Paraneoplastic syndromes are a group of rare diseases that can develop as a side effect of cancerous tumors (neoplasms). Paraneoplastic syndromes can occur during the course of many types of cancer, including ovarian cancer.

Understanding the connection between paraneoplastic syndromes and ovarian cancer is important because the presence of paraneoplastic syndromes can sometimes worsen the prognosis (outlook) of the underlying ovarian cancer, particularly if the paraneoplastic syndromes are ignored or untreated. The detection of paraneoplastic antigens (the proteins that the antibodies associated with these syndromes attack) may also be able to serve as an early biomarker for cancers such as ovarian cancer.

What Are Paraneoplastic Syndromes?

Paraneoplastic syndromes are the effects of the body’s response to tumors. Generally, paraneoplastic syndromes are caused by abnormal immune system responses to neoplasms (cancerous tumors).

These syndromes develop as a result of tumor-related antibodies that cause the immune system to mount an autoimmune response. Essentially, because of the tumor, the body begins to attack healthy cells. Paraneoplastic disorders can be considered autoimmune diseases.

Although the causes of these disorders are rather similar, paraneoplastic syndromes can show up as many different types of diseases. Paraneoplastic syndromes have the potential to affect many parts of the body, such as the nervous system (brain, spinal cord, and nerves), hormones (the endocrine system), skin, blood, and joints. People with cancer often experience fever, night sweats, loss of appetite, and weight loss as a side effect of paraneoplastic syndromes.

General Symptoms of Paraneoplastic Syndromes

There are many signs and symptoms associated with paraneoplastic syndromes. These signs or side effects of paraneoplastic syndromes may range in severity and can include:

• Fever
• Night sweats
• Weight loss
• Loss of appetite
• High blood pressure
• Dizziness
• Difficulty with speech
• Weakness
• Weight gain
• Double vision
• Loss of coordination or sensation
• Slower reflexes
• Redness of the skin
• Benign (noncancerous) skin growths
• Itching
• Neurological symptoms
• Neuropathy (damage to nerves)

How Prevalent Are Paraneoplastic Syndromes?

Paraneoplastic syndromes develop in about 20 percent of people who have any type of cancer. Middle-aged people who have ovarian cancer — as well as those with lung, breast, or lymphatic cancer — are thought to be most at risk for paraneoplastic syndromes.

When you look at each of the paraneoplastic syndrome types individually, the prevalence rates can be drastically smaller than 20 percent. Because the number of people with each disease is so small, there is little available scientific research on the exact prevalence rates across different types of cancer. Most of the available data come from case studies (small studies that involve just one person with the disease, typically).

Paraneoplastic Syndromes in Ovarian Cancer

In one case study, a woman had the paraneoplastic syndrome known as nephrotic syndrome. Nephrotic syndrome is a disease of the kidneys that causes your body to pass too much protein in the urine.

This paraneoplastic syndrome was observed before the cancer was diagnosed. It was only after the identification of nephrotic syndrome that doctors looked for cancer. A computed tomography scan and ultrasound showed a slightly enlarged ovary and enlarged lymph nodes, and a mass was removed.

In this same woman, paraneoplastic cerebellar degeneration also developed. Paraneoplastic cerebellar degeneration is a disorder in which a brain region known as the cerebellum begins to deteriorate because of nerve cells (neurons) dying.

Another study noted the following paraneoplastic syndromes (in addition to cerebellar degeneration) in women with ovarian cancer:

• Polyarteritis nodosa — A disorder characterized by widespread inflammation, weakening, and damage to small and medium-sized arteries
• Rheumatoid arthritis — A chronic disorder of joint inflammation and pain
• Reflex sympathetic dystrophy — A chronic condition characterized by severe burning pain, most often of the extremities (arms, legs, hands, or feet)
• Polycythemia — A condition of a high concentration of red blood cells in the blood
• Thrombosis/thrombophlebitis — Inflammatory conditions that cause blood clots to form and block one or more veins
• Hemolytic anemia — A condition in which red blood cells are destroyed faster than they can be made
• Hypercalcemia — A condition of high blood calcium levels

Treatment and Prognosis of Paraneoplastic Syndromes

Sometimes, people may notice the symptoms of paraneoplastic syndrome before they notice any symptoms from underlying cancer. Prompt diagnosis and treatment of paraneoplastic syndromes are important because these syndromes can affect the outcomes related to cancer. If someone has paraneoplastic syndromes, they can be treated in many different ways.

Generally, first-line treatment for paraneoplastic syndromes focuses on treating the underlying cancer.

Treatment may also target the effects of paraneoplastic syndrome. There are many types of paraneoplastic syndromes, ranging from neurological (nervous system or brain-related) to dermatological (skin-related). Because the conditions can vary greatly, the treatment of paraneoplastic symptoms also varies, depending on what part of the body is being attacked.

These syndromes are related to inflammation and the autoimmune system, so other treatment options can include:

• Corticosteroids — Drugs used to reduce inflammation
• Intravenous immunoglobulins — Substances that can boost healthy antibodies
• Immunosuppressants — Drugs used to manage the immune system’s response
• Plasmapheresis — A technique used to reduce the amount of antibodies in the blood
• Speech and physical therapy — Therapies that help people speak and move better

As paraneoplastic syndromes vary from one individual to the next, the prognosis (outlook) of these syndromes can also vary. In some cases, symptoms can be easily managed. In other cases, symptoms can be life-threatening. The paraneoplastic syndrome may make it difficult for you to receive the recommended treatment for ovarian cancer. Paraneoplastic syndromes can also make the prognosis of the underlying cancer worse, so it is important to recognize paraneoplastic syndromes when they occur. If you are experiencing new or unusual symptoms, talk to your doctor immediately.

Talk With Others Who Understand

MyOvarianCancerTeam is the social network for people with ovarian cancer. Members come together to ask questions, give advice, and share their stories with others who understand life with ovarian cancer.

Are you or someone you care for living with paraneoplastic syndromes and ovarian cancer? Share your experience in the comments below, or start a conversation by posting on MyOvarianCancerTeam.