Prostate cancer, Hu antibodies and paraneoplastic neurological syndromes.

Prostate cancer is the most common cancer among American and European men. Nervous system affection caused by local tumor growth or osseous metastases are the main causes of neurological symptoms in prostate cancer patients. Prostate cancer is rarely reported in association with paraneoplastic neurological syndromes (PNS). We have, therefore, studied clinical and paraclinical findings of a series of patients with prostate cancer and PNS, and reviewed cases reported in the literature. Case histories of 14 patients with definite PNS from the PNS Euronetwork database and from the authors' databases were reviewed. A PubMed literature search identified 23 patients with prostate cancer and PNS. Thus, a total of 37 case histories were reviewed with respect to syndrome type, cancer evolution, paraclinical investigations, antibody status, treatment and outcome. The three most frequent isolated PNS were paraneoplastic cerebellar degeneration, paraneoplastic encephalomyelitis (PEM)/limbic encephalitis and subacute sensory neuronopathy (SSN). Onconeural antibodies were detected in 23 patients, in most cases the Hu antibody (17 patients, 74 % of all antibody-positive cases). Other well-characterized onconeural antibodies (Yo, CV2/CRMP5, amphiphysin, VGCC antibodies) were found in a minority. PNS was diagnosed prior to prostate cancer diagnosis in 50 % of the cases. The association of PNS with prostate cancer is quite infrequent, but clinically important. PNS often heralds prostate cancer diagnosis. Syndromes associated with Hu antibodies predominate. Another tumor more prone to associate with PNS should always be excluded.

Onconeural antibodies in patients with neurological symptoms: detection and clinical significance.

BACKGROUND: Onconeural antibodies are strongly associated with cancer and paraneoplastic neurological syndromes (PNS). Most of these antibodies are well-characterized (antibodies against Hu, Yo, Ri, CRMP5, amphiphysin, Ma2 and Tr) and are in common use for the diagnosis of definite PNS. MATERIALS AND METHODS: Literature on detection and clinical significance of onconeural antibodies were identified by using relevant search terms in PubMed and reviewed. CONCLUSIONS: The onconeural antibodies are directed against intracellular antigens and their pathogenic role is still largely unknown. They are highly specific markers of paraneoplastic aetiology in patients with neurological symptoms. Detection of an onconeural antibody in a patient with neurological symptoms should lead to prompt investigation for cancer. However, absence of detectable onconeural antibodies does not exclude the PNS diagnosis. In particular, failure to detect antibodies in patients without classical PNS symptoms may result in less vigorous cancer screening and diagnostic delay. Neuronal antibodies that are directed to synaptic proteins or proteins of the cell membrane are also associated with neurological symptoms, and probably have pathogenic effects. The association between these antibodies and cancer is less robust, and they are usually not included among the onconeural antibodies.