Everything You Need to Know About Colon Cancer

Table of Contents

Signs and Symptoms
Risk Factors
When to See a Doctor
Staging of Colon Cancer
Living with Colon Cancer
Frequently Asked Questions


Colon cancer refers to the uncontrolled growth of cells in the colon. This disease almost always develops from abnormal growths in the colon called precancerous polyps. As such, colon cancer screening is so important in the fight against this disease.

In the United States, colon cancer is the third most common cancer diagnosed in both men and women. Plus, it has the distinction of being the third leading cause of death from cancer among American men and women.

Signs and Symptoms

Signs and symptoms of colon cancer vary. Early in the course of the disease, many people may have no symptoms at all.

As the colon cancer progresses, early-stage signs and symptoms may manifest. This includes:

Late-stage signs and symptoms of colon cancer may include:

Lastly, if colon cancer spreads, or metastasizes, to other parts of the body, the signs and symptoms may include:

Risk Factors

There is a multitude of risk factors that may increase your chances of developing colon cancer. Some of these risk factors cannot be changed, while others can be.

The most common non-modifiable risk factor for colon cancer is advancing age. The American Cancer Society estimates that 90 percent of colon cancer diagnoses occur in individuals who are 50 or older. Some other non-modifiable risk factors are:

Some modifiable risk factors for colon cancer include:


Since most colon cancers develop from precancerous polyps, screening efforts to find them early are imperative. It is imperative because this is when the treatment works best.

Colon cancer screening does indeed save lives. In fact, almost 90 percent of individuals whose colon cancers are found early, localized, and treated fittingly are still alive five years after treatment.

The U.S. Preventive Services Task Force recommends colon cancer screening commence at age 50 with strategies including:

Lastly, other screening techniques include double-contrast barium enema or virtual colonoscopy. These may be repeated every five to 10 years or five years, respectively, if negative.


As far as colon cancer prevention or at least decreasing your risk, you should consider:

When to See a Doctor

If you suspect you may be experiencing signs or symptoms of colon cancer, you should make an appointment with your doctor to discuss the matter. Furthermore, if you are at average risk for colon cancer, you should see your doctor for colon cancer screening commencing at age 50. This has the potential to become a prevention method, especially in the case of colonoscopy.

Lastly, if you suspect your risk for colon cancer has increased, you should discuss this with your doctor to determine when to begin screening, which test is appropriate for you, and how often to obtain screening.


Your doctor will start by performing a thorough medical history focusing on your symptoms and family history. This is followed by a thorough physical examination, including a rectal examination.

Although there is no specific blood test for the diagnosis of colon cancer, your doctor may check your liver function tests and complete blood count. Colon cancer — especially if has spread to other parts of the body — or other medical conditions may adversely affect these tests.

Other diagnostic strategies for colon cancer may include imaging studies, such as double-contrast barium enema and virtual colonoscopy.

Staging of Colon Cancer

If diagnosed with colon cancer, you and your doctor will want to know the extent of your cancer. This is accomplished through a process called staging. This process helps determine which treatments are most appropriate for you. Abdominal, pelvic, chest CT scans, and biopsies are usually utilized in the staging of colon cancer.

Roman numerals ranging from 0 to IV are used to indicate the stages of colon cancer. They are:


There are several types of colon cancers. The most common type is adenocarcinoma, which accounts for 96 percent of colon cancers. Two subtypes of adenocarcinoma, mucinous and signet ring cell, deserve special mention because they tend to have a worse prognosis as compared to other types of adenocarcinoma.

Other less common types of colon cancer include:


The prognosis for your colon cancer is most commonly referred to as the five-year survival rate.  For particular colon cancers, its stage at diagnosis determines the prognosis.

The Surveillance Epidemiology and End Results (SEER) database from the National Cancer Institute estimates the following five-year relative survival rates based on colon cancer stage:

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If left untreated, the complications of colon cancer may include:

These complications may be considered surgical emergencies and can become life-threatening.

Other potential complications of colon cancer include:


The treatment of colon cancer depends on many variables, including the stage of cancer. The aims of colon cancer treatment are the removal of cancer, prevention of its spread, and reduction of any uncomfortable symptoms.

Colon cancer treatments come in two broad categories:

  1. Local Therapies: Treat colon cancer without affecting the rest of the body. These include surgery and radiation therapy.
  2. Systemic Therapies: Treat colon cancer using drugs. You can receive these drugs orally or directly into the bloodstream. These include chemotherapy, targeted therapy, and immunotherapy.


Surgery for colon cancer may include:

Radiation Therapy

Radiation therapy is not commonly used in the treatment of colon cancer. Despite that, it may be useful in select cases, such as:

Side effects of radiation therapy may include:

Most of these side effects resolve within several weeks after cessation of treatment.


Almost all individuals diagnosed with stage III colon cancer receive chemotherapy after surgery for a total of six to eight months. This is adjuvant chemotherapy.

Occasionally, chemotherapy with or without radiation therapy may be used before surgery to shrink the tumor and make it easier to remove. This is neoadjuvant chemotherapy.

Also, in individuals with stage IV disease, chemotherapy may be used to help ease symptoms by shrinking the tumor. It may even prolong life in these individuals.

Some chemotherapy drugs used to treat colon cancer include:

Side effects of chemotherapy may include:

Targeted Therapy

Targeted therapy involves drugs that specifically block or inhibit either the growth of cancer cells or the formation of new blood vessels. These two functions are crucial to the perpetuation of colon cancer. Specifically, targeted therapy can block:

Examples of targeted therapy for colon cancer include:

Targeted therapy will sometimes work when standard chemotherapy drugs don’t. Plus, they often have different and less severe side effects compared to standard chemotherapy regimens.

Targeted therapy drugs can be used alone or in combination with surgery, radiation, and standard chemotherapy.


Immunotherapy focuses on drugs that have the potential to boost your immune system. This boost will hopefully lead to better recognition and destruction of colon cancer cells. Immunotherapy accomplishes this by blocking key proteins on immune cells, which boosts your immune response.

These drugs are known as “checkpoint inhibitors”. If your colon cancer is still growing, despite chemotherapy, you may be a candidate for a checkpoint inhibitor. Examples include pembrolizumab (Keytruda), nivolumab (Opdivo), and ipilimumab (Yervoy).

Side effects of this class of medications may include:

Living with Colon Cancer

For some, there is a beginning and end to their colon cancer treatment. For others, their colon cancer never totally goes away. This leaves them with regular treatments to keep the cancer at bay.

Whether you are living with or after colon cancer, there are things you can do to reduce your risk of first-time or recurrent disease. This includes:

Frequently Asked Questions

Should I Get a Colonoscopy?

The obvious answer to this question is yes.

In fact, it is estimated that 60 percent of deaths from colon cancer could be prevented with routine screening colonoscopy commencing at age 50. The proportion increases to 90 percent of deaths prevented when you add lifestyle changes to screening colonoscopy.

Do I Need to Miss Work for My Colonoscopy?

Yes. Since the sedatives are administered prior to the procedure, you will need time for the medication to wear off completely. Depending on the patient, this can take several hours.

Additionally, you will need someone to drive you home after your procedure for this same reason.

What Can I If I’m Concerned About the Costs and Insurance Coverage for My Colon Cancer Screening Test?

The Affordable Care Act requires both private insurers and Medicare to cover the costs of colon cancer screening tests starting at age 50. As a result, there should be no out-of-pocket costs for these tests in most cases.

What Is a Colorectal Surgeon?

Colorectal surgeons are experts in the surgical and non-surgical treatment of diseases of the colon, rectum, and anus. They are board-certified and well-versed in the treatment of both cancerous and non-cancerous diseases of the aforementioned areas.

Do I Need to See Any Other Doctors or Health Professionals for Colon Cancer?

Depending on your treatment, your colon cancer team could consist of a(n):

Additionally, health care professionals such as physician assistants, nurse practitioners, nurses, psychologists, nutritionists/dieticians, and social workers may be a part of your health care team.


Despite colon cancer being the third leading cause of cancer-related deaths, it is highly treatable when caught early in many cases. One of the main determinants of your prognosis is the stage of cancer, which to a certain extent also determines your treatment plan.

When treated at an early stage, colon cancer has a significant five-year survival rate. If colon cancer does not reoccur within five years, doctors consider you cured.

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