Colon cancer is one of the most common cancers in Germany. With increasing age and family history, the risk of colon cancer increases. What you can do preventively, which symptoms are typical and which therapy is possible.
Colon cancer is a group of doctors diagnosing cancer in the colon, rectum and anus. Colon cancer often develops slowly from precursors, medically called polyp or adenoma (benign tumor). Over the course of several years, this can develop into a malignant carcinoma that is fatal if left untreated.
In Germany, colorectal cancer is the second most common cancer in women after breast cancer and the third most common in men. The risk of colon cancer increases with age. The number of new cases is increasing, at the same time the death rate is falling, so that patients can increasingly live with colon cancer in the long term.
Overview of article content:
Causes: How does colorectal cancer develop?
There are several risk factors associated with colon cancer:
Assessment: Colorectal cancer risk is also in the genes
About a third of patients with colorectal cancer have inherited their disease, which means that there is a tendency in the family for this type of cancer. People who are directly related to those affected (children, siblings, parents) have an increased risk of developing colon cancer as well. The more family members already suffer from this cancer or a pre-stage, the higher the risk for the other relatives. People whose direct relatives had polyps also have a significantly increased risk of colon cancer.
If you know about the family burden, you can prevent colon cancer: Prerequisites are timely colon cancer screening and regular colonoscopy.
What symptoms can be a warning sign
In the early stages, colorectal cancer hardly causes any symptoms and often later only becomes noticeable through unspecific symptoms. But there are a number of warning signs that can indicate colorectal cancer, and many of these symptoms can also have more harmless causes. With enlarged or inflamed hemorrhoids, however, blood can get into the stool. Nevertheless, a doctor should be consulted in case of uncertainty or persistent complaints.
Diagnosis of colorectal cancer by the doctor
The first step in diagnosing colorectal cancer is a detailed discussion with the doctor (medical history). He clarifies what symptoms are present and whether there have been cases of colon cancer in the family.
Tactile examination
If the tumor is located in the rectum area, the cancer can be discovered using a tactile examination (digital rectal examination). The doctor scans the rectum with his finger over the anus. If the pelvic floor is relaxed, the exam is usually painless.
The abdominal wall is also scanned to identify polyps and tumors in the anterior abdominal area. The doctor also uses the stethoscope to determine whether the bowel sounds sound normal.
Blood test in the stool
Tumors in the intestine bleed more often than the intestinal mucosa, which is why blood in the stool can be a warning sign of colon cancer. The blood can be visibly contained in the stool. If it is not visible to the naked eye, a stool test can reveal whether there is occult (hidden) blood in the stool.
Colonoscopy with biopsy
The most meaningful examination and the standard procedure for suspected colon cancer is a complete colonoscopy (colonoscopy). To do this, the doctor inserts a flexible, approximately 1.5 meter long tube (endoscope) over the anus into the intestine. At the tip of the endoscope there is a small camera with which the mucous membrane of the entire colon can be assessed. Before that, however, the intestine must be completely emptied using a laxative.
With additional instruments in the endoscope, the doctor can remove intestinal polyps directly and take tissue samples. Colonoscopy, polyp ablation and biopsy are usually painless. Often, patients are given a sedative or light anesthetic before colonoscopy. After the examination, patients should be picked up from the practice for safety reasons, because driving is taboo.
An alternative for patients in whom conventional colonoscopy cannot be performed is capsule colonoscopy. The patient swallows a small capsule, which is equipped with video and transmission technology.
Virtual colonoscopy as an alternative to endoscopy
Virtual colonoscopy (CT or MRI colonography) is suitable for patients for whom conventional colonoscopy is not possible. However, it is less sensitive than classic colonoscopy using an endoscope, so that inflammatory areas and small polyps can be overlooked. If the doctor discovers polyps during the examination, they must be removed in a separate procedure. Prior to colon cleansing, colon cleansing is also necessary.
Further investigations after colorectal cancer findings
If cancer is actually present after the first findings, the doctor clarifies by additional examinations whether he has already affected surrounding lymph nodes or forms metastases in other organs:
Ultrasound: This can be used to detect metastases in the liver and enlarged lymph nodes in the abdominal cavity.
CT: CT scan of the abdominal cavity
Chest x-ray: The chest is X-rayed to detect or rule out metastases in the lungs.
Stages of colon cancer
Colon cancer develops in several stages: First, there are benign new forms of the intestinal mucosa, the polyps or adenomas. In most cases, these preliminary stages remain benign and can be removed by the doctor as part of a colonoscopy. The polyps can develop into colon cancer within five to ten years.
If cancer is present, the doctor clarifies the stage at which the tumor is located. This question is central to the assessment of the chances of recovery and the selection of the appropriate therapy. Medical professionals distinguish between six different stages of colon cancer:
Stage 0 (carcinoma in situ): In this early stage, colon cancer is limited to the innermost layer of the intestinal mucosa.
Stage 1: The cancer has spread to the outer layer of the intestinal wall and the surrounding muscle layer of the intestine.
Stage 2: The cancer spreads to the surrounding tissue, but has not yet affected any lymph nodes.
Stage 3: infiltration of the neighboring lymph nodes, but no further spread to other parts of the body.
Stage 4: Metastases are detectable in other parts of the body and organs.
Recurrence: after completing treatment, colorectal cancer recurs or appears as metastasis in another organ, often in the liver or lungs.
Therapy: what treatment for colorectal cancer?
The type and scope of treatment the doctor chooses depends on the location, stage and aggressiveness of the tumor, as well as on the age and physical endurance of the patient. If left untreated, colorectal cancer is fatal.
Surgical removal of the cancer
For stage one to three colorectal cancer, the current guideline recommends surgery to try to completely remove the tumor (R0 resection). In addition to the cancer, the surrounding sections of the intestine and lymph nodes are also removed. This is to prevent the formation of metastases. The earlier colorectal cancer is detected, the easier it is to completely remove it and the better the chances of recovery.
In most cases, the remaining intestine is able to take over the digestive function completely, so that the natural intestinal exit is preserved. If the tumor is too close to the sphincter, this must also be removed and an artificial bowel (stoma) placed. For this purpose, a small opening is made on the abdominal wall, through which the contents of the intestine can be emptied into special bags or through regular, controlled irrigation.
Operations on metastases
In most cases, the formation of daughter ulcers in colorectal cancer first takes place in the liver. If there are individual liver metastases, they can be removed by surgery in favorable cases. Surgical measures are almost always accompanied by chemotherapy. Targeted therapy with laser, heat or cold probes as well as cytostatics (drugs that stop tumor growth) is used in individual cases.
Colon cancer chemotherapy
In colon cancer, chemotherapy is carried out alongside the operation (adjuvant). Chemotherapy given before surgery can lead to tumor size reduction. The cytostatics also significantly improve the chances of recovery. In most cases, chemotherapy can be performed on an outpatient basis.
Radiation
Radiation therapy can also be used to treat colon cancer. In many cases, radiation is combined with chemotherapy. For cancer of the lower rectum, radiation is performed before surgery to reduce the size of the tumor. If it cannot be guaranteed during the operation that the tumor has been completely removed, radiation is given. This can significantly reduce the risk of remaining tumor remnants growing.
Immunotherapy as an innovative option
One method that has become increasingly important in cancer treatment in recent years is immunotherapy. Doctors take advantage of the body's ability to specifically destroy foreign cells or substances by forming special antibodies. Appropriate drugs have already been approved for lung cancer and skin cancer – in advanced colon cancer, immunotherapy substances are still being investigated in clinical studies.
Palliative measures in advanced colon cancer
Palliative medicine is a treatment that does not cure, but can significantly improve the patient's quality of life. Palliative measures are carried out in very advanced stages of colon cancer, which are no longer curable. They include:
Tumor surgery to avoid intestinal obstruction.
Irradiation of intestinal tumors or metastases to relieve pain.
Chemotherapy for advanced cancer with relatively well-tolerated medication.
16 healthy foods for people with cancer
Chances of recovery
If colon cancer is recognized and treated early, the chances of recovery for the patient are very good. The survival time of those affected has increased significantly in the past ten years. The reason for this are newly developed therapeutic options and preventive medical checkups that more and more Germans are using.
On the other hand, the chances of a cure for very aggressive tumors are less good – these types of cancer spread at a very early stage and spread to other organs.
Screening: Colon cancer screening for early detection
The statutory health insurance companies offer their insured persons a colon cancer screening when they turn 50. This initially includes annual tactile examinations of the intestine and an examination of the stool for blood. From the age of 55, there is the option of preventive colonoscopy.
From 50: Annual palpation and stool examination
From the age of 50, legally insured persons are entitled to an annual palpation and stool examination at the gastroenterologist. If there is a striking finding, he initiates further investigations.
Furthermore, an immunological test (iFOBT) for invisible (occult) blood in the stool is carried out. The iFOBT detects blood in the stool with the help of antibodies and is therefore less prone to failure. In addition, the immunological stool test is more sensitive and detects colon cancer and its precursors more reliably than the previously used gujaktest (biochemical test for occult blood in the stool).
From 55: Colonoscopy as a precaution
From the age of 55, insured persons can have a stool test or colonoscopy (colonoscopy) every two years every ten years.
Early detection for risk groups
Statutory health insurance companies cover the costs of an individually tailored examination program for high-risk patients.
Family cluster: If a direct relative (parents, siblings, children) is suffering from colon cancer or has been diagnosed with an intestinal polyp or adenoma, relatives should have a colonoscopy taken ten years before the age at which the event occurred – at the latest at 50 Years.
Genetic pre-exposure: If at least three direct relatives are suffering from cancer of the stomach, colon or uterus, family members aged 25 years and older are required to have colonoscopy at regular intervals. Human genetic counseling can also be considered.
Chronic inflammatory bowel diseases: According to the guidelines, health insurers for pancolitis (inflammation of the entire large intestine) have been performing a complete colonoscopy with biopsy every year for more than 15 years for over eight years or ulcerative colitis on the left side.
Prevention: Reduce risk through healthy lifestyle
In addition to preventive checkups, there are other ways to lower the risk of colon cancer. Based on the data from clinical studies and observational studies, three principles for risk reduction can be derived, according to the German Cancer Society:
Adequate movement: Physical activity is good for the digestion and the whole body. From swimming to cycling to the gym: the type of movement doesn't matter. Exercise in everyday life is also part of the sports units, for example climbing stairs instead of driving the elevator or running to the bakery instead of driving.
Healthy, balanced diet: Ideal is a light whole food with lots of fiber (30 g per day) as well as fresh vegetables and fruits. It is better to avoid foods containing fat and sugar and only enjoy in moderation. In particular, red meat (beef, pork, lamb, game) and sausages are considered risk factors for colorectal cancer and should not be on the daily menu. Alcohol should also only be consumed in small quantities and not every day.
Do not smoke: People who smoke increase their risk of many diseases, including colorectal cancer.
Again and again certain foods are said to have a risk-increasing or reducing effect. However, the underlying data are often of poor quality or are refuted by further studies. According to this, experts do not make any firm recommendations for or against certain foods or dietary supplements.