Colorectal cancer, childhood

Colorectal cancer is a disease in which malignant (cancer) cells form in the tissues of the colon or the rectum. The colon is part of the body's digestive system. The digestive system removes and processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) from foods and helps pass waste material out of the body. The digestive system is made up of the mouth, throat, esophagus, stomach, and the small and large intestines. In an adult, the colon (large bowel) is the first part of the large intestine and is about 5 feet long. Together, the rectum and anal canal make up the last part of the large intestine and are 6 to 8 inches long. The anal canal ends at the anus (the opening of the large intestine to the outside of the body).

Colon cancer with extensive metastases to the liver

Micrograph of colorectal adenocarcinoma, showing "dirty necrosis".

Causes and Risk factors

Childhood colorectal cancer may be part of an inherited syndrome. Some colorectal cancers in young people are linked to a gene mutation that causes polyps (growths in the mucous membrane that lines the colon) to form that may turn into cancer later. The risk of colorectal cancer is increased by having inherited conditions, such as the following:

• Familial adenomatous polyposis (FAP).
• Attenuated FAP.
• MUTYH-associated polyposis.
• Oligopolyposis.
• Change in the NTHL1 gene.
• Juvenile polyposis syndrome.
• Cowden syndrome.
• Peutz-Jeghers syndrome.
• Neurofibromatosis type 1 (NF1).

Signs and symptoms

Signs and symptoms of childhood colorectal cancer usually depend on where the tumor forms. These and other signs and symptoms may be caused by colorectal cancer or by other conditions. Check with your child's doctor if your child has any of the following: Tumors of the rectum or lower colon may cause pain in the abdomen, constipation, or diarrhea. Tumors in the part of the colon on the left side of the body may cause:

• A lump in the abdomen.
• Weight loss for no known reason.
• Nausea and vomiting.
• Loss of appetite.
• Blood in the stool.
• Anemia (tiredness, dizziness, fast or irregular heartbeat, shortness of breath, pale skin).
• Tumors in the part of the colon on the right side of the body may cause:
• Pain in the abdomen.
• Blood in the stool.
• Constipation or diarrhea.
• Nausea and vomiting.
• Weight loss for no known reason.

Diagnosis

The following tests and procedures may be used:

Physical exam and health history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.

Colonoscopy: A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It also has a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.

Barium enema: A series of x-rays of the lower gastrointestinal tract. A liquid that contains barium (a silver-white metallic compound) is put into the rectum. The barium coats the lower gastrointestinal tract and x-rays are taken. This procedure is also called a lower GI series.

Fecal occult blood test: A test to check stool (solid waste) for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.

Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:

• The number of red blood cells, white blood cells, and platelets.
• The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
• The portion of the blood sample made up of red blood cells.

Carcinoembryonic antigen (CEA) assay: A test that measures the level of CEA in the blood. CEA is released into the bloodstream from both cancer cells and normal cells. When found in higher than normal amounts, it can be a sign of colorectal cancer or other conditions.

Treatment

Four types of standard treatment are used: Surgery

A diagram of a local resection of early stage colon cancer

A diagram of local surgery for rectal cancer

Surgery to remove the cancer is done if the cancer has not spread to other parts of the body at diagnosis.

Radiation therapy Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. External radiation therapy uses a machine outside the body to send radiation toward the cancer.

Chemotherapy Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). Chemotherapy using more than one drug is called combination chemotherapy.

Immunotherapy

Immunotherapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer.

Immune checkpoint inhibitor therapy is a type of immunotherapy. Some types of immune cells, such as T cells, and some cancer cells have certain proteins, called checkpoint proteins, on their surface that keep immune responses in check. When cancer cells have large amounts of these proteins, they will not be attacked and killed by T cells. Immune checkpoint inhibitors block these proteins and the ability of T cells to kill cancer cells is increased.

There are two types of immune checkpoint inhibitor therapy:

PD-1 immune checkpoint inhibitor PD-1 is a protein on the surface of T cells that helps keep the body’s immune responses in check. When PD-1 attaches to another protein called PDL-1 on a cancer cell, it stops the T cell from killing the cancer cell. PD-1 inhibitors attach to PDL-1 and allow the T cells to kill cancer cells. Nivolumab has been used to treat children 12 years and older with recurrent colorectal cancer. CTLA-4 inhibitor CTLA-4 is a protein on the surface of T cells that helps keep the body’s immune responses in check. When CTLA-4 attaches to another protein called B7 on a cancer cell, it stops the T cell from killing the cancer cell. CTLA-4 inhibitors attach to CTLA-4 and allow the T cells to kill cancer cells. Ipilimumab is used to treat children 12 years and older with recurrent colorectal cancer.

Prognosis

Prognosis depends on the following:

• Whether the tumor was completely removed by surgery.
• Whether the cancer has spread to other parts of the body, such as the lymph nodes, lung, liver, pelvis, ovaries, or bone.
• Whether the cancer has just been diagnosed or has recurred (come back).

Epidemiology

Colon and rectum cancer deaths per million persons in 2012 Globally more than 1 million people get colorectal cancer every year resulting in about 715,000 deaths as of 2010 up from 490,000 in 1990.

NIH genetic and rare disease info

• NIH info on Colorectal cancer, childhood

Colorectal cancer, childhood is a rare disease.

Colorectal cancer, childhood Resources
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