Lambert-Eaton syndrome is most strongly associated with which cancer?

• A. Prostate cancer
• B. Breast cancer
• C. Small cell lung carcinoma
• D. Colon cancer

Answer: (C)

Lambert-Eaton myasthenic syndrome is a paraneoplastic autoimmune disorder caused by antibodies against presynaptic voltage-gated calcium channels at the neuromuscular junction, leading to reduced acetylcholine release and proximal weakness with autonomic symptoms. It is most strongly linked to small cell lung carcinoma, because these tumors often express neuronal antigens that trigger this autoimmune response; a significant proportion of LEMS cases are associated with underlying SCLC, and identifying the cancer is a key part of management. Clinically, strength can temporarily improve with repeated use due to facilitation of transmitter release as calcium influx increases. Among the cancer options, small cell lung carcinoma is the classic association.