A single-institution retrospective analysis of metachronous and synchronous metastatic bronchial neuroendocrine tumors.

Background: Broncho-pulmonary neuroendocrine tumors (bpNETs) are rare malignancies and there is no consensus on therapeutical management of metastatic disease and follow-up after radical resection.

Methods: Clinical records of patients with a cytological or histological diagnosis of bpNETs and distant metastases (metachronous or synchronous), evaluated at the European Institute of Oncology between 1997 and 2014, were retrospectively analyzed. Data on patient demographics, pathology, imaging exams, surgical and non-surgical treatments were collected. P value descriptive data, uni- and multi-variate survival analysis were generated for all variables.

Results: With a median follow-up of 53 [9-215] months, 61 patients with metachronous and 47 with synchronous metastases were analysed. The most common tool of first recurrence detection was computed tomography. Liver (67%), lymph node (25%), bone (22%) and lung (16%) were the most common sites of relapse. Median time to recurrence was 5 years. Median overall survival (OS) was 72 months for the whole population, with no significant difference between patients with synchronous and metachronous metastases. Age, bone metastases, liver metastases and Ki-67 as a continuous variable all significantly correlated with prognosis at the multivariate analysis.

Conclusions: This is one of the largest, single-centre, series of metastatic bpNETs. Among patients with metachronous metastases the pattern of recurrences was heterogeneous as were the follow-up exams used to detect them. The results of our analysis may represent solid bases for designing prospective clinical trials in homogeneous settings of bpNETs.