Paraneoplastic Syndromes: Symptoms, Causes, and Treatments

What is Paraneoplastic Syndrome?

Paraneoplastic syndrome is a group of rare conditions that happen when your immune system reacts to a tumour. Instead of solely targeting cancer cells, the immune system may mistakenly attack healthy cells in other parts of the body. This immune response can lead to unusual symptoms in your nervous system, skin, blood, or hormones. 

These symptoms are not caused directly by the tumour pressing on organs but are linked to how your body is responding to the cancer’s presence. Understanding this response helps guide treatment.

Who is Affected By Paraneoplastic Syndromes?

While paraneoplastic syndromes can occur in anyone with cancer, they are more commonly observed in adults over 40. You may be more at risk if you have certain cancers such as lung, ovarian, breast, or lymphoma. 

Also Read: The 14 Most Common Types of Cancer

The symptoms can sometimes appear before the cancer is diagnosed, making it even more important to pay attention to any unusual or unexplained changes in your body. These syndromes can affect people differently, depending on the type of cancer and how your immune system reacts.

How Common Are Paraneoplastic Syndromes?

Paraneoplastic syndromes are rare but affect a significant percentage of cancer patients, with estimates ranging from 8% to 20%. Some types, like paraneoplastic syndrome lung cancer, are more common due to the immune activity triggered by certain tumours. 

Because these symptoms can show up before the cancer itself is found, early recognition and discussion with your doctor can help catch and treat cancer at an earlier stage, improving outcomes and easing discomfort.

What Cancers Are Associated With Paraneoplastic Syndromes?

Paraneoplastic syndromes can occur with many types of cancer. Certain cancers are more frequently associated with paraneoplastic syndromes due to their immune-stimulating properties

• Lung cancer: Especially small-cell lung cancer, which has a strong association with neurological syndromes.
• Ovarian cancer: May trigger hormonal changes and autoimmune responses leading to specific symptoms.
• Breast cancer: Can cause a variety of autoimmune or inflammatory reactions.
• Lymphoma and leukaemia: Affect blood and immune cells directly, which can result in widespread immune complications.
• Stomach, pancreatic, kidney, and prostate cancers: Can cause paraneoplastic effects depending on tumour type and immune reaction.
• Testicular cancer: May trigger specific hormonal and neurological syndromes, particularly in younger males.

Types Of Paraneoplastic Syndromes

Paraneoplastic syndromes can affect several body systems. Identifying the specific type of paraneoplastic syndrome is crucial for selecting appropriate treatment and effectively managing symptoms.

Nervous System Paraneoplastic Syndromes

These are among the most recognised forms and can affect your brain, spinal cord, or peripheral nerves.

• Cerebellar degeneration: Leads to unsteady movement, poor coordination, and difficulty walking due to damage in the cerebellum.
• Limbic encephalitis: Causes memory loss, mood changes, seizures, and confusion as it affects emotional and memory-related brain areas.
• Myelopathy: Affects the spinal cord, causing weakness, numbness, and changes in bladder or bowel control.
• Lambert-Eaton myasthenic syndrome: Weakness in leg and pelvic muscles, often linked with small-cell lung cancer.
• Myasthenia gravis: Causes muscle fatigue, especially around the eyes, face, and throat, often worsening with activity.
• Opsoclonus-myoclonus: Involves rapid, jerky eye and limb movements.
• Stiff-person syndrome: Results in severe stiffness and painful muscle spasms in the back and legs.
• Peripheral neuropathy: Causes tingling, numbness, or pain in the hands and feet.
• Dysautonomia: Affects involuntary functions like heart rate, breathing, or blood pressure.

Endocrine System Paraneoplastic Syndromes

These syndromes are related to hormone imbalance caused by tumour-related substances.

• Cushing’s syndrome: Caused by excess cortisol, leading to weight gain, high blood pressure, and fatigue.
• SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion): Causes fluid imbalance, confusion, and headaches due to too much antidiuretic hormone.
• Hypercalcaemia: High calcium levels may cause nausea, thirst, muscle weakness, and confusion.

Rheumatic Paraneoplastic Syndromes

These affect joints, muscles, and connective tissues.

• Hypertrophic osteoarthropathy: Causes pain and swelling in the joints and clubbing of fingers.
• Paraneoplastic polyarthritis: Mimics rheumatoid arthritis with pain, stiffness, and joint inflammation.
• Eosinophilic fasciitis: Skin and connective tissue become tight and inflamed.
• Palmar fasciitis: Pain and thickening of tissue in the palms.
• Erythromelalgia: Episodes of burning pain and redness in the hands and feet.

Blood Paraneoplastic Syndromes

These involve abnormal changes in your blood cells or clotting system.

• Paraneoplastic erythrocytosis: Increased red blood cell production, leading to thick blood and fatigue.
• Paraneoplastic thrombocytosis: High platelet levels that may increase the risk of blood clots or bleeding issues.

Skin Paraneoplastic Syndromes

Changes in the skin can sometimes be the first sign of an internal cancer.

• Acanthosis nigricans: Dark, thickened patches of skin, especially in skin folds.
• Dermatomyositis: Skin rash with muscle weakness.
• Leukocytoclastic vasculitis: Causes red or purple spots on the skin due to inflamed blood vessels.
• Paraneoplastic pemphigus: Painful blisters and erosions on the skin and mucous membranes.
• Sweet syndrome: Painful, red skin bumps often accompanied by fever.

Causes of Paraneoplastic Syndromes

Paraneoplastic syndromes occur when your body’s immune system reacts to a tumour in unexpected ways. The causes can vary but often include:

• Immune system overreaction: Your immune system mistakenly attacks healthy cells while trying to fight the tumour.
• Hormone-like substances: Some tumours produce hormones or proteins that disrupt normal body functions.
• Cross-reactivity: Antibodies made to fight the tumour may also affect tissues like nerves, skin, or muscles.

Symptoms of Paraneoplastic Syndromes

The symptoms you may notice depend on the organs or systems affected, and they can vary widely.

• General symptoms: Fever, weight loss, night sweats, and feeling unwell without a clear cause.
• Nervous system symptoms: Dizziness, confusion, memory loss, seizures, and muscle weakness.
• Endocrine symptoms: Fatigue, nausea, weight gain, or swelling due to hormone imbalances.
• Skin and joint symptoms: Itching, rashes, joint pain or stiffness, and skin thickening.

Diagnosis

Diagnosing paraneoplastic syndrome involves a comprehensive evaluation, including clinical examination and various tests. Since symptoms can appear before a cancer is diagnosed, early and accurate testing is important.

Clinical Exam

Your doctor will:

• Check your medical history: Including any cancer diagnoses or treatments in the past.
• Look for neurological signs: Muscle strength, coordination, and memory tests help spot nerve-related issues.
• Assess for skin, joint, or hormonal symptoms: These may suggest specific types of paraneoplastic syndromes.

Laboratory Tests

These help to confirm a diagnosis or rule out other conditions.

• Blood tests: Can find antibodies or unusual hormone levels linked to paraneoplastic syndromes.
• Spinal fluid tests: A lumbar puncture might be done to check for antibodies in your nervous system.
• Hormone panels: Used to detect hormone imbalances caused by tumour secretions.

Imaging Tests

Used to detect hidden tumours or affected organs.

• CT or MRI scans: Help locate cancers in the lungs, brain, or other areas.
• PET scans: Can highlight active cancer cells in the body.
• Ultrasound: Used for a closer look at specific organs depending on symptoms.

Treatments

Management of paraneoplastic syndrome focuses on treating the underlying cancer and alleviating symptoms resulting from the immune response.

• Cancer treatment: Surgery, chemotherapy, or radiotherapy to remove or shrink the tumour often improves the syndrome.
• Corticosteroids: Help reduce inflammation and calm the immune system.
• Immunosuppressants: These medicines stop your immune system from attacking healthy tissues.
• Intravenous immunoglobulin (IVIG): Healthy antibodies are given to block the harmful ones in your system.
• Plasmapheresis: A treatment where harmful antibodies are removed from your blood.
• Physical or speech therapy: Aids in restoring movement, coordination, and speech abilities impacted by nervous system disorders..
• Ongoing monitoring: Regular check-ups to track progress, especially as the cancer responds to treatment.

Conclusion

While paraneoplastic syndromes can be complex, understanding their connection to cancer and their impact on the body can empower you to manage your health more effectively. With early diagnosis and the right treatment, many symptoms can be managed effectively. 

For accurate testing and timely diagnosis, Metropolis Healthcare offers advanced diagnostic services, including tests for neurological and cancer-related conditions. Their expert team and home sample collection make it easier to take care of your health with confidence.

FAQs

What can I expect if I have paraneoplastic syndrome?

You may experience varying symptoms, depending on the cancer type and treatment response, with possible long-term management.

What complications are associated with paraneoplastic syndromes?

Complications range from mild to severe, potentially affecting nerves, hormones, or organs if not treated early.

When should I call the doctor concerning paraneoplastic syndromes?

Contact your doctor if you notice unexplained symptoms, especially with a history of cancer or ongoing treatment.