The large intestine (colon) is the organ between the stomach and the anus. The first 150 cm of the large intestine is called the colon and the last 15 cm is called the rectum. The rectum, which can also be defined as the part of the large intestine before the anus, is a part of the large intestine and stool is stored in this area. Foods that are transmitted to the small intestine to continue digestion after the stomach are digested to a large extent in this region. In the large intestine, water and minerals are absorbed, and then the stool is sent to the rectum, where it is stored before being expelled from the body.
Colon Cancer and What Is Its Frequency?
With its general definition, cancer is a disease that occurs when body cells divide and multiply uncontrollably and rapidly. Colon cancer is the name given to the type of cancer seen in the large intestines (in the section up to the rectum).
Colon cancer is the most common type of cancer after lung and prostate cancers in men and lung and breast cancers in women, and its incidence is slightly higher in men than in women.
The incidence of cancer originating from the colon mucosa increases after the age of 50, and reaches its highest level at the age of 80. While the average age of colon cancer in men is 63, it is 62 in women.
The formation of colon cancer begins in the form of small clusters in the large intestine, which are called adenomatous polyps in medicine. Polyps, which can be of different sizes, can turn into cancerous structures over time. Therefore, people with a family history of cancer should participate in screening tests.
The risk of developing the disease in people with a family history of colon cancer is 1.7 times higher than in healthy people. The risk is 2.7 times higher in people with a family history of more than two colon cancers. Colon cancer is associated with malnutrition and a sedentary lifestyle as well as genetic factors.
What are the Risk Factors for Colon Cancer?
While some of the causes of colon cancer are preventable, some are not. Some of the preventable risk factors thought to cause colon cancer can be listed as follows:
- Being overweight or obese,
- Consuming processed meats such as salami and sausages,
- From carbohydrates eating rich, low in fiber,
- Having a sedentary lifestyle,
- Consuming excessive amounts of red meat,
- Using cigarettes and similar tobacco products,
- Taking large amounts of alcohol.
- Getting older,
- Polyp in the large intestine of the person,
- Ulcerative Have an inflammatory bowel disease such as colitis or Crohn's disease Having a history of bowel polyps or colon cancer,
- Having had colon cancer before,
- Having a history of ovarian, breast or uterine cancer in women.
What are the Symptoms of Colon Cancer?
The large intestine consists of 3 parts; The right, left and lower columns are sections with different structures. For this reason, the symptoms are different according to the region where the tumor is located.
Since the right colon is wider than the left colon, an obstruction that will occur here will give symptoms in a longer time and the disease will progress more insidiously. Because the left colon is narrower, the existing obstruction in the intestine starts earlier. Polyps in the colon, which initially do not cause any symptoms, become cancerous over time, increase in number and begin to grow in size. Thus, the symptoms of colon cancer appear in the person.
The first symptoms in colon cancer are usually changes in stool pattern and unexplained abdominal pain. Changes in defecation patterns manifest as diarrhea or constipation. /li>
How to Screen for Colon Cancer?
Ü For colon cancer, which is among the top 10 cancer types in our country and causes significant death and/or disability, T.C. The Ministry of Health has started the National Colon and Rectal (Colorectal) Cancer Screening Program for the people in the target group. The target audience to be screened is all men and women between the ages of 50-70. In high-risk individuals, screening is initiated from the age of 40.
High-risk individuals are individuals with a first-degree family history of colorectal cancer or adenomatous polyp, ulcerative colitis, Crohn's Disease, or hereditary polyposis or non-polyposis syndrome.
Should Colon Cancer Screening Be Performed?
Since the survival time of patients is long and quality of life is high with early diagnosis and treatment, all individuals in the 50-70 age group should have colon cancer screening.
What are the Stages of Cancer?
After the diagnosis of colon cancer is clarified, staging is done. In the staging process, the data obtained by pathological examination of the tissue sample taken from the body, as well as radiological imaging methods such as tomography, magnetic resonance imaging (MRI), chest X-ray, PET, are evaluated and the stage of the disease is determined.
Colon cancers are staged between 1 and 4. Treatment is also applied according to the stage of the disease.
The stages of colon cancer are as follows:
- Stage 1: Cancer has invaded (spread) the intestinal wall. However, it could not reach all intestinal layers.
- Stage 2: Cancer has invaded all intestinal layers.
- Stage 3: Colon cancer has metastasized and spread to regional lymph nodes.
- Stage 4: Cancer has spread to distant tissues and organs such as liver, peritoneum and lungs.
How to Diagnose Colon Cancer?
Diagnosis of colon cancer, It is determined within the framework of the screening program or when the patient consults a physician with colon cancer symptoms. The physician first takes the patient's history and then performs a physical examination.
Blood tests for diagnosis, occult blood in the stool are checked. The feces taken are processed and the presence of hemoglobin is investigated. first d If the sample is positive, false positive is investigated. For this reason, in 3 consecutive tests, 2 samples are taken in each test. Blood tests: Carcinoembryonic antigen (CEA), which is a cancer marker, is requested in addition to the blood tests requested for anemia and general condition evaluation. Although CEA is not specific to colon cancer, its elevation gives a clue for colon cancer. CEA level is used in the follow-up of the disease after treatment.
Colonoscopy Colonoscopy is a lighted endoscopy instrument and helps to examine the inner surface of the large intestine in detail. Thanks to colonoscopy, which allows the detection of lesions in the intestine and biopsy from the lesions, the tissue piece taken is examined in the laboratory environment. Depending on the pathological diagnosis, the person is diagnosed with colon cancer.
In recent years, it is possible to detect colon cancer at an early stage by looking at the genetic codes that come with feces from polyps suitable for cancer in the large intestines, called fecal DNA. Air is introduced into the colon with a catheter and multiple radiographs are taken under fluoroscopy. Intestinal preparation should be done in patients before the examination. Sedation is usually not done. Patients may feel cramp-like pain during the procedure, but they can return to work after the procedure. The examination can detect half of adenomas larger than 1 cm and 39% of all polyps. It may miss small polyps, but it may make the physician suspicious by showing non-specific findings such as increased intestinal wall thickening. differs according to the stage. Colon cancer treatment often begins with surgery.
In early stage colon cancer, the cancerous area is removed together with the surrounding tissues. Lymph nodes, one of the surrounding tissues, are also examined by the pathologist after the operation, and it is investigated whether the cancer has spread beyond the large intestine.
Chemotherapy is not applied to patients with stage 1 colon cancer. Only some of the stage 2 patients are given chemotherapy after surgery. House In cases of re 3 colon cancer, chemotherapy is given after surgery to prevent the spread of the disease (adjuvant). In advanced stage colon cancer (Stage IV), considering the general condition of the patient, surgical interventions are performed for the symptoms and the patient is tried to be relieved. The general condition of the patient, the severity of the symptoms and the available opportunities determine the treatment approaches in patients at this stage. Therefore, it is very important to detect colon cancer at an early stage.
Today, patients can be provided with a more successful and comfortable chemotherapy process with targeted chemotherapy drugs. Whether the patient can receive targeted chemotherapy or not is determined by genetic examinations in the tumor tissue. In patients who have a large part of the large intestine removed, defecation can be taken into the bag through a hole in the abdomen, permanently or temporarily in some patients. These bags are called colostomy bags. The intestinal ends, which are taken out through the hole in the anterior abdominal wall, are sutured to the abdominal skin and a colostomy bag is attached to the end. In patients with temporary colostomy, the intestines can be reinserted into the abdomen with a second surgery.
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