Key Points for This Section

After anal cancer has been diagnosed, tests are done to find out if cancer cells have spread within the anus or to other parts of the body. There are three ways that cancer spreads in the body. The following stages are used for anal cancer: Stage 0 (Carcinoma in Situ) Stage I Stage II Stage IIIA Stage IIIB Stage IV

After anal cancer has been diagnosed, tests are done to find out if cancer cells have spread within the anus or to other parts of the body.

The process used to find out if cancer has spread within the anus or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following tests may be used in the staging process:

• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. For anal cancer, a CT scan of the pelvis and abdomen may be done.
• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Endo-anal or endorectal ultrasound: A procedure in which an ultrasound transducer (probe) is inserted into the anus or rectum and used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are:

• Through tissue. Cancer invades the surrounding normal tissue.
• Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
• Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The following stages are used for anal cancer:

Stage 0 (Carcinoma in Situ)

In stage 0, abnormal cells are found in the innermost lining of the anus. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Enlarge

Pea, peanut, walnut, and lime show tumor sizes.

Stage I

In stage I, cancer has formed and the tumor is 2 centimeters or smaller.

Stage II

In stage II, the tumor is larger than 2 centimeters.

Stage IIIA

In stage IIIA, the tumor may be any size and has spread to either:

• lymph nodes near the rectum; or
• nearby organs, such as the vagina, urethra, and bladder.

Stage IIIB

In stage IIIB, the tumor may be any size and has spread:

• to nearby organs and to lymph nodes near the rectum; or
• to lymph nodes on one side of the pelvis and/or groin, and may have spread to nearby organs; or
• to lymph nodes near the rectum and in the groin, and/or to lymph nodes on both sides of the pelvis and/or groin, and may have spread to nearby organs.

Stage IV

In stage IV, the tumor may be any size and cancer may have spread to lymph nodes or nearby organs and has spread to distant parts of the body.

Glossary Terms

The area of the body that contains the pancreas, stomach, intestines, liver, gallbladder, and other organs.

Not normal. An abnormal lesion or growth may be cancerous, premalignant (likely to become cancer), or benign.

Having to do with the anus. The anus is the opening of the rectum (last part of the large intestine) to the outside of the body.

The opening of the rectum to the outside of the body.

The organ that stores urine.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

Primary bone cancer is cancer that forms in cells of the bone. Some types of primary bone cancer are osteosarcoma, Ewing sarcoma, malignant fibrous histiocytoma, and chondrosarcoma. Secondary bone cancer is cancer that spreads to the bone from another part of the body (such as the prostate, breast, or lung).

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

The smallest type of blood vessel. A capillary connects an arteriole (small artery) to a venule (small vein) to form a network of blood vessels in almost all parts of the body. The wall of a capillary is thin and leaky, and capillaries are involved in the exchange of fluids and gases between tissues and the blood.

A group of abnormal cells that remain in the tissue in which they first formed. These abnormal cells may become cancer and spread into nearby normal tissue.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

A measure of length in the metric system. There are 100 centimeters in a meter and 2½ centimeters in an inch.

An x-ray of the structures inside the chest. An x-ray is a type of high-energy radiation that can go through the body and onto film, making pictures of areas inside the chest, which can be used to diagnose disease.

Computed tomography scan. A series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called computed tomography scan, computerized tomography, computerized axial tomography scan, and CAT scan.

The area where the thigh meets the abdomen.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called infiltrating cancer.

The clear fluid that travels through the lymphatic system and carries cells that help fight infections and other diseases. Also called lymphatic fluid.

A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.

The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. This system includes the bone marrow, spleen, thymus, lymph nodes, and lymphatic vessels (a network of thin tubes that carry lymph and white blood cells). Lymphatic vessels branch, like blood vessels, into all the tissues of the body.

The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-tuh-SEEZ).

A part of the body that performs a specific function. For example, the heart is an organ.

The lower part of the abdomen, located between the hip bones.

The original tumor.

The last several inches of the large intestine. The rectum ends at the anus.

A computer picture of areas inside the body created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs. Also called an ultrasonogram.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

Abnormal cells are found in the innermost lining of the anus. These abnormal cells may become cancer and spread into nearby normal tissue.

The tumor is no larger than 2 centimeters.

The tumor is larger than 2 centimeters.

Stage III anal cancer is divided into stages IIIA and IIIB. In stage IIIA, the tumor may be any size and has spread to either (1) lymph nodes near the rectum; or (2) nearby organs, such as the vagina, urethra, and bladder.

Stage III anal cancer is divided into stages IIIA and IIIB. In stage IIIB, the tumor may be any size and has spread to (1) nearby organs and to lymph nodes near the rectum; or (2) lymph nodes on one side of the pelvis and/or groin, and may have spread to nearby organs; or (3) lymph nodes near the rectum and in the groin, and/or to lymph nodes on both sides of the pelvis and/or groin, and may have spread to nearby organs.

The tumor may be any size, and cancer has spread to distant parts of the body. It may also have spread to lymph nodes and nearby organs.

Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.

A group or layer of cells that work together to perform a specific function.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called neoplasm.

A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasonography.

The tube through which urine leaves the body. It empties urine from the bladder.

The muscular canal extending from the uterus to the exterior of the body. Also called birth canal.

A blood vessel that carries blood to the heart from tissues and organs in the body.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.