European Commission logo
English English
CORDIS - EU research results
Content archived on 2024-06-25

Paraneoplastic Neurological Syndromes (PNS) strengthening the European network

Final Report Summary - PNS-EURONET2 (Paraneoplastic neurological syndromes (PNS) strengthening the European network)

The ultimate aim of the PNS-EURONET2 project was to strengthen the Paraneoplastic neurological syndromes (PNS) Euronetwork by:

- consolidating the use of the European database by the participants in order for sufficient comparable data to be collected to:
1. control the quality of the data inserted in the database and data entry procedure;
2. make useful correlations amongst PNS and tumour types and specific antineuronal antibodies;
3. identify previously unrecognised PNS;
4. identify relevant clinical issues that could be answered in prospective studies.

- consolidating the use of the sample banks (serum, cerebrospinal fluid, lymphocytes) of patients with PNS in order to:
1. test the relevance of new antibodies initially detected in one or few patients with PNS;
2. identify and characterise new antineuronal autoantibodies that may be relevant in the pathogenesis or diagnosis of PNS;
3. collect high-quality samples in the sample bank for future studies.

- consolidating and updating the research inventory and exploiting the database for scientific research.

The database included the 'classical' PNS plus several others, less-well characterised syndromes in association with cancer. Almost all entered patients had definite PNS (968 patients) and only 11 cases were classified as possible PNS. In 65 % of these cases, the neurological syndrome preceded tumour detection. Cerebellar degeneration and sensory neuronopathy were the most frequent syndromes followed by limbic encephalitis, Paraneoplastic neurological syndromes (PEM) and brainstem encephalitis; these classical PNS confirmed the clinical profile already reported in the literature. A remarkable finding in this group of syndromes was the Rankin scale analysis that showed that patients with cerebellar degeneration and Yo antibodies had a higher level of disability than did cases with other onconeural antibodies. The antibody profile confirmed that anti-Hu was the most frequent antibody (38 %), followed by Yo (13.4 %). All other antibodies were below 10 % each. The antibody types were within the spectrum for onconeuronal antibodies and, in association with a PNS, had significant diagnostic value for an underlying cancer. The atypical antibodies were 3.1 %, but no consistent pattern was found.

Steroids were by far the most frequently used immunomodulatory drugs followed by high-dose immunoglobulins, plasma exchange and immunosuppression. Tumour treatment was instead the most frequent option and chemotherapy was used in 51.2 % of cases, followed by surgery and radiotherapy.

The outcome status was available in 62.5 % of patients, 41.2 % (403 cases) of which died: 109 (27 %) due to PNS, 150 (37.2 %) from tumour progression and 59 (14.6 %) from other causes, which were most likely tumour-related. A remarkable finding was the poor prognosis of patients with dysautonomia; a tumour was found in 37 out of 51 cases and in 28 of these the diagnosis followed the neurological syndrome with a median time of 4.6 months. Only 4/37 cases improved after tumour treatment. 32 patients died: 6 due to a tumour and 18 due to PNS; of the 14 patients with isolated dysautonomia 10 died: 5 from PNS and 1 from pneumonia; the cause of death was not known in 4.

While the database was not designed for the conduction of epidemiological studies, the data is considered to represent the relative prevalence of each syndrome. The relative distribution of disorders confirmed cerebellar degeneration and sensory neuronopathy were the most frequently appearing PNS. An additional large number of sensory neuronopathies also had significant motor involvement, and this entity was referred to as sensorimotor neuronopathy. On adding the less well-characterised neuropathies, the peripheral nerves become the predominant target of paraneoplastic attack. Besides confirming the clinical profile of many classical PNS in a much more extensive case series, analysis of database entries produced a number of interesting findings on the different clinical evolution of paraneoplastic cerebellar syndromes according to the onconeural antibody present, on the heterogeneity and prognosis of dysautonomic disorders, and on the clinical variability of paraneoplastic limbic encephalitis, as well.