Brief overview: rectal cancer
- What is rectal cancer? Colon cancer in the last section of the large intestine
- How do rectal carcinomas develop? Mostly from initially benign intestinal polyps (mainly adenomas)
- Frequency: about 25,000 people develop new rectal cancer each year, men slightly more often
- Symptoms: Blood in the stool, painful bowel movements, sometimes changes in bowel movements, later pencil stools, involuntary bowel movements and wind, sacral pain
- Causes: improper diet (little fiber, lots of meat and fat), lack of exercise, obesity, alcohol, nicotine, genetic factors, chronic inflammatory bowel disease
- Treatment: radiation and surgery to cure, often in combination with chemotherapy; sometimes artificial bowel outlet
Rectal cancer: description.
In many colorectal cancer patients, the tumor is located in the rectum or rectum. This is the last section of intestine before the anus. It is about 15 to 18 centimeters long and plays a crucial role in defecation.
Rectal cancer: causes and risk factors
Rectal cancer usually develops from benign growths of the intestinal mucosa, so-called intestinal polyps. Such polyps are found in the intestines of very many people. In most cases they remain harmless. However, they can also degenerate over the course of years and develop into cancer – a rectal carcinoma develops.
A cancerous tumor grows quickly and uncontrollably. It invades surrounding healthy tissue and destroys it. In addition, individual cancer cells can spread throughout the body via blood and lymph channels and form daughter tumors (metastases) elsewhere, for example in lymph nodes, lungs or liver.
Genetic predisposition
Sometimes rectal cancer runs in families. This suggests that there is a genetic predisposition to rectal cancer in such families: Those affected have an increased risk of developing rectal cancer from benign intestinal polyps in the rectum.
Pre-existing conditions
Chronic inflammatory bowel disease also increases the risk of rectal cancer (and other malignant bowel tumors). This is especially true for ulcerative colitis. Diabetes mellitus also increases the risk of colorectal cancer, according to current knowledge.
Unhealthy lifestyle
Very often, an unhealthy lifestyle contributes to the development of rectal cancer and colorectal cancer in general: Little exercise, being overweight and an unhealthy diet increase the risk of cancer.
In particular, a lot of red meat, processed sausages, a high-fat diet and little fiber are considered risk factors for rectal cancer and other forms of colorectal cancer. The same is true for nicotine and alcohol.
Regular consumption of vegetables and fruits as well as a low-fat, low-meat, high-fiber diet and regular exercise reduce the risk of colorectal cancer (including rectal cancer)!
Age
Another common risk factor for all forms of colorectal cancer is age: the risk of disease increases with age. Thus, the median age of onset at the time of diagnosis is about 71 years (men) or 75 years (women).
Rectal cancer: symptoms
Not every change in bowel habits means cancer. However, you should have any persistent abnormalities clarified by a doctor!
General symptoms
Rectal cancer can also cause general symptoms. For example, many patients feel diminished performance and fatigue. Some patients also report unwanted weight loss or fever.
Anemia
Symptoms of anemia also often occur. These include, for example, pallor, decreased exercise tolerance and palpitations. Anemia occurs because rectal cancer bleeds easily and often.
Pencil stool and bowel obstruction
If rectal cancer is advanced, it can narrow the passage through the rectum. Bowel movements then appear thin like a pencil (“pencil stools”). If the tumor continues to grow, there is a risk of intestinal obstruction (ileus).
Pain
In addition to pain during bowel movements, pain may also occur in the lower abdomen or sacrum. If cancer cells have spread throughout the body (metastasis), daughter tumors cause further symptoms. Liver metastases, for example, cause right-sided upper abdominal pain, while lung metastases cause coughing and breathing difficulties.
If you have noticed abnormalities in your bowel movements, it is best to contact your family doctor first. If necessary, he or she will refer you to a specialist. This is usually a gastroenterologist, proctologist or visceral surgeon.
Medical history
If rectal cancer is suspected, the doctor will first ask you in detail about your medical history. For example, he will ask you to describe your symptoms in detail, ask about any previous or underlying diseases, and about your lifestyle. He will also ask whether there are any previous cases of colorectal cancer in your family (family history).
Physical examination
The next step is a physical examination. On the one hand, this allows the doctor to better assess your general condition. For another, he looks for possible indications of cancer. This includes a digital-rectal examination: the doctor palpates your rectum with a finger through the anus. In some patients, rectal cancer can be palpated during this procedure.
Colonoscopy
During a colonoscopy, the doctor can remove intestinal polyps directly and take small tissue samples (biopsies) from suspicious mucosal sites. Pathologists then examine them under the microscope.
Ultrasound of the rectum
For a more detailed examination, the doctor sometimes also performs an ultrasound of the rectum. In this so-called endorectal sonography, the examiner pushes the ultrasound probe through the anus into the rectum, as in a colonoscopy. In this way, he can better assess the individual intestinal wall layers and neighboring organs.
Staging examinations
A detailed examination of the bowel and analysis of tissue samples taken is sufficient to diagnose rectal cancer with certainty. If the suspicion is confirmed, the physician orders further examinations, the so-called staging. This serves to determine the exact location and size of the tumor as well as its spread in the body.
If women suspect that rectal cancer has spread to the vagina or uterus, a gynecological examination is necessary.
Rectal cancer: treatment
The exact treatment for rectal cancer is adapted to each patient individually. The tumor stage, age and general condition of the patient as well as any concomitant diseases play a role.
Classification based on location
An initial classification is also made according to the location of the rectal cancer in the rectum. To do this, doctors divide the rectum into thirds and measure from the anus. This results in rectal cancer of the lower third (0-6 centimeters), the middle third (6-12 cm) and the upper third (12-18 cm). Doctors often treat the rectal cancer in the upper third like a colon cancer.
Surgery
Currently, the only way to cure rectal cancer is surgery. The surgeon cuts out the tumor as completely as possible in what is called a deep anterior rectal resection (TAR).
In most cases, the surgeon creates an artificial anus (anus praeter or stoma). It initially serves to protect the surgical site (protective stoma) and can be moved back after a certain time. However, if the doctor has had to remove parts of the sphincter muscle, the artificial bowel outlet may have to remain permanently.
Radiation and chemotherapy
For early-stage rectal cancer, surgery is usually sufficient treatment. If the tumor is more advanced, patients receive radiation therapy or combined radiation and chemotherapy (radiochemotherapy) before surgery.
They can shrink the tumor and sometimes prevent the need to remove the anal sphincter as well. This neoadjuvant therapy also reduces the risk of recurrence. Rectal cancer is less likely to recur.
Chemotherapy or radiochemotherapy can also be useful after surgery: any remaining cancer cells in the body can be killed in this way (adjuvant treatment).
Treatment of metastases
Sometimes advanced rectal cancer causes metastases to other parts of the body, such as the liver and lungs. If possible, doctors surgically remove these – like the rectal cancer itself. If doctors cannot perform surgery, other options are available for liver metastases (lasering, freezing, heat-cooking).
Read more about treatment in our article Liver Metastases.
Palliative treatment
In some cases, rectal cancer has progressed so far that doctors can no longer operate on the cancer itself or its metastases. Then, medical professionals try to contain further spread for as long as possible.
This palliative treatment delays further symptoms and, ideally, increases the quality of the remaining life. Typically, doctors use chemotherapy for this purpose.
Rectal cancer: course and prognosis
Therefore, take advantage of cancer screening! The earlier the cancer is detected, the better the prognosis.
In this way, rectal cancer can often be detected early and treated in time. Also talk to your relatives about malignant diseases in the family. This will help you better assess your risk, as well as that of your loved ones.
You can read more about this in our article on colorectal cancer screening.
A healthy lifestyle also reduces the risk of cancer. Sufficient exercise, a high-fiber diet, and abstaining from nicotine are important first steps.
If you have been affected by rectal cancer, it is important to attend regular follow-up examinations even after successful treatment has been completed. Any recurrence of rectal cancer can then be detected and treated at an early stage.
More information about colorectal cancer and colorectal cancer screening can be found on the website of the Felix Burda Foundation (www.felix-burda-stiftung.de).
