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Colon Cancer

Colon cancer is one of the most common types of cancer in the world. Although the risk of colon cancer can be seen at any age, it is most commonly observed after the age of 50. When the distribution by gender is examined, among all cancers, colon cancer ranks second in women and third in men. Specialists of Uniqacare Partner Clinics General Surgery Departments gave information about colon cancer and the treatment options.

What is Colon (Large Intestine) Cancer?

Colon cancer, which is a disease that develops in the region of the last part of the digestive system, known as the "large intestine" among the people, is seen in 1 out of every 20 people throughout his life.Colon and rectum are part of the digestive system. The large intestine is the next organ after the small intestine and is approximately 1.5 m long. It starts with the caecum from the lower right side of the abdomen in the form of an inverted U letter, goes up and turns under the liver and passes the abdomen horizontally. It comes under the spleen located in the upper left corner and again makes a turn and moves downwards from the left side and merges with the rectum. The rectum is the last part of the digestive system, with an average length of 15 cm and the enlargement of the large intestine.Colon cancer starts in cells in the colon. As the number of cells increases, it spreads around the colon in a circular fashion like a napkin ring. If diagnosed early, cancer cells can only be detected within the colon. If not diagnosed early, cancer may spread to nearby organs, lymph nodes, and through the bloodstream to the liver, lungs and other organs.The most important criterion for success in colon cancer treatment is early diagnosis. When colon or large bowel cancer is detected at an early stage, it is possible to completely get rid of the disease. 

Colon (Large Intestine) Cancer Risk Factors

In developed countries, the rate of colon and rectal cancer is 4 to 10 times higher than in developing countries. Causes of colorectal cancer; lifestyle, changes in environmental factors and hereditary genetic factors.

Genetic Factors

A person with a family history of colorectal cancer has a higher risk of cancer. Inherited genetic factors increase the risk ratio. Both familial adenomatous polyps in the large intestine and hereditary nonpolyp colorectal cancer, also known as Lynch syndrome, increase the risk of colon cancer. Although genetic colorectal cancers constitute only 5-10% of the disease, people with these genetic factors are younger than other colon cancer patients and carry a higher vital risk.

Hereditary nonpolyposis colorectal cancer (Lynch Syndrome) is the most common of the genetic colorectal cancers. It occurs as a result of incompatible DNA pairings, with inherited gene mutations. The average age at diagnosis is 45. This type of gene mutation predisposes to the formation of cancer of the endometrium (inner lining of the uterus), ovary, small intestine, ureter (urinary tract), and renal pelvis (kidney pool).

The presence of cancer in the family and first-degree relatives of the person seriously affects the occurrence of the disease. People with a family history of colon cancer should start having a colonoscopy 10 years before, at what age their relative was diagnosed with colon cancer. Completely healthy people who do not have a family history of colon cancer or do not have any complaints should have a colonoscopy at least once from the age of 50. It is easy to make an online hospital appointment to see specialist doctors.

What Causes Colon Cancer?

In the formation of colon cancer; In addition to excessive fat, red meat-based diet, obesity, smoking and alcohol consumption, polyps are effective. When polyps are seen in the large intestine during screening colonoscopies, it is possible to prevent the disease by removing them before they become cancerous. Having a history of breast and ovarian cancer in women also increases the risk of colon cancer in these people. It is recommended to be screened for colon cancer before the age of 50 in people with breast and ovarian cancer.

Polyps usually begin to show symptoms at a late stage, that is, when they turn into cancer. Only a small percentage of polyps turn into cancer. However, since the majority of cancers develop from polyps, it is an issue that needs attention. When we look at the general population, this rate is around 10-15%. Different types of polyps are seen in approximately 25% of the population around the age of 50. When we evaluate the age of 70, the incidence is close to 50%; that is, the incidence of polyps increases with age.

Features of polyps;

  • It doesn't go away on its own. It has genetic features. Patients with colon cancer in their first-degree relatives and polyps in previous examinations constitute the risk group and close follow-up is required.

  • Polyps are usually around 1 cm. Larger than 2 cm can be dangerous and must be removed.

  • Symptoms such as severe pain, intestinal obstruction, weight loss are usually late symptoms. Problems such as hemorrhoids and fissures in the anus may cause delays in the diagnosis and treatment of rectal cancer in some patients because they have similar symptoms. These symptoms can mislead both patients and, rarely, physicians. In general, the possibility of rectal and large intestine cancer should be investigated thoroughly in bleeding from the breech region over the age of 40.

  • It is not yet possible to prevent the formation of polyps. Those who have adopted a sedentary lifestyle, people with extreme stress, those who use cigarettes and alcohol, those who are obese, and those who eat predominantly red meat are at risk. However, feeding with pulpy foods, not smoking, that is, anything that regulates bowel movements is an important factor in preventing the formation of polyps.

Other Colon (Large Intestine Cancer) Risk Factors

Age:  Although it can occur at any age, it is mostly seen in people over 50 years old. The risk of colon cancer increases with age. The rate of developing colon and rectum cancers in patients over 60 years of age is 10 times higher than those under 40 years of age. 

Intestinal Inflammations:  There are basically two types of intestinal inflammation. First; It is ulcerative colitis that occurs locally in the colonic mucosa due to infection. The second is Crohn's disease, which occurs with intermittent inflammation in any part of the digestive system from the mouth to the anus, or in several different parts at the same time. Although it is a long-lasting and chronic disease, it can be treated. Because of the high risk of cancer, colorectal cancer screening tests should be done more frequently.

Nutrition:  The incidence of colon and rectal cancers is quite high, especially in the USA and European countries where fast food consumption is common. Consumption of pulp-free food increases constipation, causing stool to remain in the intestine for a long time and cancer of that region. Delicatessen products, pickles, smoked meats, barbecue type foods and fried foods are constipating foods. In addition, it has been determined that consuming foods rich in fruits, vegetables, legumes, chicken and grains reduces the risk rate.

Obesity:  Excess weight increases the risk of colon cancer, regardless of male or female.

Smoking:  Many studies have stated that there is a relationship between cigarette consumption and colon cancer.

What are the Symptoms of Colon (Large Intestine) Cancer?

The most common colon cancer symptoms are:

  • Constant diarrhea and constipation

  • The thinning of the stool, which always comes in a normal thickness,

  • Bleeding from the anus and stool,

  • It is a secretion that looks like egg white in stool. In cases where colon (large intestine) cancer progresses and obstructs the intestine, swelling and pain occur in the abdomen. It is important for those with such complaints to consult a doctor for early diagnosis. 

  • The feeling of not emptying the intestines enough,

  • defecation difficulty

  • painful defecationunexplained weight loss

  • Vomiting

Its symptoms are among the most important symptoms of colon cancer, also known as colon cancer. Colon cancer on the right side of the intestine and colon cancer on the left side of the intestine can give different symptoms. Since the left side of the intestine is a narrower region, complaints such as thinning of the stool, bleeding and change in stool pattern are more common in cancers of this region, while on the right side, since the intestine is wider, the cancer progresses insidiously here and takes longer to show symptoms.The patient has symptoms such as weakness, anemia, loss of appetite and abdominal pain. Painful defecation, iron deficiency anemia, and a feeling of mass in the abdomen are important symptoms for colon cancer. Diagnosing colon cancer before the disease progresses greatly increases the chances of survival. Therefore, it is very important to follow the signs of colon cancer for early diagnosis.

How is colon cancer diagnosed?

Colon cancer is a type of cancer included in screening programs. The most effective way to prevent cancer or to detect the disease at an early stage is regular endoscopic examinations. Colonoscopy is one of them. Colonoscopy is a procedure that can both detect an existing tumor at an early stage and detect polyps and similar problems that may lead to cancer before they become cancerous and protect the person from the development of cancer. It is recommended that every individual over the age of 50 should undergo a colonoscopic examination at intervals of 2-5 years, depending on their risk status, personal health history, and family history. The preparation and application of colonoscopy has become much easier and more comfortable for the patient today. The new colonoscopes are extremely easy to apply and the desired results are obtained without any discomfort to the patient.

Colon cancer diagnosis is made with some tests under the leadership of specialist physicians. Following the patient's application to the doctor and the physical examination, the following tests are performed respectively;

  • Examination for occult blood in stool:  It is an extremely simple test, small amounts of stool samples are examined in the laboratory.

  • Radiological examinations:  Double contrast colon radiography and computed tomography are performed.

  • Laboratory tests:  Complete blood count, biochemical tests are performed. Among them, CEA (Carcinoembryonic antigen) examination is one of the tests that can be elevated in the blood and helps diagnosis in large intestine cancers.

  • Endoscopic examinations for definitive diagnosis:  Rectoscopy, sigmoidoscopy, colonoscopy and biopsy are performed. A piece of the seen lesion is taken and examined by the pathologist.

If there is a case of colon cancer before the age of 50 in the family of the person, it is necessary to have a colonoscopy from the age of 40. It is very important to repeat the colonoscopy once every 5 years. In addition, checking for occult blood in the stool once a year is very important for the detection and early diagnosis of cancer. If the person does not have a family history of colon cancer, it is appropriate to have a colonoscopy every 5 years, starting from the age of 50. 

Classical colonoscopy provides the diagnosis of polyp or cancer, and if the patient has a polyp, it also has the feature of curing it and preventing the formation of cancer. It should not be difficult for the patient to have this done once in 5 years. Because colonoscopy is now a procedure performed by providing relief to the patient with intravenous needles and made more tolerable with sedation and painkillers.

What are Colon (Large Intestine) Cancer Treatment Methods?

In colon cancer, surgery may not be required when the cancer is detected at an early stage on polyps taken in colonoscopy. Only closely followed. Colonoscopy is of great importance in the diagnosis of polyps at an early stage, before they turn into cancer. In recent years, it has been shown that colon cancer can be largely prevented by early removal of polyps by performing colonoscopy. For this reason, every man after the age of 45 and every woman after the age of 50 should have a stool screening for occult blood and a colonoscopy. Patient comfort is given great importance during colonoscopy. For this reason, the patient is made semi-conscious with a mild pain reliever called "conscious sedation". Beforehand, the intestine must be completely emptied by various methods. Then, the intestine is entered with a fiberoptic camera and all visible polyps are removed. However, the experience of the physician performing the colonoscopy, the disinfection of the device used and the high image quality are of great importance.

The standard treatment option in advanced colon cancer is surgery; In other words, it is the removal of the tumor area with some healthy tissue and lymph nodes from the environment. Studies show that surgery performed by experienced surgeons in accordance with the principles of oncology is the most important factor for the patient's future. After surgery in colon cancer, additional, protective chemotherapy is applied according to the stage of the disease. For example, in “stage III” cases where the tumor has spread to lymph nodes adjacent to the intestine, “adjuvant” chemotherapy (preventing the spread of the disease) is now standardized practice all over the world.

In colon cancers, in tumors very close to the anus, it is sometimes inevitable to cancel the anus and pass from the abdomen to defecation (with colostomy bags). However, in recent years, preoperative chemotherapy with radiotherapy can significantly protect the anus. In patients who have spread to other organs (metastatic), all three treatment methods (surgery, chemotherapy, radiotherapy) are applied depending on the general condition of the patient, age, and extent of the disease. The aim is to increase the life expectancy and quality of patients. Thanks to the new targeted biological drug therapies in the last few years, the success rates in treatment are increasing day by day.

Nutritional styles and screening tests are of great importance in the protection of individuals who have not been diagnosed with colon cancer. It is important to consume plenty of fibrous foods such as vegetables, fruits and cereals, and to get enough calcium and vitamin D. Besides these; Early diagnosis with screening tests as a secondary prevention measure has a special importance. For this, screening tests are recommended for both sexes, starting from the age of 50. In individuals with a family history of colon cancer, screening tests should be started at an earlier age.

Lower Your Risk for Colon Cancer

Although it is not yet possible to prevent colon cancer, it can reduce the risk of colon cancer by paying attention to harmful habits such as diet that is not suitable for daily life, sedentary life, obesity, smoking and alcohol. For this, some life changes must be made.


Nutrition:  Eating foods rich in fruits, vegetables and legumes is beneficial in reducing the risk of colon cancer. Consumption of red meat and alcohol should be in moderation as they increase the risk of colon cancer. Eating a healthy diet and consuming foods low in fat will help keep the weight at a certain rate.

Exercise:  Studies have shown that regular exercise reduces the risk of colon and rectal cancer, as well as many types of cancer. Before starting the exercise program, it is necessary to consult a doctor. The doctor will help the person with the appropriate exercise program. Exercise for 30 minutes, 5 days a week or more than 5 days a week is recommended. Exercise for 45 minutes to 1 hour may provide more benefits. moderate activities; brisk walking, cycling on flat terrain… Active activities are; climbing and running.

Non-Steroidal Anti-Inflammatory Drugs (such as Aspirin): At the end of the researches, it is suggested that these types of drugs reduce the risk of cancer. There are potential benefits if used regularly. However, when it comes to a potential colon cancer risk, it will be beneficial to use it under the supervision of a doctor. Otherwise, it may cause damage with the risk of stomach bleeding.

Calcium:  May be of little benefit for colon cancer. It is known that 1200 mg of calcium consumed daily reduces colorectal adenoma form by 20% and advanced adenoma form by 45%. Beyond that, it has been determined that vitamin D and calcium consumed together reduce the adenoma form.

Vitamin D:  It is a fat-soluble vitamin and is found in fortified milk, cereal, dietary products containing certain types of fish, such as mackerel, salmon, tuna, and sunlight. Vitamin D is hypothesized to play an important role in preventing certain types of cancer, including colon cancer.

Precancerous (polyps that can lead to cancer) Polyp Screening and Treatment: Screening tests applied in cancer types, especially in breast cancer, do not prevent the development of cancer, but increase the success rate in treatment by helping to diagnose it at an early stage. The development of cancer can be prevented by screening tests applied to identify precancerous polyps. Removing the detected polyps can prevent the cancer that will develop later.

Preventive Surgical Intervention:  Preventive surgical intervention may be recommended for people at high risk of colorectal cancer. In this surgery, the colon and sometimes the rectum and other related organs are removed before cancer development is seen. However, this type of surgery may only be available for patients at high risk of colon and rectal cancer. It is important to discuss the benefits and results with your doctor before the decision of surgery.


What are the stages of colon cancer?

Colon cancer consists of four stages. In the first stage, the cancer has spread to the intestinal wall. In stage 2, cancer has spread to all intestinal folds. In stage 3, the cancer has spread to the lymph nodes. In stage 4, there is a spread to places such as the liver, peritoneum and lungs.

What is the most important symptom of colon cancer?

In colon cancer, bleeding from the 15 cm part of the large intestine, which is close to the breech region, is among the most important symptoms. However, colon cancers originating from the initial part of the large intestine, which is close to the small intestine, cause blood loss with more occult bleeding from the rectum and manifest with anemia.

How does colon cancer bleed?

Bleeding in the rectum, which is among the symptoms of colon cancer, can be in the form of fresh, bright red.

Will colon cancer be completely cured?

In many types of cancer, the disease may spread and spread to different organs. Colon cancer can often metastasize to the liver. To prevent this situation, chemotherapy can be applied after surgery.

Can colon cancer be cured by surgery?

The studies performed and the surgeries performed in accordance with the principles of oncology and performed by experienced surgeons are the most important factors for the future of the patient.

Does colon cancer recur after surgery?

After surgery in colon cancer, chemotherapy is applied to prevent recurrence according to the stage of the disease.

What is the risk of colon cancer death?

Colon cancer, the most common type of cancer, is the third leading cause of cancer-related death in both men and women. However, with early diagnosis and treatment, the risk of death from colon cancer can be reduced.

Where does colon cancer pain occur?

In colon cancer, where diarrhea and constipation are symptoms, the frequent desire to go to the sink and severe abdominal pain negatively affect the quality of life. These symptoms, which will lead to a loss of self-confidence, can bring along a psychologically challenging period. Psychological support can be provided at this stage where depression and anxiety disorders can be experienced.

I am a person with no family history of colon cancer or polyps. Should I start getting tested for colon cancer?It is possible to transmit diseases to the next generation with genetic transmission. However, the absence of a family history does not mean that colon cancer will not occur. Therefore, even if it is for control purposes, testing should be done in the early period.

Do polyps mean I will get colon cancer?

Polyps are usually benign. However, the part of whether polyps will cause cancer should be evaluated under the follow-up of a specialist physician.

Is colon cancer genetic?

In colon cancer, in which environmental factors play an important role, it is possible that some genetic disorders will be passed on from parents to the next generation. Genetic disorders can develop with environmental factors.

Can women get colon cancer?

Colon cancer which is one of the most life-threatening cancer types, can be seen in men and women regardless of gender.

What kind of diet should I follow to prevent colon cancer?

It is thought by experts that the Mediterranean type of diet plays an important role in the prevention of colon cancer. According to studies, excessive consumption of red meat can trigger colon cancer. According to the Mediterranean type of diet, the consumption of red meat is reduced to a minimum and mostly vegetables are fed. Cooking and consuming fresh fruits and vegetables in daily life is a part of this diet.

Who gets colon cancer?

It is stated that it is more common in older people, those with a sedentary lifestyle, those who are overweight, those who use alcohol or tobacco, and those who consume processed meat products.

Where is colon cancer most common?

It is stated that colon cancer is more common in African and American races. It is a common cancer in Turkey as well.

Will colon cancer be detected in a blood test?

Colon cancer cannot be diagnosed with a blood test alone. Additional examinations are required.

Why does colon cancer occur? 

Causes of colorectal cancer; lifestyle, malnutrition, excess weight, changes in environmental factors and hereditary genetic factors.

Does stage 4 colon cancer get better?

Surgery is not preferred in stage 4. It is aimed to shrink cancerous cells with chemotherapy and radiotherapy. The treatment and course of all 4 stage patients are not the same. It varies according to the extent of the disease and its response to treatments.

Is colon cancer benign? 

Colon cancer is a malignant tumor of the large intestine. Sometimes benign polyps can turn into cancer.

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