The Importance of Early Detection and Screening Methods in Colon Cancer

Colon cancer is a serious health issue that occurs when polyps on the inner lining of the large intestine turn into malignant cells over time. Early detection of this disease allows for the removal of polyps before the cancerization process even begins, increasing the treatment success rate to over 90 percent.

At a Glance:

• Colon cancer usually begins with benign polyps growing over a period of 10 to 15 years.
• Having regular screening tests starting at age 45 is life-saving.
• It often shows no symptoms in the early stages, making routine check-ups essential.
• Colonoscopy is the gold standard for both diagnosis and the removal of polyps (treatment).
• Unexplained weight loss and blood in the stool require immediate medical evaluation.

What is Colon Cancer?

Cancers starting in the large intestine (colon) and rectum are generally called colorectal cancers. The disease begins with the uncontrolled multiplication of cells lining the inner surface of the intestine. In the initial stage, small, skin tag-like structures called polyps form. Although most polyps are harmless, types called adenomatous polyps can mutate over the years and become cancerous.

The process of polyps turning into cancer usually spans a long period, typically 10 to 15 years. This slow progression offers a great opportunity to catch the disease in its early stages. Ranking among the most common types of cancer in both women and men, this disease is highly preventable thanks to the advanced imaging and diagnostic capabilities provided by modern medicine.

Causes and Risk Factors of Colon Cancer

Although the exact mechanism of the disease's onset is not fully known for every patient, a combination of genetic predisposition and environmental factors stands out among the causes of colon cancer. Age is one of the most important risk factors; the vast majority of cases are seen in individuals aged 50 and older. A family history of bowel cancer or polyps significantly increases the risk. People with hereditary genetic mutations, such as Lynch syndrome or Familial Adenomatous Polyposis (FAP), are at a much higher risk.

Lifestyle habits also play a critical role in the development of the disease. Excessive consumption of red and processed meats, a diet low in fiber, obesity, leading a sedentary life, smoking, and excessive alcohol use can disrupt the structure of intestinal cells. Additionally, long-term inflammatory bowel diseases like Crohn's disease or ulcerative colitis lead to chronic inflammation in the intestinal wall, raising the risk of cancerization.

Why is Early Detection Important?

When colon cancer is detected early, it is one of the cancer types with the highest treatment success rates. If the disease is detected while it is only on the inner lining of the intestine—meaning before it has spread to lymph nodes or other organs—the five-year survival rate is over 90 percent. The primary goal of early detection is to stop the disease before it reaches the cancerous stage.

Through screening programs, polyps on the inner lining of the intestine are detected and removed from the body during the exact same procedure. This completely eliminates the groundwork on which cancer could develop. In cases diagnosed at advanced stages, the treatment process becomes much more complex; in addition to surgical intervention, long-term chemotherapy and radiotherapy sessions may be required. Therefore, even if you have no complaints, participating in screening tests within the designated age ranges is the most important step for a healthy and long life.

Symptoms of Colon Cancer

The most insidious aspect of the disease is that it usually presents no symptoms during the initial stage and the growth phase of polyps. As the tumor grows and begins to obstruct the normal functioning of the intestine, colon cancer symptoms emerge. The most common finding is a sudden and persistent change in bowel habits. A clinical picture of constipation or diarrhea that suddenly begins and lasts for weeks, especially when you previously had a regular digestive system, should be taken seriously.

Seeing bright red or dark black blood in the stool, or stools that are much narrower than normal (pencil-thin), are important signs. In addition to these, a feeling that the bowels are not completely emptied, cramps that resemble gas pains but do not go away, and bloating and pain in the abdominal area may be experienced. In advanced stages, profound anemia due to chronic blood loss caused by the tumor, constant fatigue, and unexplained weight loss without dieting are observed.

Bowel Cancer Screening Tests and Diagnostic Methods

According to current medical guidelines, it is recommended that every individual in the average risk group have regular bowel cancer screening tests starting at age 45. For people with a family history or genetic predisposition, these screenings are initiated at much earlier ages, usually 10 years before the age at which the cancer case in the family was diagnosed. During the diagnostic process, different methods may be preferred considering the patient's general health status, age, and risk factors.

What is a Colonoscopy?

The question of what a colonoscopy is is one of the most curious topics for patients entering the screening process. This procedure is the detailed internal examination of the entire large intestine and rectum using a flexible tube (colonoscope) equipped with a light and high-resolution camera at its tip. A colonoscopy is not just a diagnostic tool but also a therapeutic method. When a suspicious polyp is seen during the procedure, it can be instantly cut and removed (polypectomy) with the help of special instruments and sent for pathological examination. Because the procedure is performed under mild sedation (a sleep-like state), the patient does not feel any pain.

Fecal Occult Blood Test (FOBT)

The fecal occult blood test is a fast and practical laboratory examination used to detect bleeding in the stool that is too small to be seen by the naked eye. As polyps or tumors pass through the intestine, they can rub against the stool and cause slight bleeding. A positive result on this test does not directly mean you have cancer; however, it indicates that a colonoscopy must be performed to find the source of the bleeding.

Sigmoidoscopy and Virtual Colonoscopy

A sigmoidoscopy is a procedure similar to a colonoscopy, but it only examines the sigmoid colon and rectum, which are the last parts of the large intestine. A virtual colonoscopy is an imaging method where three-dimensional images of the intestine are created using computed tomography (CT), without inserting a tube into the body. Although both methods are preferred in certain situations, when a suspicious lesion is seen, a standard colonoscopy is still required for a biopsy or polyp removal.

Treatment Options and the Recovery Process

The treatment plan for colon cancer is determined with a multidisciplinary approach based on the stage of the disease, the location of the tumor, and the patient's general health. For cancers caught in the early stages (Stage 0 and Stage 1), surgical intervention is usually sufficient alone. The removal of polyps during a colonoscopy (polypectomy) or the surgical removal of the cancerous part of the intestine (colectomy) is performed. In modern medicine, surgical procedures are frequently performed using minimally invasive methods such as laparoscopic or robotic surgery, which shortens the patient's hospital stay and accelerates the recovery process.

If the disease has spread to lymph nodes or surrounding tissues (Stage 2 and Stage 3), chemotherapy and sometimes radiotherapy are introduced in addition to surgery. In advanced-stage cancers that have spread to other organs (metastasized), modern treatment options like targeted smart drugs and immunotherapy are used in an attempt to stop the tumor's growth and improve the patient's quality of life.

Complications and High-Risk Groups

Untreated or late-detected colon cancer can lead to serious health problems. The growing tumor can completely block the inner cavity of the intestine, causing a bowel obstruction. This is a medical emergency that manifests with severe abdominal pain, vomiting, and the inability to pass stool. Furthermore, the tumor can perforate the intestinal wall, leading to inflammation of the abdominal lining (peritonitis).

When cancer cells spread through the blood or lymph, they most commonly metastasize to the liver, lungs, and abdominal lining. The elderly, patients with suppressed immune systems, and people with additional chronic illnesses like severe diabetes or heart failure are in a higher risk group regarding both the surgical process and the side effects of chemotherapy. The treatment planning for these patients is managed much more delicately with the joint decision of physicians from all relevant branches.

When Should You See a Doctor?

You should never take unusual situations regarding your bowel health lightly. If you clearly see blood or a slimy discharge (mucus) in your stool, or if you experience a change in your bowel habits, such as constipation or diarrhea lasting longer than a few weeks, you should consult a gastroenterologist or general surgeon without wasting time. Unexplained weight loss, constant fatigue, and a palpable hardness in the abdominal area are also serious signals that require expert evaluation.

On the other hand, in cases of sudden and increasingly severe abdominal pain, the abdomen becoming as hard as a board, continuous vomiting, and the inability to pass gas and stool, there is a risk of bowel obstruction or perforation. In such sudden and severe clinical pictures, you should call the 112 emergency call center without waiting or go to the emergency room of the nearest hospital.

The Process at BHT CLINIC İstanbul Tema Hastanesi

BHT CLINIC İstanbul Tema Hastanesi brings together the most up-to-date medical technologies and an expert medical staff for colon cancer screening, diagnosis, and treatment processes. When you apply to our hospital with your complaints, you will undergo a detailed evaluation in our Gastroenterology or General Surgery departments. In our advanced endoscopy unit, your colonoscopy procedures are performed while you are asleep, completely pain-free, and comfortably.

Our hospital also successfully applies innovative techniques such as early diagnosis in stomach and bowel cancer with the staining method. Furthermore, comprehensive counseling is offered to our patients regarding colon cancer symptoms and treatment. In the event of a possible bowel obstruction or severe abdominal pain, our 24/7 emergency service and fully equipped operating rooms are ready to intervene at any moment. Post-diagnosis treatment planning is customized for the patient in tumor councils attended by medical oncology, radiology, pathology, and general surgery specialists.

Frequently Asked Questions

Can colon cancer be detected with a blood test?

Colon cancer cannot be diagnosed with just a standard blood test. However, unexplained anemia seen in a complete blood count can raise suspicion. Also, tumor markers like CEA (Carcinoembryonic Antigen) can be measured in the blood, but these tests are generally used for monitoring the treatment of patients already diagnosed with cancer, rather than for initial diagnosis.

Is a colonoscopy a difficult procedure?

No, because a colonoscopy is performed under sedation (mild anesthesia), patients do not feel any pain, ache, or discomfort during the procedure. The procedure usually takes 20-30 minutes, and the patient does not remember it upon waking up. The most important stage is the bowel cleansing (diet and laxative use) process done at home the day before the procedure.

How often should colon cancer screening be done starting at age 45?

For individuals in the average risk group, if no polyps or abnormalities are found during a colonoscopy, it is generally recommended to repeat the procedure every 10 years. If a fecal occult blood test (FOBT) is used, this test should be repeated every year. However, if you have a family history of cancer or if polyps were removed in previous procedures, your doctor may reduce the screening interval to 1, 3, or 5 years.

Can hemorrhoid bleeding be confused with colon cancer?

Yes, in both cases, bright red blood can be seen in the stool. Many patients delay going to the doctor, thinking the bleeding is caused by hemorrhoids, and this situation can lead to a delay in cancer diagnosis. If blood is seen in the stool, a specialist doctor must be consulted to definitively determine the underlying cause, and a colonoscopy should be performed if deemed necessary.

Do all colon polyps turn into cancer?

No, not all polyps that form in the intestine become cancerous. The risk of hyperplastic or inflammatory polyps turning into cancer is very low. However, adenomatous polyps (adenomas) are considered precancerous and carry the potential to turn into cancer over time. Which polyp is risky can only be understood by removing it during a colonoscopy and examining it pathologically.

To protect your bowel health and benefit from the life-saving advantages of early detection, do not delay your regular screenings. You can book an appointment to get support from our specialist physicians and plan your screening tests.

This article is for informational purposes only; please consult your physician for diagnosis and treatment.