Carcinoma of unknown primary (CUP)

Carcinoma of unknown primary (CUP)

Carcinoma of unknown primary (CUP) arises when cancer cells have migrated throughout the body and established metastatic tumours, but the source malignancy’s location is unknown. It’s also known as occult primary tumor.

The most common way for doctors to detect cancer is when they find the site where it started (primary tumor). Those areas may be detected as well if the cancer has spread (metastasized).

Doctors can identify cancer cells that have spread throughout the body in carcinoma of unknown primary, also known as occult primary cancer, but they can’t find the underlying tumour.

When deciding on the best treatment, doctors evaluate the main tumor’s location. When a carcinoma with an unknown source is discovered, clinicians strive to determine the primary tumour site. When trying to figure out where your cancer started, your doctor may look at your risk factors, symptoms, and exam, imaging, and pathology test results.

Why is the primary cancer can’t be found?

The primary cancer (cancer that first formed) may not be found because:

• It was too small to be found by imaging tests.
• Your body’s immune system destroyed it.
• It was removed during an operation for another reason (not knowing any cancer was present).

Types of carcinoma of unknown primary (CUP)

Adenocarcinoma:  Adenocarcinoma accounts for over 60% of tumours classified as cancer of uncertain origin. These tumours are made up of gland-forming epithelial cells. Because glands are involved in secreting or transporting chemicals, adenocarcinoma can form in almost any organ in the body.

The lining of most internal organs is made up of glandular epithelial cells. This can make determining the primary tumour site difficult. The lungs, pancreas, breasts, prostate, stomach, liver, and colon are all common primary sites for adenocarcinoma.

Poorly differentiated carcinoma:

Poorly differentiated cancer cells are found in 20 to 30 percent of all malignancies of uncertain origin. These malignancies don’t seem like normal cells and are frequently more aggressive than other types of cancer.

These cancers may have started in lymphocytes, skin cells, neuroendocrine cells (which produce hormones into the blood), or other specialised cells, according to specialised tests. Many weakly differentiated cancer cells, on the other hand, appear so unlike to normal cells that clinicians are unable to establish their original cell type.

Squamous cell carcinoma: Squamous cell carcinoma makes up fewer than 10% of malignancies with no known cause. It’s made up of flat epithelial cells that can be found on the skin’s surface or in the lining of specific organs including the mouth and oesophagus. Squamous cell carcinoma is a kind of lung cancer.

Neuroendocrine carcinoma: Neuroendocrine cells are found in some malignancies of unclear origin. Hormone-containing or hormone-producing cells are a wide range of cell types. Because neuroendocrine carcinoma can start anywhere in the body, determining the main site can be difficult.

Symptoms of carcinoma of unknown primary (CUP)

Signs and symptoms of carcinoma of unknown primary depend on what part of the body is involved. In general, they might include:

• A lump that can be felt through the skin
• Pain
• Changes in bowel habits, such as new and persistent constipation or diarrhea
• Frequent urination
• Cough
• Fever
• Night sweats
• Losing weight without trying

Causes of carcinoma of unknown primary

In general, cancer develops when cells’ DNA undergoes alterations (mutations). The DNA code contains instructions for cells to follow. Certain mutations can allow a cell to proliferate uncontrollably and to live even when it would normally perish. The aberrant cells clump together and form a tumour as a result. Tumor cells can break off and spread to other places of the body (metastasize).

Cancer cells that have spread to other places of the body are observed in carcinoma of unknown source. However, the primary tumour has not been discovered.

This can happen if:

• The original cancer is too small to be detected by imaging tests
• The original cancer was killed by the body’s immune system
• The original cancer was removed in an operation for another condition

Diagnosis of carcinoma of unknown primary

The following tests and techniques are used to identify carcinoma of unknown origin:

Examination of the body: To obtain clues regarding your diagnosis, your doctor may question you about your signs and symptoms and examine the area that worries you.
Imaging tests are performed. Imaging tests, such as an X-ray, CT scan, or MRI, may be used to aid in your diagnosis.
Taking a tissue sample for testing: Your doctor may propose a procedure to extract a sample of cells for lab testing to confirm that your symptoms are caused by cancer (biopsy). This could be accomplished by injecting a needle into your skin, or it could necessitate an operation. Doctors will examine the cells in the lab to see whether they are malignant and where they came from.

Treatment of carcinoma of unknown primary

Your doctor will evaluate where your cancer cells were discovered, the sort of normal cells they most closely resemble, and the findings of lab testing when deciding which treatments are best for you. The treatment plan is tailored to your specific clinical needs as well as your personal preferences.

The following treatments may be used:

Chemotherapy: Chemotherapy is a treatment that uses chemicals to kill cancer cells. One or more chemotherapy medications may be given intravenously (via a vein in your arm), or taken orally, or a combination of the two. If you have cancer cells in more than one location, chemotherapy may be suggested.

Radiation therapy: Radiation therapy is a type of treatment that involves the use of To kill cancer cells, radiation therapy uses high-powered energy beams from sources such as X-rays and protons. You lie on a table during radiation therapy as a machine rotates around you, distributing radiation to specific locations on your body. For carcinoma of unknown origin that is restricted to one part of the body, radiation therapy may be employed. It can also be used to manage symptoms, such as discomfort caused by a growing malignancy.

Surgery: If your carcinoma of unknown source is limited to one region, such as a lymph node or the liver, an operation to remove the cancer may be a possibility. After surgery, your doctor may recommend radiation to destroy any cancer cells that remain.

Palliative (supportive) care: Palliative care is a type of medical treatment that focuses on relieving pain and other symptoms associated with a serious illness. Palliative care professionals collaborate with you, your family, and your other doctors to add an extra layer of support to your ongoing treatment. Palliative care can be used in conjunction with other aggressive treatments such surgery, chemotherapy, or radiation.