What is Colon Cancer?
Colon cancer, also known as Intestinal cancer, is the formation of tumors by the cells in the large intestine, which is the last part of the digestive system, by undergoing genetic changes. Most cases of colon cancer occur as small, benign cell aggregates called adenomatous polyps. Some of these benign cells can turn into malignant colon cancer as time progresses and changes. Regular screenings in cancer diseases are very important factors for diagnosis and treatment.
What are the Symptoms of Intestinal Cancer (Colon Cancer)?
Symptoms of Intestinal cancer can include changes in the Intestinal, including constipation and diarrhea, rectal bleeding, blood in the stool, a feeling that the Intestinal is not completely emptied, cramps, pain, weakness, and unexplained weight loss. When these factors are encountered in colon cancer, which usually does not show many symptoms at early stage, the tumor will differ in size depending on where it originates. If you encounter such factors, you should consult your doctor. Especially, individuals with a family history should be more attentive to this issue, and it will be beneficial to the treatment process.
What are the causes of Intestinal Cancer (Colon Cancer)?
In most cases, the causes of cancer are not definitively determined. Experts believe that in colon cancer, healthy cells are exposed to certain effects and turn into cancerous cells with a change in their genetic structure. If DNA damage occurs in a cell and turns into a cancerous cell, these cells will multiply and grow very quickly, unlike normal. The growth and proliferation of these cells forms a tumor. As time passes, the spread of cancerous cells beyond the starting point to different parts of the body is called metastasis.
What are the Risk Factors of Intestinal Cancer (Colon Cancer)?
Mutations that increase the risk of Intestinal cancer can be passed on in families. Inherited gene mutations create cancerous cells and increase the risk of cancer.
Hereditary Nonpolyposis Colorectal Cancer (HNPCC))
Also known as Lynch syndrome. The presence of this cancer increases the risk of developing colon cancer and other cancers.
Familial Adenomatous Polyposis (FAP))
It is a disease that causes the formation of a high amount of polyps lining the inner part of the rectum and colon. If left untreated, the risk of developing colon cancer increases.
How is the diagnosis of Intestinal cancer (colon cancer) made?
Colon cancer screening
A number of screening tests are performed to diagnose colon cancer at an early stage. Diagnosis of the disease at an early stage will increase the success of treatment. People with a family history are advised to start these tests earlier.
Diagnosing colon cancer
Colonoscopy: It is important to do one or more tests if the symptoms raise the suspicion of colon cancer. In the colonoscopy procedure, a tube with a camera is used to see the entire large intestine and rectum. The suspicious region is observed through the camera and a biopsy can be performed in the region where the sample is to be taken.
Blood tests: Blood tests can be done to measure the working capacity of the kidney and liver. Analysis can be made according to the results. A blood test may also be ordered to detect carcinoembryonic antigen (CEA). Monitoring this CEA level is important to understand the prognosis and to see the response to treatment.
What are the treatment methods of Intestinal cancer (colon cancer)?
The stage of cancer is a great resource for determining treatment options. Treatment options include treatments such as surgery, chemotherapy, and radiation.
Surgical intervention in early-stage colon cancer
If the cancer has not yet reached large sizes, it can be completely removed during a colonoscopy. Endoscopic mucosal resection may require removal of some cells from the large intestine or part of the rectum. In minimally invasive surgery, polyps that cannot be removed by colonoscopy can be removed by laparoscopic surgery.
Surgery in invasive colon cancer
When the colon cancer reaches a certain size, the following procedures can be applied.
Partial Colectomy
It is the process of removing the cancerous part of the large intestine and a part of it.
Surgery of cancer in advanced stage
If the cancer is in advanced stages, the aim of surgical operations is usually to eliminate symptoms such as bleeding and pain and the patient’s complaints. In this process, different treatments may be preferred.
Chemotherapy
It is a drug treatment given to kill the cancer cells. It can be applied if there is a spatter in the lymph nodes after the surgery. Chemotherapy can also be given against the risk of cancer recurrence. In some cases, it is used to shrink the tumor before surgery. In cancers that spread throughout the body, chemotherapy is given to minimize symptoms and complaints.
Radiation therapy
The aim of radiation therapy, which is also called radiotherapy, is to eliminate the tumor by sending radiation. At this point, sources such as X-rays with high energy are used. In order for a disease to be treated with radiotherapy, its location should not move as much as possible. Since the colon is moving, radiotherapy is applied only in fixed tumors that are attached to the surrounding tissues in cancers of this organ, or it can be discussed in case of recurrent disease.
Microsatellite instability
DNA mismatch repair deficiency and genomic instability are terms that are related and sometimes used interchangeably. Genomic instability occurs because DNA mismatches cannot be repaired to the desired degree.
This concept has been analyzed in detail in colon cancer. When all colon cancers are considered, the cases formed by tumors with high microsatellite instability (MSI-H) are too many to be underestimated. Detecting these tumors is very important as tumors respond effectively to immunotherapy drugs but are less responsive to chemotherapy. It is also possible in the near future that tumors will be classified according to whether they are MSI positive or negative.
Targeted drug treatment
Cancerous cells tend to multiply and grow rapidly. At this point, some agents have been developed by targeting the defects that allow it to grow. These targeted drugs can be used alone or in combination with chemotherapy. It is used in the usual advanced stage of the disease that does not respond to standard chemotherapies. However, with the age of tumor agnosia, genetic testing is applied to an increasing number of patients and treatments are directed in the light of genetic information from the beginning.
Immunotherapy
It is a treatment that enables the immune system to fight cancerous cells more effectively with an external effect. Immunotherapy treatment with some antibodies can be applied to the patients at advanced stages.
Supportive (palliative) care
Palliative care is applied to relieve symptoms and pain of diseases. In addition to the ongoing treatment, in this treatment, which is applied to increase the comfort of life, patients can feel better and lead a comfortable life.