How is the disease diagnosed?

Colorectal cancer may be diagnosed in several ways, including:

• colonoscopy, a procedure in which a healthcare professional can look into the entire colon and collect tissue samples through the scope
• colon surgery
• endoscopy, a procedure in which a small tube is used to take a sample of tissue

Colorectal cancer is divided into stages, and the likelihood of cure and long-term disease-free survival is determined by the stage.

To determine the stage of the cancer, a surgeon removes the primary tumor and surrounding colon. Local lymph nodes are also removed and the abdomen is explored. The tissue is then examined under a microscope.

The stages of colorectal cancer are:

• Stage A, which is very limited and highly curable
• Stages B1 and B2, in which the cancer has invaded the bowel wall but hasn't spread to any of the lymph nodes
• Stages C1 and C2, in which cancer has invaded the bowel wall and has spread to some of the nearby lymph nodes
• Stage D, in which the cancer has spread to distant sites such as the lung, liver, and lymph nodes

Sometimes, the primary tumor or the sites where the cancer has spread cannot be removed entirely. In these cases, other tests can help in diagnosis, such as:

• CEA tumor marker, a blood test to determine whether the cancer cells have spread to another site
• CT scans of the liver and abdomen
• chest X-ray

What are the long-term effects of the disease?

People with Stage D cancer generally cannot be cured. They can survive for several weeks to a few years depending on the tumor's location and behavior. Home healthcare or hospice care may be helpful.

What are the risks to others?

Colorectal cancer is not contagious and poses no risk to others. However, it does tend to run in families.