Confirm Cancer-Associated LEMS with a VGCC-Ab test, both P/Q and N types

/test

Testing for Cancer-Associated LEMS

Updated NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) recommend VGCC-Ab testing, preferably in consultation with neurology, in SCLC and suspected neurologic paraneoplastic syndrome12

“Neurologic workup, preferably in consultation with neurology, may include but not limited to tests for PQ- and N-type voltage gated calcium channel (VGCC) antibodies.”12

From NCCN Guidelines®
Small Cell Lung Cancer Version 1.2026

There is a simple and inexpensive blood test to confirm LEMS in your patients with SCLC when you suspect Cancer-Associated LEMS3

When Cancer-Associated LEMS is suspected,

VGCC-Ab testing

both P/Q and N types, is one of the ways to confirm the diagnosis3,12

VGCCs are transmembrane protein structures that play a pivotal role in neuromuscular signal transmission3,19

Multiple types of VGCCs have been described in both the central and peripheral nervous systems20

VGCC-Ab Testing

Order test

In collaboration with a national diagnostic lab provider, Catalyst offers no-cost VGCC-Ab testing, both P/Q and N types, for patients who have symptoms suggestive of Cancer-Associated LEMS

Sensitivity for LEMS

Elevated serum titers of autoantibodies to VGCC are found in:

  • Virtually all patients with SCLC-associated LEMS and are invariably present in patients with other forms of Cancer-Associated LEMS21,22
  • Up to 90% of patients with non–cancer-associated LEMS21

Clinical significance

A pathogenic role for anti-VGCC antibodies has been established for LEMS in which autoantibodies target VGCC on the presynaptic nerve terminal of the neuromuscular junction and impair neurotransmission of acetylcholine3,7

Interpreting results

>30 pmol/L* indicates that the patient has a positive test result, suggestive of LEMS23

  • <30 pmol/L is considered to be a negative test result and a normal titer level; however23:
  • A negative test result does not rule out a diagnosis of LEMS24
  • Electrodiagnostic testing may be performed as a follow-up24

*30 pmol/L = 0.03 nmol/L. Reference ranges may vary based on specific laboratories.11,23

A negative anti-VGCC titer does not exclude LEMS; up to 15% of patients with LEMS have undetectable anti-VGCC antibody levels.24

Why comprehensive VGCC-Ab testing matters

Multiple types of VGCCs have been described in both the central and peripheral nervous systems; 2 different VGCC antibodies are most commonly associated with Cancer-Associated LEMS: P/Q and N types20,24

Catalyst Pharmaceuticals provides free VGCC-Ab testing

In collaboration with a national diagnostic lab provider, Catalyst offers no-cost VGCC-Ab testing, both VGCC-P/Q type and VGCC-N type, for patients who have symptoms suggestive of Cancer-Associated LEMS

You can also get the test request form by calling 1-866-226-8046 or contacting a Catalyst Representative below

Order a free test

Learn About an FDA-Approved Treatment

/treat/

References:

  1. Gandhi L, Johnson BE. Paraneoplastic syndromes associated with small cell lung cancer. J Natl Compr Canc Netw. 2006;4(6):631-638.
  2. Titulaer MJ, Lang B, Verschuuren JJ. Lambert-Eaton myasthenic syndrome: from clinical characteristics to therapeutic strategies. Lancet Neurol. 2011;10(12):1098-1107.
  3. Gilhus NE. Lambert-Eaton myasthenic syndrome; pathogenesis, diagnosis, and therapy. Autoimmune Dis. 2011;2011:973808.
  4. Bebb DG, Murray C, Giannopoulou A, Felip E. Symptoms and experiences with small cell lung cancer: a mixed methods study of patients and caregivers. Pulm Ther. 2023;9:435-450.
  5. Yoon CH, Owusu-Guha J, Smith A, Buschur P. Amifampridine for the management of Lambert-Eaton myasthenic syndrome: a new take on an old drug. Ann Pharmacother. 2020;54(1):56-63.
  6. Wirtz PW, Smallegange TM, Wintzen AR, Verschuuren JJ. Differences in clinical features between the Lambert-Eaton myasthenic syndrome with and without cancer: an analysis of 227 published cases. Clin Neurol Neurosurg. 2002;104(4):359-363.
  7. Hartmann GG, Sage J. Small-cell lung cancer neuronal features and their implications for tumor progression, metastases, and therapy. Mol Cancer Res. 2024;22(9):787-795.
  8. Maddison P, Gozzard P, Grainge MJ, Lang B. Long-term survival in paraneoplastic Lambert-Eaton myasthenic syndrome. Neurology. 2017;88:1-6.
  9. Titulaer MJ, Verschuuren JJ. Lambert-Eaton myasthenic syndrome: tumor versus nontumor forms. Ann N Y Acad Sci. 2008;1132:129-34.
  10. Lipka AF, Boldingh MI, van Zwet EW, et al. Long-term follow-up, quality of life, and survival of patients with Lambert-Eaton myasthenic syndrome. Neurology. 2020;94(5):e511-e520.
  11. ARUP Laboratories. Accessed August 2, 2025. https://ltd.aruplab.com/Tests/Pub/3002046
  12. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Small Cell Lung Cancer V.1.2026. © National Comprehensive Cancer Network, Inc. 2025. All rights reserved. Accessed August 8, 2025. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
  13. Kunii E, Owaki S, Yamada K, et al. Lambert-Eaton myasthenic syndrome caused by atezolizumab in a patient with small-cell lung cancer. Intern Med. 2022;61:1739-1742.
  14. Giannoccaro MP, Avoni P, Liguori R. Presynaptic paraneoplastic disorders of the neuromuscular junction: an update. Brain Sci. 2021;11(8):1035.
  15. Titulaer MJ, Lang B, Verschuuren JJ. Lambert-Eaton myasthenic syndrome: from clinical characteristics to therapeutic strategies. Lancet Neurol. 2011; Appendix:1-4.
  16. Harms L, Sieb JP, Williams AE, et al. Long-term disease history, clinical symptoms, health status, and healthcare utilization in patients suffering from Lambert Eaton myasthenic syndrome: results of a patient interview survey in Germany. J Med Econ. 2012;15(3):521-530.
  17. Morrell D, Drapkin B, Shechter G, Grebla R. Lambert-Eaton myasthenic syndrome is underrecognized in small cell lung cancer: an analysis of real-world data. Presented as a poster at the International Association for the Study of Lung Cancer (IASLC) – WCLC Annual Meeting 2023. September 9-12, 2023, Singapore.
  18. Sanders DB. Lambert-Eaton myasthenic syndrome: diagnosis and treatment. Ann N Y Acad Sci. 2003;998:500-508.
  19. Catterall WA. Voltage-gated calcium channels. Cold Spring Harb Perspect Biol. 2011;3:a003947.
  20. Schampel A, Kuerten S. Danger: High voltage—the role of voltage-gated calcium channels in central nervous system pathology. Cells. 2017;6(4):43.
  21. Loser V, Vicino A, Théaudin M. Autoantibodies in neuromuscular disorders: a review of their utility in clinical practice. Front Neurol. 2024;15:1495205.
  22. Alhammad RM, Alshamian Y, Alneseyan R, Al-Harbi TM, Ajhijab A, Alanazy MH. Clinical presentations, electrophysiologic features, and long-term follow-up in Lambert-Eaton myasthenic syndrome: a series of six patients. Front Neurol. 2024;15:1525155.
  23. Labcorp. Voltage-gated calcium channel antibody (VGCCA). Accessed August 16, 2025. https://www.labcorp.com/tests/140640/voltage-gated-calcium-channel-antibody-vgcca
  24. Kesner VG, Shin JO, Dimachkie MM, Barohn RJ. Lambert-Eaton myasthenic syndrome. Neurol Clin. 2018;36(2):379-394.
  25. Silva T. Understanding lambert-eaton myasthenic syndrome: pathophysiology, diagnosis, and treatment. J Neurol Neurorehab Res. 2024;9(1):1-2.
  26. Ivanovski T, Miralles F. Lambert-Eaton myasthenic syndrome: early diagnosis is key. Degener Neurol Neuromuscul Dis. 2019;13:27-37.

Connect with us

For US Residents Only

Privacy Policy

Contact Catalyst Pharmaceuticals

© 2025 Catalyst Pharmaceuticals, Inc. All Rights Reserved. LEM-0463-4 August 2025

Corner Rock

You are now leaving the CancerAssociatedLEMS.com website

Continue