What is carcinoma of unknown primary?

What is carcinoma of unknown primary?

Carcinoma of unknown primary (CUP) is a disease in which cancer (malignant) cells are found somewhere in the body, but the place where they first started growing (the origin or primary site) cannot be found. This occurs in about 2%-4% of cancer patients.

Actually, CUP can be described as a group of different types of cancer all of which have become known by the place or places in the body where the cancer has spread (metastasized) from another part of the body. Because all of these diseases are not alike, chance of recovery (prognosis) and choice of treatment may be different for each patient.

If CUP is suspected, a doctor will order several tests, one of which may be a biopsy. This means a small piece of tissue is cut from the tumor and looked at under a microscope. The doctor may also do a complete history and physical examination, and order chest x-rays along with blood, urine, and stool tests. A cancer can be called CUP when the doctor cannot tell from the test results where the cancer began.

The pattern of how CUP has spread may also give the doctor information to help determine where it started. For example, lung metastases are more common when cancer begins above the diaphragm (the thin muscle under the lungs that helps the breathing process). Most large studies have shown that CUP often starts in the lungs or pancreas. Less often, it may start in the colon, rectum, breast, or prostate.

An important part of trying to find out where the cancer started is to see how the cancer cells look under a microscope (histology). Other special tests may also be done that help the doctor find out where the cancer started and choose the best type of treatment.

Glossary Terms

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

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.

Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk. Also called mammary gland.

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.

A case in which cancer cells are found in the body, but the place where the cells first started growing (the origin or primary site) cannot be determined. Also called carcinoma of unknown primary and CUP.

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

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.

The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus.

The thin muscle below the lungs and heart that separates the chest from the abdomen.

The study of tissues and cells under a microscope.

One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.

Cancer that has spread from the original (primary) tumor to the lung.

To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.

A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones, including insulin. The pancreas is surrounded by the stomach, intestines, and other organs.

An exam of the body to check for general signs of disease.

The original tumor.

The likely outcome or course of a disease; the chance of recovery or recurrence.

A gland in the male reproductive system. The prostate surrounds the part of the urethra (the tube that empties the bladder) just below the bladder, and produces a fluid that forms part of the semen.

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

The material in a bowel movement. Stool is made up of food that was not digested, bacteria, mucus, and cells from the intestines. Also called feces.

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.

Fluid containing water and waste products. Urine is made by the kidneys, stored in the bladder, and leaves the body through the urethra.