Clinical analysis of extrapulmonary neuroendocrine carcinoma: a retrospective and single institution experience

Abstract

Introduction: Extrapulmonary neuroendocrine carcinoma (EPNEC) is a clinicopathological entity distinct from neuroendocrine carcinoma (NEC) of the lung. Here, we reviewed the clinical features, treatment modalities, and prognosis of EPNEC patients in a single-institution series. Methods: We retrospectively reviewed the medical records of EPNEC patients, and examined the clinical profiles and treatment outcomes at our hospital between 2013 and 2021. Results: Thirty-one EPNEC patients (21 men, 10 women) with a median age of 65 years were included. The primary sites were as follows: stomach (n = 7); rectum and bladder (n=3 each); prostate, esophagus, cervix and pancreas (n=2 each); maxillary sinus, parotid gland, gallbladder, anal canal, larynx, uterine body, ovary, appendix, anterior mediastinum, and unknown primary lesion (n = 1 each). Thirteen patients had locally advanced stage and 18 cases had distant metastases. Chemotherapy using platinum-combined CPT-11 or VP-16 was mainly performed. Various therapeutic modalities were used, especially in locally advanced cases. Ten patients underwent surgery, including initial surgery in 5 and conversion in 5 after chemotherapy. The response rate to initial chemotherapy was 56.5% and the median overall survival in all patients was 12.8 (95%CI: 9.6–34.5) months. Survival was significantly longer in patients with locally advanced (80.3 months) and receiving surgery (not reached) than in those with metastatic disease (9.9 months) and without surgery (9.6 months). Disscussion/Conclusion: EPNEC occurs in various organs and has poor prognosis. Long-term survival may be possible with surgical resection in cases with early-stage disease or tumor shrinkage due to chemotherapy.