Symptoms of Colon Cancer

What is Colon Cancer?

Colon cancer (also known as bowel cancer, colorectal cancer, or rectal cancer) is cancer that develops in the rectum or colon. Most colon cancers begin in the cells that produce mucus and other fluids (adenocarcinomas). 

Colon cancer has no single cause. Most colon cancers begin as a growth on the colon’s inner lining (polyp). While some polyps can become cancerous over time, not all polyps will become cancerous. 

 

Who is at Risk for Colon Cancer?

Individuals with specific risk factors are more prone to developing colon cancer. Some of the common risk factors include:

Over 50 Years Old

Colon cancer is more likely to develop in people over 50 years old. At least 90% of people with colon cancer are over the age of 50.

Colorectal Polyps

Colorectal polyps are growths on the colon or rectum’s inner wall. While most polyps are not cancerous (benign), some can become cancerous.

Personal History of Cancer

It is possible for a colon cancer survivor to develop colon cancer for the second time. Women with a history of ovary, uterus, or breast cancer are also at a higher risk.

Crohn’s Disease or Ulcerative Colitis

Crohn’s disease or ulcerative colitis is a condition that causes the colon to swell over many years. This also increases one’s risk of developing colon cancer.

Family History of Colorectal Cancer

If you have a family history of colon cancer, you have a higher risk of developing the condition. This is especially true if the relative or family member had cancer at a young age.

Lifestyle Factors

If you smoke or have a diet low in fruits and vegetables and high in fat, you have a higher chance of developing colon cancer.

 

What are the Symptoms of Colon Cancer?

In its early stages, colon cancer may not have any symptoms. Therefore it is important to get screened when you turn 50. If you are at a higher risk, getting screened early is recommended. 

Signs and symptoms of colon cancer will typically appear once the tumor has grown or has spread into the surrounding organs or tissues. When this happens, some of the common symptoms can include:

• Unexplained weight loss. Weight loss for no apparent reason needs to be investigated.  Nausea and vomiting are also potential symptoms.
• Fatigue or weakness. Fatigue or weakness can be another sign of colon cancer. Weakness or fatigue may also be accompanied by low red blood cell count (anemia).
• Changing bowel habits. Changing bowel habits can include constant or intermittent constipation or diarrhea. You might also notice a change in the consistency of your stool.
• Rectal bleeding. Blood on or in your stool is another symptom of colon or rectal cancer. The stool can be tarry or brick red or black and the blood can be bright red.
• Persistent abdominal discomfort. Abdominal discomfort can appear as pain, gas, or cramps. You can also feel like your bowel is not completely empty. You can also feel bloated or full. 

Other possible symptoms or signs that might point to colon cancer include:

• Narrow stools
• Rectal pressure or pain
• Decreased appetite
• Lump in the rectum or abdomen
• Bowel perforation
• Bowel obstruction

If the cancer has already spread to the other parts of the body, you might experience other symptoms such as:

• Shortness of breath – this occurs if the cancer has spread to the lungs
• Jaundice – this occurs if the cancer has spread to the liver
• Bone pain – this occurs if the cancer has spread to the bone

Many of the symptoms of colon cancer might be caused by other conditions. Still, it is recommended that you see your doctor immediately if you experience any of the symptoms above.

 

How is Colon Cancer Diagnosed?

If you have an abnormal screening test or have symptoms of the condition, tests and examinations will be recommended to pinpoint the cause. For people with an average chance of developing colon cancer, the following is recommended:

• Colonoscopy every 10 years
• High sensitivity guaiac-based fecal occult blood test (gFOBT) or fecal immunochemical test (FIT) every 2 years
• Flexible sigmoidoscopy at least every 5 years (plus fecal immunochemical test every 2 years)

If you have a higher chance of developing colorectal cancer, you must talk with your doctor about the frequency and method of screening that is best for your case. If you are diagnosed with colon cancer, additional tests will be done to stage the cancer and plan the ideal course of treatment.

 

Physical Examination and Medical History

Your doctor will examine your medical history to determine if you have any risk factors. Your doctor will also ask about the symptoms you have experienced and how long you’ve had them. 

A physical examination will include feeling the abdomen for enlarged organs or masses. A DRE or digital rectal exam might also be recommended. During DRE, your doctor will check your rectum to check for any abnormalities.

 

Fecal Tests

Your doctor might recommend tests to check for any blood in your stool. Since blood in the stool is not always visible to the naked eye, fecal tests can help detect blood that is not visible. The tests can include FIT or FOBT will be done at home using a kit. You will use the kit to collect samples (at least one to three) of your stool for analysis.

 

Blood Tests

Your doctor may also order blood tests to check for signs of colon cancer like anemia. Liver function tests and tests that will check for tumor markers (i.e., carcinoembryonic antigen (CEA) and CA 19-9 may also be ordered. However, blood tests alone will not be able to diagnose colon cancer.

 

Sigmoidoscopy

Also known as flexible sigmoidoscopy, this diagnostic test is used to look inside the sigmoid colon. The procedure is less invasive compared to full colonoscopy and may only be recommended if colonoscopy is not possible.

 

Colonoscopy

If a colonoscopy is done because some abnormalities were found during a screening test, it is called diagnostic colonoscopy. This test is used to view the rectum and the entire length of the colon.

Colonoscopy is done using a thin and flexible tube with a camera at the end. The camera is called a colonoscope. The colonoscope is inserted into your body through your anus.

If the doctor will remove polyps or tissue samples for a biopsy, special instruments may be passed through the colonoscope.

 

Proctoscopy

This procedure involves inserting a thin tube with a camera on the end (proctoscope) through the anus. The camera is used to view the inside of your rectum. Proctoscopy is also used to check for rectum cancer.

Imaging Tests

 

Imaging tests are done to:

• Check if treatment is working
• Check how far the cancer has spread
• View possible suspicious areas that might be cancerous

Imaging tests that can be used to diagnose colon cancer include:

• Computed Tomography (CT) scan
• Abdominal ultrasound
• Chest X-ray
• Positron emission tomography (PET) scan
• Magnetic Resonance Imaging (MRI)
• Endorectal ultrasound
• Abdominal ultrasound

Biopsy

 

This is a lab test that will examine the sample of tissue. Suspicious areas or polyps are typically removed during a colonoscopy. However, they can also be removed during a surgical procedure if required.

 

The tissue will be sent to a lab and will be examined under a microscope. If cancer is found, a test to check for gene changes may also be done. Other tests may also be requested to classify the cancer.

Who Needs Early Screening?

 

Early screening may be recommended for certain individuals even if they have not reached 50 years old yet. Early screening might be recommended for those who:

• Have an inflammatory bowel disease or IBD (i.e., Crohn’s disease or ulcerative colitis)
• Have a family member or close relative with colon cancer or polyps
• Have a genetic disorder such as hereditary non-polyposis, Lynch syndrome, or familial adenomatous polyposis (FAP)

What are the Treatment Options for Colon Cancer?

 

The treatment option for colon cancer will depend on a few important factors including:

• Location
• Stage
• Where the cancer has spread

When creating your treatment plan, your doctor will discuss the treatment options available, the possible side effects, and the benefits of each treatment. One or a combination of the following may be used to treat colon cancer:

• Radiation therapy
• Chemotherapy
• Surgery
• Cryoablation or radiofrequency ablation (RFA)
• Targeted therapies such as immunotherapy, anti-angiogenesis therapy, and epidermal growth factor receptors (EGFR) inhibitors

What is the Outlook for Those with Colon Cancer?

 

The outlook for people with colon cancer will depend on some factors including:

 

• Treatments
• Stage of the cancer
• Characteristics of the cancer
• Response to the treatment

Other medical conditions and your overall health will also play an important role. Your doctor can provide a prognosis based on the statistics and predictive factors. However, it is still impossible to predict how a patient will respond to the treatment. Based on survival rates, the outlook for colon cancer is excellent as long as it is diagnosed and treated early.