Late-stage esophageal neuroendocrine carcinoma in a patient treated with tislelizumab combined with anlotinib: a case report

Esophageal neuroendocrine carcinoma (ENEC) is an extremely rare tumor with highly malignant potential, rapid growth, and a poor prognosis. Advanced extrapulmonary neuroendocrine carcinoma should be treated with chemotherapeutic regimens suitable for small cell lung cancer. However, ENEC has no clear second-line treatment options. The clinical application of immunotherapy and targeted therapy in small cell lung cancer has produced good therapeutic effects. We describe the case of an elderly woman with multiple metastatic advanced ENEC treated with tislelizumab combined with anlotinib as second-line therapy, achieving complete remission in a short period and long-term survival. In total, 21 cycles of tislelizumab combined with anlotinib were given to this patient. After two cycles, the patient's neuron-specific enolase level decreased from 181.8 to 22.9 µg/L and remained at normal levels throughout treatment. Progression-free survival and overall survival were 16 and 21 months, respectively, in this patient. No obvious side effects were observed. Thus, tislelizumab and anlotinib could represent a novel therapeutic option for advanced ENEC.