Dr. Ertan Beyatlı

Colon cancer symptoms and causes

(Update: ) - Digestive System Diseases

Colorectal cancer usually begins as a growth inside the colon or rectum called a polyp. Finding and removing polyps can prevent colorectal cancer.

I've covered this article to learn more about colorectal cancer prevention, screening, treatment, statistics, research, clinical trials, and more.

What is colon cancer?

Colon cancer (often referred to as colorectal cancer) is preventable and highly treatable if detected at an early stage. Column CA. Its English is "Colon Cancer".

The colon is the longest part of the large intestine. It takes digested food from the cecum, absorbs water and nutrients, and passes waste (feces) into the rectum. The column is divided into 4 sections.

  • Ascending colon (ascendan) is the beginning of the colon and is located on the right side of the abdomen. Called bend in the liver (Hepatic flexure) continues until a curve in the column.
  • Transverse colonfollows the ascending column and hepatic flexure. It runs along the upper part of the abdomen. Spleen flexion (Splenic flexure) ends with a curve in the column.
  • Descending colon (Dessendan) follows the transverse colon and splenic flexure. It is located on the left side of the abdomen.
  • Sigmoid colonis the last part of the colon that connects to the rectum.
Photograph showing anatomical parts of the large intestine (Colon).

Colorectal cancer is the second cause of death in the UK and the third in the USA. Colorectal cancer is the second most common cancer in women and the third in men in terms of frequency.

70 percent of this is colon cancer and the rest is rectal cancer. Age is an important risk factor, especially in the non-familial type of colorectal cancer. The risk increases from the age of 40. Especially in the USA, the rate of getting colorectal cancer is 5 percent and 90 percent of patients diagnosed with colorectal cancer are over the age of 50.

The incidence in men is 25 percent higher than in women. Recently, right-sided colon cancers are more common than left. The increase in the rate of colonoscopy since 1980 has increased the chance of early detection of these cancers and the survival of patients has been prolonged with new effective treatment methods.


Colorectal cancer the exact cause is unknown. However, understanding of some genetic causes continues to increase. The following factors can increase a person's risk of colorectal cancer:

  • Age: More than 90% of people are diagnosed with colorectal cancer after the age of 50.
  • Colorectal cancer family history (especially parents or siblings).
  • Eight years or more personal Crohn's disease or ulcerative colitis history (IBD).
  • Colorectal polyps.
  • Personal history of breast, uterine, or ovarian cancer.
  • Diabetes. People with Type 2 Diabetes are more likely than other people to develop colorectal cancer.
  • Diet. People who eat too much fat, cholesterol, and small amounts of fiber are more likely to develop colorectal cancer.
  • Life style. You may be more likely to get colorectal cancer if you drink large amounts of alcohol, smoke, do not exercise, and are overweight (obesity).

Inherited gene mutations that increase colon cancer risk

Inherited gene mutations that increase colon cancer risk can be passed down in families, but these inherited genes are only linked to a small (5%) percentage of colon cancer. Inherited gene mutations do not make cancer inevitable, but can significantly increase an individual's risk of cancer.

The most common forms of hereditary colon cancer syndromes are:

  • Hereditary Non-polyposis colorectal cancer (HNPCC). HNPCC, also called Lynch syndrome, increases the risk of colon cancer and other cancers. People with HNPCC tend to develop colon cancer before the age of 50.
  • Familial adenomatous polyposis (FAP). FAP is a rare disease that causes you to develop thousands of polyps in the lining of the colon and rectum. People with untreated FAP greatly increase their risk of developing colon cancer before the age of 40.

The relationship between diet and colon cancer

Clinical studies conducted are a typical Western diet showed a relationship between increased colon cancer risk. A typical Western diet, high in fat and low in fiber.

When people move from regions where the typical diet is low in fat and high in fiber to areas where the typical Western diet is most common, the risk of colon cancer increases significantly in these individuals. The cause of this condition is not yet clear, but researchers are examining whether a high-fat, low-fiber diet affects microbes living in the colon or causes underlying inflammation that may contribute to cancer risk. This is an active research area and research is ongoing.


Colorectal cancer can be prevented.

Almost all cases of colorectal cancer from polyps arises. They start from the inner lining of the colon and most commonly affect the left side of the colon. Of polyps colonoscopy Detection and removal with (Colonoscopic Polypectomy - Watch Youtube Video) reduces the risk of colorectal cancer. Colorectal cancer screening recommendations are based on medical and family history. Screening typically begins at age 45 in patients at average risk. Those at higher risk are generally advised to have their first screening at a young age.

Although not certain, there is some evidence that diet can play an important role in preventing colorectal cancer. High in fiber (whole grains, fruits, vegetables, and nuts) and low in fat diet is the only dietary measure that can help prevent colorectal cancer.

In 2018, secondary to new data on an increased risk of colon cancer in patients under the age of 50, the American Society of Colon and Rectal Surgery changed recommendations to initiate screening at age 45.


Colorectal cancer is often asymptomatic and is detected during routine screenings. It is important to note that other common health problems can cause some of the same symptoms. For example, hemorrhoids It is a common cause of rectal bleeding but does not cause colorectal cancer. Colorectal cancer symptoms include:

  • Change in bowel habits (constipation or diarrhea).
  • Narrow shaped defecation.
  • Bright red or very dark blood in the stool.
  • Ongoing pelvic or lower stomach pain (for example, gas, bloating, or pain).
  • Unexplained weight loss.
  • Nausea or vomiting.
  • Constant feeling of tiredness.

Abdominal pain and weight loss typically are late symptoms and this points to a wide-ranging disease. Anyone experiencing any of the above symptoms should see a doctor as soon as possible.

Colon CA Diagnosis

  • Physical examination and medical history.
  • Blood tests
  • Occult Blood in Stool (GGK) test
  • Colonoscopy: Examination of the entire colon with a long and thin flexible tube with a camera and a light at the end (colonoscope).
  • Biopsy: Removal of cells or tissues can be viewed under a microscope to check for signs of cancer.

The following tests can be used for staging:

  • CEA assay: Carcinoembryonic antigen is a substance that can rise in the blood if cancer is present. This test is usually done with other diagnostic tests, although it's not entirely accurate on its own.
  • Abdominal ultrasound: It shows tumors that have spread to the liver, gallbladder, pancreas, or elsewhere in the abdomen.
  • Computed Tomography (CT) scan: It can accurately detect the presence of most cancer cells that have spread out of the colon.
  • Magnetic Resonance imagin (MRI): It helps determine whether the tumor has spread along the wall of the rectum and is invading nearby structures (invasion).
  • Positron emission tomography (PET) scan: An imaging test using a special dye with radioactive traces. This allows doctors to detect the presence of most cancer cells that have spread (metastasize) outside of the colon.

Colorectal Cancer Classification (Staging)

The extent of cancer (clinical stage) is linked to treatment decision making and post-treatment patient outcome. Staging is based on whether the tumor invades nearby tissues or lymph nodes and / or whether the cancer has spread (metastasized) to other parts of the body. The exact stage is usually not clear until after surgery.

Colon cancer stages, staging, classification, grading
  • Stage 0: It is the earliest stage. Cancer did not move from where it started; it is still limited to the innermost lining of the column. To this stage "Carcinoma in SituAlso called.
  • Stage I: Cancer started to spreadbut still in inner lining. Stage I is also called Dukes A colon cancer.
  • Stage II: Most cancers have grown along the wall of the colon and to nearby tissues could reach out. They have not yet spread to the lymph nodes. Stage II is also called Dukes B colon cancer.
  • Stage III: Cancer to lymph nodes it has spread but has not been carried to distant parts of the body. Stage III is also called Dukes C colon cancer.
  • Stage IV: Cancer throughout the lymphatic system to remote areasmost frequently transported to the lungs and liver. This "METASTASISIt is known as ”. Stage IV is also called Dukes D colon cancer.

TNM Staging

Tumor (T): describe the size of the tumor (area of ​​cancer). This is a simplified explanation of the T stage. There are 4 stages of tumor in bowel cancer:

  • T1 means the tumor is only in the lining of the intestine
  • T2 means the tumor has grown into the muscle layer of the intestinal wall
  • T3 means the tumor has grown into the outer lining of the intestinal wall
  • T4 means the tumor has grown from the outer lining of the intestinal wall (into another part of the intestines, into a nearby organ or structure).
T - staging for colorectal cancer

Node (N): explains whether the cancer has spread to the lymph nodes. There are 3 possible stages that explain whether cancer cells are in the lymph nodes:

  • N0, no lymph nodes containing cancer cells
  • N1 contains cancer cells from 1-3 lymph nodes close to the intestines
  • N2, 4 or more nearby lymph nodes have cancer cells

Metastasis (M): explains whether the cancer has spread to a different part of the body. There are 2 stages of cancer spread (metastasis):

  • M0 means the cancer has not spread to other organs
  • M1 means cancer has spread to other parts of the body
The regions where colorectal cancer metastasizes most
The regions where colorectal cancer metastasizes most


Surgery is almost always necessary for colorectal cancer. The tumor and lymph nodes are removed along with a small portion of the normal colon on either side of the tumor. The general name of these surgeries is Colectomy.

What is a colectomy?

Colectomy is surgery to remove all or part of the colon. It is used in the treatment of diseases affecting the colon. There are 4 main types of colectomy:

  • Total colectomyinvolves removing the entire colon.
  • Partial colectomyinvolves removing part of the colon and is also called subtotal colectomy.
  • Hemicolectomyinvolves removing the right or left portion of the colon.
  • Proctocolectomyinvolves removing both the colon and the rectum. To this operation Ileostomy Added.

In colectomy surgery, the remaining parts of your digestive system usually need to be reattached or stitched to the abdominal wall.

Colostomyis a surgically created opening that connects part of the colon to the skin of the abdominal wall. This procedure is typically only performed in a very small number of colorectal cancer patients.

Minimally invasive surgical techniques can be used by trained surgeons on the basis of individual cases. Your surgeon will meet with you before surgery and decide on the most appropriate approach.


Chemotherapy can be applied before and / or after surgery, depending on the stage of the cancer. Unlike rectal cancer, radiation therapy is rarely used for colorectal cancer.


Patient outcomes are strongly correlated with colorectal cancer stage at the time of diagnosis. Cancer limited to the lining of the colon is associated with the highest probability of success. This is one reason why early detection is so important with screening methods such as colonoscopy.

Post-treatment follow-up and control is important for colorectal cancer. Even if the cancer appears to be completely removed or destroyed, the disease can recur. Unspecified cancer cells may remain in the body after treatment. Your colon and rectal surgeon monitors your recovery and periodically checks for cancer recurrence. Blood tests, clinical examinations and imaging tests can be performed according to the stage of the cancer.


Colon and rectal surgeons (Colorectal surgery) are experts in the surgical and non-surgical treatment of colon, rectum and anus diseases.

Prepared, Compiled and Translated by: Ertan BEYATLI, MD, PhD



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