The inner surfaces of the large intestines are covered with a cellular surface called the mucosa. As a result of the proliferation of the surface (mucosa) cells at a certain point, a “polyp” is formed and over time, cell division becomes uncontrolled and “colon cancer” develops.
There are four layers in the colon wall from the inside out. Colon cancer, which starts in the inner layer, first goes deep in the wall and reaches other layers. Simultaneously with its progression to the wall layers, it spreads to other organs (metastasis) by entering the lymph (immune system) and vascular pathways (invasion).
Colon Cancer Risk Factors
Heavy alcohol intake
Presence of inflammatory bowel disease
Family history of colorectal cancer or adenomatous polyps
Carrier of hereditary syndrome (Lynch, FAP etc.)
Ethnicity (African-American, Eastern European Jews, etc.)
Type 2 diabetes mellitus
What are Colon Cancer Symptoms?
Bright red bleeding from the rectum
Contaminated blood in stool, darkening of stool color
pen-like thinning of stool
Feeling that the intestines are not fully emptied after defecation
Long-lasting cramping and abdominal pain relieved by defecation
Weakness and fatigue
involuntary weight loss
New and persistent diarrhea or constipation
What is a colonoscopy?
A detailed physical examination is first performed in patients with the above-mentioned symptoms. As a result of this examination, patients who do not have signs of intestinal obstruction colonoscopy is planned. Patients without signs of obstruction (tightness in the abdomen, bloating, absence of gas or stool from the anus in the last few days) consume copious amounts of clear liquids and use drugs/syrups to empty the contents of the intestines, as they wake up the day before the shooting at home. The description of this application, which is called bowel cleansing, is given to the patients in writing while scheduling the shooting appointment. Relaxing / sedative drugs are applied just before the colonoscopy extraction, so that the patient does not feel pain and the procedure is comfortable.
The colonoscope, which is a flexible and highly mobile thin tube containing a wide-angle camera at its end, is advanced through the rectum and advanced through the large intestine, reaching the starting point of the large intestine called the cecum, entering the small intestine and proceeding for about 10-20 cm. After this stage, the colonoscope is carefully withdrawn and all parts of the large intestine are examined. Samples are taken from the detected masses and sent for pathological examination. The area where the mass is detected is marked so that it can be seen from outside the intestine. If a polyp is detected during colonoscopy, it is evaluated whether it can be removed as a whole according to the width and size of the inner surface of the intestine, which sits on the mucosa.
Ideally, polyps should be removed intact and sent for pathological examination. If cancer is detected even in a part of the polyp in cases where the integrity is impaired, the extent of wall spread cannot be known, and it may be necessary to surgically remove the part of the large intestine where it is located. Polyps that are not suitable for removal by colonoscopy should be marked and surgical resection can be planned after examination with appropriate imaging methods (computerized tomography – CT, magnetic resonance – MR, positron emission tomography – PET, etc.). Laparoscopic method is the most preferred application in these cases.
How is Colon Cancer Diagnosed?
Colon cancer diagnosis is confirmed when cancer cells are detected in the samples taken from the masses detected during colonoscopy. Various imaging methods (computed tomography – CT, magnetic resonance – MR, positron emission tomography – PET, etc.) are used to evaluate the spread of cancer in the large intestine wall and its relationship with neighboring organs / structures and to determine whether it has spread (metastasized). With the findings obtained, the clinical stage of the disease is determined and the appropriate treatment method is decided.
Two ways are possible in cases where cancer cells are not observed in biopsy samples taken during colonoscopy, but a mass is seen. By repeating the colonoscopy, more extensive and deep biopsies are taken, the pathological examination is repeated, and cancer cells can be seen. Another way is to mark the place where the mass is observed and surgically remove it.
Before the surgery, it is tried to obtain information about the location, size and possible metastases (splash) of the mass by using imaging methods as much as the conditions allow. If this method is preferred, the diagnosis of cancer will be made by pathological examination of the surgically removed mass. This route may have to be preferred for both diagnosis and treatment, especially in masses that have caused intestinal obstruction (abdominal bloating, vomiting, absence of rectal gas/stool in the last few days, etc.).
Colon Cancer Treatment
It is determined by the stage at which the cancer is detected. Surgery is the gold standard treatment for cancers that have not metastasized and are confined to the colon wall. The large intestine section containing the mass and the mesenteric area containing the vascular network are cleaned from the surrounding tissues and removed as a whole, then the remaining intestinal ends are combined with each other.
Tumor staging is done as a result of pathological examination. Adequate surgical resection ensures accurate staging of the cancer and determination of the necessary oncological treatment. Depending on the size of the mass and the degree of lymph node involvement, chemotherapy by medical oncology specialists and radiotherapy by radiation oncology specialists can be applied when necessary.
What is Laparoscopic Colon Cancer Surgery?
With special instruments placed on the anterior abdominal wall, the abdominal cavity can be inflated first and then examined with a camera and surgical removal (resection) stage is started. By means of special tools, both the mass located on the wall and the lymphatic networks spreading from the mass are cleaned as a whole and sent out for pathological examination through a short, horizontal incision made in the lower abdomen.
After laparoscopic surgeries, patients feel less pain compared to open surgeries, the digestive system works earlier, patients begin to move earlier, and hospital stays are shortened. The short and long term results of laparoscopic surgery are equivalent to open surgeries, and it is the first preferred method in suitable patients.