Paraneoplastic syndromes (PNS) are a group of rare diseases caused by the presence of tumors in the body. They occur in about 10 to 15 percent of people with cancer and can develop before the cancer is discovered.
Read on to learn what paraneoplastic syndromes are, what types of cancer they are associated with, what common symptoms they have, and how they are diagnosed and treated.
PNS is a set of symptoms that are different from cancer. They occur because you have cancer and you can outlast the cancer itself. Although tumors cause PNS, they have nothing to do with the size or number of tumors in the body.
PNS are caused by an altered immune response to a tumor in your body. There are generally six main types of PNS based on the body system they affect:
- Endocrine. These affect your body’s glands and hormones.
- Neurological. These affect the brain and the nervous system.
- Musculoskeletal system. These affect muscles and bones.
- Skin. These affect the skin and connective tissue.
- Hematological. These affect the blood and blood cells.
- Other. These syndromes include those that affect multiple body systems or do not fit into any other category.
The symptoms of paraneoplastic syndrome depend on the specific body system or organ that the condition affects.
Common symptoms are:
- Fever (most common)
- Night sweats
- Loss of appetite
- Weight loss (which can lead to muscle wasting)
- altered sense of taste
Less common PNS can affect other body systems and organs, such as:
Brain and nervous system
PNS, which affect the brain and nervous system, can cause:
- dizziness
- Double vision
- Seizure
- Changes in the way you think and act
- Trouble sleeping
- Difficulty swallowing or speaking
- Muscle weakness
- Impaired nerve function
- less coordination, reflexes, or sensations
Endocrine glands
PNS, which affect the endocrine glands, can lead to high levels of the hormones cortisol and adrenocorticotropic hormone (ACTH), causing the following symptoms:
- a headache
- Muscle spasms
- irritability
- sleepiness
- Nausea and vomiting
- fatigue
- weakness
- confusion
- slow heart rate
- high blood pressure
- coma
- Weight gain
- Deposits of fat in the middle and face, and between the shoulders and upper back
- swollen hands or legs
- low blood sugar
- low levels of sodium or calcium in the blood
- acute kidney failure
skin
Reddened skin, or redness and itching, are most common, but some syndromes can cause other skin problems, such as:
- itching
- Flaky skin
- Hair loss
- abnormal hair growth
- Tightening of the skin
- black or brown pigmentation of the skin
- skin rash
- Skin ulcers
Musculoskeletal system
Syndromes affecting the musculoskeletal system can cause:
- Pain
- Joint swelling and stiffness
- Muscle weakness and sore muscles
- beaten fingers
blood
Too few red blood cells or too many platelets and white blood cells can cause:
- unusually pale skin
- fatigue
- Difficulty breathing
- Blood clot in a deep vein, especially if found in more than one place
- increased number of red blood cells
- abnormally circulating blood proteins
Digestive tract
PNS can cause persistent diarrhea. This can lead to low levels of protein in your blood because too much protein is released in your stool.
Kidneys
PNS, which affect the kidneys, can alter the acid-base balance in your body, a system known as acid-base balance. If this system gets out of whack, it can lead to kidney damage and other serious health problems, and it can even be fatal.
Symptoms can be:
- Swelling of both legs
- Fluid retention
- too much protein in the urine
PNS occur when a tumor releases hormones or proteins that target specific body systems.
They can also happen when proteins known as antibodies or white blood cells called T cells attack your healthy cells instead of cancer cells. This is a type of autoimmune reaction.
Squamous cell carcinoma and small cell lung cancer (SCLC) are most commonly associated with these syndromes, but can also occur in the following cancers:
Before each test, your doctor will take your full medical history and perform a physical exam. Your doctor and medical team may order several other types of tests, including:
Blood tests
Blood tests your doctor may order include:
Marker tests
Markers are substances made by cancer cells or normal cells that cancer causes in your body. Tumor or cancer markers can also be found in your blood, urine, or other body tissue.
Other tests
Your doctor may order other tests to diagnose what PNS you have and how it is affecting your body systems and organs. These tests can include:
- imaging tests of your brain, chest, abdomen, pelvis, or breasts
- Skin or muscle biopsy
There is no known way to prevent these syndromes, but measures that lower your overall risk for cancer can also help keep these syndromes at bay.
Your risk increases if you are middle-aged and have a close blood relative who has cancer or has had cancer in the past.
The first step is to treat the cancer yourself. Other treatment options can include:
- Corticosteroids. These medications can help relieve swelling and reduce the overactive response of your body’s immune system.
- Immunosuppressive drugs. These drugs also help reduce your body’s autoimmune response.
- Intravenous immunoglobulins (IVIG). These drugs are given intravenously (into your vein) and help limit the number of antibodies in your blood.
- Plasmapheresis. This is a process by which antibodies are filtered out from the plasma or the liquid part of your blood.
- Physiotherapy and speech therapy. These therapies can help improve speech, swallowing, and movement, and help you function better for longer.
The outlook for a person with paraneoplastic syndrome depends on the type of cancer and the stage of cancer they are at when they are diagnosed and the specific PNS they have. PNS is incurable and damage to the body and individual organs can be permanent. A person can die from their cancer or from the effects of a PNS.
PNS associated with lung cancer tend to have more serious consequences. A 2019 review of paraneoplastic pemphigus (a type of PNS) found a high death rate from:
- severe infections such as sepsis and pneumonia
- Cancer often involved
- Autoimmune reaction that prevents air from flowing through the small airways in your lungs.
A 2019 study of quality of life and survival in people with Lambert-Eaton myasthenic syndrome (LEMS) found that people lived longer when they had both LEMS and SCLC, rather than just SCLC.
However, some PNS can go away on their own.
PNS are a group of rare diseases caused by an altered immune response to tumors in the body.
These syndromes are a number of different symptoms, the most common of which is fever. Many body systems and organs can be involved.
Diagnosis may include performing a variety of tests, such as: B. Imaging tests of your brain, chest, abdomen, pelvis and breasts, and laboratory tests of your blood and urine.
Treatments aim to relieve symptoms, reduce swelling, and suppress the body’s immune response to these syndromes.