Clinical Dutch-English Lambert-Eaton Myasthenic syndrome (LEMS) tumor association prediction score accurately predicts small-cell lung cancer in the LEMS.
OBJECTIVE
Approximately one half of patients with Lambert-Eaton myasthenic syndrome (LEMS) have small-cell lung carcinomas (SCLC), aggressive tumors with poor prognosis. In view of its profound impact on therapy and survival, we developed and validated a score to identify the presence of SCLC early in the course of LEMS.


METHODS
We derived a prediction score for SCLC in LEMS in a nationwide cohort of 107 Dutch patients, and validated it in a similar cohort of 112 British patients. A Dutch-English LEMS Tumor Association Prediction (DELTA-P) score was developed based on multivariate logistic regression.


RESULTS
Age at onset, smoking behavior, weight loss, Karnofsky performance status, bulbar involvement, male sexual impotence, and the presence of Sry-like high-mobility group box protein 1 serum antibodies were independent predictors for SCLC in LEMS. A DELTA-P score was derived allocating 1 point for the presence of each of the following items at or within 3 months from onset: age at onset ≥ 50 years, smoking at diagnosis, weight loss ≥ 5%, bulbar involvement, erectile dysfunction, and Karnofsky performance status lower than 70. The area under the curve of the receiver operating curve was 94.4% in the derivation cohort and 94.6% in the validation set. A DELTA-P score of 0 or 1 corresponded to a 0% to 2.6% chance of SCLC, whereas scores of 4, 5, and 6 corresponded to chances of SCLC of 93.5%, 96.6%, and 100%, respectively.


CONCLUSIONS
The simple clinical DELTA-P score discriminated patients with LEMS with and without SCLC with high accuracy early in the course of LEMS.
Leiden University Medical Center, Leiden, The Netherlands. m.j.titulaer@lumc.nl
Maarten J
MJ
Titulaer
Paul
P
Maddison
Jacob K
JK
Sont
Paul W
PW
Wirtz
David
D
Hilton-Jones
Rinse
R
Klooster
Nick
N
Willcox
Marko
M
Potman
Peter A E
PA
Sillevis Smitt
Jan B M
JB
Kuks
Bart O
BO
Roep
Angela
A
Vincent
Silvère M
SM
van der Maarel
J Gert
JG
van Dijk
Bethan
B
Lang
Jan J G M
JJ
Verschuuren
D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D017567:Karnofsky Performance Status; D015624:Lambert-Eaton Myasthenic Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D016015:Logistic Models; D008175:Lung Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009426:Netherlands / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012720:Severity of Illness Index; D017678:Sex Distribution; D055752:Small Cell Lung Carcinoma / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D016019:Survival Analysis; D006113:United Kingdom / Q000453:epidemiology