Paraneoplastic Syndrome and Lung Cancer

The National Cancer Institute estimates that in 2009, more than 219,000 new cases of lung cancer will be diagnosed in the United States. Lung cancer forms in the tissues of the lungs, and there are two main kinds: small-cell lung cancer and non-small-cell lung cancer. The kind of lung cancer is diagnosed by how the cancer cells look under a microscope. Lung cancer is one of the cancers in which paraneoplastic syndromes are likely to occur. This article explores what those syndromes entail and their impact on health.

Definition of Paraneoplastic Syndromes

• Paraneoplastic syndromes occur when a cancerous tumor triggers an abnormal immune response. They are hypothesized to occur when cancer-fighting antibodies start attacking healthy cells in the patient's nervous system. This often happens in patients who are middle-aged or older, with lung, ovarian, lymphatic or breast cancer. Paraneoplastic syndromes, however, can occur in various organ systems, including neurological, endocrine, renal, hematologic and gastrointestinal.

Symptoms

• Symptoms of paraneoplastic syndromes occur gradually, and are often noticeable before a cancer has been diagnosed. They include slurred speech, sleep problems, seizures, difficulty walking or swallowing, memory loss, loss of fine motor coordination, sensory loss in the limbs and dizziness.

Paraneoplastic Syndromes and Lung Cancer

• Lambert-Eaton is a paraneoplastic syndrome that can occur in patients with small-cell lung cancer and is characterized by extreme muscle weakness. Small-cell lung cancer can also produce a substance that increases hormone levels, causing weakness, high blood pressure and weight gain. It may also cause the body to produce an antidiuretic hormone, resulting in water retention, low sodium levels, confusion and seizures. Small-cell lung cancer is more likely to produce paraneoplastic syndromes than non-small-cell lung cancer.

Treatment

• For paraneoplastic syndromes in small-cell lung cancer, the endocrine-related problems can be alleviated with chemotherapy, but the syndromes affecting the neurological system cannot. There are no cures for paraneoplastic syndromes, and the prognosis is often dependent on the stage of the cancer. Medication may be used to alleviate symptoms, and speech and physical therapy may also be part of recovery. Treating the cancer may help relieve some of the symptoms of paraneoplastic syndromes.

Future Developments

• Scientists are working on researching the epidemiology of paraneoplastic syndromes, and future developments may include antibody testing to help prevent these syndromes, better therapeutic interventions, and a better scientific understanding of their occurrence. Talk to your doctor about whether there are any clinical trials you may be able to participate in, and whether they would have any benefit for your particular cancer and syndromes.