Extrapulmonary small cell carcinoma: A review

Extrapulmonary small cell carcinoma (EPSCC) is a relatively rare malignancy accounting for only 2.5-4% of all small cell carcinomas. The head and neck, gastrointestinal tract, genitourinary and gynecologic organs are most common tumor sites. EPSCC behaves aggressively like the small cell lung cancer (SCLC) and its prognosis is dismal. Its tumorigenesis and molecular alternations remain poorly understood. The clinical diagnosis, staging and treatment of EPSCC are challenging. The extent of disease is important for prognosis whereas the tumor location affects the choice of treatment modality. Currently there is no standard guideline as yet. Combined modality (surgery, radiation or chemotherapy) treatment has often been applied to limited-stage EPSCCs in which long-term survivors have ever been reported. However, the sequence of these combinations is not well-defined. Palliative chemotherapy is used for extensive and recurrent/ metastatic EPSCCs with high response rate but short progression-free interval. More research is warranted for improving the survival.