Description

What is carcinoma of unknown primary?

Stage Explanation

Stages of carcinoma of unknown primary

Treatment Option Overview

How carcinoma of unknown primary is treated Treatment in a clinical trial

Newly Diagnosed Carcinoma of Unknown Primary
Recurrent Carcinoma of Unknown Primary
To Learn More About Carcinoma of Unknown Primary
Get More Information From NCI
Changes to This Summary (06/13/2008)
About PDQ

Description

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.

Stage Explanation

Stages of carcinoma of unknown primary

When cancer is diagnosed, more tests are usually done to find out if cancer cells have spread to other parts of the body. This is called staging. But, when CUP is diagnosed, the number and type of tests done may be different for each patient. The treatment options in this summary are based on whether the cancer has just been found (newly diagnosed) or the cancer has come back after it has been treated (recurrent).

The treatment options are also based on where the cancer is found, where the doctor thinks the cancer started, what the cancer cells look like under a microscope, and other factors. A doctor may find that the cancer fits into one of the following groups:

• Cancer in the cervical lymph nodes: cancer in the small, bean-shaped organs that make and store infection -fighting cells (lymph nodes) in the neck area
• Poorly differentiated carcinomas: the cancer cells look very different from normal cells
• Metastatic melanoma to a single nodal site: cancer of the cells that color the skin (melanocytes) that has spread to lymph nodes in only one part of the body
• Isolated axillary metastasis: cancer that has spread only to lymph nodes in the area of the armpits
• Inguinal node metastasis: cancer that has spread to lymph nodes in the groin area
• Multiple involvement: cancer that has spread to several different areas of the body

Treatment Option Overview

How carcinoma of unknown primary is treated

Different types of treatment are available for patients with carcinoma of unknown primary (CUP). Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Some of the standard treatments that are used are:

• Surgery (taking out the cancer in an operation)
• Radiation therapy (using high- dose x-rays to kill cancer cells)
• Chemotherapy (using drugs to kill cancer cells)
• Hormone therapy (using hormones to stop the cancer cells from growing)

Surgery is a common treatment for CUP. A doctor may remove the cancer and some of the healthy tissue around it. Different operations are used depending on where the cancer is found. If the cancer has spread to lymph nodes, the lymph nodes may be removed (lymph node dissection). If the nodes involved are in the groin, this operation is called a superficial groin dissection. If the cancer has spread to lymph nodes and also to some surrounding areas, the doctor may have to remove a larger portion of tissue around the nodes. When muscles, nerves, and other tissue in the neck are removed, this is called a radical neck dissection.

Radiation therapy uses x-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation may be used alone or before or after surgery.

Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by mouth or it may be put into the body by a needle in a vein or muscle. Chemotherapy is called a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells throughout the body. Chemotherapy may be used alone or after surgery. Therapy given after an operation when there are no cancer cells that can be seen is called adjuvant therapy.

Hormone therapy is used to stop the hormones in the body that help cancer cells grow. This may be done by using drugs that change the way hormones work or by surgery that takes out organs that make hormones, such as the testicles (orchiectomy).

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country. In the following lists of treatments for the different stages, a link to search results for current clinical trials is included for each section. These have been retrieved from NCI's clinical trials database. For some types or stages of cancer, there may not be any trials listed. Check with your doctor for clinical trials that are not listed here but may be right for you.

Newly Diagnosed Carcinoma of Unknown Primary

If the cancer is in the neck area (cervical lymph nodes), treatment may be one of the following:

1. Surgery to remove the tonsils (tonsillectomy).
2. Radiation therapy.
3. Radiation therapy followed by surgery.
4. Neck surgery (radical neck dissection).
5. Neck surgery followed by radiation therapy.

(Refer to the PDQ summary on Metastatic Squamous Neck Cancer With Occult Primary ¹ for more information.)

If the cancer is a poorly differentiated carcinoma (the cancer cells look very different than normal cells), the treatment will probably be chemotherapy. Surgery or radiation therapy has also been used for patients with neuroendocrine (nervous system and hormonal system) cancer.

If the cancer is peritoneal adenocarcinomatosis (the tumor is in the lining inside the abdomen), the treatment will probably be chemotherapy.

If the cancer is an isolated axillary nodal metastasis, it is likely that the cancer started in the lung or breast. If female, a mammogram (an x-ray picture of the breast) will be used to check for breast cancer. After tests to check for lung and breast cancer, the treatment may be one of the following:

1. Surgery to remove the lymph nodes with or without surgery to remove the breast (mastectomy) or radiation therapy to the breast.
2. Treatment as described above plus chemotherapy that is used for breast cancer.

If the cancer is in the inguinal nodes, the treatment may be one of the following:

1. Surgery to remove the cancer.
2. Groin surgery (superficial groin dissection).
3. Surgery to remove some of the tumor (biopsy) with or without radiation therapy, surgery to remove the lymph nodes, or chemotherapy.

If the cancer is melanoma that has spread to a single nodal site, the treatment will probably be surgery to remove the lymph nodes.

If there is cancer in several different areas of the body and the doctor thinks that the origin of the cancer is one for which there is standard systemic therapy, then that therapy should be given. The following are examples:

1. Hormone therapy for prostate cancer.
2. Chemotherapy or hormone therapy for breast cancer.
3. Chemotherapy for ovarian cancer.

If the source of the cancer cannot be found, then the best treatment may not be known. Patients may want to consider taking part in a clinical trial.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with newly diagnosed carcinoma of unknown primary ².

Recurrent Carcinoma of Unknown Primary

Treatment of recurrent CUP depends on the type of cancer, what treatment was received before, the part of the body where the cancer has come back, and other factors. A patient may want to consider taking part in a clinical trial.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with recurrent carcinoma of unknown primary ³.

To Learn More About Carcinoma of Unknown Primary

For more information from the National Cancer Institute about carcinoma of unknown primary, see the following:

• Carcinoma of Unknown Primary Home Page ⁴
• Cancer of Unknown Primary Origin ⁵
• Metastatic Cancer: Questions and Answers ⁶

For general cancer information and other resources from the National Cancer Institute, see the following:

• What You Need to Know About™ Cancer - An Overview ⁷
• Understanding Cancer Series: Cancer ⁸
• Staging: Questions and Answers ⁹
• Chemotherapy and You: Support for People With Cancer ¹⁰
• Radiation Therapy and You: Support for People With Cancer ¹¹
• Coping with Cancer ¹²
• Support and Resources ¹³
• Cancer Library ¹⁴
• Information For Survivors/Caregivers/Advocates ¹⁵

Get More Information From NCI

Call 1-800-4-CANCER

For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. Deaf and hard-of-hearing callers with TTY equipment may call 1-800-332-8615. The call is free and a trained Cancer Information Specialist is available to answer your questions.

Chat online

The NCI's LiveHelp® ¹⁶ online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 9:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.

Write to us

For more information from the NCI, please write to this address:

NCI Public Inquiries Office

Suite 3036A

6116 Executive Boulevard, MSC8322

Bethesda, MD 20892-8322

Search the NCI Web site

The NCI Web site ¹⁷ provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use our “Best Bets” search box in the upper right hand corner of each Web page. The results that are most closely related to your search term will be listed as Best Bets at the top of the list of search results.

There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator ¹⁸. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.

Changes to This Summary (06/13/2008)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Several enhancements have been made to this summary to better explain certain medical concepts and to help readers find information about clinical trials. The following changes were made:

• Information about patients taking part in clinical trials was added to the Treatment Option Overview ¹⁹ section.
• Links to ongoing clinical trials listed in NCI's PDQ Cancer Clinical Trials Registry were added to the treatment sections.
• A new section called "To Learn More ²⁰" was added. It includes links to more information about this type of cancer and about cancer in general.
• The "Get More Information from NCI" section (originally called "To Learn More") was revised.

About PDQ

PDQ is a comprehensive cancer database available on NCI's Web site.

PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site ¹⁷. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.

PDQ contains cancer information summaries.

The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.

The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.

Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.

PDQ also contains information on clinical trials.

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Listings of clinical trials are included in PDQ and are available online at NCI's Web site ²¹. Descriptions of the trials are available in health professional and patient versions. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.

Glossary Terms

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

Treatment given after the primary treatment to increase the chances of a cure. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, or biological therapy.

Pertaining to the armpit area, including the lymph nodes that are located there.

A lymph node in the armpit region that drains lymph channels from the breast.

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.

Cancer that begins in the skin or in tissues that line or cover internal organs.

CUP. 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 cancer of unknown primary origin and CUP.

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

Relating to the neck, or to the neck of any organ or structure. Cervical lymph nodes are located in the neck. Cervical cancer refers to cancer of the uterine cervix, which is the lower, narrow end (the “neck”) of the uterus.

Treatment with drugs that kill cancer 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.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called a clinical study.

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 process of identifying a disease, such as cancer, from its signs and symptoms.

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

In cancer, refers to how mature (developed) the cancer cells are in a tumor. Differentiated tumor cells resemble normal cells and tend to grow and spread at a slower rate than undifferentiated or poorly differentiated tumor cells, which lack the structure and function of normal cells and grow uncontrollably.

The amount of medicine taken, or radiation given, at one time.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

The area where the thigh meets the abdomen.

The study of tissues and cells under a microscope.

One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body’s natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called hormonal therapy, hormone treatment, or endocrine therapy.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

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.

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 surgical procedure in which the lymph nodes are removed and examined to see whether they contain cancer. For a regional lymph node dissection, some of the lymph nodes in the tumor area are removed; for a radical lymph node dissection, most or all of the lymph nodes in the tumor area are removed. Also called lymphadenectomy.

An x-ray of the breast.

Surgery to remove the breast (or as much of the breast tissue as possible).

A cell in the skin and eyes that produces and contains the pigment called melanin.

A form of cancer that begins in melanocytes (cells that make the pigment melanin). It may begin in a mole (skin melanoma), but can also begin in other pigmented tissues, such as in the eye or in the intestines.

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).

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.

Having to do with metastasis, which is the spread of cancer from one part of the body to another.

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

NCI, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. It conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the NCI Web site at http://www.cancer.gov. Also called National Cancer Institute.

Surgery to remove lymph nodes and other tissues in the neck.

A bundle of fibers that receives and sends messages between the body and the brain. The messages are sent by chemical and electrical changes in the cells that make up the nerves.

Having to do with the interactions between the nervous system and the endocrine system. Neuroendocrine describes certain cells that release hormones into the blood in response to stimulation of the nervous system.

Surgery to remove one or both testicles. Also called orchidectomy.

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

Having to do with the ovaries, the female reproductive glands in which the ova (eggs) are formed. The ovaries are located in the pelvis, one on each side of the uterus.

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.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

Having to do with the parietal peritoneum (the tissue that lines the abdominal wall and pelvic cavity) and visceral peritoneum (the tissue that covers most of the organs in the abdomen, including the intestines).

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 use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called radiotherapy and irradiation.

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

To come back or to return.

Cancer that has recurred (come back), usually after a period of time during which the cancer could not be detected. The cancer may come back to the same place as the original (primary) tumor or to another place in the body. Also called recurrent cancer.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

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.

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.

In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with standard therapy. Also called standard of care or best practice.

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.

Affecting cells on the surface. Not invasive.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

Treatment using substances that travel through the bloodstream, reaching and affecting cells all over the body.

One of two egg-shaped glands found inside the scrotum that produce sperm and male hormones. Also called a testis.

Treatment.

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

One of two small masses of lymphoid tissue on either side of the throat.

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.

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.