Paraneoplastic neurologic disorders in small cell lung cancer are more common than appreciated

---in this study:

Methods: Two hundred sixty-four consecutive patients with biopsy-proven SCLC were recruited at the time of tumor diagnosis. All patients underwent full neurologic examination. Serum samples were taken prior to chemotherapy and analyzed for 15 neuronal antibodies…

Results: PNDs were quite prevalent (n = 24, 9.4%), most frequently Lambert-Eaton myasthenic syndrome (3.8%), sensory neuronopathy (1.9%), and limbic encephalitis (1.5%). Eighty-seven percent of all patients with PNDs had antibodies to SOX2 (62.5%), HuD (41.7%), or P/Q VGCC (50%), irrespective of their syndrome. Other neuronal antibodies were found at lower frequencies (GABAb receptor [12.5%] and N-type VGCC [20.8%]) or very rarely (GAD65, amphiphysin, Ri, CRMP5, Ma2, Yo, VGKC complex, CASPR2, LGI1, and NMDA receptor [all less than 5%]).

Conclusions: The spectrum of PNDs is broader and the frequency is higher than previously appreciated, and selected antibody tests (SOX2, HuD, VGCC) can help determine the presence of an SCLC.

Some background from the full text of the paper:

Currently almost half of all patients diagnosed with PNDs have associated SCLC,2 so this study is relevant to the broad epidemiology of these neurologic disorders. We found a higher frequency of PNDs (9.1% of SCLC) than previous SCLC surveys, perhaps because of the single-center prospective design with neurology input and high recruitment among the SCLC population. The findings suggest that PNDs in patients with SCLC may be underdiagnosed due to misattribution of symptoms; recognition of the disorders and their common antibody associations is important because the earlier the diagnosis is made, the better the oncologic and neurologic outcome.23,24

Via Clinical Correlations.