Prospective study into the incidence of Lambert Eaton myasthenic syndrome in small cell lung cancer.
BACKGROUND
The Lambert Eaton myasthenic syndrome (LEMS) is a paraneoplastic disorder associated with raised serum voltage-gated calcium channel (VGCC) antibodies in patients with small cell lung cancer (SCLC). VGCC can also be found in patients with SCLC and cerebellar ataxia. This was a prospective study to assess the incidence of clinical and subclinical LEMS or other neurologic disease in patients with SCLC.


METHODS
Sixty-three unselected patients with cytologically or histologically confirmed SCLC consented to participate. Pretreatment assessment included a neurologic symptom questionnaire, examination for physical signs of LEMS or ataxia, measurement of serum titers of antibodies to P/Q-type VGCCs by radioimmunoassay in all patients and electrophysiological examination where appropriate.


RESULTS
Neurologic symptoms unrelated to LEMS occurred in 26% of patients. Five patients (8%) had raised serum VGCC antibodies (range, 69-1553 pM/l) diagnostic of LEMS, two (3%) of whom had LEMS on clinical and electrophysiological grounds. Both also had mild cerebellar ataxia. There was no association between serum VGCC antibody titer and survival.


CONCLUSIONS
Routine measurement of VGCC antibodies in patients without clinical LEMS is unlikely to assist either in management of SCLC or in assessment of prognosis.
Payne
Miranda
M
Department of Medical Oncology, University of Oxford Medical Oncology Unit, Oxford, United Kingdom.
Bradbury
Penny
P
Lang
Bethan
B
Vincent
Angela
A
Han
Cheng
C
Newsom-Davis
John
J
Talbot
Denis
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D015220:Calcium Channels / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D015640:Ion Channel Gating; D015624:Lambert-Eaton Myasthenic Syndrome / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011863:Radioimmunoassay; D055752:Small Cell Lung Carcinoma / Q000453:epidemiology* / Q000276:immunology / Q000473:pathology; D015996:Survival Rate
D001323:Autoantibodies; D015220:Calcium Channels