer to be detected before it causes symptoms. Colon polyps, as precancerous lesions, can also be removed before they degenerate.
Removal of a colon polyp during a colonoscopy © phonlamaiphoto | AdobeStock
Nowadays, the treatment of rectal cancer is no longer the responsibility of just one specialist discipline, but should be carried out on an interdisciplinary basis. Therefore, every case of a patient with rectal cancer should be discussed in an interdisciplinary tumor conference. The stage-appropriate therapy is determined taking all findings into account.
After successful treatment, be it surgery and/or chemotherapy, the patient is presented again and the next steps are determined. In this way, each patient is always cared for by an interdisciplinary team. This procedure is mandatory for all certified colorectal cancer centers.
The treatment of rectal cancer depends on its localization, the depth of invasion and the presence of lymph nodes or distant metastases.
Local measures
The prerequisites for the direct surgical removal of rectal cancer are
- a very early stage of cancer
- spread below the upper layer of the submucosa (layer directly below the mucosa)
- the location of the carcinoma in the lower two thirds of the rectum
Removal can be
- as part of colonoscopy, a so-called endoscopic mucosal resection (EMR),
- via the anus by means of transanal endoscopic microsurgery (TEM) or
- a conventional transanal tumor resection
can be performed.
Surgical treatment
A rectal carcinoma with a greater depth of invasion than mentioned above, but which has not yet spread beyond the wall or metastasized to the lymph nodes, can be treated directly with radical surgery.
Nowadays, this procedure is usually performed in a minimally invasive way, i.e. laparoscopically with the help of a camera through several small incisions. A surgical robot can also be used. Whether the sphincter muscle can be preserved also depends on whether it is already affected by the tumor.
In the case of tumors located just above the sphincter, it should also be borne in mind that pre-existing incontinence may worsen after the operation.
Even if the sphincter muscle is preserved, an artificial anus often had to be inserted as part of the operation. This considerably impairs the quality of life of those affected. Today, modern surgical procedures can often avoid the need for an artificial anus.
TME (total mesorectal excision)
The aim is to remove the tumor together with its lymphatic drainage pathways and thus its main metastatic routes.
The TME technique describes the removal of the rectal cancer together with its surrounding fatty tissue and its surrounding envelope layer(mesorectal fascia). This can be carried out minimally invasively or openly using an abdominal incision.
The bowel continuity is then restored. This is done using a special stapling device (stapler) or sutures. The connection is also called an anastomosis. In the case of very deep anastomoses, a temporary artificial anus is often created so that the intestinal suture can heal without any problems.
This can usually be closed after three months in another minor operation.
Under certain circumstances, rectal cancer surgery is performed using a minimally invasive procedure (example photo of a minimally invasive operation) © Kadmy | AdobeStock
Pre-treatment with radiation chemotherapy
If the tumor has already grown into the surrounding fatty tissue or the surrounding lymph nodes are already enlarged, a combination of radiation and chemotherapy is used before the operation.
Chemotherapy is then carried out after the operation. This concept is called neoadjuvant pre-treatment. The aim is to shrink the tumor before surgery and reduce the risk of tumor recurrence.
Post-operative treatment / fast-track scheme
Post-operative follow-up treatment in hospital is carried out whenever possible according to a defined scheme (fast-track scheme / ERAS scheme). The aim here is to regain independence as quickly as possible.
The regimen includes adequate pain therapy, a rapid build-up of nutrition and early mobilization with the help of physiotherapy.
Palliative chemotherapy
Chemotherapy is also usually used for locally inoperable tumors or advanced metastases. It cannot cure the tumor disease. However, it can prolong life and improve quality of life.
After successful surgery and therapy, follow-up care is essential. The aim is to detect and treat any recurrence of the tumor or new distant metastases as early as possible.
Aftercare for rectal cancer is very structured and set out in guidelines. It includes the
- clinical examination,
- a blood test,
- regular colonoscopies and
- imaging by means of sonography and CT
over a period of five years.
Today, we can cure 60% of patients with rectal cancer. But the chances of recovery depend crucially on the stage of the tumor.
While 95% of patients in stage I still survive the next five years, the survival rate drops sharply in stage IV. In recent years, a change in the treatment concept has significantly improved the chances of survival, even in the presence of individual distant metastases.
If these can all be removed, there is now a real chance of recovery.
