What Is the Most Common Paraneoplastic Syndrome?

Living with the paraneoplastic syndrome can be challenging because the symptoms can vary widely and be severe.

Paraneoplastic syndrome develops when cancer cells release certain substances that affect healthy cells in the body. These substances can disrupt the normal functioning of healthy cells and tissues, leading to various symptoms. Paraneoplastic syndrome can even occur when the immune cells release antibodies against cancer cells that instead attack healthy cells and damage them.

Paraneoplastic syndrome can occur with any form of cancer but is more often linked to lymphatic system malignancies, breast cancer, ovarian cancer, and lung cancer. Not everyone who has cancer will have a paraneoplastic syndrome.

If you experience any unusual symptoms after you have been diagnosed with cancer, consult your doctor. Your doctor will identify the underlying reason and provide you with the best treatment possible.

Paraneoplastic syndrome is a rare condition that can occur with any cancer. However, some types of paraneoplastic syndromes are more commonly reported.

1. Lambert-Eaton myasthenic syndrome (LEMS): Caused by substances produced by cancer cells. They affect healthy cells in the body, causing weakness, poor mobility, and breathing difficulties. It is often associated with small-cell lung cancer.
2. Peripheral neuropathy: The most typical neurologic paraneoplastic condition. Distal sensorimotor polyneuropathy causes moderate motor weakness, sensory loss, and absence of distal reflexes.
3. Dermatomyositis: A less severe polymyositis and likely to be more common among people with cancer, especially those older than 50 years. Proximal muscle weakness typically progresses, along with pathologically visible muscle necrosis and inflammation. A periorbital edema and a dusky, erythematous butterfly rash with a heliotrope tint may appear on the cheekbones. Corticosteroids may provide relief.
4. Paraneoplastic erythrocytosis: Causes an abnormal increase in the number of red blood cells, leading to symptoms such as fatigue, dizziness, and shortness of breath. It is often associated with kidney cancer.
5. Paraneoplastic pemphigus: A rare autoimmune disorder that causes blisters and sores on the skin and mucus membranes. It is often associated with lymphoma and other blood cancers.
6. Erythromelalgia: An example of rheumatic paraneoplastic syndromes. It causes intense redness, warmth, and pain in the hands and feet. It is popularly called the man on fire syndrome because it causes a burning sensation.
7. Syndrome of inappropriate antidiuretic hormone secretion (SIADH):
   • The pituitary gland produces too much antidiuretic hormone (ADH). It helps regulate the balance of water and electrolytes in the body. Cancer in the pituitary gland can cause excessive secretion of ADH.
   • Symptoms include excessive thirst, frequent urination, muscle weakness, and low blood sodium levels (which can cause fatigue, confusion, and seizures).

The symptoms of paraneoplastic syndrome can vary widely and may depend on the specific type of paraneoplastic syndrome and the location of cancer in the body.

Some common symptoms of paraneoplastic syndrome include:

• Weakness
• Muscle wasting
• Changes in mental function, such as confusion, memory loss, or hallucinations
• Chest pain
• Anemia
• Abnormal blood clotting
• Unintended weight loss
• Changes in bowel or bladder function
• Cough
• Hoarseness
• Difficulty breathing
• Difficulty with daily activities, such as eating, speaking, or walking
• Skin changes, such as rashes or blistering

It is quite challenging to diagnose paraneoplastic syndrome because the symptoms can vary greatly and are not always directly related to cancer. Additionally, paraneoplastic syndrome can develop at any stage of the malignancy, even before it is discovered.

To confirm the diagnosis of paraneoplastic syndrome, your doctor will order various tests after taking note of your medical history, symptoms, and results of a physical examination.

• Blood tests: Determine abnormal levels of substances in the blood that could be related to paraneoplastic syndrome.
• Imaging tests: CT scans or MRIs can generate pictures of the inside of your body and help the doctor find signs of cancer or other abnormalities.
• Electroencephalogram: Measures the electrical activity of the brain and can help diagnose certain types of paraneoplastic syndrome that affect brain function.
• Nerve conduction studies: Measure the speed and strength of the signals that travel along the nerves and can help diagnose certain types of paraneoplastic syndrome that affect nerve function.
• Biopsy: A small sample of abnormal tissue is examined under a microscope to detect possible cancer and determine the type of cancer.

There is no cure for paraneoplastic syndrome. Treatment typically involves addressing underlying cancer and managing the symptoms. The specific treatment approach will depend on the type and location of cancer and the severity of the symptoms.

Treatment options for paraneoplastic syndrome include:

• Cancer treatment: Addresses underlying cancer. This may involve surgery to remove cancer, chemotherapy, radiation therapy, or a combination of these.
• Symptom management: Depending on the type and severity of the symptoms, your doctor may recommend medications or other therapies to help manage them. For example, if you have muscle weakness due to Lambert-Eaton myasthenic syndrome, your doctor may prescribe medications to help improve muscle strength.
• Physical therapy: Helps regain strength and improve mobility.
• Supportive care: Pain management, nutrition support, or psychological counseling help you manage your symptoms and improve your quality of life.

Living with paraneoplastic syndrome can be challenging because the symptoms can vary widely and be severe. It may require hospital stays and can affect any time in a person with cancer. 

Symptom management and cancer treatment are frequently used to treat paraneoplastic syndrome.

As there is no cure for paraneoplastic syndrome, you must work closely with your healthcare team to better manage the symptoms and improve your quality of life. You must seek support from your family, friends, and support groups to cope with the challenges of living with paraneoplastic syndrome.