Colon Cancer: Symptoms, Stages, Causes, Risk Factors and Complications

Colon cancer, also known as colorectal cancer, is a type of cancer that starts in the colon or rectum, which are part of the digestive system. It is the third most common cancer diagnosed in both men and women and can be life-threatening if not detected and treated early.

Colon cancer usually begins as a small growth called a polyp, which may be benign (non-cancerous) or malignant (cancerous). Over time, the cancer cells can invade the colon and spread to other parts of the body, such as the liver, lungs, or lymph nodes.

Colon cancer typically affects older adults, though it can happen at any age. It usually begins as small, noncancerous (benign) clumps of cells called polyps that form on the inside of the colon. Over time some of these polyps can become colon cancers.

Polyps may be small and produce few, if any, symptoms. For this reason, doctors recommend regular screening tests to help prevent colon cancer by identifying and removing polyps before they turn into cancer.

Symptoms

Colon cancer can cause a range of symptoms, but many people with the early stages of colon cancer may not have any noticeable symptoms. Some of the common symptoms of colon cancer can include:

  • Changes in bowel habits, such as diarrhea or constipation
  • Rectal bleeding or blood in the stool
  • Abdominal pain or discomfort, including cramps, bloating, or gas
  • Unexplained weight loss or loss of appetite
  • Fatigue or weakness
  • Iron deficiency anemia (low red blood cell count) due to chronic bleeding from the colon
  • Feeling like the bowel does not completely empty during a bowel movement

It is important to note that these symptoms can also be caused by other conditions, such as hemorrhoids or inflammatory bowel disease. If you are experiencing any of these symptoms or have concerns about colon cancer, it is important to talk to your doctor. They can help determine if further testing, such as a colonoscopy, is needed to diagnose or rule out colon cancer.

When Too See a Doctor?

If you have any of these symptoms, or if you are at increased risk for colon cancer due to age, family history, or other factors, you should talk to your doctor about getting screened for colon cancer. Regular screening is recommended for people over the age of 50, or earlier for those with an increased risk of colon cancer. Early detection and treatment of colon cancer can improve the chances of successful treatment and reduce the risk of complications.

Stages

There are several different staging systems used to describe the extent of colon cancer. The most commonly used system is the American Joint Committee on Cancer (AJCC) staging system, which stages colon cancer from stage 0 to stage IV. Here’s a brief overview of each stage:

Stage 0: Also called carcinoma in situ, cancer cells are present only in the innermost lining of the colon and have not spread to the deeper layers or outside of the colon.

Stage I: Cancer has grown through the innermost lining of the colon into the middle layers, but has not spread beyond the colon wall.

Stage II: Cancer has grown through the outermost layers of the colon wall and may have spread to nearby tissues or organs, but has not spread to nearby lymph nodes.

Stage III: Cancer has spread to nearby lymph nodes but not to other parts of the body.

Stage IV: Cancer has spread to distant parts of the body, such as the liver or lungs.

The stage of colon cancer is an important factor in determining the appropriate treatment options and predicting the prognosis (outlook) for the person with the cancer. The earlier the stage of colon cancer, the better the chances of successful treatment and long-term survival.

Causes and Risk Factors

The exact causes of colon cancer are not fully understood, but it is believed to be caused by a combination of genetic and environmental factors. Here are some of the factors that may increase the risk of developing colon cancer:

  • Age: The risk of developing colon cancer increases with age, with most cases occurring in people over the age of 50.
  • Genetics: Colon cancer can run in families, and some people may inherit genetic mutations that increase their risk of developing the disease.
  • Personal history of polyps or colon cancer: People who have had colon polyps or colon cancer in the past are at an increased risk of developing the disease again.
  • Inflammatory bowel disease: People with inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease, have an increased risk of developing colon cancer.
  • Unhealthy lifestyle habits: A diet high in red and processed meats, low in fruits and vegetables, and lacking in fiber can increase the risk of colon cancer. Sedentary lifestyle habits, smoking, and heavy alcohol consumption can also increase the risk.
  • Obesity: Being overweight or obese increases the risk of developing colon cancer.
  • Type 2 diabetes: People with type 2 diabetes have an increased risk of developing colon cancer.

It’s important to note that having one or more of these risk factors does not necessarily mean that someone will develop colon cancer. Regular screening and early detection are crucial in the prevention and treatment of colon cancer.

Complications

Colon cancer can lead to several complications, some of which can be life-threatening. Here are some of the complications associated with colon cancer:

  • Obstruction: Colon cancer can cause a blockage in the colon, preventing stool from passing through. This can cause abdominal pain, bloating, and constipation.
  • Perforation: If the colon cancer grows through the wall of the colon, it can cause a perforation, allowing bacteria to leak into the abdomen. This can lead to a serious infection called peritonitis.
  • Bleeding: Colon cancer can cause bleeding in the colon, leading to anemia and weakness.
  • Metastasis: If colon cancer spreads to other parts of the body, it can cause complications specific to the affected organ, such as liver failure if the cancer spreads to the liver.
  • Recurrence: Even after successful treatment for colon cancer, there is a risk of the cancer returning.
  • Emotional impact: Coping with a cancer diagnosis and treatment can be challenging and can have emotional and psychological effects, such as anxiety and depression.

It’s important to note that not everyone with colon cancer will experience complications, and some people may have a better prognosis than others. The best way to prevent complications is to get regular screenings and detect colon cancer at an early stage, when it is most treatable.

Overall

Colon cancer is a type of cancer that affects the colon, which is the large intestine. It is the third most common cancer in both men and women. The exact causes of colon cancer are not fully understood, but it is believed to be caused by a combination of genetic and environmental factors.

Signs of colon cancer may not be obvious in its earlier stages. However, they may include pain, rectal bleeding, or blood in the stool.

If colon cancer develops, many treatments are available to help control it, including surgery, radiation therapy and drug treatments, such as chemotherapy, targeted therapy and immunotherapy.