Paraneoplastic neurological syndromes in lung cancer patients with or without onconeural antibodies

Paraneoplastic neurological syndromes (PNS) are poorly described in patients without onconeural antibodies and in patients with non-small cell lung cancer (NSCLC). We compared the clinical characteristics of PNS in lung cancer patients with and without onconeural antibodies.

Medical records from patients with lung cancer and neurological symptoms referred for onconeural antibody analysis in the period 1995-2004 were analyzed and well-established diagnostic criteria used for the retrospective diagnosis of PNS. Thirty-one patients were diagnosed with PNS and included in the study. Data from the Cancer Registry of Norway and follow-up medical data were analyzed.

Small-cell lung cancer (SCLC) was the most common lung cancer in the 31 PNS patients (77%, P<0.01). Onconeural antibodies were found in 18 of the PNS patients (58%). Paraneoplastic encephalomyelitis (PEM) was the most common PNS among the seropositive patients (11 of 18 patients), of which 10 had SCLC. Various types of PNS were found in the 13 seronegative patients.

Approximately 40% of PNS patients with lung cancer do not have onconeural antibodies. PEM was the most common PNS in the seropositive patients. Our results underline the importance of recognizing PNS in patients with NSCLC and those without onconeural antibodies.