Colon Cancer

Colon Cancer


Colon cancer is a type of cancer that may occur anywhere in the colon. It’s a very common type of cancer worldwide. There are screening programs to detect it early. Learning about colon cancer is very crucial part of prevention.

Facts about colon cancer

  • Colon cancer is number three on the list of the most common types of cancer.

  • Colon cancer is the second killer in the list of cancer deaths in the United States.

  • More than 100,000 of colon cancer cases are diagnosed yearly.

  • Approximately 5% of the normal population have risk of being diagnosed with colon cancer during their life time.

Colon cancer causes

As with all types of cancer, there is no specific cause for colon cancer. Multiple risk factors may contribute to the etiology of colon cancer. The following are the most important risk factors:

  • Age: the chance of getting colon cancer will increase after age of 50

  • Previous history of colon cancer or colon polyps

  • History of inflammatory bowel disease especially Ulcerative Colitis

  • History of colon cancer in the family

  • Family history of inherited colon cancer syndrome

Colon cancer signs and symptoms

Many symptoms may be related to colon cancer. Following are some of them:

  • Frequent change in your bowel habit; constipation or diarrhea

  • Change in the shape of stool; thinning of stool

  • Persistent urgent feeling that one needs to defecate which will not be eased by defecating

  • Blood mixed with stool

  • Dark-colored stool

  • Bleeding per rectum

  • Cramping in the belly

  • Frequent pain in the belly

  • Persistent fatigue

  • Unintentional loss of weight

Almost all of the above symptoms can be caused by benign conditions such as hemorrhoids, infection, and inflammatory bowel disease, but they may be also an early symptom(s) of colon cancer. It is better to be suspicious than to regret later! If you have any of above symptoms, contact your doctor to guide you to the diagnosis and treatment.

Colon Cancer Treatment

There are four options for the treatment of colon cancer:

  1. Surgical

  2. Radiotherapy

  3. Chemotherapy

  4. Special targeted therapy

The decision to choose any of the above treatment options depends on the stage of colon cancer. In some case, it’s possible to use more than one option to treat colon cancer. After a colon cancer diagnosis, the options of treatment need to be discussed between patient and oncologist to choose the best treatment modality after understanding the advantages and the disadvantages of each modality.

What you need to know about colon cancer prevention

After recent advancements in the field of colon cancer screening during the past decades, more and more people survive colon cancer via early diagnosis through adopting the recommended screening guidelines. The aims of colon cancer screening tests are to diagnose the presence of precancerous tissues, thus removing it through surgery before it is converted into cancerous cells.

It’s recommended to have regular screening tests for colon cancer starting at age of 50. People with suggestive family history or with multiple risk factors of colon cancer should consult their physician early to choose the proper type and frequency of colon cancer screening!

Types of screening test for colon cancer

  • Colonoscopy: It’s simply the process of using a small scope with long tube that has a small camera at the end. It’s used to visualize the whole colon and rectum. During this procedure, any precancerous tissues (polyps) will be removed and sent to the histopathology lab. Usually before performing this test, the doctor will ask the patient to adopt a special diet and laxatives to evacuate the bowels, thus making the colon clean for visualization. A colonoscopy is usually performed under sedation.

  • Flexible sigmoidoscopy: Technically, it’s the same process as a colonoscopy except that a flexible sigmoidoscopy is used to visualize the small part of the colon called the sigmoid colon. If the doctor visualizes polyps during this test, he can remove them or ask for a full colonoscopy later. A flexible sigmoidoscopy can be performed without sedation.

  • Double-contrast barium enema: This is a form of x-ray taken after the patient has been given a particular type of enema. If any suspicious areas were seen during the double-contrast barium enema, a colonoscopy should be performed soon.

  • CT colonography (also called virtual colonoscopy): This is a detailed scan of the entire colon. It requires no sedation. If any suspicious areas were seen through CT colonography, a colonoscopy should be performed as soon as possible.

  • Fecal occult blood test: This is a lab test for stool aimed at detecting any small amount of fresh blood which may indicate the possibility of having precancerous polyps or even cancer. It can be performed at home using a special home kit. A positive test indicates the need for a colonoscopy. It can be positive in some benign conditions such as hemorrhoids.

The decision to use any of the above treatment options depends on the stage of colon cancer. In some cases, it’s possible to use more than one option to treat colon cancer. After a colon cancer diagnosis, the options of treatment need to be discussed between patient and oncologist in order to choose the best treatment modality after understanding the advantages and the disadvantages of each modality.

How to decrease risk of colon cancer?

Adopting a healthy lifestyle, a healthy diet, reduction of excess weight, and regular exercising are very crucial to prevent colon cancer. Eating more fruits, whole grains, and vegetables may contribute to colon cancer prevention. Eating less beef, pork, lamb, hot dogs, and other processed meat will help fight colon cancer. One should also limit alcohol intake to less than two drinks daily for men, and one drink for women. Stay slim via regular exercising; this will lower the colon cancer risk. Quitting smoking is very important as well.

Overview on stages of colon cancer

The term “stage” means the description of the extent of a certain type of cancer in the body and it’s one of the most crucial factors when deciding the cancer treatment options as well as predicting a positive outcome.

Clinically, colon cancer stages depend on different diagnostic methods, such as physical exam, biopsy of the cancer itself, CT scan, MRI scan, and other diagnostic modalities. There are two ways to determine the stage of colon cancer:

  1. The clinical-based staging; depends on the doctor’s examination, the biopsy from cancer, and other imaging modalities.

  2. The pathologic staging; depends on the surgical appearance of the cancer in addition to the clinical-based staging.

Colon cancer staging (TNM system)

The standard staging system for colon cancer is called the TNM system. In this system, certain letters and numbers are used to give certain information. The “TNM” stands for:

  • T stands for Tumor; the extension of spread of the tumor itself within the wall of the colon.

  • N stands for Nodes; the possible extension of cancer into the lymph nodes.

  • M stands for Metastasis; it is the extension of the tumor into other parts in the human body.

The numbers which are written after the T, N, and M indicate the severity. The letter "X" after T, N, and M indicates that this part can’t be assessed.

T staging of colon cancer

  • TX stands for the inconclusive information about the extension of the tumor.

  • TIS stand for the inner layer of the colon which is known as mucosa; this is pathologically named as carcinoma in situ.

  • T0 stands for no cancer in any layer of the colon.

  • T1-T4 stands for the extension of caner into different layers of the colon.

N staging of colon cancer

  • NX stands for the inconclusive information about the involvement of lymph nodes.

  • N0 stands for no involvement of the lymph nodes.

  • N1 stands for the involvement of the lymph nodes, not more than three lymph nodes.

  • N2 stands for the involvement of the lymph nodes, more than four lymph nodes.

M staging of colon cancer

  • MX stands for the inconclusive information about the involvement of distant organs.

  • M0 stands for no involvement in the distant organs.

  • M1 stands for the involvement of the distant organs.

Grouping of TNM data

After determining the value of T, N, and M, the data will be grouped to find out what would be the stage of colon cancer (0 to stage IV). The earlier the diagnosis, the better the outcome will be. Survival rates in the early stages, especially stage I and II, are very high in comparison with stage III. Stage IV owns the worst prognosis among all the stages. More screening tests are available nowadays and it’s very important to consult your doctor about different colon tests and the timing of those tests.

"Regular screening that leads to early detection is the key to survive colon cancer."